Wikipedia - User contributions [en]

Dapsone

2016-02-12T20:34:30Z

71.109.148.145: /* Medical uses */ Fix caps

{{Drugbox
| verifiedrevid = 460773489
| IUPAC_name = 4-[(4-aminobenzene)sulfonyl]aniline
| image = Dapsone.svg
| image2 = Dapsone3d.png

| tradename = Aczone
| Drugs.com = {{drugs.com|monograph|dapsone}}
| MedlinePlus = a682128
| pregnancy_AU = B2
| pregnancy_US = C
| legal_status = ℞-only (U.S.), [[Prescription drug|POM]] (UK)
| routes_of_administration = Oral, Topical

| bioavailability = 70 to 80%
| protein_bound = 70 to 90%
| metabolism = [[Liver|Hepatic]] (mostly [[CYP2E1]]-mediated)
| elimination_half-life = 20 to 30 hours
| excretion = [[Kidney|Renal]]

| CAS_number_Ref = {{cascite|correct|??}}
| CAS_number = 80-08-0
| ATC_prefix = D10
| ATC_suffix = AX05
| ATC_supplemental = {{ATC|J04|BA02}}
| PubChem = 2955
| DrugBank_Ref = {{drugbankcite|correct|drugbank}}
| DrugBank = DB00250
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 2849
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 8W5C518302
| KEGG_Ref = {{keggcite|correct|kegg}}
| KEGG = D00592
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI = 4325
| ChEMBL_Ref = {{ebicite|correct|EBI}}
| ChEMBL = 1043

| C=12 | H=12 | N=2 | O=2 | S=1
| molecular_weight = 248.302 g/mol
| SMILES = O=S(=O)(c1ccc(N)cc1)c2ccc(N)cc2
| InChI = 1/C12H12N2O2S/c13-9-1-5-11(6-2-9)17(15,16)12-7-3-10(14)4-8-12/h1-8H,13-14H2
| InChIKey = MQJKPEGWNLWLTK-UHFFFAOYAJ
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C12H12N2O2S/c13-9-1-5-11(6-2-9)17(15,16)12-7-3-10(14)4-8-12/h1-8H,13-14H2
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = MQJKPEGWNLWLTK-UHFFFAOYSA-N
}}
'''Dapsone''', also known as '''diaminodiphenyl sulfone''' ('''DDS'''),<ref>{{cite book|author1=Thomas L. Lemke|title=Foye's Principles of Medicinal Chemistry|date=2008|publisher=Lippincott Williams & Wilkins|isbn=9780781768795|page=1142|url=https://books.google.ca/books?id=R0W1ErpsQpkC&pg=PA1142}}</ref> is an [[antibiotic]] commonly used in combination with [[rifampicin]] and [[clofazimine]] for the treatment of [[leprosy]].<ref name=AHFS2015>{{cite web|title=Dapsone
| url=http://www.drugs.com/monograph/dapsone.html|publisher=The American Society of Health-System Pharmacists|accessdate=Jan 12, 2015}}</ref> It is a second-line medication for the treatment and prevention of [[Pneumocystis pneumonia]] and for the prevention of [[toxoplasmosis]] in those who have [[immunocompromise|poor immune function]].<ref name=AHFS2015/> Additionally, it has been used for [[acne vulgaris|acne]] as well as other skin conditions.<ref name=Zhu2001>{{cite journal | pmid=11511841 |title=Dapsone and sulfones in dermatology: overview and update |year=2001 |last1=Zhu |journal=Journal of the American Academy of Dermatology | doi=10.1067/mjd.2001.114733 | first1=YI | last2=Stiller | first2=MJ | volume=45 | issue=3 | pages=420–34 |display-authors=etal}}</ref> Dapsone is available both topically and by mouth.<ref name=Joe2012>{{cite book|author1=Joel E. Gallant|title=Johns Hopkins HIV Guide 2012|date=2008|publisher=Jones & Bartlett Publishers|isbn=9781449619794|page=193|url=https://books.google.ca/books?id=nooCC0_5F0AC&pg=PA193}}</ref>


Severe side effects may include: a [[agranulocytosis|decrease in blood cells]], [[hemolysis|red blood cell breakdown]] especially in those with [[glucose-6-phosphate dehydrogenase deficiency]] (G-6-PD), or hypersensitivity.<ref name=AHFS2015/> Common side effects include nausea and loss of appetite.<ref name=Joe2012/> Other side effects include [[hepatitis|liver inflammation]] and a number of types of skin rashes.<ref name=AHFS2015/> While it is not entirely clear the safety of use during pregnancy some physicians recommend that it be continued in those with leprosy.<ref name=AHFS2015/> It is of the [[sulfone]] class.<ref name=AHFS2015/>


Dapsone was first studied as an antibiotic in 1937.<ref name=Zhu2001/> Its use for leprosy began in 1945.<ref name=Zhu2001/> It is on the [[World Health Organization's List of Essential Medicines]], the most important medications needed in a basic [[health system]].<ref>{{cite web|title=WHO Model List of EssentialMedicines|url=http://apps.who.int/iris/bitstream/10665/93142/1/EML_18_eng.pdf?ua=1|work=World Health Organization|accessdate=22 April 2014|date=October 2013}}</ref> The oral form is available as a [[generic drug]] and not very expensive.<ref name=AHFS2015/><ref>{{cite book |first=David |last=Greenwood |title=Antimicrobial Drugs: Chronicle of a Twentieth Century Medical Triumph |date=2008 |publisher=Oxford University Press |isbn=9780199534845 |page=197 |url=https://books.google.ca/books?id=i4_FZHmzjzwC&pg=PA197}}</ref>

== Medical uses ==
Dapsone is used to combat
* [[Leprosy]], often in combination with [[rifampicin]] and [[clofazimine]]<ref name=AHFS2015/>
* [[Pneumocystis pneumonia]]<ref name=AHFS2015/>
* [[Dermatitis herpetiformis]], often in combination with a gluten free diet<ref name=AHFS2015/>
* [[Toxoplasmosis]] in people unable to tolerate [[trimethoprim]] with [[sulfamethoxazole]].<ref name="AMH">{{cite book | editor = Rossi S | title = [[Australian Medicines Handbook]] | year = 2006 | location = Adelaide | isbn = 0-9757919-2-3}}</ref>
* Moderate to severe [[acne vulgaris]]<ref>{{cite journal | pmid=14494150 |title=The treatment of acne vulgaris with dapsone |year=1961 |last1=Ross |journal=Br J Dermatol | doi=10.1111/j.1365-2133.1961.tb14398.x | first1=CM | volume=73 | pages=367–70 | issue=10 }}</ref><ref>{{cite web|url=http://scienceofacne.com/dapsone-aczone/|title=Dapsone and Acne Vulgaris |publisher=ScienceOfAcne.com |date=2012-10-10 |accessdate=2012-08-17}}</ref><ref>{{cite journal|last1=Pickert|first1=A|last2=Raimer|first2=S|title=An evaluation of dapsone gel 5% in the treatment of acne vulgaris |journal=Expert opinion on pharmacotherapy|date=June 2009|volume=10|issue=9|pages=1515–21|pmid=19505219|doi=10.1517/14656560903002097}}</ref>
===under study===
* Dapsone may be used to treat [[brown recluse spider]] bites that become [[necrotic]].<ref>{{cite journal|last1=Forks|first1=TP|title=Brown recluse spider bites.|journal=J Am Board Fam Pract |date=2000|volume=13|issue=6|pages=415–23|pmid=11117338|doi=10.3122/15572625-13-6-415}}</ref> It, along with a [[gluten free diet]] may also help with
* Dapsone, in combination with [[pyrimethamine]] may be useful in the prevention of [[malaria]].<ref>{{cite journal|last1=Croft|first1=AM|title=Malaria: prevention in travellers.|journal=Clinical evidence|date=29 November 2007|volume=2007|pmid=19450348|pmc=2943798}}</ref>

== Adverse effects ==
The dapsone hypersensitivity syndrome develops in 0.5–3.6% of persons treated with the drug, and is associated with a mortality of 9.9%.<ref name="Zhang2013">{{cite journal
| title =HLA-B*13:01 and the dapsone hypersensitivity syndrome. | journal =N Engl J Med. | date =October 2013 | authors =Zhang FR, Liu, H; Irwanto, A | volume =369 | issue =17 | pages =1620–8 | url =http://www.nejm.org/doi/full/10.1056/NEJMoa1213096 | doi =10.1056/NEJMoa1213096 | pmid =24152261 | pmc = |display-authors=etal}}</ref>

=== Blood ===

The most prominent side-effects of this drug are dose-related [[hemolysis]] (which may lead to [[hemolytic anemia]]) and [[methemoglobinemia]].<ref>{{cite journal |author=Jopling WH |title=Side-effects of antileprosy drugs in common use |journal=Lepr Rev |volume=54 |issue=4 |pages=261–70 |year=1983 |pmid=6199637 }}</ref> About 20% of patients treated with dapsone suffer hemolysis<ref>{{cite journal |author=Puavilai S, Chutha S, Polnikorn N |title=Incidence of anemia in leprosy patients treated with dapsone |journal=J Med Assoc Thai |volume=67 |issue=7 |pages=404–7 |date=July 1984 |pmid=6512448 |display-authors=etal}}</ref> and the side-effect is more common and severe in those with [[glucose-6-phosphate dehydrogenase deficiency]], leading to the dapsone-containing antimalarial combination Lapdap being withdrawn from clinical use.<ref>{{cite web |title=Antimalarial chlorproguanil-dapsone (LapDap™) withdrawn following demonstration of post-treatment haemolytic anaemia in G6PD deficient patients in a Phase III trial of chlorproguanil-dapsone-artesunate (Dacart™) versus artemether-lumefantrine (Coartem®) and confirmation of findings in a comparative trial of LapDap™ versus Dacart ™ |date=4 March 2008 |publisher=World Health Organization |format=PDF |id=QSM/MC/IEA.1 |url=http://www.who.int/medicines/publications/drugalerts/Alert_117_LapDap.pdf}}</ref><ref>{{cite journal |author=Luzzatto L |title=The rise and fall of the antimalarial Lapdap: a lesson in pharmacogenetics |journal=Lancet |volume=376 |issue=9742 |pages=739–41 |date=August 2010 |pmid=20599264 |doi=10.1016/S0140-6736(10)60396-0 |url=}}</ref> A case of hemolysis in a neonate from dapsone in breast milk has been reported.<ref name="Sanders1982">{{cite journal| title =Hemolytic anemia induced by dapsone transmitted through breast milk. | journal =Ann Intern Med. | date =April 1982 | author =Sanders SW, Zone JJ, Foltz RL, Tolman KG, Rollins DE. | volume =96 | issue =4 | pages =465-6 | url =http://annals.org/article.aspx?articleid=695480 | doi =10.7326/0003-4819-96-4-465 | pmid =7065565 | pmc = }}</ref> [[Agranulocytosis]] occurs rarely when dapsone is used alone but more frequently in combination regimens for malaria prophylaxis.<ref>{{cite journal |author=Firkin FC, Mariani AF |title=Agranulocytosis due to dapsone |journal=Med. J. Aust. |volume=2 |issue=8 |pages=247–51 |year=1977 |pmid=909500 }}</ref> Abnormalities in [[white blood cell]] formation, including [[aplastic anemia]], are rare, yet are the cause of the majority of deaths attributable to dapsone therapy.<ref>{{cite journal |author=Foucauld J, Uphouse W, Berenberg J |title=Dapsone and aplastic anemia |journal=Ann. Intern. Med. |volume=102 |issue=1 |pages=139 |year=1985 |pmid=3966740 |url=http://www.annals.org/article.aspx?volume=102&issue=1&page=139 |doi=10.7326/0003-4819-102-1-139_2}}</ref><ref>{{cite journal |author=Meyerson MA, Cohen PR |title=Dapsone-induced aplastic anemia in a woman with bullous systemic lupus erythematosus |journal=Mayo Clin. Proc. |volume=69 |issue=12 |pages=1159–62 |year=1994 |pmid=7967777 |doi=10.1016/s0025-6196(12)65768-1}}</ref><ref>{{cite journal |author=Björkman A, Phillips-Howard PA |title=Adverse reactions to sulfa drugs: implications for malaria chemotherapy |journal=Bull. World Health Organ. |volume=69 |issue=3 |pages=297–304 |year=1991 |pmid=1893504 |pmc=2393107 }}</ref>

=== Liver ===

Toxic [[hepatitis]] and [[cholestatic jaundice]] have been reported by the manufacturer. [[Jaundice]] may also occur as part of the dapsone reaction or dapsone syndrome (see below). Dapsone is metabolized by the [[Cytochrome P450]] system, specifically [[isozymes]] [[CYP2D6]], [[CYP2B6]], [[CYP3A4]], and [[CYP2C19]].<ref>{{cite journal|last=Ganesan|first=S|author2=Sahu, R |author3=Walker, LA |author4= Tekwani, BL |title=Cytochrome P450-dependent toxicity of dapsone in human erythrocytes|journal=J Appl Toxicol|date=April 2010|volume=30|issue=3|pages=271–5|doi=10.1002/jat.1493|pmid=19998329}}</ref> Dapsone metabolites produced by the [[CYP2C19|cytochrome P450 2C19]] isozyme are associated with the [[methemoglobinemia]] side effect of the drug.

=== Skin ===

When used topically, dapsone can cause mild skin irritation, redness, dry skin, burning and itching. When used together with benzoyl peroxide products, temporary yellow or orange skin discolorations can occur.<ref>Aczone(Dapsone) Package insert. Irvine CA: Allergan Inc; September 2008</ref><ref>{{cite web |title=Dapsone (Aczone) |date= |work=Medications For Acne |publisher=PharmacistAnswers |url=http://pharmacistanswers.com/medications-for-acne-guide.html}}</ref>

=== Other adverse effects ===

Other adverse effects include [[nausea]], [[headache]], and [[rash]] (which are common), and [[insomnia]], [[psychosis]], and [[peripheral neuropathy]]. Effects on the [[lung]] occur rarely and may be serious, though are generally reversible.<ref>{{cite journal |author=Jaffuel D, Lebel B, Hillaire-Buys D, Pene J, Godard P, Michel FB, Blayac JP, Bousquet J, Demolyi P |title=Eosinophilic pneumonia induced by dapsone |journal=BMJ |volume=317 |issue=7152 |pages=181 |year=1998 |pmid=9665900 |pmc=28611 |url=http://www.bmj.com/cgi/pmidlookup?view=long&pmid=9665900 |doi=10.1136/bmj.317.7152.181}}</ref>

=== Dapsone reaction ===

[[Hypersensitivity]] reactions occur in some patients. This reaction may be more frequent in patients receiving multiple-drug therapy.<ref>{{cite journal |author=Richardus JH, Smith TC |title=Increased incidence in leprosy of hypersensitivity reactions to dapsone after introduction of multidrug therapy |journal=Lepr Rev |volume=60 |issue=4 |pages=267–73 |year=1989 |pmid=2491425 }}</ref><ref>{{cite journal |author=Kumar RH, Kumar MV, Thappa DM |title=Dapsone syndrome—a five year retrospective analysis |journal=Indian J Lepr |volume=70 |issue=3 |pages=271–6 |year=1998 |pmid=9801899 }}</ref><ref>{{cite journal |author=Rao PN, Lakshmi TS |title=Increase in the incidence of dapsone hypersensitivity syndrome—an appraisal |journal=Lepr Rev |volume=72 |issue=1 |pages=57–62 |year=2001 |pmid=11355519 }}</ref>

The reaction always involves a [[rash]] and may also include [[fever]], jaundice, and [[eosinophilia]].<ref>{{cite journal |author=Joseph MS |title=Hypersensitivity reaction to dapsone. Four case reports |journal=Lepr Rev |volume=56 |issue=4 |pages=315–20 |year=1985 |pmid=4079634 }}</ref><ref>{{cite journal |author=Jamrozik K |title=Dapsone syndrome occurring in two brothers |journal=Lepr Rev |volume=57 |issue=1 |pages=57–62 |year=1986 |pmid=3702581 }}</ref><ref>{{cite journal |author=Hortaleza AR, Salta-Ramos NG, Barcelona-Tan J, Abad-Venida L |title=Dapsone syndrome in a Filipino man |journal=Lepr Rev |volume=66 |issue=4 |pages=307–13 |year=1995 |pmid=8637384 }}</ref><ref>{{cite journal |author=Tomecki KJ, Catalano CJ |title=Dapsone hypersensitivity. The sulfone syndrome revisited |journal=Arch Dermatol |volume=117 |issue=1 |pages=38–9 |year=1981 |pmid=6450569 |url=http://archderm.jamanetwork.com/article.aspx?volume=117&page=38 |doi=10.1001/archderm.1981.01650010044023}}</ref><ref>{{cite journal |author=Kromann NP, Vilhelmsen R, Stahl D |title=The dapsone syndrome |journal=Arch Dermatol |volume=118 |issue=7 |pages=531–2 |year=1982 |pmid=7092282 |url=http://archderm.jamanetwork.com/article.aspx?volume=118&page=531 |doi=10.1001/archderm.1982.01650190085028}}</ref> In general, these symptoms will occur within the first six weeks of therapy or not at all, and may be ameliorated by [[corticosteroid]] therapy.<ref name="AMH" />

==Mechanism of action==
As an [[antibacterial]], dapsone inhibits [[bacteria]]l synthesis of [[dihydrofolic acid]], via competition with [[4-Aminobenzoic acid|para-aminobenzoate]] for the active site of dihydropteroate synthase.<ref>{{cite web |url=https://web.archive.org/web/20110517013634/http://www.medscape.com/viewarticle/440403_5 |publisher=Medscape Today |title=Mechanisms of Action of Dapsone in Dermatological Diseases |work=Dapsone: Clinical Uses in Various Cutaneous Diseases }}</ref> Though structurally distinct from dapsone, the sulfonamide group of antibacterial drugs also work in this way.

When used for the treatment of skin conditions in which bacteria do not have a role, the mechanism or action of dapsone is not well understood. Dapsone has [[anti-inflammatory]] and immunomodulatory effects,<ref>{{cite journal |author=Begon E, Chosidow O, Wolkenstein P |title=[Disulone] |language=French |journal=Ann Dermatol Venereol |volume=131 |issue=12 |pages=1062–73 |date=December 2004 |pmid=15692440 |doi= 10.1016/S0151-9638(04)93842-2|url=}}</ref> which are thought to come from the drug's blockade of [[myeloperoxidase]]. This is thought to be its mechanism of action in treating [[dermatitis herpetiformis]].<ref>{{cite journal |author=Uetrecht JP |title=Myeloperoxidase as a generator of drug free radicals |journal=Biochem. Soc. Symp. |volume=61 |pages=163–70 |year=1995 |pmid=8660393 }}</ref>

As part of the [[respiratory burst]] that [[neutrophil]]s use to kill bacteria, myeloperoxidase converts hydrogen peroxide ({{chem|H|2|O|2}}) into [[hypochlorous acid]] (HOCl). HOCl is the most potent oxidant generated by neutrophils, and can cause significant tissue damage during inflammation. Dapsone arrests myeloperoxidase in an inactive intermediate form, reversibly inhibiting the enzyme. This prevents accumulation of hypochlorous acid, and reduces tissue damage during inflammation.<ref>{{cite journal |author=Bozeman PM, Learn DB, Thomas EL |title=Assay of the human leukocyte enzymes myeloperoxidase and eosinophil peroxidase |journal=J. Immunol. Methods |volume=126 |issue=1 |pages=125–33 |year=1990 |pmid=2154520 |url=http://linkinghub.elsevier.com/retrieve/pii/0022-1759(90)90020-V |doi=10.1016/0022-1759(90)90020-v}}</ref><ref>{{cite journal |author=Bozeman PM, Learn DB, Thomas EL |title=Inhibition of the human leukocyte enzymes myeloperoxidase and eosinophil peroxidase by dapsone |journal=Biochem. Pharmacol. |volume=44 |issue=3 |pages=553–63 |year=1992 |pmid=1324677 |url=http://linkinghub.elsevier.com/retrieve/pii/0006-2952(92)90449-S |doi=10.1016/0006-2952(92)90449-s}}</ref><ref>{{cite journal |author=Stendahl O, Molin L, Lindroth M |title=Granulocyte-mediated release of histamine from mast cells. Effect of myeloperoxidase and its inhibition by antiinflammatory sulfone compounds |journal=Int. Arch. Allergy Appl. Immunol. |volume=70 |issue=3 |pages=277–84 |year=1983 |pmid=6186607 |doi=10.1159/000233335}}</ref><ref>{{cite journal |author=Kettle AJ, Gedye CA, Winterbourn CC |title=Superoxide is an antagonist of antiinflammatory drugs that inhibit hypochlorous acid production by myeloperoxidase |journal=Biochem. Pharmacol. |volume=45 |issue=10 |pages=2003–10 |year=1993 |pmid=8390258 |url=http://linkinghub.elsevier.com/retrieve/pii/0006-2952(93)90010-T |doi=10.1016/0006-2952(93)90010-t}}</ref><ref>{{cite journal |author=Kettle AJ, Winterbourn CC |title=Mechanism of inhibition of myeloperoxidase by anti-inflammatory drugs |journal=Biochem. Pharmacol. |volume=41 |issue=10 |pages=1485–92 |year=1991 |pmid=1850278 |url=http://linkinghub.elsevier.com/retrieve/pii/0006-2952(91)90565-M |doi=10.1016/0006-2952(91)90565-m}}</ref>

Myeloperoxidase inhibition has also been suggested as a neuron-sparing mechanism for reducing inflammation in neurodegenerative diseases such as [[Alzheimer's disease]] and stroke.<ref>{{cite journal |author=Diaz-Ruiz A, Zavala C, Montes S |title=Antioxidant, antiinflammatory and antiapoptotic effects of dapsone in a model of brain ischemia/reperfusion in rats |journal=J. Neurosci. Res. |volume=86 |issue=15 |pages=3410–9 |date=November 2008 |pmid=18615706 |doi=10.1002/jnr.21775 |url=|display-authors=etal}}</ref>

Though dapsone is an anti-inflammatory agent and not a steroid, it does not fit the usual definition of an [[NSAID]]. By definition, NSAIDs block [[cyclo-oxygenase]] as their primary mechanism of action, which dapsone does not do.

Dapsone is an odorless white to creamy-white crystalline powder with a slightly bitter taste.

== Specific considerations ==

Certain patients are at higher risks of adverse effects when using dapsone. Some specific issues that should be considered are:<ref name="AMH" />

* Related to the blood (a [[full blood count]] should be obtained prior to initiating therapy):
** [[Porphyria]]
** [[Anemia]]
** [[Cardiac disease]]
** [[Pulmonary disease]]
** [[HIV]] infection
** [[G6PD deficiency]]

* Related to the liver (obtain [[liver function test]]s before starting therapy):
** Liver impairment

* Related to [[allergy]]:
** Sulfonamide allergy is associated with dapsone allergy

People with [[diabetes mellitus]] have been seen to exhibit unexpectedly low [[HbA1c]] results when taking Dapsone, and HbA1c i an unreliable test in states of increased red cell turnover, e.g. a drug induced haemolytic anaemia.

== History ==
In the early 20th century, the German chemist [[Paul Ehrlich]] was developing theories of [[selective toxicity]] based largely on the ability of certain [[dye]]s to kill [[microbe]]s. [[Gerhard Domagk]], who would later win a [[Nobel Prize]] for his efforts, made a major breakthrough in 1932 with the discovery of the antibacterial [[prontosil|prontosil red]] (sulfonamidochrysoidine). Further investigation into the involved chemicals opened the way to [[sulfa drug]] and [[sulfone|sulfone therapy]], first with the discovery of [[sulfanilamide]], the active agent of prontosil, by [[Daniel Bovet]] and his team at [[Pasteur Institute]] (1935),<ref>{{cite journal |first=J. et T. |last=Tréfouël |first2=F. |last2=Nitti |first3=D. |last3=Bovet |title=Activité du p.aminophénylsulfamide sur l’infection streptococcique expérimentale de la souris et du lapin |journal=Comptes rendus des séances de la Société de biologie et de ses filiales |volume=120 |page=756 |date=23 November 1935 |url=http://gallica.bnf.fr/ark:/12148/bpt6k65430169/f766.image.r=Comptes%20rendus%20des%20society%20biol.langEN |language=fr}}</ref> then with of dapsone independently by [[Ernest Fourneau]]<ref>{{cite journal |first=E. |last=Fourneau |first2=Th. et J. |last2=Tréfouël |first3=F. |last3=Nitti |first4=D. |last4=Bovet |title=Action antistreptococcique des dérivés sulfurés organiques |journal=Comptes rendus de l'Académie des sciences |volume=204 |page=1763 |year=1937 |url=http://gallica.bnf.fr/ark:/12148/bpt6k31562/f1763.image |language=fr}}</ref> in France and Gladwin Buttle<ref>{{cite journal |last=Buttle |first= G.A.H. |last2=Stephenson |first2=D. |last3=Smith |first3=S. |last4=Dewing |first4=T. |last5=Foster |first5=G.E. |title=Treatment of streptococcal infections in mice with 4:4'diamino-dipheni-sulphone |journal=Lancet |volume=229 |issue=5936 |pages=1331–4 |date=June 1937 |doi=10.1016/S0140-6736(00)75868-5 |url=http://www.thelancet.com/journals/lancet/article/PIIS0140-6736%2800%2975868-5/abstract}}</ref> in United-Kingdom.<ref name="urlLeprosy | 14 History of dapsone and dyes">{{cite web |url=http://www.itg.be/itg/DistanceLearning/LectureNotesVandenEndenE/22_Leprosyp14.htm |title=Leprosy | 14 History of dapsone and dyes |work= |accessdate=2009-02-24}} (1937)</ref>
==See also==
*[[Bisphenol S]]
== References ==

{{reflist|2}}

== External links ==
*[http://www.nlm.nih.gov/medlineplus/druginfo/meds/a682128.html MedlinePlus Drug Information]
* [http://druginfo.nlm.nih.gov/drugportal/dpdirect.jsp?name=Dapsone U.S. National Library of Medicine: Drug Information Portal - Dapsone]

{{Antimycobacterials}}
{{Nucleic acid inhibitors}}
{{Acne Agents}}

[[Category:Anilines]]
[[Category:Sulfones]]
[[Category:Dihydropteroate synthetase inhibitors]]
[[Category:Antibiotics]]
[[Category:Anti-acne preparations]]
[[Category:Leprosy]]
[[Category:World Health Organization essential medicines]]
[[Category:RTT]]

Dapsone

2016-02-12T20:34:03Z

71.109.148.145: /* Medical uses */ Cleanup on aisle seven

{{Drugbox
| verifiedrevid = 460773489
| IUPAC_name = 4-[(4-aminobenzene)sulfonyl]aniline
| image = Dapsone.svg
| image2 = Dapsone3d.png

| tradename = Aczone
| Drugs.com = {{drugs.com|monograph|dapsone}}
| MedlinePlus = a682128
| pregnancy_AU = B2
| pregnancy_US = C
| legal_status = ℞-only (U.S.), [[Prescription drug|POM]] (UK)
| routes_of_administration = Oral, Topical

| bioavailability = 70 to 80%
| protein_bound = 70 to 90%
| metabolism = [[Liver|Hepatic]] (mostly [[CYP2E1]]-mediated)
| elimination_half-life = 20 to 30 hours
| excretion = [[Kidney|Renal]]

| CAS_number_Ref = {{cascite|correct|??}}
| CAS_number = 80-08-0
| ATC_prefix = D10
| ATC_suffix = AX05
| ATC_supplemental = {{ATC|J04|BA02}}
| PubChem = 2955
| DrugBank_Ref = {{drugbankcite|correct|drugbank}}
| DrugBank = DB00250
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 2849
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 8W5C518302
| KEGG_Ref = {{keggcite|correct|kegg}}
| KEGG = D00592
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI = 4325
| ChEMBL_Ref = {{ebicite|correct|EBI}}
| ChEMBL = 1043

| C=12 | H=12 | N=2 | O=2 | S=1
| molecular_weight = 248.302 g/mol
| SMILES = O=S(=O)(c1ccc(N)cc1)c2ccc(N)cc2
| InChI = 1/C12H12N2O2S/c13-9-1-5-11(6-2-9)17(15,16)12-7-3-10(14)4-8-12/h1-8H,13-14H2
| InChIKey = MQJKPEGWNLWLTK-UHFFFAOYAJ
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C12H12N2O2S/c13-9-1-5-11(6-2-9)17(15,16)12-7-3-10(14)4-8-12/h1-8H,13-14H2
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = MQJKPEGWNLWLTK-UHFFFAOYSA-N
}}
'''Dapsone''', also known as '''diaminodiphenyl sulfone''' ('''DDS'''),<ref>{{cite book|author1=Thomas L. Lemke|title=Foye's Principles of Medicinal Chemistry|date=2008|publisher=Lippincott Williams & Wilkins|isbn=9780781768795|page=1142|url=https://books.google.ca/books?id=R0W1ErpsQpkC&pg=PA1142}}</ref> is an [[antibiotic]] commonly used in combination with [[rifampicin]] and [[clofazimine]] for the treatment of [[leprosy]].<ref name=AHFS2015>{{cite web|title=Dapsone
| url=http://www.drugs.com/monograph/dapsone.html|publisher=The American Society of Health-System Pharmacists|accessdate=Jan 12, 2015}}</ref> It is a second-line medication for the treatment and prevention of [[Pneumocystis pneumonia]] and for the prevention of [[toxoplasmosis]] in those who have [[immunocompromise|poor immune function]].<ref name=AHFS2015/> Additionally, it has been used for [[acne vulgaris|acne]] as well as other skin conditions.<ref name=Zhu2001>{{cite journal | pmid=11511841 |title=Dapsone and sulfones in dermatology: overview and update |year=2001 |last1=Zhu |journal=Journal of the American Academy of Dermatology | doi=10.1067/mjd.2001.114733 | first1=YI | last2=Stiller | first2=MJ | volume=45 | issue=3 | pages=420–34 |display-authors=etal}}</ref> Dapsone is available both topically and by mouth.<ref name=Joe2012>{{cite book|author1=Joel E. Gallant|title=Johns Hopkins HIV Guide 2012|date=2008|publisher=Jones & Bartlett Publishers|isbn=9781449619794|page=193|url=https://books.google.ca/books?id=nooCC0_5F0AC&pg=PA193}}</ref>


Severe side effects may include: a [[agranulocytosis|decrease in blood cells]], [[hemolysis|red blood cell breakdown]] especially in those with [[glucose-6-phosphate dehydrogenase deficiency]] (G-6-PD), or hypersensitivity.<ref name=AHFS2015/> Common side effects include nausea and loss of appetite.<ref name=Joe2012/> Other side effects include [[hepatitis|liver inflammation]] and a number of types of skin rashes.<ref name=AHFS2015/> While it is not entirely clear the safety of use during pregnancy some physicians recommend that it be continued in those with leprosy.<ref name=AHFS2015/> It is of the [[sulfone]] class.<ref name=AHFS2015/>


Dapsone was first studied as an antibiotic in 1937.<ref name=Zhu2001/> Its use for leprosy began in 1945.<ref name=Zhu2001/> It is on the [[World Health Organization's List of Essential Medicines]], the most important medications needed in a basic [[health system]].<ref>{{cite web|title=WHO Model List of EssentialMedicines|url=http://apps.who.int/iris/bitstream/10665/93142/1/EML_18_eng.pdf?ua=1|work=World Health Organization|accessdate=22 April 2014|date=October 2013}}</ref> The oral form is available as a [[generic drug]] and not very expensive.<ref name=AHFS2015/><ref>{{cite book |first=David |last=Greenwood |title=Antimicrobial Drugs: Chronicle of a Twentieth Century Medical Triumph |date=2008 |publisher=Oxford University Press |isbn=9780199534845 |page=197 |url=https://books.google.ca/books?id=i4_FZHmzjzwC&pg=PA197}}</ref>

== Medical uses ==
Dapsone is used to combat
* [[Leprosy]], often in combination with [[rifampicin]] and [[clofazimine]]<ref name=AHFS2015/>
* [[Pneumocystis pneumonia]]<ref name=AHFS2015/>
* [[dermatitis herpetiformis]], often in combination with a gluten free diet<ref name=AHFS2015/>
* [[toxoplasmosis]] in people unable to tolerate [[trimethoprim]] with [[sulfamethoxazole]].<ref name="AMH">{{cite book | editor = Rossi S | title = [[Australian Medicines Handbook]] | year = 2006 | location = Adelaide | isbn = 0-9757919-2-3}}</ref>
* Moderate to severe [[acne vulgaris]]<ref>{{cite journal | pmid=14494150 |title=The treatment of acne vulgaris with dapsone |year=1961 |last1=Ross |journal=Br J Dermatol | doi=10.1111/j.1365-2133.1961.tb14398.x | first1=CM | volume=73 | pages=367–70 | issue=10 }}</ref><ref>{{cite web|url=http://scienceofacne.com/dapsone-aczone/|title=Dapsone and Acne Vulgaris |publisher=ScienceOfAcne.com |date=2012-10-10 |accessdate=2012-08-17}}</ref><ref>{{cite journal|last1=Pickert|first1=A|last2=Raimer|first2=S|title=An evaluation of dapsone gel 5% in the treatment of acne vulgaris |journal=Expert opinion on pharmacotherapy|date=June 2009|volume=10|issue=9|pages=1515–21|pmid=19505219|doi=10.1517/14656560903002097}}</ref>
===under study===
* Dapsone may be used to treat [[brown recluse spider]] bites that become [[necrotic]].<ref>{{cite journal|last1=Forks|first1=TP|title=Brown recluse spider bites.|journal=J Am Board Fam Pract |date=2000|volume=13|issue=6|pages=415–23|pmid=11117338|doi=10.3122/15572625-13-6-415}}</ref> It, along with a [[gluten free diet]] may also help with
* Dapsone, in combination with [[pyrimethamine]] may be useful in the prevention of [[malaria]].<ref>{{cite journal|last1=Croft|first1=AM|title=Malaria: prevention in travellers.|journal=Clinical evidence|date=29 November 2007|volume=2007|pmid=19450348|pmc=2943798}}</ref>

== Adverse effects ==
The dapsone hypersensitivity syndrome develops in 0.5–3.6% of persons treated with the drug, and is associated with a mortality of 9.9%.<ref name="Zhang2013">{{cite journal
| title =HLA-B*13:01 and the dapsone hypersensitivity syndrome. | journal =N Engl J Med. | date =October 2013 | authors =Zhang FR, Liu, H; Irwanto, A | volume =369 | issue =17 | pages =1620–8 | url =http://www.nejm.org/doi/full/10.1056/NEJMoa1213096 | doi =10.1056/NEJMoa1213096 | pmid =24152261 | pmc = |display-authors=etal}}</ref>

=== Blood ===

The most prominent side-effects of this drug are dose-related [[hemolysis]] (which may lead to [[hemolytic anemia]]) and [[methemoglobinemia]].<ref>{{cite journal |author=Jopling WH |title=Side-effects of antileprosy drugs in common use |journal=Lepr Rev |volume=54 |issue=4 |pages=261–70 |year=1983 |pmid=6199637 }}</ref> About 20% of patients treated with dapsone suffer hemolysis<ref>{{cite journal |author=Puavilai S, Chutha S, Polnikorn N |title=Incidence of anemia in leprosy patients treated with dapsone |journal=J Med Assoc Thai |volume=67 |issue=7 |pages=404–7 |date=July 1984 |pmid=6512448 |display-authors=etal}}</ref> and the side-effect is more common and severe in those with [[glucose-6-phosphate dehydrogenase deficiency]], leading to the dapsone-containing antimalarial combination Lapdap being withdrawn from clinical use.<ref>{{cite web |title=Antimalarial chlorproguanil-dapsone (LapDap™) withdrawn following demonstration of post-treatment haemolytic anaemia in G6PD deficient patients in a Phase III trial of chlorproguanil-dapsone-artesunate (Dacart™) versus artemether-lumefantrine (Coartem®) and confirmation of findings in a comparative trial of LapDap™ versus Dacart ™ |date=4 March 2008 |publisher=World Health Organization |format=PDF |id=QSM/MC/IEA.1 |url=http://www.who.int/medicines/publications/drugalerts/Alert_117_LapDap.pdf}}</ref><ref>{{cite journal |author=Luzzatto L |title=The rise and fall of the antimalarial Lapdap: a lesson in pharmacogenetics |journal=Lancet |volume=376 |issue=9742 |pages=739–41 |date=August 2010 |pmid=20599264 |doi=10.1016/S0140-6736(10)60396-0 |url=}}</ref> A case of hemolysis in a neonate from dapsone in breast milk has been reported.<ref name="Sanders1982">{{cite journal| title =Hemolytic anemia induced by dapsone transmitted through breast milk. | journal =Ann Intern Med. | date =April 1982 | author =Sanders SW, Zone JJ, Foltz RL, Tolman KG, Rollins DE. | volume =96 | issue =4 | pages =465-6 | url =http://annals.org/article.aspx?articleid=695480 | doi =10.7326/0003-4819-96-4-465 | pmid =7065565 | pmc = }}</ref> [[Agranulocytosis]] occurs rarely when dapsone is used alone but more frequently in combination regimens for malaria prophylaxis.<ref>{{cite journal |author=Firkin FC, Mariani AF |title=Agranulocytosis due to dapsone |journal=Med. J. Aust. |volume=2 |issue=8 |pages=247–51 |year=1977 |pmid=909500 }}</ref> Abnormalities in [[white blood cell]] formation, including [[aplastic anemia]], are rare, yet are the cause of the majority of deaths attributable to dapsone therapy.<ref>{{cite journal |author=Foucauld J, Uphouse W, Berenberg J |title=Dapsone and aplastic anemia |journal=Ann. Intern. Med. |volume=102 |issue=1 |pages=139 |year=1985 |pmid=3966740 |url=http://www.annals.org/article.aspx?volume=102&issue=1&page=139 |doi=10.7326/0003-4819-102-1-139_2}}</ref><ref>{{cite journal |author=Meyerson MA, Cohen PR |title=Dapsone-induced aplastic anemia in a woman with bullous systemic lupus erythematosus |journal=Mayo Clin. Proc. |volume=69 |issue=12 |pages=1159–62 |year=1994 |pmid=7967777 |doi=10.1016/s0025-6196(12)65768-1}}</ref><ref>{{cite journal |author=Björkman A, Phillips-Howard PA |title=Adverse reactions to sulfa drugs: implications for malaria chemotherapy |journal=Bull. World Health Organ. |volume=69 |issue=3 |pages=297–304 |year=1991 |pmid=1893504 |pmc=2393107 }}</ref>

=== Liver ===

Toxic [[hepatitis]] and [[cholestatic jaundice]] have been reported by the manufacturer. [[Jaundice]] may also occur as part of the dapsone reaction or dapsone syndrome (see below). Dapsone is metabolized by the [[Cytochrome P450]] system, specifically [[isozymes]] [[CYP2D6]], [[CYP2B6]], [[CYP3A4]], and [[CYP2C19]].<ref>{{cite journal|last=Ganesan|first=S|author2=Sahu, R |author3=Walker, LA |author4= Tekwani, BL |title=Cytochrome P450-dependent toxicity of dapsone in human erythrocytes|journal=J Appl Toxicol|date=April 2010|volume=30|issue=3|pages=271–5|doi=10.1002/jat.1493|pmid=19998329}}</ref> Dapsone metabolites produced by the [[CYP2C19|cytochrome P450 2C19]] isozyme are associated with the [[methemoglobinemia]] side effect of the drug.

=== Skin ===

When used topically, dapsone can cause mild skin irritation, redness, dry skin, burning and itching. When used together with benzoyl peroxide products, temporary yellow or orange skin discolorations can occur.<ref>Aczone(Dapsone) Package insert. Irvine CA: Allergan Inc; September 2008</ref><ref>{{cite web |title=Dapsone (Aczone) |date= |work=Medications For Acne |publisher=PharmacistAnswers |url=http://pharmacistanswers.com/medications-for-acne-guide.html}}</ref>

=== Other adverse effects ===

Other adverse effects include [[nausea]], [[headache]], and [[rash]] (which are common), and [[insomnia]], [[psychosis]], and [[peripheral neuropathy]]. Effects on the [[lung]] occur rarely and may be serious, though are generally reversible.<ref>{{cite journal |author=Jaffuel D, Lebel B, Hillaire-Buys D, Pene J, Godard P, Michel FB, Blayac JP, Bousquet J, Demolyi P |title=Eosinophilic pneumonia induced by dapsone |journal=BMJ |volume=317 |issue=7152 |pages=181 |year=1998 |pmid=9665900 |pmc=28611 |url=http://www.bmj.com/cgi/pmidlookup?view=long&pmid=9665900 |doi=10.1136/bmj.317.7152.181}}</ref>

=== Dapsone reaction ===

[[Hypersensitivity]] reactions occur in some patients. This reaction may be more frequent in patients receiving multiple-drug therapy.<ref>{{cite journal |author=Richardus JH, Smith TC |title=Increased incidence in leprosy of hypersensitivity reactions to dapsone after introduction of multidrug therapy |journal=Lepr Rev |volume=60 |issue=4 |pages=267–73 |year=1989 |pmid=2491425 }}</ref><ref>{{cite journal |author=Kumar RH, Kumar MV, Thappa DM |title=Dapsone syndrome—a five year retrospective analysis |journal=Indian J Lepr |volume=70 |issue=3 |pages=271–6 |year=1998 |pmid=9801899 }}</ref><ref>{{cite journal |author=Rao PN, Lakshmi TS |title=Increase in the incidence of dapsone hypersensitivity syndrome—an appraisal |journal=Lepr Rev |volume=72 |issue=1 |pages=57–62 |year=2001 |pmid=11355519 }}</ref>

The reaction always involves a [[rash]] and may also include [[fever]], jaundice, and [[eosinophilia]].<ref>{{cite journal |author=Joseph MS |title=Hypersensitivity reaction to dapsone. Four case reports |journal=Lepr Rev |volume=56 |issue=4 |pages=315–20 |year=1985 |pmid=4079634 }}</ref><ref>{{cite journal |author=Jamrozik K |title=Dapsone syndrome occurring in two brothers |journal=Lepr Rev |volume=57 |issue=1 |pages=57–62 |year=1986 |pmid=3702581 }}</ref><ref>{{cite journal |author=Hortaleza AR, Salta-Ramos NG, Barcelona-Tan J, Abad-Venida L |title=Dapsone syndrome in a Filipino man |journal=Lepr Rev |volume=66 |issue=4 |pages=307–13 |year=1995 |pmid=8637384 }}</ref><ref>{{cite journal |author=Tomecki KJ, Catalano CJ |title=Dapsone hypersensitivity. The sulfone syndrome revisited |journal=Arch Dermatol |volume=117 |issue=1 |pages=38–9 |year=1981 |pmid=6450569 |url=http://archderm.jamanetwork.com/article.aspx?volume=117&page=38 |doi=10.1001/archderm.1981.01650010044023}}</ref><ref>{{cite journal |author=Kromann NP, Vilhelmsen R, Stahl D |title=The dapsone syndrome |journal=Arch Dermatol |volume=118 |issue=7 |pages=531–2 |year=1982 |pmid=7092282 |url=http://archderm.jamanetwork.com/article.aspx?volume=118&page=531 |doi=10.1001/archderm.1982.01650190085028}}</ref> In general, these symptoms will occur within the first six weeks of therapy or not at all, and may be ameliorated by [[corticosteroid]] therapy.<ref name="AMH" />

==Mechanism of action==
As an [[antibacterial]], dapsone inhibits [[bacteria]]l synthesis of [[dihydrofolic acid]], via competition with [[4-Aminobenzoic acid|para-aminobenzoate]] for the active site of dihydropteroate synthase.<ref>{{cite web |url=https://web.archive.org/web/20110517013634/http://www.medscape.com/viewarticle/440403_5 |publisher=Medscape Today |title=Mechanisms of Action of Dapsone in Dermatological Diseases |work=Dapsone: Clinical Uses in Various Cutaneous Diseases }}</ref> Though structurally distinct from dapsone, the sulfonamide group of antibacterial drugs also work in this way.

When used for the treatment of skin conditions in which bacteria do not have a role, the mechanism or action of dapsone is not well understood. Dapsone has [[anti-inflammatory]] and immunomodulatory effects,<ref>{{cite journal |author=Begon E, Chosidow O, Wolkenstein P |title=[Disulone] |language=French |journal=Ann Dermatol Venereol |volume=131 |issue=12 |pages=1062–73 |date=December 2004 |pmid=15692440 |doi= 10.1016/S0151-9638(04)93842-2|url=}}</ref> which are thought to come from the drug's blockade of [[myeloperoxidase]]. This is thought to be its mechanism of action in treating [[dermatitis herpetiformis]].<ref>{{cite journal |author=Uetrecht JP |title=Myeloperoxidase as a generator of drug free radicals |journal=Biochem. Soc. Symp. |volume=61 |pages=163–70 |year=1995 |pmid=8660393 }}</ref>

As part of the [[respiratory burst]] that [[neutrophil]]s use to kill bacteria, myeloperoxidase converts hydrogen peroxide ({{chem|H|2|O|2}}) into [[hypochlorous acid]] (HOCl). HOCl is the most potent oxidant generated by neutrophils, and can cause significant tissue damage during inflammation. Dapsone arrests myeloperoxidase in an inactive intermediate form, reversibly inhibiting the enzyme. This prevents accumulation of hypochlorous acid, and reduces tissue damage during inflammation.<ref>{{cite journal |author=Bozeman PM, Learn DB, Thomas EL |title=Assay of the human leukocyte enzymes myeloperoxidase and eosinophil peroxidase |journal=J. Immunol. Methods |volume=126 |issue=1 |pages=125–33 |year=1990 |pmid=2154520 |url=http://linkinghub.elsevier.com/retrieve/pii/0022-1759(90)90020-V |doi=10.1016/0022-1759(90)90020-v}}</ref><ref>{{cite journal |author=Bozeman PM, Learn DB, Thomas EL |title=Inhibition of the human leukocyte enzymes myeloperoxidase and eosinophil peroxidase by dapsone |journal=Biochem. Pharmacol. |volume=44 |issue=3 |pages=553–63 |year=1992 |pmid=1324677 |url=http://linkinghub.elsevier.com/retrieve/pii/0006-2952(92)90449-S |doi=10.1016/0006-2952(92)90449-s}}</ref><ref>{{cite journal |author=Stendahl O, Molin L, Lindroth M |title=Granulocyte-mediated release of histamine from mast cells. Effect of myeloperoxidase and its inhibition by antiinflammatory sulfone compounds |journal=Int. Arch. Allergy Appl. Immunol. |volume=70 |issue=3 |pages=277–84 |year=1983 |pmid=6186607 |doi=10.1159/000233335}}</ref><ref>{{cite journal |author=Kettle AJ, Gedye CA, Winterbourn CC |title=Superoxide is an antagonist of antiinflammatory drugs that inhibit hypochlorous acid production by myeloperoxidase |journal=Biochem. Pharmacol. |volume=45 |issue=10 |pages=2003–10 |year=1993 |pmid=8390258 |url=http://linkinghub.elsevier.com/retrieve/pii/0006-2952(93)90010-T |doi=10.1016/0006-2952(93)90010-t}}</ref><ref>{{cite journal |author=Kettle AJ, Winterbourn CC |title=Mechanism of inhibition of myeloperoxidase by anti-inflammatory drugs |journal=Biochem. Pharmacol. |volume=41 |issue=10 |pages=1485–92 |year=1991 |pmid=1850278 |url=http://linkinghub.elsevier.com/retrieve/pii/0006-2952(91)90565-M |doi=10.1016/0006-2952(91)90565-m}}</ref>

Myeloperoxidase inhibition has also been suggested as a neuron-sparing mechanism for reducing inflammation in neurodegenerative diseases such as [[Alzheimer's disease]] and stroke.<ref>{{cite journal |author=Diaz-Ruiz A, Zavala C, Montes S |title=Antioxidant, antiinflammatory and antiapoptotic effects of dapsone in a model of brain ischemia/reperfusion in rats |journal=J. Neurosci. Res. |volume=86 |issue=15 |pages=3410–9 |date=November 2008 |pmid=18615706 |doi=10.1002/jnr.21775 |url=|display-authors=etal}}</ref>

Though dapsone is an anti-inflammatory agent and not a steroid, it does not fit the usual definition of an [[NSAID]]. By definition, NSAIDs block [[cyclo-oxygenase]] as their primary mechanism of action, which dapsone does not do.

Dapsone is an odorless white to creamy-white crystalline powder with a slightly bitter taste.

== Specific considerations ==

Certain patients are at higher risks of adverse effects when using dapsone. Some specific issues that should be considered are:<ref name="AMH" />

* Related to the blood (a [[full blood count]] should be obtained prior to initiating therapy):
** [[Porphyria]]
** [[Anemia]]
** [[Cardiac disease]]
** [[Pulmonary disease]]
** [[HIV]] infection
** [[G6PD deficiency]]

* Related to the liver (obtain [[liver function test]]s before starting therapy):
** Liver impairment

* Related to [[allergy]]:
** Sulfonamide allergy is associated with dapsone allergy

People with [[diabetes mellitus]] have been seen to exhibit unexpectedly low [[HbA1c]] results when taking Dapsone, and HbA1c i an unreliable test in states of increased red cell turnover, e.g. a drug induced haemolytic anaemia.

== History ==
In the early 20th century, the German chemist [[Paul Ehrlich]] was developing theories of [[selective toxicity]] based largely on the ability of certain [[dye]]s to kill [[microbe]]s. [[Gerhard Domagk]], who would later win a [[Nobel Prize]] for his efforts, made a major breakthrough in 1932 with the discovery of the antibacterial [[prontosil|prontosil red]] (sulfonamidochrysoidine). Further investigation into the involved chemicals opened the way to [[sulfa drug]] and [[sulfone|sulfone therapy]], first with the discovery of [[sulfanilamide]], the active agent of prontosil, by [[Daniel Bovet]] and his team at [[Pasteur Institute]] (1935),<ref>{{cite journal |first=J. et T. |last=Tréfouël |first2=F. |last2=Nitti |first3=D. |last3=Bovet |title=Activité du p.aminophénylsulfamide sur l’infection streptococcique expérimentale de la souris et du lapin |journal=Comptes rendus des séances de la Société de biologie et de ses filiales |volume=120 |page=756 |date=23 November 1935 |url=http://gallica.bnf.fr/ark:/12148/bpt6k65430169/f766.image.r=Comptes%20rendus%20des%20society%20biol.langEN |language=fr}}</ref> then with of dapsone independently by [[Ernest Fourneau]]<ref>{{cite journal |first=E. |last=Fourneau |first2=Th. et J. |last2=Tréfouël |first3=F. |last3=Nitti |first4=D. |last4=Bovet |title=Action antistreptococcique des dérivés sulfurés organiques |journal=Comptes rendus de l'Académie des sciences |volume=204 |page=1763 |year=1937 |url=http://gallica.bnf.fr/ark:/12148/bpt6k31562/f1763.image |language=fr}}</ref> in France and Gladwin Buttle<ref>{{cite journal |last=Buttle |first= G.A.H. |last2=Stephenson |first2=D. |last3=Smith |first3=S. |last4=Dewing |first4=T. |last5=Foster |first5=G.E. |title=Treatment of streptococcal infections in mice with 4:4'diamino-dipheni-sulphone |journal=Lancet |volume=229 |issue=5936 |pages=1331–4 |date=June 1937 |doi=10.1016/S0140-6736(00)75868-5 |url=http://www.thelancet.com/journals/lancet/article/PIIS0140-6736%2800%2975868-5/abstract}}</ref> in United-Kingdom.<ref name="urlLeprosy | 14 History of dapsone and dyes">{{cite web |url=http://www.itg.be/itg/DistanceLearning/LectureNotesVandenEndenE/22_Leprosyp14.htm |title=Leprosy | 14 History of dapsone and dyes |work= |accessdate=2009-02-24}} (1937)</ref>
==See also==
*[[Bisphenol S]]
== References ==

{{reflist|2}}

== External links ==
*[http://www.nlm.nih.gov/medlineplus/druginfo/meds/a682128.html MedlinePlus Drug Information]
* [http://druginfo.nlm.nih.gov/drugportal/dpdirect.jsp?name=Dapsone U.S. National Library of Medicine: Drug Information Portal - Dapsone]

{{Antimycobacterials}}
{{Nucleic acid inhibitors}}
{{Acne Agents}}

[[Category:Anilines]]
[[Category:Sulfones]]
[[Category:Dihydropteroate synthetase inhibitors]]
[[Category:Antibiotics]]
[[Category:Anti-acne preparations]]
[[Category:Leprosy]]
[[Category:World Health Organization essential medicines]]
[[Category:RTT]]

Tert-Butyllithium

2016-02-09T05:38:22Z

71.109.148.145: /* Safety */ 6 mos no cite, and no substantiation for term glymes. Deleting.

{{DISPLAYTITLE:''tert''-Butyllithium}}
{{Chembox
| Watchedfields = changed
| verifiedrevid = 470602967
| Name = ''tert''-Butyllithium
| ImageFile1 = TBuLitetramer.svg
| ImageName1 =
| ImageFile2 = Tert-Butyllithium.png
| ImageFile_Ref = {{chemboximage|correct|??}}
| ImageName2 = Skeletal formula of ''tert''-butyllithium with all implicit hydrogens shown, and partial charges added
| PIN = ''tert''-Butyllithium{{Citation needed|date = October 2011}}
|Section1={{Chembox Identifiers
| CASNo = 594-19-4
| CASNo_Ref = {{cascite|correct|CAS}}
| PubChem = 638178
| ChemSpiderID = 10254347
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| EINECS = 209-831-5
| UNNumber = 3394
| MeSHName =
| Beilstein = 3587204
| SMILES = [Li]C(C)(C)C
| StdInChI = 1S/C4H9.Li/c1-4(2)3;/h1-3H3;
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = BKDLGMUIXWPYGD-UHFFFAOYSA-N
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
}}
|Section2={{Chembox Properties
| Formula = {{Chem|LiC|4|H|9}}
| MolarMass = 64.055 g mol−1
| Appearance = Colorless solid
| Density = 660 mg cm−3
| BoilingPtC = 36 to 40
| Solubility = Reacts
| pKa = 53
}}
|Section3={{Chembox Hazards
| GHSPictograms = {{GHS flame}} {{GHS corrosion}} {{GHS exclamation mark}} {{GHS health hazard}} {{GHS environment}}
| GHSSignalWord = '''DANGER'''
| HPhrases = {{H-phrases|225|250|260|304|314|336|411}}
| PPhrases = {{P-phrases|210|222|223|231+232|370+378|422}}
| EUClass = {{Hazchem F+}} {{Hazchem C}} {{Hazchem N}} {{Hazchem T+}}
| RPhrases = {{R11}}, {{R15}}, {{R17}}, {{R34}}, {{R50/53}}, {{R65}}, {{R66}}, {{R67}}, {{R50/53}}, {{R38}}
| SPhrases = {{S26}}, {{S36/37/39}}, {{S43}}, {{S45}}, {{S62}}, {{S61}}, {{S16}}, {{S33}}
| NFPA-H = 3
| NFPA-F = 4
| NFPA-R = 4
| NFPA-S = W
| FlashPtC = -6.6
}}
|Section4={{Chembox Related
| OtherCompounds = [[n-butyllithium|''n''-Butyllithium]] 
[[sec-butyllithium|''sec''-Butyllithium]]
}}
}}

'''''tert''-Butyllithium''' is a [[chemical compound]] with the [[Chemical formula|formula]] (CH3)3CLi. As an [[organolithium compound]], it has applications in [[organic synthesis]] since it is a strong [[Base (chemistry)|base]], capable of deprotonating many carbon acids, including [[benzene]]. ''tert''-Butyllithium is available commercially as hydrocarbon solutions; it is not usually prepared in the laboratory. Its synthesis was first reported by [[R. B. Woodward]] in 1941.<ref>{{cite journal|last=Bartlett|first=Paul D.|author2=C. Gardner Swain |author3=Robert B. Woodward |journal=J. Am. Chem. Soc. | title = t-Butyllithium |year=1941 |volume=63 |issue=11 |pages=3229–3230 |doi=10.1021/ja01856a501 }}</ref>

==Structure and bonding==
Like other organolithium compounds, ''tert''-butyllithium is a cluster. Whereas ''n''-butyllithium exists both as a hexamer and a tetramer, ''tert''-Butyllithium exists as tetramer with a cubane structure. Bonding in organolithium clusters involves sigma delocalization and significant Li---Li bonding.<ref>Elschenbroich, C. ”Organometallics” (2006) Wiley-VCH: Weinheim. ISBN 978-3-527-29390-2</ref>

The lithium–carbon bond in ''tert''-butyllithium is highly polarized, having about 40 percent [[Chemical polarity|ionic character]]. The molecule reacts like a [[carbanion]], as is represented by these two [[Resonance (chemistry)|resonance structures]].<ref>Organometallic reagents: sources of nucleophilic carbon for alcohol synthesis. K. P. C. Vollhardt, N. E. Schore: ''Organic Chemistry : Structure And Function''. 3rd edition, 1999, §8.7.</ref> (Given the polarity calculations on the C–Li bond, the "real" structure of a single molecule of ''t''-butyllithium is likely a near-average of the two resonance contributors shown, in which the central carbon atom has a ~50% partial negative charge while the lithium atom has a ~50% partial positive charge.)

:[[Image:tert-Butyllithium, Mesomerie.svg|300px]]

== Chemical properties ==
Similar to [[n-Butyllithium|''n''-butyllithium]], ''tert''-butyllithium can be used for the exchange of lithium with halogens and for the deprotonation of amines and activated C—H compounds.

This compound and other alkyllithium compounds are known to react with ether solvents; the [[half-life]] of ''tert''-butyllithium is 60 minutes at 0 °C in [[diethyl ether]], 40 minutes at -20 °C in [[tetrahydrofuran]] (THF),<ref>{{cite journal | author = Stanetty, P; Koller, H.; Mihovilovic, M. | title = Directed ortho lithiation of phenylcarbamic acid 1,1-dimethylethyl ester (N-BOC-aniline). Revision and improvements | journal = [[Journal of Organic Chemistry]] | year = 1992 | volume = 57 | pages = 6833–6837 | doi=10.1021/jo00051a030 | issue = 25}}</ref> and about 11 minutes at -70 °C in [[dimethoxyethane]].<ref>{{cite journal | author = Fitt, J. J.; Gschwend, H. E. | title = Reaction of n-, sec-, and tert-butyllithium with dimethoxyethane (DME): a correction | journal = [[Journal of Organic Chemistry]] | year = 1984 | volume = 49 | pages = 209–210 | doi=10.1021/jo00175a056}}</ref>
In this example, the reaction of ''tert''-butyllithium with (THF) is shown:

:[[Image:Zersetzung THF tert-Butyllithium1.svg|450px]]

:[[Image:Zersetzung THF tert-Butyllithium2.svg|250px]]
To minimize degradation by these solvents, reactions involving ''tert''-butyllithium are often conducted very low temperatures in special solvents, such as the [[Trapp solvent]] mixture.

==Safety==
''tert''-Butyllithium is a [[pyrophoric]] substance, meaning that it easily catches fire on exposure to air. (A precise definition of a pyrophoric material is one "that ignite[s] spontaneously in air at or below 54.55 °C (130.19 °F)".<ref>[[SEMI]], standard F6-92, [http://webstore.ansi.org/RecordDetail.aspx?sku=SEMI+F6-92 ''Guide for Secondary Containment of Hazardous Gas Piping Systems''], [http://www.chemicool.com/definition/pyrophoric.html as cited by ChemiCool.com]</ref>) The solvents used in common commercial preparations are themselves flammable. While it is possible to work with this compound using [[cannula transfer]], traces of ''tert''-butyllithium at the tip of the needle or cannula may catch fire and clog the cannula with lithium salts. While some researchers take this "pilot light" effect as a sign that the product is "fresh" and has not degraded due to time or improper storage/handling, some workers prefer to enclose the needle tip or cannula in a short glass tube, which is flushed with an inert gas and sealed at each end with septa.<ref>{{cite book |author=Errington, R. M. |title=Advanced practical inorganic and metalorganic chemistry |publisher=Blackie Academic & Professional |location=London |year=1997 |pages=47–48 |isbn=0-7514-0225-7 |oclc= |doi= |accessdate= | url = http://books.google.com/?id=yI_mq_mCf2AC&pg=PA47&lpg=PA48#PPA48,M1 | format = [[Google Books]] excerpt}}</ref> Serious laboratory accidents involving ''tert''-butyllithium have occurred. For example, in 2008 a staff research assistant, [[Sheri Sangji case|Sheharbano Sangji]], in the lab of [[Patrick Harran]]<ref>{{cite web|title=Harran Lab: UCLA|url=http://faculty.chemistry.ucla.edu/institution/personnel?personnel_id=552980}}</ref> at the [[University of California, Los Angeles]], died after being severely burned by a fire ignited by ''tert''-butyllithium.<ref>{{cite news | publisher = [[Chemical & Engineering News]] | author = Jyllian Kemsley | title = Researcher Dies After Lab Fire | date = 2009-01-22 | url = http://pubs.acs.org/cen/news/87/i04/8704news1.html}}</ref><ref>{{cite news | publisher = [[Chemical & Engineering News]] | author = Jyllian Kemsley | title = Learning From UCLA: Details of the experiment that led to a researcher’s death prompt evaluations of academic safety practices | date = 2009-04-03 | url = http://pubs.acs.org/cen/science/87/8731sci1.html}}</ref><ref>[http://www.latimes.com/news/local/traffic/la-me-uclaburn1-2009mar01,0,5638579.story ''Los Angeles Times'', 2009-03-01]</ref>

Large-scale reactions may lead to runaway reactions, fires, and explosions when ''tert''-butyllithium is mixed with ethers such as diethyl ether, and tetrahydrofuran. The use of hydrocarbon solvents may be preferred.

[[Air-free technique]]s are important so as to prevent this compound from reacting violently with oxygen and moisture in the air:

:''t''-BuLi + O2 → ''t''-BuOOLi
:''t''-BuLi + H2O → ''t''-BuH + LiOH

==References==

{{Reflist}}

{{DEFAULTSORT:Butyllithium, t-}}
[[Category:Reagents for organic chemistry]]
[[Category:Bases]]
[[Category:Organolithium compounds]]

Crown ether

2016-02-09T03:40:54Z

71.109.148.145: /* Azacrowns */ No meaning for "lariat" under "lasso" (the redirect) OR the disambiguation page contain this meaning. So (for now) delete link.

[[Image:18-crown-6-potassium-3D-balls-A.png|thumb|right|200px|[[18-crown-6]] coordinating a potassium ion]]
'''Crown ethers''' are cyclic [[chemical compound]]s that consist of a ring containing several [[ether]] groups. The most common crown ethers are [[oligomer]]s of [[ethylene oxide]], the repeating unit being ethyleneoxy, i.e., -CH2CH2O-. Important members of this series are the tetramer (n = 4), the pentamer (n = 5), and the hexamer (n = 6). The term "crown" refers to the resemblance between the structure of a crown ether bound to a [[cation]], and a [[crown (headgear)|crown]] sitting on a person's head. The first number in a crown ether's name refers to the number of atoms in the cycle, and the second number refers to the number of those atoms that are [[oxygen]]. Crown ethers are much broader than the [[oligomer]]s of ethylene oxide; an important group are derived from [[catechol]].

Crown ethers strongly bind certain cations, forming [[complex (chemistry)|complexes]]. The oxygen atoms are well situated to coordinate with a cation located at the interior of the ring, whereas the exterior of the ring is hydrophobic. The resulting cations often form salts that are soluble in nonpolar solvents, and for this reason crown ethers are useful in [[phase transfer catalysis]]. The [[ligand|denticity]] of the polyether influences the affinity of the crown ether for various cations. For example, 18-crown-6 has high affinity for potassium cation, 15-crown-5 for sodium cation, and 12-crown-4 for lithium cation. The high affinity of 18-crown-6 for potassium ions contributes to its toxicity. Crown ethers are not the only macrocyclic ligands that have affinity for the potassium cation. [[Ionophore]]s such as [[valinomycin]] also display a marked preference for the potassium cation over other cations.

::[[Image:Various crown ethers (molecular diagrams).png|thumb|center|700px|structures of common crown ethers: [[12-crown-4]], [[15-crown-5]], [[18-crown-6]], [[dibenzo-18-crown-6]], and [[diaza-18-crown-6]] ]]

==History==
In 1967, [[Charles Pedersen]], who was a [[chemist]] working at [[DuPont]], discovered a simple method of synthesizing a crown ether when he was trying to prepare a [[complexing agent]] for [[divalent cation]]s.<ref>{{Cite journal| last1 = Pedersen | first1 = C. J.| title = Cyclic polyethers and their complexes with metal salts| journal = Journal of the American Chemical Society| volume = 89| issue = 26| pages = 7017–7036| year = 1967 | doi = 10.1021/ja01002a035}}</ref><ref>{{Cite journal| last1 = Pedersen | first1 = C. J.| title = Cyclic polyethers and their complexes with metal salts| journal = Journal of the American Chemical Society| volume = 89| issue = 10| pages = 2495–2496| year = 1967 | doi = 10.1021/ja00986a052}}</ref> His strategy entailed linking two [[catechol]]ate groups through one [[hydroxyl]] on each molecule. This linking defines a polydentate ligand that could partially envelop the cation and, by [[ionization]] of the phenolic hydroxyls, neutralize the bound dication. He was surprised to isolate a [[by-product]] that strongly complexed [[potassium]] cations. Citing earlier work on the dissolution of [[potassium]] in 16-crown-4,<ref name="stewart">D. G. Stewart. D. Y. Waddan and E. T. Borrows, {{Patent|GB|785229}} Oct. 23, '''1957'''.</ref><ref name="down">J. L. Down, J. Lewis, B. Moore and G. W. Wilkinson, Proc. Chem. Soc., 1959, 209; J. Chem. Soc., '''1959''', 3767.</ref> he realized that the cyclic [[polyether]]s represented a new class of complexing agents that were capable of binding [[alkali metal]] cations. He proceeded to report systematic studies of the synthesis and binding properties of crown ethers in a seminal series of papers. The fields of [[organic synthesis]], [[phase transfer catalyst]]s, and other emerging disciplines benefited from the discovery of crown ethers. Pedersen particularly popularized the dibenzo crown ethers.<ref>{{OrgSynth | author = Charles J. Pedersen | title = Macrocyclic Polyethers: Dibenzo-18-Crown-6 Polyether and Dicyclohexyl-18-Crown-6 Polyether | collvol = 6 | collvolpages = 395 | year = 1988 | prep = CV6P0395}}</ref>

Pedersen shared the 1987 [[Nobel Prize in Chemistry]] for the discovery of the synthetic routes to, and binding properties of, crown ethers.

==Affinity for cations==
Apart from its high affinity for potassium cations, [[18-crown-6]] can also bind to protonated amines and form very stable complexes in both solution and the gas phase. Some [[amino acids]], such as [[lysine]], contain a primary [[amine]] on their side chains. Those protonated amino groups can bind to the cavity of 18-crown-6 and form stable complexes in the gas phase. Hydrogen-bonds are formed between the three hydrogen atoms of protonated amines and three oxygen atoms of 18-crown-6. These hydrogen-bonds make the complex a stable adduct.
By incorporating luminescent substituents into their backbone, these compounds have proved to be sensitive ion probes, as changes in the absorption or fluorescence of the photoactive groups can be measured for very low concentrations of metal present.<ref>Fabbrizzi, L.; Francese, G.; Licchelli, M.; Pallavicini, P.; Perotti, A.; Poggi, A.; Sacchi, D.; Taglietti, A. Chemosensors of Ion and Molecule Recognition; NATO ASI Ser., Ser. C, Vol. 492; Desvergne, J. P., Czarnik, A. W., Eds., Kluwer Academic Publishers, Dordrecht, 1997, 75.</ref> Some attractive examples include macrocycles, incorporating oxygen and/or nitrogen donors, that are attached to polyaromatic species such as anthracenes (via the 9 and/or 10 positions)<ref>Bouas-Laurent, H.; Desvergne, J. P.; Fages, F.; Marsau, P. Fluorescent Chemosensors for Ion and Molecule Recognition ACS Symposium Series 538, Czarnik, A. W. (Editors) American Chemical Society, Washington D.C., 1993, p 59.</ref> or naphthalenes (via the 2 and 3 positions).<ref>http://onlinelibrary.wiley.com/doi/10.1002/hlca.200890148/abstract</ref><ref>H Sharghi, S Ebrahimpourmoghaddam Helvetica Chimica Acta 2008, 91 (7), 1363-1373, DOI: 10.1002/hlca.200890148</ref>

==Azacrowns==
21- and 18-membered diazacrown ether derivatives exhibit excellent [[calcium]] and [[magnesium]] selectivities and are widely used in [[ion-selective electrode]]s.<ref>{{cite journal |author = K. Suzuki, K. Watanabe, Y. Matsumoto, M. Kobayashi, S. Sato, D. Siswanta, H. Hisamoto |title = Design and Synthesis of Calcium and Magnesium Ionophores Based on Double-Armed Diazacrown Ether Compounds and Their Application to an Ion Sensing Component for an Ion-Selective Electrode |journal = Anal. Chem. |year = 1995 |volume = 67 |issue = 2 |pages = 324–334 |doi = 10.1021/ac00098a016}}</ref> Some or all of the oxygen atoms in crown ethers can be replaced by nitrogens to form [[cryptand]]s. A well-known tetrazacrown is [[cyclen]] in which there are no oxygens.<ref>{{OrgSynth | author = Vincent J. Gatto, Steven R. Miller, and George W. Gokel | title = 4,13-Diaza-18-Crown-6 | collvol = 8 | collvolpages = 152| year = 1988 | prep = CV8P0152}}</ref>

Lariat crown ethers have sidearms that can augment complexation of cation. The lariat is typically attached to an amine centre in an azacrown.<ref>G. W. Gokel, L. J. Barbour, R. Ferdani and J. Hu, "Lariat Ether Receptor Systems Show Experimental Evidence for Alkali Metal Cation- Interactions", Acc. Chem. Res. 2002, volume 35, 878 -886. {{DOI|10.1021/ar000093p}}</ref>

==See also==
* [[Cryptand]]
* [[Metallacrown]]

==References==
{{Reflist}}

==External links ==
* [http://nobelprize.org/chemistry/laureates/1987/pedersen-lecture.pdf Charles Pedersen's Nobel Lecture]
* [http://www.org-chem.org/yuuki/crown/crown_en.html molecular crown]

{{Authority control}}
[[Category:Crown ethers| ]]

RD-701

2016-02-09T03:39:20Z

71.109.148.145: /* Specifications */

{{Infobox rocket engine
|name =RD-701 (''РД-701'')
|image =
|image_size =300
|caption =Photo of rocket engine ''RD-701'' exhibited for viewers.
|country_of_origin=[[USSR]]/[[Russia]]
|date = late 1980's
|manufacturer =[[NPO Energomash|Energomash]]
|successor =''RD-704''
|designer =
|status =Experimental
|purpose =
|type =liquid
|fuel =[[LH2]]&[[RP-1]]; ''Mode#2:'' [[LOX]] / [[LH2]]
|oxidiser =''Mode#1:'' [[LOX]]
|capacity =
|cycle =[[Staged combustion cycle (rocket)|staged combustion]]
|thrust(SL) =''Mode#1:'' 714,000 [[Pound-force|lbf]] (3.2 [[Newton (unit)|MN]])<ref name="NSPO">[http://www.buran.ru/htm/rd-701.htm ''Engines of MAKS: RD-701''].</ref>
|thrust(Vac) =''Mode#1:'' 900,000 [[Pound-force|lbf]] (4 [[Newton (unit)|MN]]) ''Mode#2:'' 357,000 [[Pound-force|lbf]] (1.6 [[Newton (unit)|MN]])
|specific_impulse_vacuum =''Mode#1:'' 415 [[Second|s]] ''Mode#2:'' 460 [[Second|s]]
|specific_impulse_sea_level=''Mode#1:'' 330 [[Second|s]]
|chamber_pressure =''Mode#1:'' 4,351 [[Pounds per square inch|psi]] (30 [[Pascal (unit)|MPa]]) ''Mode#2:'' 2,176 [[Pounds per square inch|psi]] (15 [[Pascal (unit)|MPa]])
|thrust_to_weight =
|length =
|diameter ={{convert|94|in|abbr=on}} (''1 nozzle'')
|dry_weight =4,240 [[Pound (mass)|lb]] (1,923 [[kilogram|kg]])<ref name="NSPO" />
|used_in =
}}
'''RD-701''' ({{lang-ru|''Раке́тный дви́гатель 701''}}, '''Rocket Engine 701''') - [[liquid-fuel rocket]] [[rocket engine|engine]] developed by [[NPO Energomash|Energomash]], [[Russia]]. It was proposed to propel the reusable [[MAKS space plane]] before cancellation of this project. The ''RD-701'' is a tripropellant engine that uses [[Staged combustion cycle (rocket)|staged combustion cycle]] afterburning of [[oxidizer]]-rich hot [[turbine]] gas. This engine has two modes. ''Mode #1'' uses three components: [[LOX]] as an [[oxidizer]] and a [[fuel]] mixture of [[RP-1]] / [[LH2]] which is applied for near earth surface conditions. ''Mode #2'' also uses LOX, with [[LH2]] as fuel in vacuum where atmospheric influence is negligible.

The use of less dense fuel components at maximum [[specific impulse|efficiency]] conditions allows minimizing the volume of fuel tanks and subsequently their mass down to 30%. As of 2009 the engine is characterized by highest value of pressure, 300 [[Bar (unit)|bar]], ever used in [[combustion chamber]] of rocket engines when running in ''Mode #1'' with mixture of fuel components. The ''RD-701'' became the base model for '''RD-704''' with one combustion chamber.

== Specifications ==
Two-chamber ''RD-701'' has two modes. The first one uses three components: [[RP-1]] (mass flow — 73.7 kg/s), [[LH2]] (mass flow — 29.5 kg/s) and [[LOX]] (mass flow — 388.4 kg/s). This mode is applied in lower atmosphere to minimize fuel tanks volume. The total thrust for altitude 10 km is 2х1,890.2 KN and specific impulse is 3,845 m/s.

The second mode uses just two components: [[LH2]] (mass flow — 24.7 kg/s) and [[LOX]] (mass flow — 148.5 kg/s). This mode applied for near space conditions and gives thrust 2х784.5 KN, specific impulse — 4,532 m/s.{{clarify|units of specific impulse are SECONDS, not m/s}}

The mixing block of the main combustion chamber has three groups of injectors, one for each of the three available components. When running in ''Mode #2'' the engine doesn't use the kerosene group. The engine uses [[regenerative cooling]] by [[liquid hydrogen]].

== RD-704 ==
The ''RD-704'' is a smaller version of basic engine and uses the same components and scheme of work but with one preburner, turbopump, combustion chamber and nozzle.

== See also ==
* [[MAKS space plane]]
* [[Staged combustion cycle (rocket)|Staged combustion cycle]]
* [[RD-170]] - [[RP-1]]/[[LOX]] Russian engine
* [[RD-0120]] - [[LH2]]/[[LOX]] Russian engine

== References ==
<references/>

==External links==
*[http://www.buran.ru/htm/rd-701.htm ''Engines of MAKS: RD-701'']
*[http://www.buran.ru/htm/40-3.htm B.I. Gubanov. ''Triumph and tragedy of "Energia"'', Chapter 40: ''Engines of reusable systems.''] (in Russian)
*[http://www.npoenergomash.ru/about/news/news2_24.html ''Astronautix: RD-701'']
*[http://www.astronautix.com/engines/rd704.htm ''Astronautix: RD-704'']
*[http://www.npoenergomash.ru/about/news/news2_24.html NPO «Energomash»: ''News of ... ''] ''19 June 2007year'' (in Russian)

[[Category:Rocket engines of Russia]]
[[Category:Rocket engines using hydrogen propellant]]
[[Category:Rocket engines of the Soviet Union]]

Rocketdyne F-1

2016-02-09T01:30:38Z

71.109.148.145: /* F-1A after Apollo */ Clarifying

{{Refimprove|date=July 2009}}
{{infobox rocket engine
|image=F-1 rocket engine.jpg
|image_size=300
|caption=F-1 rocket engine specifications
|name=F-1
|country_of_origin=[[United States]]
|manufacturer=[[Rocketdyne]]
|purpose=

|type=liquid
|fuel=[[RP-1]]
|oxidiser=[[LOX]]
|capacity=

|thrust(SL)={{convert|1522000|lbf|kN|abbr=on}}
|thrust(Vac)={{convert|1746000|lbf|kN|abbr=on}}
|specific_impulse_vacuum={{convert|304|isp}}
|specific_impulse_sea_level= {{convert|263|isp}}
|chamber_pressure={{convert|70|bar|psi MPa|0}}
|thrust_to_weight=94.1
|cycle=[[Gas-generator cycle (rocket)|Gas-generator]]
}}
The '''F-1''' is a [[gas-generator cycle]] [[rocket engine]] developed in the [[United States]] by [[Rocketdyne]] in the late 1950s and used in the [[Saturn V]] rocket in the 1960s and early 1970s. Five F-1 engines were used in the [[S-IC]] first stage of each Saturn V, which served as the main launch vehicle of the [[Apollo program]]. The F-1 remains the most powerful single-[[combustion chamber]] [[liquid-propellant rocket]] engine ever developed.<ref>W. David Woods, ''How Apollo Flew to the Moon'', Springer, 2008, ISBN 978-0-387-71675-6, p. 19</ref>

== History ==
[[File:S-IC engines and Von Braun.jpg|thumb|right|[[Wernher von Braun]] with the F-1 engines of the Saturn V first stage at the [[U.S. Space and Rocket Center]]]]

The F-1 was originally developed by Rocketdyne to meet a 1955 [[United States Air Force|U.S. Air Force]] requirement for a very large rocket engine. The eventual result of that requirement was two engines, the [[Rocketdyne E-1|E-1]] and the much larger F-1. The E-1, although successfully tested in static firing, was quickly seen as a technological dead-end, and was abandoned for the larger, more powerful F-1. The Air Force eventually halted development of the F-1 because of a lack of requirement for such a large engine. However, the recently created [[National Aeronautics and Space Administration]] (NASA) appreciated the usefulness of an engine with so much power, and contracted Rocketdyne to complete its development. Test firings of F-1 components had been performed as early as 1957. The first static firing of a full-stage developmental F-1 was performed in March 1959. The first F-1 was delivered to NASA [[Marshall Space Flight Center|MSFC]] in October 1963. In December 1964, the F-1 completed flight-rating tests. Testing continued at least through 1965.<ref>{{cite web |url=http://history.msfc.nasa.gov/saturn_apollo/documents/Background_F-1_Rocket_Engine.pdf |title=NASA Rocketdyne document |format=PDF |date= |accessdate=2013-12-27}}</ref>

Early development tests revealed serious [[combustion instability]] problems which sometimes caused [[catastrophic failure]].<ref>{{Citation
|first= Renea
|last= Ellison
|first2= Marlow
|last2= Moser
|title= Combustion Instability Analysis and the Effects of Drop Size on Acoustic Driving Rocket Flow
|place= Huntsville, Alabama
|publisher= Propulsion Research Center, University of Alabama in Huntsville
|url= http://reap.uah.edu/publications/Ellison.pdf
|format=PDF
}}</ref> Initially, progress on this problem was slow, as it was intermittent and unpredictable. Oscillations of 4 kHz with harmonics to 24 kHz were observed. Eventually, engineers developed a diagnostic technique of detonating small explosive charges (which they called "bombs") outside the combustion chamber, through a tangential tube (RDX, C4 or black powder were used) while the engine was firing. This allowed them to determine exactly how the running chamber responded to variations in pressure, and to determine how to nullify these oscillations. The designers could then quickly experiment with different co-axial fuel-injector designs to obtain the one most resistant to instability. These problems were addressed from 1959 through 1961. Eventually, engine combustion was so stable, it would [[Damping ratio|self-damp]] artificially induced instability within 1/10 of a second.

== Design ==
[[File:SaturnF1EngineDiagram.png|thumb|right|upright=1.35|F-1 rocket engine components]]

The [[Rocketdyne]]-developed ''F-1'' engine is the most powerful single-nozzle [[Liquid rocket|liquid-fueled rocket engine]] ever flown. The [[M-1 (rocket engine)|M-1 rocket engine]] was designed to have more thrust, however it was only tested at the component level. The F-1 was a liquid-fueled rocket motor, burning [[RP-1]] ([[kerosene]]) as fuel, and using [[liquid oxygen]] (LOX) as the oxidizer ([[kerolox]]). A [[turbopump]] was used to inject fuel and oxygen into the combustion chamber.

The heart of the engine was the thrust chamber, which mixed and burned the fuel and oxidizer to produce thrust. A domed chamber at the top of the engine served as a [[Manifold (general engineering)|manifold]] supplying liquid oxygen to the [[Injector (Rocket)|injectors]], and also served as a mount for the [[gimbal]] bearing which transmitted the thrust to the body of the rocket. Below this dome were the injectors, which directed fuel and oxidizer into the thrust chamber in a way designed to promote mixing and combustion. Fuel was supplied to the injectors from a separate manifold; some of the fuel first travelled in 178 tubes down the length of the thrust chamber—which formed approximately the upper half of the [[Rocket engine nozzle|exhaust nozzle]]—and back, to cool the nozzle.

A [[gas-generator cycle (rocket)|gas-generator]] was used to drive a [[turbine]] which in turn drove separate fuel and oxygen pumps, each feeding the thrust chamber assembly. The turbine was driven at 5,500 [[RPM]] by the gas generator, producing {{convert|55000|bhp|MW}}. The fuel pump delivered {{convert|15,471|gal|l|abbr=off}} of RP-1 per minute while the oxidizer pump delivered {{convert|24,811|gal|l|abbr=on}} of liquid oxygen per minute. Environmentally, the turbopump was required to withstand temperatures ranging from input gas at {{convert|1500|F|-1}} to liquid oxygen at {{convert|−300|F|0}}. Structurally, fuel was used to lubricate and cool the turbine [[Bearing (mechanical)|bearings]].

[[File:F-1 Engine Test Firing.jpg|right|thumb|Test firing of an F-1 engine at [[Edwards Air Force Base]]]]
[[File:F-1 Engines Being Installed.jpg|right|thumb|Installation of F-1 engines to the Saturn V S-IC Stage. The [[nozzle extension]] is absent from the engine being fitted.]]
Below the thrust chamber was the [[nozzle extension]], roughly half the length of the engine. This extension increased the [[Rocket_engine#Propellant_efficiency|expansion ratio]] of the engine from 10:1 to 16:1. The exhaust from the turbopump was fed into the nozzle extension by a large, tapered manifold; this relatively cool gas formed a film which protected the nozzle extension from the hot ({{convert|5800|F|-1}}) exhaust gas.<ref name=SVPressKit>{{Citation
|date= December 1968
|title= Saturn V News Reference: F-1 Engine Fact Sheet
|publisher= National Aeronautics and Space Administration
|url= http://history.msfc.nasa.gov/saturn_apollo/documents/F-1_Engine.pdf
|format=PDF
|pages= 3–3, 3–4
|accessdate= 2008-06-01
}}</ref>

Each second, a single F-1 burned {{convert|5683|lb}} of oxidizer and fuel: {{convert|3945|lb|abbr=on}} of liquid oxygen and {{convert|1738|lb|abbr=on}} of RP-1, generating {{convert|1500000|lbf|MN|abbr=on}} of thrust. This equated to a flow rate of {{convert|671.4|USgal|l|abbr=on}} per second; {{convert|413.5|gal|l|abbr=on}} of LOX and {{convert|257.9|gal|l|abbr=on}} of RP-1. During their two and a half minutes of operation, the five F-1s propelled the Saturn V vehicle to a height of {{convert|42|mi|ft km}} and a speed of {{convert|6164|mph|km/h|abbr=on}}. The combined flow rate of the five F-1s in the Saturn V was {{convert|3357|gal|l|abbr=on}} per second,<ref name=SVPressKit/> or {{convert|28415|lb|-1|abbr=on}}. Each F-1 engine had more thrust than three [[Space Shuttle Main Engine]]s combined.<ref>{{Citation
|title= NSTS 1988 News Reference Manual
|publisher= NASA
|url= http://science.ksc.nasa.gov/shuttle/technology/sts-newsref/sts_overview.html#sts_overview
|accessdate= 2008-07-03
}}</ref>

Designer of the pump for the E-1/F-1 for Rocketdyne was Ernest A. Lamont. His hand-written original calculations are part of the family archives and available for display. He stated that the design of the rocket engine hinged on the question of whether the pump design was viable.{{Citation needed|date=April 2011}}

===Pre and post ignition procedures===
During static test firing, the kerosene-based RP-1 fuel left [[hydrocarbon]] deposits and vapors in the engine post test firing. These had to be removed from the engine to avoid problems during engine handling and future firing, and the solvent [[trichloroethylene]] (TCE) was used to clean the engine's fuel system immediately before and after each test firing. The cleaning procedure involved pumping TCE through the engine's fuel system and letting the solvent overflow for a period ranging from several seconds to 30–35 minutes, depending upon the engine and the severity of the deposits. For some engines, the engine's gas generator and LOX dome were also flushed with TCE prior to test firing.<ref>{{cite web|url=http://ssfl.msfc.nasa.gov/public-involvement/docs/SSFL_TCE_Final_Fact_Sheet.pdf |title=The Use of Trichloroethylene at NASA’s SSFL Sites |format=PDF |date= |accessdate=2013-12-27}}</ref><ref name="ntrs.nasa.gov">{{cite web|url=http://ntrs.nasa.gov/search.jsp?N=0&Ntk=all&Ntx=mode%20matchall&Ntt=19750070175 |title=F-1 Rocket Engine Operating Instructions |publisher=Ntrs.nasa.gov |date=2013-03-01 |accessdate=2013-12-27}}</ref> The F-1 rocket engine had its LOX dome, gas generator, and thrust chamber fuel jacket flushed with TCE during launch preparations.<ref name="ntrs.nasa.gov"/>

=== Specifications ===
{| class=wikitable
!
! Apollo 4, 6, and 8
! Apollo 9–17
|-
| [[Thrust]] (sea level):
| {{convert|1500000|lbf|MN|abbr=on}}
| {{convert|1522000|lbf|MN|abbr=on}}
|-
| Burn time:
| 150 seconds
| 165 seconds
|-
| [[Specific impulse]]:
| {{convert|260|isp}}
| {{convert|263|isp}}
|-
| Chamber pressure:
| {{convert|70|bar|psi MPa|0|abbr=on}}
| {{convert|70|bar|psi MPa|0|abbr=on}}
|-
| Engine weight dry:
| {{convert|18416|lb|abbr=on}}
| {{convert|18500|lb|abbr=on}}
|-
| Engine weight burnout:
| {{convert|20096|lb|abbr=on}}
| {{convert|20180|lb|abbr=on}}
|-
| Height:
| colspan=2 | {{convert|19|ft|abbr=on}}
|-
| Diameter:
| colspan=2 | {{convert|12.3|ft|abbr=on}}
|-
| Exit to throat ratio:
| colspan=2 |16 to 1
|-
| Propellants:
| colspan=2 |[[LOX]] & [[RP-1]]
|-
| Mixture mass ratio:
| colspan=2 |2.27:1 oxidizer to fuel
|-
| Contractor:
| colspan=2 |NAA/Rocketdyne
|-
| Vehicle application:
| colspan=2 |Saturn V / [[S-IC]] 1st stage - 5-engines
|}

Sources:<ref name=SVPressKit/><ref>{{Citation
|title= F-1 Engine (chart)
|id= MSFC-9801771
|publisher= NASA Marshall Space Flight Center
|url= http://ntrs.nasa.gov/search.jsp?R=MSFC-9801771
|accessdate= 2008-06-01
}}</ref>

=== F-1 improvements ===
[[File:F-1 rocket engine at United States Space and Rocket Center in 2006.jpg|right|thumb|F-1 on display at the [[U.S. Space & Rocket Center]] in [[Huntsville, Alabama]].]]

F-1 thrust and efficiency were improved between [[Apollo 8]] (SA-503) and [[Apollo 17]] (SA-512), which was necessary to meet the increasing payload capacity demands of later [[Project Apollo|Apollo]] missions. There were small performance variations between engines on a given mission, and variations in average thrust between missions. For [[Apollo 15]], F-1 performance was:

*Thrust (average, per engine, sea level liftoff): {{convert|1553200|lbf|MN|abbr=on}}
*Burn time: 159 seconds
*[[Specific impulse]]: {{convert|264.72|isp}}{{clarify|is convert broken for Isp?}}
*Mixture ratio: 2.2674
*[[S-IC]] total sea level liftoff thrust: {{convert|7766000|lbf|MN|abbr=on}}

Measuring and making comparisons of rocket engine thrust is more complicated than it first appears. Based on actual measurement the liftoff thrust of [[Apollo 15]] was {{convert|7823000|lbf|MN|abbr=on}}, which equates to an average F-1 thrust of {{convert|1565000|lbf|MN|abbr=on}} – significantly more than the specified value.

{{Further|Saturn V#S-IC thrust comparisons}}

=== F-1A after Apollo ===
[[File:F-1 rocket engine at KSC.jpg|right|thumb|F-1 engine on display at [[Kennedy Space Center]] ]]
{{See also|Saturn MLV}}

During the 1960s, Rocketdyne undertook uprating development of the F-1 resulting in the new engine specification F-1A. While outwardly very similar to the F-1, the F-1A produced a larger thrust of about {{convert|8|MN|lbf|disp=flip|abbr=on}} in tests,<ref>{{cite web|url=http://www.airingnews.com/articles/86793/New-F1B-rocket-engine-upgrades-Apolloera-design-with-18M-lbs-of-thrust |title=Evacuation order lifted near derailed Alberta propane cars |publisher=Airingnews.com |date= |accessdate=2013-12-27}}</ref> and would have been used on future Saturn V vehicles in the post-[[Project Apollo|Apollo]] era. However, the Saturn V production line was closed prior to the end of Project Apollo and no F-1A engine flew on a launch vehicle.<ref name=ars20130414>{{cite news |last=Hutchinson |first=Lee |title=New F-1B rocket engine upgrades Apollo-era design with 1.8M lbs of thrust |url=http://arstechnica.com/science/2013/04/new-f-1b-rocket-engine-upgrades-apollo-era-deisgn-with-1-8m-lbs-of-thrust/ |accessdate=2013-04-15 |newspaper=ARS technica |date=2013-04-14}}</ref>

There were proposals to use eight F-1 engines on the first stage of the [[Nova rocket]]. Numerous proposals have been made from the 1970s on to develop new expendable boosters based around the F-1 engine design. These include the [[Saturn-Shuttle]], and one in 2013.<ref name=ars20130414/> {{As of|2013}}, none has proceeded beyond the initial study phase.

The F-1 is the largest, highest thrust single-chamber, single-nozzle liquid fuel engine flown. The [[RD-170]] from the [[Soviet space program]] used a cluster of four separate combustion chambers and nozzles, giving the appearance of four engines; however, the combustion chambers were all driven by a single turbopump. The assembly produced 7.2% more sea level thrust than the F-1, making the RD-170 the highest thrust liquid-fuel engines ever flown.{{Citation needed|reason=Was the RD-170 actually flown? Are its current derivatives as large?|date=December 2015}} Larger [[solid rocket|solid-fuel]] engines exist, such as the [[Space Shuttle Solid Rocket Booster]] with a sea-level liftoff thrust of {{convert|12.45|MN|lbf|disp=flip|abbr=on}} apiece.

==F-1B booster==
As part of the [[Space Launch System]] (SLS) program, NASA had been running the Advanced Booster Competition, which was scheduled to end with the selection of a winning booster configuration in 2015. In 2012, [[Pratt & Whitney Rocketdyne]] (PWR) proposed using a derivative of the F-1 engine in the competition as a [[Liquid rocket booster]].<ref name="Lee Hutchinson">{{cite news |url=http://arstechnica.com/science/2013/04/new-f-1b-rocket-engine-upgrades-apollo-era-deisgn-with-1-8m-lbs-of-thrust/ |title=New F-1B rocket engine upgrades Apollo-era design with 1.8M lbs of thrust|author=Lee Hutchinson |publisher=Ars Technica |date=2013-04-15 |accessdate=2013-04-15}}</ref><ref>{{cite web |title=Rocket companies hope to repurpose Saturn 5 engines |url=http://www.spaceflightnow.com/news/n1204/18dynetics/}}</ref> In 2013, engineers at the [[Marshall Space Flight Center]] began tests with an original F-1, serial number F-6049, which was removed from Apollo 11 due to a glitch. The engine was never used, and for many years it was at the [[Smithsonian Institution]]. The tests are designed to refamiliarize NASA with the design and propellants of the F-1 in anticipation of using an evolved version of the engine in future deep space flight applications.<ref>{{cite news|url=http://www.usnews.com/science/news/articles/2013/01/24/nasa-testing-vintage-engine-from-apollo-11-rocket |title=NASA testing vintage engine from Apollo 11 rocket |author=Jay Reeves |agency=Associated Press |date=2013-01-24 |accessdate=2013-01-24}}</ref>

[[Pratt and Whitney]], [[Rocketdyne]], and [[Dynetics]], Inc. presented a competitor known as [[Saturn C-3#Pyrios|''Pyrios'']] in NASA's Advanced Booster Program, which aims to find a more powerful successor to the five-segment Space Shuttle Solid Rocket Boosters intended for early versions of the Space Launch System, using two increased-thrust and heavily modified F-1B engines per booster. Due to the engine's potential advantage in [[specific impulse]] (a unit analogous to car [[fuel efficiency]]), if this F-1B configuration (using four F-1Bs in total) were integrated with the SLS Block II, the vehicle could deliver 150 [[metric ton]]s to [[low earth orbit]],<ref>{{cite web |author=Chris Bergin |url=http://www.nasaspaceflight.com/2012/11/dynetics-pwr-liquidize-sls-booster-competition-f-1-power/ |title=Dynetics and PWR aiming to liquidize SLS booster competition with F-1 power |publisher=NASASpaceFlight.com |date=2012-11-09 |accessdate=2013-12-27}}</ref> while 113 metric tons is what is regarded as achievable with the currently planned solid boosters combined with a 4 engine [[RS-25]] core stage.<ref>{{Cite web |url=http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=30862.0;attach=515287;image |title=Table 2. ATK Advanced Booster Satisfies NASA Exploration Lift Requirements}}</ref>

The F-1B engine has a design goal to be at least as powerful as the un-flight-tested F-1A, while also being more cost effective. The design incorporates a greatly simplified combustion chamber, a reduced number of engine parts, and the removal of the F-1 exhaust recycling system, including the [[Gas-generator cycle (rocket)|turbopump exhaust]] mid-nozzle and the "curtain" cooling [[manifold]], with the turbopump exhaust having a separate outlet passage beside the shortened main nozzle on the F-1B. The reduction in parts costs is aided by using [[selective laser melting]] in the production of some metallic parts.<ref name="Lee Hutchinson"/><ref>{{cite news|url=http://arstechnica.com/science/2013/08/dynetics-reporting-outstanding-progress-on-f-1b-rocket-engine/|title=Dynetics reporting "outstanding" progress on F-1B rocket engine.|publisher=Ars Technica|date=2013-08-13|accessdate=2013-08-13}}</ref> The resulting F-1B engine is intended to produce {{convert|1800000|lbf|MN|abbr=on}} of thrust at sea level, a 15% increase over the approximate {{convert|1550000|lbf|MN|abbr=on}} of thrust that the mature [[Apollo 15]] F-1 engines produced.<ref name="Lee Hutchinson"/>

==Locations of F-1 engines==
[[File:Pratt & Whitney Rocketdyne Division.JPG|right|thumb|Unflown F-1 engine on display at [[Pratt & Whitney Rocketdyne|Pratt & Whitney]] (now [[Aerojet Rocketdyne|Aerojet]]) [[Rocketdyne]], [[Canoga Park, Los Angeles]]]]

Sixty-five F-1 engines were launched aboard thirteen Saturn Vs, and each first stage landed in the Atlantic Ocean after about two and a half minutes of flight. Ten of these followed approximately the same flight [[azimuth]] of 72 degrees, but [[Apollo 15]] and [[Apollo 17]] followed significantly more southerly azimuths (80.088 degrees and 91.503 degrees, respectively). The [[Skylab]] launch vehicle flew at a more northerly azimuth to reach a higher inclination orbit (50 degrees versus the usual 32.5 degrees).<ref>Orloff, Richard (September 2004). NASA, [http://history.nasa.gov/SP-4029/Apollo_18-21_Earth_Orbit_Data.htm ''Apollo By the Numbers'', "Earth Orbit Data"]</ref>

Ten F-1 engines were installed on two production Saturn Vs that never flew. The first stage from SA-514 is on display at the [[Lyndon B. Johnson Space Center|Johnson Space Center]] in [[Houston]] and the first stage from SA-515 is on display at the [[Michoud Assembly Facility]] in [[New Orleans]].

Another ten engines were installed on two ground test Saturn Vs never intended to fly. The S-IC-T "All Systems Test Stage," a ground-test replica, is on display as the first stage of a complete Saturn V at the [[Kennedy Space Center]] in Florida. [[SA-500D]], the Dynamic Test Vehicle, is on display at the [[U.S. Space and Rocket Center ]] in [[Huntsville, Alabama]].<ref name="displays">{{cite web |url=http://history.msfc.nasa.gov/saturn_apollo/display.html |title=Three Saturn Vs on Display Teach Lessons in Space History |last1=Wright |first1=Mike |publisher=NASA |accessdate=January 18, 2016}}</ref>

A test engine is on display at the [[Powerhouse Museum]] in [[Sydney]], [[Australia]]. It was the 25th out of 114 research and development engines built by [[Rocketdyne]] and it was fired 35 times. The engine is on loan to the museum from the Smithsonian's [[National Air and Space Museum]]. It is the only F-1 on display outside the United States.<ref>Doherty, Kerry (November 2009). Powerhouse Museum [http://www.powerhousemuseum.com/insidethecollection/tag/f-1-rocket/ "Inside the Collection"]</ref>

===Recovery===
On March 28, 2012, a team funded by [[Jeff Bezos]], founder of [[Amazon.com]], reported that they had located the F-1 rocket engines from an Apollo mission using sonar equipment.<ref name="time20120429">{{cite news |url=http://www.time.com/time/health/article/0,8599,2110516,00.html |title=Has Bezos Really Found the Apollo 11 Engines? |work=Time.com |first=Jeffrey |last=Kluger |date=April 29, 2012 |archiveurl=http://www.webcitation.org/67NjuEz1P |archivedate=May 3, 2012 |deadurl=no}}</ref> Bezos stated he planned to raise at least one of the engines, which rest at a depth of {{convert|14000|ft|m}}, about {{convert|400|mi|-1}} east of Cape Canaveral, Florida; however, the condition of the engines, which have been submerged for more than 40 years, was unknown.<ref name="sfn20120429">{{cite news |url=http://www.spaceflightnow.com/news/n1203/29f1engines/ |title=NASA sees no problem recovering Apollo engines |work=Spaceflight Now |first=Stephen |last=Clark |date=April 29, 2012 |archiveurl=http://www.webcitation.org/67NjuM6kA |archivedate=May 3, 2012 |deadurl=no}}</ref> NASA Administrator Charles Bolden released a statement congratulating Bezos and his team for their find and wished them success. He also affirmed NASA's position that any recovered artifacts would remain property of the agency, but that they would likely be offered to the [[Smithsonian Institution]] and other museums, depending on the number recovered.<ref name="nasa20120430">{{cite news |url=http://www.nasa.gov/home/hqnews/2012/mar/HQ_12-102_Bolden_Bezos_Ap_Eng.html |title=NASA Administrator Supports Apollo Engine Recovery |work=NASA.gov |first=David |last=Weaver |id=Release 12-102 |date=April 30, 2012 |archiveurl=http://www.webcitation.org/67NjuU8sb |archivedate=May 3, 2012 |deadurl=no}}</ref>

On March 20, 2013, Bezos announced he had succeeded in bringing parts of an F-1 engine to the surface, and released photographs. Bezos noted, "Many of the original serial numbers are missing or partially missing, which is going to make mission identification difficult. We might see more during restoration."<ref name="recovered">Walker, Brian (March 20, 2013). [http://lightyears.blogs.cnn.com/2013/03/20/apollo-mission-rocket-engines-recovered/?hpt=hp_t2 "Apollo Mission Rocket Engines Recovered"], CNN ''Light Years'' blog</ref> The recovery ship was ''[[Seaboard Worker]]'', and had on board a team of specialists organized by Bezos for the recovery effort.<ref name=forbes20140801/> On July 19, 2013, Bezos revealed that the serial number of one of the recovered engine is [[Rocketdyne]] serial number 2044 (equating to NASA number 6044), the #5 (center) engine that helped [[Neil Armstrong]], [[Buzz Aldrin]], and [[Michael Collins (astronaut)|Michael Collins]] to reach the Moon with the [[Apollo 11]] mission.<ref name="Updates">[http://www.bezosexpeditions.com/updates.html Updates: 19 July 2013], Bezos Expeditions, 19 July 2013, accessed 21 July 2013.</ref> The recovered parts are at the [[Kansas Cosmosphere and Space Center]] in [[Hutchinson, Kansas|Hutchinson]] for the process of conservation.<ref name="Updates" /><ref name=forbes20140801/>

In August 2014, it was revealed that parts of two different F-1 engines were recovered, one from Apollo 11 and one from another Apollo flight, while a photograph of a cleaned-up engine was released. Bezos plans to put the engines on display at various places, including the [[National Air and Space Museum]] in [[Washington, DC]].<ref name=forbes20140801>{{cite news |last1=Clash|first1=Jim |title=Billionaire Jeff Bezos Talks About His Secret Passion: Space Travel |url=http://www.forbes.com/sites/jimclash/2014/08/01/billionaire-jeff-bezos-talks-about-his-secret-passion-space-travel/ |accessdate=2014-08-03 |publisher=Forbes |date=2014-08-01 |archiveurl=https://web.archive.org/web/20140808020745/http://www.forbes.com/sites/jimclash/2014/08/01/billionaire-jeff-bezos-talks-about-his-secret-passion-space-travel/ |archivedate=2014-08-08 |deadurl=yes}}</ref>

== See also ==
* [[Comparison of orbital rocket engines]]

== References ==
;Notes
{{reflist|2}}

;Bibliography
* [http://www.hq.nasa.gov/alsj/a15/A15_PressKit.pdf Apollo 15 Press Kit]
* [http://ntrs.nasa.gov/search.jsp?N=0&Ntk=all&Ntx=mode%20matchall&Ntt=19730025086 Saturn V Launch Vehicle, Flight Evaluation Report, AS-510], MPR-SAT-FE-71-2, October 28, 1971.

== External links ==
{{Commons category|F-1 (rocket engine)}}
* [http://www.astronautix.com/engines/e1.htm E-1 at the Encyclopedia Astronautica]
* [http://www.astronautix.com/engines/f1.htm F-1 at the Encyclopedia Astronautica]
* [http://www.astronautix.com/engines/f1a.htm F-1A at the Encyclopedia Astronautica]
* [http://history.nasa.gov/SP-4206/sp4206.htm NASA SP-4206 Stages to Saturn - the official NASA history of the Saturn launch vehicle]
* [http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19750070175_1975070175.pdf F-1 Engine Operating Instructions] (310MB)
* [http://www.springer.com/astronomy/space+exploration/book/978-0-387-09629-2 The Saturn V F-1 Engine: Powering Apollo into History] at Springer.com
* [http://history.nasa.gov/monograph45.pdf Remembering The Giants: Apollo Rocket Propulsion Development], 2009, John C. Stennis Space Center. Monograph in Aerospace History No. 45 NASA
* [http://arstechnica.com/science/2013/04/how-nasa-brought-the-monstrous-f-1-moon-rocket-back-to-life/ How NASA brought the monstrous F-1 “moon rocket” engine back to life]
* [http://arstechnica.com/science/2013/04/new-f-1b-rocket-engine-upgrades-apollo-era-deisgn-with-1-8m-/ New F-1B rocket engine upgrades Apollo-era design with 1.8M lbs of thrust]
* [http://history.msfc.nasa.gov/saturn_apollo/documents/F-1_Engine.pdf MSFC History office F-1 Fact sheet]

{{Rocket Engines}}

{{DEFAULTSORT:F-1 (Rocket Engine)}}
[[Category:Rocket engines]]
[[Category:Rocket engines using kerosene propellant]]
[[Category:Rocketdyne engines]]
[[Category:North American Aviation]]

Rocketdyne F-1

2016-02-09T01:24:59Z

71.109.148.145: /* F-1 improvements */

{{Refimprove|date=July 2009}}
{{infobox rocket engine
|image=F-1 rocket engine.jpg
|image_size=300
|caption=F-1 rocket engine specifications
|name=F-1
|country_of_origin=[[United States]]
|manufacturer=[[Rocketdyne]]
|purpose=

|type=liquid
|fuel=[[RP-1]]
|oxidiser=[[LOX]]
|capacity=

|thrust(SL)={{convert|1522000|lbf|kN|abbr=on}}
|thrust(Vac)={{convert|1746000|lbf|kN|abbr=on}}
|specific_impulse_vacuum={{convert|304|isp}}
|specific_impulse_sea_level= {{convert|263|isp}}
|chamber_pressure={{convert|70|bar|psi MPa|0}}
|thrust_to_weight=94.1
|cycle=[[Gas-generator cycle (rocket)|Gas-generator]]
}}
The '''F-1''' is a [[gas-generator cycle]] [[rocket engine]] developed in the [[United States]] by [[Rocketdyne]] in the late 1950s and used in the [[Saturn V]] rocket in the 1960s and early 1970s. Five F-1 engines were used in the [[S-IC]] first stage of each Saturn V, which served as the main launch vehicle of the [[Apollo program]]. The F-1 remains the most powerful single-[[combustion chamber]] [[liquid-propellant rocket]] engine ever developed.<ref>W. David Woods, ''How Apollo Flew to the Moon'', Springer, 2008, ISBN 978-0-387-71675-6, p. 19</ref>

== History ==
[[File:S-IC engines and Von Braun.jpg|thumb|right|[[Wernher von Braun]] with the F-1 engines of the Saturn V first stage at the [[U.S. Space and Rocket Center]]]]

The F-1 was originally developed by Rocketdyne to meet a 1955 [[United States Air Force|U.S. Air Force]] requirement for a very large rocket engine. The eventual result of that requirement was two engines, the [[Rocketdyne E-1|E-1]] and the much larger F-1. The E-1, although successfully tested in static firing, was quickly seen as a technological dead-end, and was abandoned for the larger, more powerful F-1. The Air Force eventually halted development of the F-1 because of a lack of requirement for such a large engine. However, the recently created [[National Aeronautics and Space Administration]] (NASA) appreciated the usefulness of an engine with so much power, and contracted Rocketdyne to complete its development. Test firings of F-1 components had been performed as early as 1957. The first static firing of a full-stage developmental F-1 was performed in March 1959. The first F-1 was delivered to NASA [[Marshall Space Flight Center|MSFC]] in October 1963. In December 1964, the F-1 completed flight-rating tests. Testing continued at least through 1965.<ref>{{cite web |url=http://history.msfc.nasa.gov/saturn_apollo/documents/Background_F-1_Rocket_Engine.pdf |title=NASA Rocketdyne document |format=PDF |date= |accessdate=2013-12-27}}</ref>

Early development tests revealed serious [[combustion instability]] problems which sometimes caused [[catastrophic failure]].<ref>{{Citation
|first= Renea
|last= Ellison
|first2= Marlow
|last2= Moser
|title= Combustion Instability Analysis and the Effects of Drop Size on Acoustic Driving Rocket Flow
|place= Huntsville, Alabama
|publisher= Propulsion Research Center, University of Alabama in Huntsville
|url= http://reap.uah.edu/publications/Ellison.pdf
|format=PDF
}}</ref> Initially, progress on this problem was slow, as it was intermittent and unpredictable. Oscillations of 4 kHz with harmonics to 24 kHz were observed. Eventually, engineers developed a diagnostic technique of detonating small explosive charges (which they called "bombs") outside the combustion chamber, through a tangential tube (RDX, C4 or black powder were used) while the engine was firing. This allowed them to determine exactly how the running chamber responded to variations in pressure, and to determine how to nullify these oscillations. The designers could then quickly experiment with different co-axial fuel-injector designs to obtain the one most resistant to instability. These problems were addressed from 1959 through 1961. Eventually, engine combustion was so stable, it would [[Damping ratio|self-damp]] artificially induced instability within 1/10 of a second.

== Design ==
[[File:SaturnF1EngineDiagram.png|thumb|right|upright=1.35|F-1 rocket engine components]]

The [[Rocketdyne]]-developed ''F-1'' engine is the most powerful single-nozzle [[Liquid rocket|liquid-fueled rocket engine]] ever flown. The [[M-1 (rocket engine)|M-1 rocket engine]] was designed to have more thrust, however it was only tested at the component level. The F-1 was a liquid-fueled rocket motor, burning [[RP-1]] ([[kerosene]]) as fuel, and using [[liquid oxygen]] (LOX) as the oxidizer ([[kerolox]]). A [[turbopump]] was used to inject fuel and oxygen into the combustion chamber.

The heart of the engine was the thrust chamber, which mixed and burned the fuel and oxidizer to produce thrust. A domed chamber at the top of the engine served as a [[Manifold (general engineering)|manifold]] supplying liquid oxygen to the [[Injector (Rocket)|injectors]], and also served as a mount for the [[gimbal]] bearing which transmitted the thrust to the body of the rocket. Below this dome were the injectors, which directed fuel and oxidizer into the thrust chamber in a way designed to promote mixing and combustion. Fuel was supplied to the injectors from a separate manifold; some of the fuel first travelled in 178 tubes down the length of the thrust chamber—which formed approximately the upper half of the [[Rocket engine nozzle|exhaust nozzle]]—and back, to cool the nozzle.

A [[gas-generator cycle (rocket)|gas-generator]] was used to drive a [[turbine]] which in turn drove separate fuel and oxygen pumps, each feeding the thrust chamber assembly. The turbine was driven at 5,500 [[RPM]] by the gas generator, producing {{convert|55000|bhp|MW}}. The fuel pump delivered {{convert|15,471|gal|l|abbr=off}} of RP-1 per minute while the oxidizer pump delivered {{convert|24,811|gal|l|abbr=on}} of liquid oxygen per minute. Environmentally, the turbopump was required to withstand temperatures ranging from input gas at {{convert|1500|F|-1}} to liquid oxygen at {{convert|−300|F|0}}. Structurally, fuel was used to lubricate and cool the turbine [[Bearing (mechanical)|bearings]].

[[File:F-1 Engine Test Firing.jpg|right|thumb|Test firing of an F-1 engine at [[Edwards Air Force Base]]]]
[[File:F-1 Engines Being Installed.jpg|right|thumb|Installation of F-1 engines to the Saturn V S-IC Stage. The [[nozzle extension]] is absent from the engine being fitted.]]
Below the thrust chamber was the [[nozzle extension]], roughly half the length of the engine. This extension increased the [[Rocket_engine#Propellant_efficiency|expansion ratio]] of the engine from 10:1 to 16:1. The exhaust from the turbopump was fed into the nozzle extension by a large, tapered manifold; this relatively cool gas formed a film which protected the nozzle extension from the hot ({{convert|5800|F|-1}}) exhaust gas.<ref name=SVPressKit>{{Citation
|date= December 1968
|title= Saturn V News Reference: F-1 Engine Fact Sheet
|publisher= National Aeronautics and Space Administration
|url= http://history.msfc.nasa.gov/saturn_apollo/documents/F-1_Engine.pdf
|format=PDF
|pages= 3–3, 3–4
|accessdate= 2008-06-01
}}</ref>

Each second, a single F-1 burned {{convert|5683|lb}} of oxidizer and fuel: {{convert|3945|lb|abbr=on}} of liquid oxygen and {{convert|1738|lb|abbr=on}} of RP-1, generating {{convert|1500000|lbf|MN|abbr=on}} of thrust. This equated to a flow rate of {{convert|671.4|USgal|l|abbr=on}} per second; {{convert|413.5|gal|l|abbr=on}} of LOX and {{convert|257.9|gal|l|abbr=on}} of RP-1. During their two and a half minutes of operation, the five F-1s propelled the Saturn V vehicle to a height of {{convert|42|mi|ft km}} and a speed of {{convert|6164|mph|km/h|abbr=on}}. The combined flow rate of the five F-1s in the Saturn V was {{convert|3357|gal|l|abbr=on}} per second,<ref name=SVPressKit/> or {{convert|28415|lb|-1|abbr=on}}. Each F-1 engine had more thrust than three [[Space Shuttle Main Engine]]s combined.<ref>{{Citation
|title= NSTS 1988 News Reference Manual
|publisher= NASA
|url= http://science.ksc.nasa.gov/shuttle/technology/sts-newsref/sts_overview.html#sts_overview
|accessdate= 2008-07-03
}}</ref>

Designer of the pump for the E-1/F-1 for Rocketdyne was Ernest A. Lamont. His hand-written original calculations are part of the family archives and available for display. He stated that the design of the rocket engine hinged on the question of whether the pump design was viable.{{Citation needed|date=April 2011}}

===Pre and post ignition procedures===
During static test firing, the kerosene-based RP-1 fuel left [[hydrocarbon]] deposits and vapors in the engine post test firing. These had to be removed from the engine to avoid problems during engine handling and future firing, and the solvent [[trichloroethylene]] (TCE) was used to clean the engine's fuel system immediately before and after each test firing. The cleaning procedure involved pumping TCE through the engine's fuel system and letting the solvent overflow for a period ranging from several seconds to 30–35 minutes, depending upon the engine and the severity of the deposits. For some engines, the engine's gas generator and LOX dome were also flushed with TCE prior to test firing.<ref>{{cite web|url=http://ssfl.msfc.nasa.gov/public-involvement/docs/SSFL_TCE_Final_Fact_Sheet.pdf |title=The Use of Trichloroethylene at NASA’s SSFL Sites |format=PDF |date= |accessdate=2013-12-27}}</ref><ref name="ntrs.nasa.gov">{{cite web|url=http://ntrs.nasa.gov/search.jsp?N=0&Ntk=all&Ntx=mode%20matchall&Ntt=19750070175 |title=F-1 Rocket Engine Operating Instructions |publisher=Ntrs.nasa.gov |date=2013-03-01 |accessdate=2013-12-27}}</ref> The F-1 rocket engine had its LOX dome, gas generator, and thrust chamber fuel jacket flushed with TCE during launch preparations.<ref name="ntrs.nasa.gov"/>

=== Specifications ===
{| class=wikitable
!
! Apollo 4, 6, and 8
! Apollo 9–17
|-
| [[Thrust]] (sea level):
| {{convert|1500000|lbf|MN|abbr=on}}
| {{convert|1522000|lbf|MN|abbr=on}}
|-
| Burn time:
| 150 seconds
| 165 seconds
|-
| [[Specific impulse]]:
| {{convert|260|isp}}
| {{convert|263|isp}}
|-
| Chamber pressure:
| {{convert|70|bar|psi MPa|0|abbr=on}}
| {{convert|70|bar|psi MPa|0|abbr=on}}
|-
| Engine weight dry:
| {{convert|18416|lb|abbr=on}}
| {{convert|18500|lb|abbr=on}}
|-
| Engine weight burnout:
| {{convert|20096|lb|abbr=on}}
| {{convert|20180|lb|abbr=on}}
|-
| Height:
| colspan=2 | {{convert|19|ft|abbr=on}}
|-
| Diameter:
| colspan=2 | {{convert|12.3|ft|abbr=on}}
|-
| Exit to throat ratio:
| colspan=2 |16 to 1
|-
| Propellants:
| colspan=2 |[[LOX]] & [[RP-1]]
|-
| Mixture mass ratio:
| colspan=2 |2.27:1 oxidizer to fuel
|-
| Contractor:
| colspan=2 |NAA/Rocketdyne
|-
| Vehicle application:
| colspan=2 |Saturn V / [[S-IC]] 1st stage - 5-engines
|}

Sources:<ref name=SVPressKit/><ref>{{Citation
|title= F-1 Engine (chart)
|id= MSFC-9801771
|publisher= NASA Marshall Space Flight Center
|url= http://ntrs.nasa.gov/search.jsp?R=MSFC-9801771
|accessdate= 2008-06-01
}}</ref>

=== F-1 improvements ===
[[File:F-1 rocket engine at United States Space and Rocket Center in 2006.jpg|right|thumb|F-1 on display at the [[U.S. Space & Rocket Center]] in [[Huntsville, Alabama]].]]

F-1 thrust and efficiency were improved between [[Apollo 8]] (SA-503) and [[Apollo 17]] (SA-512), which was necessary to meet the increasing payload capacity demands of later [[Project Apollo|Apollo]] missions. There were small performance variations between engines on a given mission, and variations in average thrust between missions. For [[Apollo 15]], F-1 performance was:

*Thrust (average, per engine, sea level liftoff): {{convert|1553200|lbf|MN|abbr=on}}
*Burn time: 159 seconds
*[[Specific impulse]]: {{convert|264.72|isp}}{{clarify|is convert broken for Isp?}}
*Mixture ratio: 2.2674
*[[S-IC]] total sea level liftoff thrust: {{convert|7766000|lbf|MN|abbr=on}}

Measuring and making comparisons of rocket engine thrust is more complicated than it first appears. Based on actual measurement the liftoff thrust of [[Apollo 15]] was {{convert|7823000|lbf|MN|abbr=on}}, which equates to an average F-1 thrust of {{convert|1565000|lbf|MN|abbr=on}} – significantly more than the specified value.

{{Further|Saturn V#S-IC thrust comparisons}}

=== F-1A after Apollo ===
[[File:F-1 rocket engine at KSC.jpg|right|thumb|F-1 engine on display at [[Kennedy Space Center]] ]]
{{See also|Saturn MLV}}

During the 1960s, Rocketdyne undertook uprating development of the F-1 resulting in the new engine specification F-1A. While outwardly very similar to the F-1, the F-1A produced a larger thrust of about {{convert|8|MN|lbf|disp=flip|abbr=on}} in tests,<ref>{{cite web|url=http://www.airingnews.com/articles/86793/New-F1B-rocket-engine-upgrades-Apolloera-design-with-18M-lbs-of-thrust |title=Evacuation order lifted near derailed Alberta propane cars |publisher=Airingnews.com |date= |accessdate=2013-12-27}}</ref> and would have been used on future Saturn V vehicles in the post-[[Project Apollo|Apollo]] era. However, the Saturn V production line was closed prior to the end of Project Apollo and no F-1A engine flew on a launch vehicle.<ref name=ars20130414>{{cite news |last=Hutchinson |first=Lee |title=New F-1B rocket engine upgrades Apollo-era design with 1.8M lbs of thrust |url=http://arstechnica.com/science/2013/04/new-f-1b-rocket-engine-upgrades-apollo-era-deisgn-with-1-8m-lbs-of-thrust/ |accessdate=2013-04-15 |newspaper=ARS technica |date=2013-04-14}}</ref>

There were proposals to use eight F-1 engines on the first stage of the [[Nova rocket]]. Numerous proposals have been made from the 1970s on to develop new expendable boosters based around the F-1 engine design. These include the [[Saturn-Shuttle]], and one in 2013.<ref name=ars20130414/> {{As of|2013}}, none has proceeded beyond the initial study phase.

The F-1 is the largest, highest thrust single-chamber, single-nozzle liquid fuel engine flown. The [[RD-170]] from the [[Soviet space program]] used a cluster of four separate combustion chambers and nozzles, giving the appearance of four engines; however, the combustion chambers were all driven by a single turbopump. The assembly produced 7.2% more sea level thrust than the F-1, the highest thrust liquid-fuel engines ever flown.{{Citation needed|reason=Was the RD-170 actually flown? Are its current derivatives as large?|date=December 2015}} Larger [[solid rocket|solid-fuel]] engines exist, such as the [[Space Shuttle Solid Rocket Booster]] with a sea-level liftoff thrust of {{convert|12.45|MN|lbf|disp=flip|abbr=on}} apiece.

==F-1B booster==
As part of the [[Space Launch System]] (SLS) program, NASA had been running the Advanced Booster Competition, which was scheduled to end with the selection of a winning booster configuration in 2015. In 2012, [[Pratt & Whitney Rocketdyne]] (PWR) proposed using a derivative of the F-1 engine in the competition as a [[Liquid rocket booster]].<ref name="Lee Hutchinson">{{cite news |url=http://arstechnica.com/science/2013/04/new-f-1b-rocket-engine-upgrades-apollo-era-deisgn-with-1-8m-lbs-of-thrust/ |title=New F-1B rocket engine upgrades Apollo-era design with 1.8M lbs of thrust|author=Lee Hutchinson |publisher=Ars Technica |date=2013-04-15 |accessdate=2013-04-15}}</ref><ref>{{cite web |title=Rocket companies hope to repurpose Saturn 5 engines |url=http://www.spaceflightnow.com/news/n1204/18dynetics/}}</ref> In 2013, engineers at the [[Marshall Space Flight Center]] began tests with an original F-1, serial number F-6049, which was removed from Apollo 11 due to a glitch. The engine was never used, and for many years it was at the [[Smithsonian Institution]]. The tests are designed to refamiliarize NASA with the design and propellants of the F-1 in anticipation of using an evolved version of the engine in future deep space flight applications.<ref>{{cite news|url=http://www.usnews.com/science/news/articles/2013/01/24/nasa-testing-vintage-engine-from-apollo-11-rocket |title=NASA testing vintage engine from Apollo 11 rocket |author=Jay Reeves |agency=Associated Press |date=2013-01-24 |accessdate=2013-01-24}}</ref>

[[Pratt and Whitney]], [[Rocketdyne]], and [[Dynetics]], Inc. presented a competitor known as [[Saturn C-3#Pyrios|''Pyrios'']] in NASA's Advanced Booster Program, which aims to find a more powerful successor to the five-segment Space Shuttle Solid Rocket Boosters intended for early versions of the Space Launch System, using two increased-thrust and heavily modified F-1B engines per booster. Due to the engine's potential advantage in [[specific impulse]] (a unit analogous to car [[fuel efficiency]]), if this F-1B configuration (using four F-1Bs in total) were integrated with the SLS Block II, the vehicle could deliver 150 [[metric ton]]s to [[low earth orbit]],<ref>{{cite web |author=Chris Bergin |url=http://www.nasaspaceflight.com/2012/11/dynetics-pwr-liquidize-sls-booster-competition-f-1-power/ |title=Dynetics and PWR aiming to liquidize SLS booster competition with F-1 power |publisher=NASASpaceFlight.com |date=2012-11-09 |accessdate=2013-12-27}}</ref> while 113 metric tons is what is regarded as achievable with the currently planned solid boosters combined with a 4 engine [[RS-25]] core stage.<ref>{{Cite web |url=http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=30862.0;attach=515287;image |title=Table 2. ATK Advanced Booster Satisfies NASA Exploration Lift Requirements}}</ref>

The F-1B engine has a design goal to be at least as powerful as the un-flight-tested F-1A, while also being more cost effective. The design incorporates a greatly simplified combustion chamber, a reduced number of engine parts, and the removal of the F-1 exhaust recycling system, including the [[Gas-generator cycle (rocket)|turbopump exhaust]] mid-nozzle and the "curtain" cooling [[manifold]], with the turbopump exhaust having a separate outlet passage beside the shortened main nozzle on the F-1B. The reduction in parts costs is aided by using [[selective laser melting]] in the production of some metallic parts.<ref name="Lee Hutchinson"/><ref>{{cite news|url=http://arstechnica.com/science/2013/08/dynetics-reporting-outstanding-progress-on-f-1b-rocket-engine/|title=Dynetics reporting "outstanding" progress on F-1B rocket engine.|publisher=Ars Technica|date=2013-08-13|accessdate=2013-08-13}}</ref> The resulting F-1B engine is intended to produce {{convert|1800000|lbf|MN|abbr=on}} of thrust at sea level, a 15% increase over the approximate {{convert|1550000|lbf|MN|abbr=on}} of thrust that the mature [[Apollo 15]] F-1 engines produced.<ref name="Lee Hutchinson"/>

==Locations of F-1 engines==
[[File:Pratt & Whitney Rocketdyne Division.JPG|right|thumb|Unflown F-1 engine on display at [[Pratt & Whitney Rocketdyne|Pratt & Whitney]] (now [[Aerojet Rocketdyne|Aerojet]]) [[Rocketdyne]], [[Canoga Park, Los Angeles]]]]

Sixty-five F-1 engines were launched aboard thirteen Saturn Vs, and each first stage landed in the Atlantic Ocean after about two and a half minutes of flight. Ten of these followed approximately the same flight [[azimuth]] of 72 degrees, but [[Apollo 15]] and [[Apollo 17]] followed significantly more southerly azimuths (80.088 degrees and 91.503 degrees, respectively). The [[Skylab]] launch vehicle flew at a more northerly azimuth to reach a higher inclination orbit (50 degrees versus the usual 32.5 degrees).<ref>Orloff, Richard (September 2004). NASA, [http://history.nasa.gov/SP-4029/Apollo_18-21_Earth_Orbit_Data.htm ''Apollo By the Numbers'', "Earth Orbit Data"]</ref>

Ten F-1 engines were installed on two production Saturn Vs that never flew. The first stage from SA-514 is on display at the [[Lyndon B. Johnson Space Center|Johnson Space Center]] in [[Houston]] and the first stage from SA-515 is on display at the [[Michoud Assembly Facility]] in [[New Orleans]].

Another ten engines were installed on two ground test Saturn Vs never intended to fly. The S-IC-T "All Systems Test Stage," a ground-test replica, is on display as the first stage of a complete Saturn V at the [[Kennedy Space Center]] in Florida. [[SA-500D]], the Dynamic Test Vehicle, is on display at the [[U.S. Space and Rocket Center ]] in [[Huntsville, Alabama]].<ref name="displays">{{cite web |url=http://history.msfc.nasa.gov/saturn_apollo/display.html |title=Three Saturn Vs on Display Teach Lessons in Space History |last1=Wright |first1=Mike |publisher=NASA |accessdate=January 18, 2016}}</ref>

A test engine is on display at the [[Powerhouse Museum]] in [[Sydney]], [[Australia]]. It was the 25th out of 114 research and development engines built by [[Rocketdyne]] and it was fired 35 times. The engine is on loan to the museum from the Smithsonian's [[National Air and Space Museum]]. It is the only F-1 on display outside the United States.<ref>Doherty, Kerry (November 2009). Powerhouse Museum [http://www.powerhousemuseum.com/insidethecollection/tag/f-1-rocket/ "Inside the Collection"]</ref>

===Recovery===
On March 28, 2012, a team funded by [[Jeff Bezos]], founder of [[Amazon.com]], reported that they had located the F-1 rocket engines from an Apollo mission using sonar equipment.<ref name="time20120429">{{cite news |url=http://www.time.com/time/health/article/0,8599,2110516,00.html |title=Has Bezos Really Found the Apollo 11 Engines? |work=Time.com |first=Jeffrey |last=Kluger |date=April 29, 2012 |archiveurl=http://www.webcitation.org/67NjuEz1P |archivedate=May 3, 2012 |deadurl=no}}</ref> Bezos stated he planned to raise at least one of the engines, which rest at a depth of {{convert|14000|ft|m}}, about {{convert|400|mi|-1}} east of Cape Canaveral, Florida; however, the condition of the engines, which have been submerged for more than 40 years, was unknown.<ref name="sfn20120429">{{cite news |url=http://www.spaceflightnow.com/news/n1203/29f1engines/ |title=NASA sees no problem recovering Apollo engines |work=Spaceflight Now |first=Stephen |last=Clark |date=April 29, 2012 |archiveurl=http://www.webcitation.org/67NjuM6kA |archivedate=May 3, 2012 |deadurl=no}}</ref> NASA Administrator Charles Bolden released a statement congratulating Bezos and his team for their find and wished them success. He also affirmed NASA's position that any recovered artifacts would remain property of the agency, but that they would likely be offered to the [[Smithsonian Institution]] and other museums, depending on the number recovered.<ref name="nasa20120430">{{cite news |url=http://www.nasa.gov/home/hqnews/2012/mar/HQ_12-102_Bolden_Bezos_Ap_Eng.html |title=NASA Administrator Supports Apollo Engine Recovery |work=NASA.gov |first=David |last=Weaver |id=Release 12-102 |date=April 30, 2012 |archiveurl=http://www.webcitation.org/67NjuU8sb |archivedate=May 3, 2012 |deadurl=no}}</ref>

On March 20, 2013, Bezos announced he had succeeded in bringing parts of an F-1 engine to the surface, and released photographs. Bezos noted, "Many of the original serial numbers are missing or partially missing, which is going to make mission identification difficult. We might see more during restoration."<ref name="recovered">Walker, Brian (March 20, 2013). [http://lightyears.blogs.cnn.com/2013/03/20/apollo-mission-rocket-engines-recovered/?hpt=hp_t2 "Apollo Mission Rocket Engines Recovered"], CNN ''Light Years'' blog</ref> The recovery ship was ''[[Seaboard Worker]]'', and had on board a team of specialists organized by Bezos for the recovery effort.<ref name=forbes20140801/> On July 19, 2013, Bezos revealed that the serial number of one of the recovered engine is [[Rocketdyne]] serial number 2044 (equating to NASA number 6044), the #5 (center) engine that helped [[Neil Armstrong]], [[Buzz Aldrin]], and [[Michael Collins (astronaut)|Michael Collins]] to reach the Moon with the [[Apollo 11]] mission.<ref name="Updates">[http://www.bezosexpeditions.com/updates.html Updates: 19 July 2013], Bezos Expeditions, 19 July 2013, accessed 21 July 2013.</ref> The recovered parts are at the [[Kansas Cosmosphere and Space Center]] in [[Hutchinson, Kansas|Hutchinson]] for the process of conservation.<ref name="Updates" /><ref name=forbes20140801/>

In August 2014, it was revealed that parts of two different F-1 engines were recovered, one from Apollo 11 and one from another Apollo flight, while a photograph of a cleaned-up engine was released. Bezos plans to put the engines on display at various places, including the [[National Air and Space Museum]] in [[Washington, DC]].<ref name=forbes20140801>{{cite news |last1=Clash|first1=Jim |title=Billionaire Jeff Bezos Talks About His Secret Passion: Space Travel |url=http://www.forbes.com/sites/jimclash/2014/08/01/billionaire-jeff-bezos-talks-about-his-secret-passion-space-travel/ |accessdate=2014-08-03 |publisher=Forbes |date=2014-08-01 |archiveurl=https://web.archive.org/web/20140808020745/http://www.forbes.com/sites/jimclash/2014/08/01/billionaire-jeff-bezos-talks-about-his-secret-passion-space-travel/ |archivedate=2014-08-08 |deadurl=yes}}</ref>

== See also ==
* [[Comparison of orbital rocket engines]]

== References ==
;Notes
{{reflist|2}}

;Bibliography
* [http://www.hq.nasa.gov/alsj/a15/A15_PressKit.pdf Apollo 15 Press Kit]
* [http://ntrs.nasa.gov/search.jsp?N=0&Ntk=all&Ntx=mode%20matchall&Ntt=19730025086 Saturn V Launch Vehicle, Flight Evaluation Report, AS-510], MPR-SAT-FE-71-2, October 28, 1971.

== External links ==
{{Commons category|F-1 (rocket engine)}}
* [http://www.astronautix.com/engines/e1.htm E-1 at the Encyclopedia Astronautica]
* [http://www.astronautix.com/engines/f1.htm F-1 at the Encyclopedia Astronautica]
* [http://www.astronautix.com/engines/f1a.htm F-1A at the Encyclopedia Astronautica]
* [http://history.nasa.gov/SP-4206/sp4206.htm NASA SP-4206 Stages to Saturn - the official NASA history of the Saturn launch vehicle]
* [http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19750070175_1975070175.pdf F-1 Engine Operating Instructions] (310MB)
* [http://www.springer.com/astronomy/space+exploration/book/978-0-387-09629-2 The Saturn V F-1 Engine: Powering Apollo into History] at Springer.com
* [http://history.nasa.gov/monograph45.pdf Remembering The Giants: Apollo Rocket Propulsion Development], 2009, John C. Stennis Space Center. Monograph in Aerospace History No. 45 NASA
* [http://arstechnica.com/science/2013/04/how-nasa-brought-the-monstrous-f-1-moon-rocket-back-to-life/ How NASA brought the monstrous F-1 “moon rocket” engine back to life]
* [http://arstechnica.com/science/2013/04/new-f-1b-rocket-engine-upgrades-apollo-era-deisgn-with-1-8m-/ New F-1B rocket engine upgrades Apollo-era design with 1.8M lbs of thrust]
* [http://history.msfc.nasa.gov/saturn_apollo/documents/F-1_Engine.pdf MSFC History office F-1 Fact sheet]

{{Rocket Engines}}

{{DEFAULTSORT:F-1 (Rocket Engine)}}
[[Category:Rocket engines]]
[[Category:Rocket engines using kerosene propellant]]
[[Category:Rocketdyne engines]]
[[Category:North American Aviation]]

Friedel–Crafts reaction

2016-02-07T12:02:05Z

71.109.148.145: /* Friedel–Crafts acylation */ The link is post-cn, and appears to include all the data proposed. Move cn to link target if needed.

{{Use dmy dates|date=May 2013}}
{{Reactionbox
| Name = Friedel-Crafts reaction
| Type = Coupling reaction
| NamedAfter = [[Charles Friedel]] [[James Crafts]]
| Section3 = {{Reactionbox Identifiers
| RSC_ontology_id = 0000369
}}
}}
The '''Friedel–Crafts reactions''' are a set of [[organic reaction|reactions]] developed by [[Charles Friedel]] and [[James Crafts]] in 1877 to attach substituents to an [[Aromatic hydrocarbon|aromatic ring]].<ref>Friedel, C.; Crafts, J. M. (1877) "Sur une nouvelle méthode générale de synthèse d’hydrocarbures, d’acétones, etc.," ''Compt. Rend.'', '''84''': [http://gallica.bnf.fr/ark:/12148/bpt6k30410/f1386.table 1392] & [http://gallica.bnf.fr/ark:/12148/bpt6k30410/f1444.table 1450].</ref> There are two main types of Friedel–Crafts reactions: [[alkylation]] reactions and [[acylation]] reactions. Both proceed by [[electrophilic aromatic substitution]]. The general reaction scheme is shown below.

:[[File:Benzene Friedel-Crafts alkylation-diagram.svg|400px|The Friedel–Crafts Alkylation of benzene with chloromethane]]

Several reviews have been written.<ref>{{cite journal|author=Price, C. C. | journal =Org. React.| year =1946| volume =3| page = 1|doi=10.1002/0471264180.or003.01|title=The Alkylation of Aromatic Compounds by the Friedel-Crafts Method|isbn=0471264180}}</ref><ref>{{cite journal | author = Groves, J. K. | journal = [[Chem. Soc. Rev.]] | year = 1972 | volume = 1 | page = 73 | doi = 10.1039/cs9720100073 | title = The Friedel–Crafts acylation of alkenes}}</ref><ref>{{cite journal|author=Eyley, S. C. | journal =Comp. Org. Syn.| year =1991| volume =2| pages = 707–731|doi=10.1016/B978-0-08-052349-1.00045-7|title=The Aliphatic Friedel–Crafts Reaction|isbn=978-0-08-052349-1}}</ref><ref>{{cite journal|author=Heaney, H. | journal =Comp. Org. Syn.| year =1991| volume =2| pages = 733–752|doi=10.1016/B978-0-08-052349-1.00046-9|title=The Bimolecular Aromatic Friedel–Crafts Reaction|isbn=978-0-08-052349-1}}</ref>

== Friedel–Crafts alkylation ==
{{Reactionbox
| Name = Friedel-Crafts alkylation
| Type = Coupling reaction
| NamedAfter = [[Charles Friedel]] [[James Crafts]]
| Section3 = {{Reactionbox Identifiers
| OrganicChemistryNamed = friedel-crafts-alkylation
| RSC_ontology_id = 0000046
}}
}}
Friedel–Crafts alkylation involves the alkylation of an [[aromatic ring]] with an [[alkyl halide]] using a strong [[Lewis acid]] catalyst.<ref>{{cite journal | author = Rueping, M. and Nachtsheim, B. J. | title = A review of new developments in the Friedel–Crafts alkylation – From green chemistry to asymmetric catalysis | year = 2010 | journal = Beilstein J. Org. Chem. | volume = 6 | article = 6 | doi = 10.3762/bjoc.6.6}}</ref> With anhydrous [[ferric chloride]] as a [[catalyst]], the alkyl group attaches at the former site of the chloride ion. The general mechanism is shown below.<ref name="Smith2007">{{March6th}}</ref>

:[[File:Friedel Crafts mechanism.png|500px|Mechanism for the Friedel Crafts alkylation]]

This reaction has one big disadvantage, namely that the product is more [[nucleophile|nucleophilic]] than the reactant due to the electron donating alkyl-chain. Therefore, another hydrogen is substituted with an alkyl-chain, which leads to overalkylation of the molecule. Also, if the chloride is not on a [[tertiary carbon]] or secondary carbon, then the carbocation formed (R+) will undergo a [[carbocation]] [[rearrangement reaction]]. This reactivity is due to the relative stability of the tertiary and secondary [[carbocation]] over the primary carbocations.<ref name="Smith2007">{{March6th}}</ref>

[[Steric hindrance]] can be exploited to limit the number of alkylations, as in the ''t''-butylation of 1,4-dimethoxybenzene.{{Citation needed|date=December 2011}}
:[[File:Friedel-CraftsAlkylationStericProtection.png|350px|t-butylation of 1,4-dimethoxybenzene]]

Alkylations are not limited to alkyl halides: Friedel–Crafts reactions are possible with any [[carbocation]]ic intermediate such as those derived from [[alkene]]s and a [[protic acid]], [[Lewis acid]], [[enone]]s, and [[epoxide]]s. An example is the synthesis of [[neophyl chloride]] from benzene and methallyl chloride:<ref>{{OrgSynth | prep = cv4p0702 | year = 1963 | title = Neophyl chloride | author = Smith, W. T. Jr. and Sellas, J. T.}}</ref>

:H2C=C(CH3)CH2Cl + C6H6 → C6H5C(CH3)2CH2Cl

In one study the electrophile is a [[bromonium ion]] derived from an alkene and [[N-Bromosuccinimide|NBS]]:<ref>{{cite journal | author = Hajra, S.; Maji, B. and Bar, S. | title = Samarium Triflate-Catalyzed Halogen-Promoted Friedel–Crafts Alkylation with Alkenes | year = 2007 | journal = [[Org. Lett.]] | volume = 9 | issue = 15 | pages = 2783–2786 | doi = 10.1021/ol070813t}}</ref>

:[[File:FriedelCraftsAlkylationAlkenes.png|400px|Friedel–Crafts alkylation by an alkene]]
In this reaction [[samarium(III) triflate]] is believed to activate the NBS halogen donor in halonium ion formation.

==Friedel–Crafts dealkylation==
Friedel–Crafts alkylation is a [[reversible reaction]]. In a '''reversed Friedel–Crafts reaction''' or '''Friedel–Crafts dealkylation''', alkyl groups can be removed in the presence of protons and a [[Lewis acid]]. {{Citation needed|date=December 2011}}

For example, in a multiple addition of [[bromoethane|ethyl bromide]] to [[benzene]], [[Arene substitution patterns|''ortho'' and ''para'' substitution]] is expected after the first monosubstitution step because an alkyl group is an [[activating group]]. However, the actual reaction product is 1,3,5-triethylbenzene with all alkyl groups as a [[aromatic meta substituent|''meta'' substituent]].<ref>{{Cite journal | last1 = Anslyn | first1 = E. | last2 = Wallace | first2 = K. J. | last3 = Hanes | first3 = R. | last4 = Morey | first4 = J. | last5 = Kilway | first5 = K. V. | last6 = Siegel | first6 = J. | doi = 10.1055/s-2005-869963 | title = Preparation of 1,3,5-Tris(aminomethyl)-2,4,6-triethylbenzene from Two Versatile 1,3,5-Tri(halosubstituted) 2,4,6-Triethylbenzene Derivatives | journal = Synthesis | volume = 2005 | issue = 12 | pages = 2080–2083 | year = 2005 | pmid = | pmc = }}</ref> [[Thermodynamic reaction control]] makes sure that thermodynamically favored ''meta'' substitution with [[steric hindrance]] minimized takes prevalence over less favorable ''ortho'' and ''para'' substitution by [[chemical equilibrium|chemical equilibration]]. The ultimate reaction product is thus the result of a series of alkylations and dealkylations.

:[[File:246triethylbenzene.png|300px|synthesis of 2,4,6-triethylbenzene]]

== Friedel–Crafts acylation ==
{{Reactionbox
| Name = Friedel-Crafts acylation
| Type = Coupling reaction
| NamedAfter = [[Charles Friedel]] [[James Crafts]]
| Section3 = {{Reactionbox Identifiers
| OrganicChemistryNamed = friedel-crafts-acylation
| RSC_ontology_id = 0000045
}}
}}
Friedel–Crafts acylation is the [[acylation]] of aromatic rings with an [[acyl chloride]] using a strong [[Lewis acid]] catalyst. Friedel–Crafts acylation is also possible with [[acid anhydride]]s. Reaction conditions are similar to the Friedel–Crafts alkylation mentioned above. This reaction has several advantages over the alkylation reaction. Due to the electron-withdrawing effect of the [[carbonyl]] group, the [[ketone]] product is always less reactive than the original molecule, so multiple acylations do not occur. Also, there are no [[carbocation]] rearrangements, as the [[carbonium ion]] is stabilized by a resonance structure in which the positive charge is on the oxygen.{{Citation needed|date=December 2011}}

:[[File:Friedel-Crafts-acylation-overview.png|350px|Friedel–Crafts acylation overview]]

The viability of the Friedel–Crafts acylation depends on the stability of the acyl chloride reagent. Formyl chloride, for example, is too unstable to be isolated. Thus, synthesis of [[benzaldehyde]] via the Friedel–Crafts pathway requires that formyl chloride be synthesized ''in situ''. This is accomplished via the [[Gattermann-Koch reaction]], accomplished by treating [[benzene]] with [[carbon monoxide]] and [[hydrogen chloride]] under high pressure, catalyzed by a mixture of [[aluminium chloride]] and [[cuprous chloride]].

=== Reaction mechanism ===
In a simple mechanistic view, the first step consists of dissociation of a chloride ion to form an [[acyl]] cation (acylium ion){{Citation needed|date=December 2011}}:

:[[File:Friedel-Crafts-acylation-step-1.png|250px|FC acylation step 1]]

In some cases, the Lewis acid binds to the oxygen of the acyl chloride to form an adduct.<ref name="Smith2007" /> Regardless, the resulting [[acylium]] ion or a related adduct is subject to nucleophilic attack by the arene:

Finally, chloride anion (or AlCl4−) deprotonates the ring (an [[arenium ion]]) to form HCl, and the AlCl3 catalyst is regenerated:

:[[File:Friedel-Crafts-acylation-step-3.png|300px|FC acylation step III]]

If desired, the resulting ketone can be subsequently reduced to the corresponding alkane substituent by either [[Wolff–Kishner reduction]] or [[Clemmensen reduction]]. The net result is the same as the Friedel–Crafts alkylation except that rearrangement is not possible.<ref>[http://www.organic-chemistry.org/namedreactions/friedel-crafts-acylation.shtm Friedel-Crafts Acylation]. Organic-chemistry.org. Retrieved on 2014-01-11.</ref>

==Friedel–Crafts hydroxyalkylation==
Arenes react with certain [[aldehyde]]s and [[ketone]]s to form the hydroxyalkylated product for example in the reaction of the [[mesityl]] derivative of [[glyoxal]] with benzene<ref>{{cite journal | author = Fuson, R. C.; Weinstock, H. H. and Ullyot, G. E. | title = A New Synthesis of Benzoins. 2′,4′,6′-Trimethylbenzoin | year = 1935 | journal = [[J. Am. Chem. Soc.]] | volume = 57 | issue = 10 | pages = 1803–1804 | doi = 10.1021/ja01313a015}}</ref> to form a [[benzoin]] with an [[alcohol]] rather than a [[carbonyl]] group:

:[[File:FriedelCraftsHydroAlkylation.png|400px|Friedel–Crafts hydroxyalkylation]]

==Friedel–Crafts sulfonylation==
Under Friedel–Crafts reaction conditions, arenes react with [[sulfonyl halides]] and [[Methanesulfonic anhydride|sulfonic acid anhydrides]] affording [[sulfone]]s. Commonly used catalysts include AlCl3, FeCl3, GaCl3, BF3, SbCl5, BiCl3 and Bi(OTf)3, among others.<ref>{{cite journal | author = Truce, W. E. and Vriesen; C. W. | title = Friedel—Crafts Reactions of Methanesulfonyl Chloride with Benzene and Certain Substituted Benzenes| year = 1953 | journal = [[J. Am. Chem. Soc.]] | volume = 75 | pages = 5032–5036 | doi = 10.1021/ja01116a043 | issue = 20 }}</ref><ref>{{Cite journal | last1 = Répichet | first1 = S. | last2 = Le Roux | first2 = C. | last3 = Hernandez | first3 = P. | last4 = Dubac | first4 = J. | last5 = Desmurs | first5 = J. R. | title = Bismuth(III) Trifluoromethanesulfonate: An Efficient Catalyst for the Sulfonylation of Arenes | doi = 10.1021/jo9902603 | journal = The Journal of Organic Chemistry | volume = 64 | issue = 17 | pages = 6479–6482 | year = 1999 | pmid = | pmc = }}</ref> Intramolecular Friedel–Crafts cyclization occurs with 2-phenyl-1-ethanesulfonyl chloride, 3-phenyl-1-propanesulfonyl chloride and 4-phenyl-1-butanesulfonyl chloride on heating in nitrobenzene with AlCl3.<ref>{{cite journal | author = Truce, W. E. and Milionis, J. P. | title = Friedel-Crafts Cyclization of ω-Phenylalkanesulfonyl Chlorides | year = 1952 | journal = [[J. Am. Chem. Soc.]] | volume = 74 | pages = 974–977 | doi = 10.1021/ja01124a031 | issue = 4 }}</ref> Sulfenyl and sulfinyl chlorides also undergo Friedel–Crafts–type reactions, affording sulfides and sulfoxides, respectively.<ref>{{cite journal | author = Fujisawa, T.; Kakutani, M. and Kobayashi, N. | title = On the Reaction of ''p''-Toluenesulfinyl Chloride with Anisole| year = 1973 | journal = Bull. Chem. Soc. Jpn. | volume = 46 | pages = 3615–3617 | doi = 10.1246/bcsj.46.3615 | issue = 11 }}</ref> Both aryl sulfinyl chlorides and diaryl sulfoxides can be prepared from arenes through reaction with [[thionyl chloride]] in the presence of catalysts such as BiCl3, Bi(OTf)3, LiClO4 or NaClO4.<ref>{{Cite journal | last1 = Le Roux | first1 = C. | last2 = Mazières | first2 = S. P. | last3 = Peyronneau | first3 = M. | last4 = Roques | first4 = N. | title = Catalytic Lewis Acid Activationof Thionyl Chloride: Application to the Synthesis of ArylSulfinyl Chlorides Catalyzed by Bismuth(III) Salts | doi = 10.1055/s-2003-38358 | journal = Synlett | issue = 5 | pages = 0631–0634 | year = 2003 | pmid = | pmc = }}</ref><ref>{{cite journal | author = Bandgar, B. P. and Makone, S. S. | title = Lithium/Sodium Perchlorate Catalyzed Synthesis of Symmetrical Diaryl Sulfoxides| year = 2004 | journal = Syn. Commun. | volume = 34| pages = 743–750 | doi = 10.1081/SCC-120027723 | issue = 4 }}</ref>

==Scope and variations==
This reaction is related to several classic named reactions:
* The acylated reaction product can be converted into the alkylated product via a [[Clemmensen reduction]].<ref>{{cite journal
|author=Clemmensen, E.
|title=Reduktion von Ketonen und Aldehyden zu den entsprechenden Kohlenwasserstoffen unter Anwendung von amalgamiertem Zink und Salzsäure
|journal=Chemische Berichte|year=1913|volume=46|pages=1837–1843
|doi=10.1002/cber.19130460292
}}</ref><ref>{{cite journal
|author=Clemmensen, E.
|title=Über eine allgemeine Methode zur Reduktion der Carbonylgruppe in Aldehyden und Ketonen zur Methylengruppe
|journal=Chemische Berichte|year=1914|volume=47|pages=51–63
|doi=10.1002/cber.19140470108
}}</ref><ref>{{cite journal
|author=Clemmensen, E.
|title=Über eine allgemeine Methode zur Reduktion der Carbonylgruppe in Aldehyden und Ketonen zur Methylengruppe. (III. Mitteilung.)
|journal=Chemische Berichte|year=1914|volume=47|pages=681–687
|doi=10.1002/cber.191404701107
}}</ref>
* The [[Gattermann–Koch reaction]] can be used to synthesize benzaldehyde from benzene.<ref>{{cite journal | author = Gattermann, L.; Koch, J. A. | journal = [[Chemische Berichte|Ber.]] | title = Eine Synthese aromatischer Aldehyde | doi = 10.1002/cber.18970300288 | year = 1897 | volume = 30 | pages = 1622–1624}}</ref>
* The [[Gatterman reaction]] describes arene reactions with hydrocyanic acid.<ref>{{cite journal | author= L. Gattermann, W. Berchelmann| title = Synthese aromatischer Oxyaldehyde| journal = Berichte der deutschen chemischen Gesellschaft| year = 1898| volume = 31| issue = 2
| pages = 1765–1769| doi = 10.1002/cber.18980310281}}</ref>
* The [[Houben–Hoesch reaction]] describes arene reactions with nitriles.<ref>{{cite journal | last1 = Hoesch | first1 = Kurt | year = 1915 | title = Eine neue Synthese aromatischer Ketone. I. Darstellung einiger Phenol-ketone | url = | journal = Berichte der deutschen chemischen Gesellschaft | volume = 48 | issue = 1| pages = 1122–1133 | doi = 10.1002/cber.191504801156 }}</ref><ref>J. Houben (1926). Über die Kern-Kondensation von Phenolen und Phenol-äthern mit Nitrilen zu Phenol- und Phenol-äther-Ketimiden und -Ketonen (I.). Berichte der deutschen chemischen Gesellschaft (A and B Series) '''59''' (11) 2878–2891. {{DOI|10.1002/cber.19260591135}}</ref>
* A reaction modification with an aromatic phenyl ester as a reactant is called the [[Fries rearrangement]].{{Citation needed|date=December 2011}}
* In the [[Scholl reaction]] two arenes couple directly (sometimes called '''Friedel–Crafts arylation''').<ref>M B Smith, J March. ''March's Advanced Organic Chemistry'' (Wiley, 2001) (ISBN 0-471-58589-0)</ref><ref name=Grzybowski>{{cite journal | last1 = Grzybowski | first1 = M. | last2 = Skonieczny | first2 = K. | last3 = Butenschön | first3 = H. | last4 = Gryko | first4 = D. T. | year = 2013 | title = Comparison of Oxidative Aromatic Coupling and the Scholl Reaction | url = | journal = Angew. Chem. Int. Ed | volume = 52 | issue = | pages = 9900–9930 | doi = 10.1002/anie.201210238 }}</ref>
* In the [[Zincke–Suhl reaction]] p-cresol is alkylated to a cyclohexadienone with tetrachloromethane.<ref>{{cite journal
| title = Ueber die Einwirkung von Tetrachlorkohlenstoff und Aluminiumchlorid auf p-Kresol und p-Kresolderivate
| author = [[Theodor Zincke|Zincke, Th.]]; Suhl. R.
| journal = Chemische Berichte
| volume = 39
| issue = 4
| pages = 4148–4153
| year = 1906
| url =
| doi = 10.1002/cber.190603904115}}</ref>
* In the [[Blanc chloromethylation]] a chloromethyl group is added to an arene with formaldehyde, hydrochloric acid and zinc chloride.<ref>{{cite journal | last1 = Blanc | first1 = Gustave Louis | authorlink = Gustave Louis Blanc | title = | year = 1923 | url = | journal = Bulletin de la Société chimique de France [4] | volume = 33 | issue = | pages = 313-319 }}</ref><ref>G. Grassi and C. Maselli (1898) [https://archive.org/stream/lagazzettachimi02unkngoog#page/n999/mode/2up "Su alcuni derivati clorurati de trossimetilene"] (On some chlorinated derivatives of 1,3,5-trioxane), ''Gazzetta chimica Italiana'', '''28''' (part 2) : 477-500 ; see especially p. 495.</ref>
* The '''Bogert–Cook Synthesis''' (1933) involves the [[dehydration]] and [[isomerization]] of ''1-β-phenylethylcyclohexanol'' to the octahydro derivative of [[phenanthrene]]<ref>This reaction with
[[phosphorus pentoxide]]: {{Cite journal | last1 = Kamp | first1 = J. V. D. | last2 = Mosettig | first2 = E. | doi = 10.1021/ja01297a514 | title = Trans- and Cis-As-Octahydrophenanthrene | journal = Journal of the American Chemical Society | volume = 58 | issue = 6 | pages = 1062–1063 | year = 1936 | pmid = | pmc = }}</ref>

[[File:Bogert-Cook Synthesis.png|500px]]

* The '''Darzens–Nenitzescu Synthesis of Ketones''' (1910, 1936) involves the acylation of [[cyclohexene]] with [[acetyl chloride]] to methylcyclohexenylketone.
* In the related '''Nenitzescu reductive acylation''' (1936) a [[Saturation (chemistry)|saturated]] [[hydrocarbon]] is added making it a reductive acylation to methylcyclohexylketone
* '''Nencki Reaction''' (1881) is the ring acetylation of phenols with acids in the presence of zinc chloride.<ref>{{cite journal|author=Nencki, M. and Sieber, N. |journal=J. Prakt. Chem. |volume=23|pages= 147–156 |year=1881|doi=10.1002/prac.18810230111|title=Ueber die Verbindungen der ein- und zweibasischen Fettsäuren mit Phenolen}}</ref>
* In a [[green chemistry]] variation [[aluminium chloride]] is replaced by [[graphite]] in an alkylation of [[P-Xylene|''p''-xylene]] with [[2-bromobutane]]. This variation will not work with primary halides from which less carbocation involvement is inferred.<ref>{{cite journal | title = A Green Alternative to Aluminum Chloride Alkylation of Xylene | author = Sereda, Grigoriy A.; Rajpara, Vikul B. | journal = [[J. Chem. Educ.]] | year = 2007 | volume = 2007 | issue = 84 | page = 692| doi = 10.1021/ed084p692|bibcode = 2007JChEd..84..692S }}</ref>

===Dyes===
Friedel–Crafts reactions have been used in the synthesis of several [[Triphenylmethane|triarylmethane]] and [[xanthene]] [[dye]]s.<ref>{{Cite journal | last1 = McCullagh | first1 = James V. | last2 = Daggett | first2 = Kelly A. | journal = [[J. Chem. Educ.]] | year = 2007 | title = Synthesis of Triarylmethane and Xanthene Dyes Using Electrophilic Aromatic Substitution Reactions | volume = 84 | page = 1799 | doi = 10.1021/ed084p1799}}</ref> Examples are the synthesis of [[thymolphthalein]] (a pH indicator) from two equivalents of [[thymol]] and [[phthalic anhydride]]:

:[[File:ThymolphthaleinSynthesis.png|400px|Thymolphthalein Synthesis]]

A reaction of phthalic anhydride with [[resorcinol]] in the presence of [[zinc chloride]] gives the fluorophore [[Fluorescein#Synthesis|Fluorescein]]. Replacing resorcinol by N,N-diethylaminophenol in this reaction gives [[rhodamine B]]:

:[[File:RhodamineBsynthesis.png|400px|Rhodamine B synthesis]]

===Haworth reactions===
The '''Haworth reaction''' is a classic method for the synthesis of [[1-Tetralone|1-tetralone]].<ref>{{cite journal | title = Syntheses of alkylphenanthrenes. Part I. 1-, 2-, 3-, and 4-Methylphenanthrenes | author = Haworth, Robert Downs | journal = [[J. Chem. Soc.]] | year = 1932 | page = 1125 | doi = 10.1039/JR9320001125}}</ref> In it [[benzene]] is reacted with [[succinic anhydride]], the intermediate product is reduced and a second FC acylation takes place with addition of acid.<ref>Li, Jie Jack (2003) [http://books.google.com/books?id=6mZJ3084ouAC&pg=PA175 ''Name Reactions: A Collection of Detailed Reaction Mechanisms''], Springer, ISBN 3-540-40203-9, p. 175.</ref>

:[[File:Haworth-reaction.svg|600px|Haworth reaction]]

In a related reaction, [[phenanthrene]] is synthesized from [[naphthalene]] and [[succinic anhydride]] in a series of steps.

:[[File:Haworth Phenanthrene synthesis.svg|600px|Haworth Phenanthrene synthesis]]

===Friedel–Crafts test for aromatic hydrocarbons===
Reaction of [[chloroform]] with aromatic compounds using an [[aluminium chloride]] catalyst gives triarylmethanes, which are often brightly colored, as is the case in triarylmethane dyes. This is a bench test for aromatic compounds.{{Citation needed|date=December 2011}}

==See also==
* [[Friedel family]], a rich lineage of French scientists
* [[Hydrodealkylation]]
* [[Transalkylation]]
* [[Ethylene oxide#Alkylation of aromatic compounds|Ethylene oxide]]

==References==
{{reflist|35em}}

===FC (Friedel–Crafts) reactions in organic syntheses===
* Alkylations:
** Diphenylacetone, Organic Syntheses, Coll. Vol. 3, p. 343 (1955); Vol. 29, p. 38 (1949) [http://orgsynth.org/orgsyn/pdfs/CV3P0343.pdf Article link].
** Reaction of [[P-Xylene|''p''-xylene]] with [[chloromethane]] to [[durene]] Organic Syntheses, Coll. Vol. 2, p. 248 (1943); Vol. 10, p. 32 (1930). [http://orgsynth.org/orgsyn/pdfs/CV2P0248.pdf Article link]
** Synthesis of [[benzophenone]] from [[benzene]] and [[tetrachloromethane]] Organic Syntheses, Coll. Vol. 1, p. 95 (1941); Vol. 8, p. 26 (1928).[http://orgsynth.org/orgsyn/pdfs/CV1P0095.pdf Article link]
* Acylations:
** Dibenzoylethylene Organic Syntheses, Coll. Vol. 3, p. 248 (1955); Vol. 20, p. 29 (1940) [http://orgsynth.org/orgsyn/pdfs/CV3P0248.pdf Article link].
** reaction of [[acenaphthene]] plus [[succinic acid]] Organic Syntheses, Coll. Vol. 3, p. 6 (1955); Vol. 20, p. 1 (1940).[http://orgsynth.org/orgsyn/pdfs/CV3P0006.pdf Article link]
** Desoxybenzoin Organic Syntheses, Coll. Vol. 2, p. 156 (1943); Vol. 12, p. 16 (1932). [http://orgsynth.org/orgsyn/pdfs/CV2P0156.pdf Article link]
** Acylation of a [[phenanthrene]] compound Organic Syntheses, Vol. 80, p. 227 [http://orgsynth.org/orgsyn/pdfs/v80p0227.pdf Link]
** Reaction of [[bromobenzene]] with [[acetic anhydride]] Organic Syntheses, Coll. Vol. 1, p. 109 (1941); Vol. 5, p. 17 (1925). [http://orgsynth.org/orgsyn/pdfs/CV1P0109.pdf Article link]
** beta-methylanthraquinone, Organic Syntheses, Coll. Vol. 1, p. 353 (1941); Vol. 4, p. 43 (1925). [http://orgsynth.org/orgsyn/pdfs/CV1P0353.pdf Article link]
** Benzoylation of [[ferrocene]] Organic Syntheses, Coll. Vol. 6, p. 625 (1988); Vol. 56, p. 28 (1977). [http://orgsynth.org/orgsyn/pdfs/CV6P0625.pdf Article link]

{{Authority control}}

{{DEFAULTSORT:Friedel-Crafts Reaction}}
[[Category:Substitution reactions]]
[[Category:Carbon-carbon bond forming reactions]]
[[Category:Name reactions]]

Nitrophenol

2016-02-07T11:51:56Z

71.109.148.145: /* Safety */ Don't know why a citation would be required, but here's some internal ones, which are in turn cited.

[[File:P-Nitrophenol.svg|thumb|75px|right|''p''-Nitrophenol]]
'''Nitrophenols''' consist of a [[phenol]] molecule with one or more [[nitro compound|nitro]]-groups attached to the aromatic ring. The term is most often used to describe singly nitrated phenols.

==Mono-nitrophenols==
with the [[chemical formula|formula]] HOC6H4NO2. Three [[isomer]]ic nitrophenols exist:
* ''o''-Nitrophenol (1-hydroxy-2-nitrobenzene; OH and NO2 groups are neighboring; CAS number: 88-75-5), a yellow crystalline solid (m.p. 46 °C).
* ''m''-Nitrophenol (1-hydroxy-3-nitrobenzene, CAS number: 554-84-7), a yellow solid (m.p. 97 °C) and precursor to the drug [[mesalazine]] (5-aminosalicylic acid).
* [[4-Nitrophenol|''p''-Nitrophenol]] (1-hydroxy-4-nitrobenzene, CAS number: 100-02-7), yellow crystals (m.p. 114 °C). It is a precursor to the [[rice]] herbicide fluorodifen and the pesticide [[parathion]].
The nitrophenols are produced industrially by the reaction of chlorides with [[sodium hydroxide]] at temperatures around 200 °C. The mononitrated phenols are often [[hydrogenation|hydrogenated]] to the corresponding [[aminophenol]]s that are also useful industrially.<ref name=Booth>Gerald Booth "Nitro Compounds, Aromatic" in "Ullmann's Encyclopedia of Industrial Chemistry" 2007; Wiley-VCH, Weinheim. {{DOI|10.1002/14356007.a17_411}}</ref>

==Di- and trinitrophenols==
[[Image:2,4-Dinitrophenol.svg|thumb|upright|[[2,4-Dinitrophenol|2,4-dinitrophenol]]]]
[[2,4-Dinitrophenol]] (m.p. 83 °C) is a moderately strong acid (pKa = 4.89). 2,4,6-trinitrophenol is better known as [[picric acid]], which has a well-developed chemistry.

==Safety==
Nitrophenols are poisonous.<ref>[[4-nitrophenol#Toxicity|Nitrophenol]]</ref><ref>[[2,4-Dinitrophenol#Health_effects|Dinitrophenol]]</ref> Occasionally, nitrophenols contaminate the soil near former explosives or fabric factories and military plants, and current research is aimed at remediation.

==References==
<references/>

==External links==
* [http://www.atsdr.cdc.gov/tfacts50.html Fact sheet at atsdr.cdc.gov]

{{Authority control}}
[[Category:Nitrobenzenes]]
[[Category:Phenols]]

Nitrophenol

2016-02-07T11:46:21Z

71.109.148.145: Cleanup

[[File:P-Nitrophenol.svg|thumb|75px|right|''p''-Nitrophenol]]
'''Nitrophenols''' consist of a [[phenol]] molecule with one or more [[nitro compound|nitro]]-groups attached to the aromatic ring. The term is most often used to describe singly nitrated phenols.

==Mono-nitrophenols==
with the [[chemical formula|formula]] HOC6H4NO2. Three [[isomer]]ic nitrophenols exist:
* ''o''-Nitrophenol (1-hydroxy-2-nitrobenzene; OH and NO2 groups are neighboring; CAS number: 88-75-5), a yellow crystalline solid (m.p. 46 °C).
* ''m''-Nitrophenol (1-hydroxy-3-nitrobenzene, CAS number: 554-84-7), a yellow solid (m.p. 97 °C) and precursor to the drug [[mesalazine]] (5-aminosalicylic acid).
* [[4-Nitrophenol|''p''-Nitrophenol]] (1-hydroxy-4-nitrobenzene, CAS number: 100-02-7), yellow crystals (m.p. 114 °C). It is a precursor to the [[rice]] herbicide fluorodifen and the pesticide [[parathion]].
The nitrophenols are produced industrially by the reaction of chlorides with [[sodium hydroxide]] at temperatures around 200 °C. The mononitrated phenols are often [[hydrogenation|hydrogenated]] to the corresponding [[aminophenol]]s that are also useful industrially.<ref name=Booth>Gerald Booth "Nitro Compounds, Aromatic" in "Ullmann's Encyclopedia of Industrial Chemistry" 2007; Wiley-VCH, Weinheim. {{DOI|10.1002/14356007.a17_411}}</ref>

==Di- and trinitrophenols==
[[Image:2,4-Dinitrophenol.svg|thumb|upright|[[2,4-Dinitrophenol|2,4-dinitrophenol]]]]
[[2,4-Dinitrophenol]] (m.p. 83 °C) is a moderately strong acid (pKa = 4.89). 2,4,6-trinitrophenol is better known as [[picric acid]], which has a well-developed chemistry.

==Safety==
Nitrophenols are poisonous.{{cn|date=October 2015}} Occasionally, nitrophenols contaminate the soil near former explosives or fabric factories and military plants, and current research is aimed at remediation.

==References==
<references/>

==External links==
* [http://www.atsdr.cdc.gov/tfacts50.html Fact sheet at atsdr.cdc.gov]

{{Authority control}}
[[Category:Nitrobenzenes]]
[[Category:Phenols]]

Carbonium ion

2016-02-07T11:34:32Z

71.109.148.145: typo

In [[chemistry]], '''carbonium ion''' is any [[cation]] that has a [[pentavalent]] [[carbon]] atom,<ref name="olah-JACS-1972">{{cite journal | title = Stable carbocations. CXVIII. General concept and structure of carbocations based on differentiation of trivalent (classical) carbenium ions from three-center bound penta- of tetracoordinated (nonclassical) carbonium ions. Role of carbocations in electrophilic reactions | author = [[George Andrew Olah]] | journal = [[J. Am. Chem. Soc.]] | year = 1972 | volume = 94 | issue = 3 | pages = 808–820 | doi = 10.1021/ja00758a020}}</ref><ref>{{GoldBookRef|title=Carbonium ion|file=C00839}}</ref> The name '''carbonium''' may also be used for the simplest member of the class, properly called [[methanium]] ({{chem|CH|5|+}}), where the five valences are filled with [[hydrogen]] atoms.<ref name=boo>
Doo Wan Boo and Yuan T. Lee (1995), "Infrared spectroscopy of the molecular hydrogen solvated carbonium ions, {{chem|CH|5|+}}({{chem|H|2}})n (n=1–6)". J. Chem. Phys. volume 103, page 520; {{doi|10.1063/1.470138}}
</ref>

The next simplest carbonium ions after methanium have two carbons. [[Ethanium]] or protonated [[acetylene]] {{chem|C|2|H|3|+}} and [[ethenium]] {{chem|C|2|H|5|+}} are usually classified in other families. The [[ethanium]] ion {{chem|C|2|H|7|+}} has been studied as an extremely rarefied gas by infrared spectroscopy.<ref name=yeh>
L. I. Yeh, J. M. Price, and Y. T. Lee (1989), "Infrared spectroscopy of the pentacoordinated carbonium ion {{chem|C|2|H|7|+}}". Journal of the American Chemical Society, volume 111, pages 5591-5604. {{doi|10.1021/ja00197a015}}
</ref>

In older literature the name "carbonium ion" was used for what is today called [[carbenium ion|carbenium]]. The current definitions were proposed by the chemist [[George Andrew Olah]] in 1972.<ref name="olah-JACS-1972"/> and are now widely accepted.

A stable carbonium ion is the complex penta(triphenylphosphine gold(I))methanium {{chem|({{chem|Ph|3|PAu}})|5|C|+}}, produced by Schmidbauer and others.<ref name=OlahBk/>

==Preparation==
Carbonium ions can be obtained by treating [[alkane]]s with very strong acids.<ref name=sommer/>
Industrially, they are formed in the refining of petroleum during primary thermal [[cracking_(chemistry)|cracking]].<ref name=eere/>

== See also ==
*More carbonium ions called [[non-classical ion]]s are found in certain [[Norbornane|norbornyl]] systems
*[[Onium compounds]]
*[[Carbenium ion]]

== References ==
<references>
<ref name=sommer>
J. Sommer and R. Jost (2000), [http://195.37.231.82/publications/pac/pdf/2000/pdf/7212x2309.pdf "Carbenium and carbonium ions in liquid- and solid-superacid-catalyzed activation of small alkanes"]. Pure and Applied Chemistry, volume 72, pages 2309–2318. {{doi|10.1351/pac200072122309}}
</ref>

<ref name=OlahBk>
George A. Olah (1998), "Onium Ions". John Wiley & Sons, 509 pages. ISBN 9780471148777
</ref>

<ref name=eere>
Office of Energy Efficiency and Renewable Energy, U.S. DOE (2006). [http://www1.eere.energy.gov/manufacturing/resources/petroleum_refining/pdfs/bandwidth.pdf "Energy Bandwidth for Petroleum Refining Processes"]
</ref>

</references>

[[Category:Reactive intermediates]]
[[Category:Carbocations]]

Naphthalene

2016-02-07T08:44:54Z

71.109.148.145: /* Reduction and oxidation */ redundant

{{Distinguish|naphtha|naphthene}}
{{Chembox
| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 477170210
| Name = Naphthalene
| ImageFileL1 = Naphthalene numbering.svg
| ImageSizeL1 = 100px
| ImageNameL1 = Skeletal formula and numbering system of naphthalene
| ImageFileR1 = Naphthalene-from-xtal-3D-balls.png
| ImageSizeR1 = 100px
| ImageNameR1 = Ball-and-stick model of naphthalene
| ImageFile2 = Naphthalene-from-xtal-3D-vdW.png
| ImageSize2 = 150px
| ImageName2 = Spacefill model of naphthalene
| ImageFile3 = Naphthalene-xtal-3D-vdW-B.png
| ImageSize3 = 150px
| ImageName3 = Unit cells of naphthalene
| IUPACName = Bicyclo[4.4.0]deca-1,3,5,7,9-pentene
| SystematicName = Bicyclo[4.4.0]deca-1,3,5,7,9-pentene; Bicyclo[4.4.0]deca-2,4,6,8,10-pentene
| OtherNames = White tar, Mothballs, Naphthalin, Moth flakes, Camphor tar, Tar camphor, Naphthaline, Antimite, Albocarbon, Hexalene
|Section1={{Chembox Identifiers
| CASNo = 91-20-3
| CASNo_Ref = {{cascite|correct|CAS}}
| PubChem = 931
| ChemSpiderID = 906
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| UNII = 2166IN72UN| ChEBI_Ref = {{ebicite|correct|EBI}}
| UNII_Ref = {{fdacite|changed|FDA}}
| EINECS = 214-552-7
| KEGG = C00829
| KEGG_Ref = {{keggcite|correct|kegg}}
| ChEBI = 16482
| ChEMBL = 16293
| ChEMBL_Ref = {{ebicite|correct|EBI}}
| RTECS = QJ0525000
| SMILES = c1ccc2ccccc2c1
| InChI = 1/C10H8/c1-2-6-10-8-4-3-7-9(10)5-1/h1-8H
| InChIKey = UFWIBTONFRDIAS-UHFFFAOYAC
| StdInChI = 1S/C10H8/c1-2-6-10-8-4-3-7-9(10)5-1/h1-8H
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = UFWIBTONFRDIAS-UHFFFAOYSA-N
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
}}
|Section2={{Chembox Properties
| C=10 | H=8
| Appearance = White solid crystals/ flakes
| Odor = Strong odor of coal tar
| Density = 1.145 g/cm3 (15.5 °C)<ref name=water.epa>{{cite web|website = http://water.epa.gov|url = http://water.epa.gov/scitech/swguidance/standards/upload/2001_10_12_criteria_ambientwqc_napthalene80.pdf|title = Ambient Water Quality Criteria for Naphthalene|publisher = United States Environmental Protection Agency|accessdate = 2014-06-21}}</ref> 1.0253 g/cm3 (20 °C)<ref name=crc /> 0.9625 g/cm3 (100 °C)<ref name=water.epa />
| Solubility = 19 mg/L (10 °C) 31.6 mg/L (25 °C) 43.9 mg/L (34.5 °C) 80.9 mg/L (50 °C)<ref name=crc /> 238.1 mg/L (73.4 °C)<ref name=chemister>{{cite web|last = Anatolievich|first = Kiper Ruslan|website = http://chemister.ru|url = http://chemister.ru/Database/properties-en.php?dbid=1&id=1005|title = naphthalene|accessdate = 2014-06-21}}</ref>
| Solubility1 = 5 g/100 g (0 °C) 11.3 g/100 g (25 °C) 19.5 g/100 g (40 °C) 179 g/100 g (70 °C)<ref name=sioc>{{cite book|last = Seidell|first = Atherton|last2 = Linke|first2 = William F.|year = 1919|title = Solubilities of Inorganic and Organic Compounds|publisher = D. Van Nostrand Company|place = New York|edition = 2nd|pages = 443–446}}</ref>
| Solvent1 = ethanol
| Solubility2 = 6.8 g/100 g (6.75 °C) 13.1 g/100 g (21.5 °C) 31.1 g/100 g (42.5 °C) 111 g/100 g (60 °C)<ref name=sioc />
| Solvent2 = acetic acid
| Solubility3 = 19.5 g/100 g (0 °C) 35.5 g/100 g (25 °C) 49.5 g/100 g (40 °C) 87.2 g/100 g (70 °C)<ref name=sioc />
| Solvent3 = chloroform
| Solubility4 = 5.5 g/100 g (0 °C) 17.5 g/100 g (25 °C) 30.8 g/100 g (40 °C) 78.8 g/100 g (70 °C)<ref name=sioc />
| Solvent4 = hexane
| Solubility5 = 13.6 g/100 g (6.75 °C) 22.1 g/100 g (21.5 °C) 131.6 g/100 g (60 °C)<ref name=sioc />
| Solvent5 = butyric acid
| SolubleOther = Soluble in [[alcohol]]s, liquid [[ammonia]], [[carboxylic acid]]s, [[benzene|C6H6]], [[sulfur dioxide|SO2]],<ref name=chemister /> [[carbon tetrachloride|CCl4]], [[carbon disulfide|CS2]], [[toluene]], [[aniline]]<ref name=sioc />
| MeltingPtC = 78.2
| MeltingPt_notes = {{convert|80.26|C|F K}} at 760 mmHg<ref name=crc />
| BoilingPtC = 217.97
| BoilingPt_notes = at 760 mmHg<ref name=water.epa /><ref name=crc />
| VaporPressure = 8.64 Pa (20 °C) 23.6 Pa (30 °C) 0.93 kPa (80 °C)<ref name=chemister /> 2.5 kPa (100 °C)<ref name=nist>{{nist|name=Naphthalene|id=C91203|accessdate=2014-05-24|mask=FFFF|units=SI}}</ref>
| LogP = 3.34<ref name=crc />
| RefractIndex = 1.5898<ref name=crc />
| HenryConstant = 0.42438 L·atm/mol<ref name=crc />
| ThermalConductivity = 98 kPa: 0.1219 W/m·K (372.22 K) 0.1174 W/m·K (400.22 K) 0.1152 W/m·K (418.37 K) 0.1052 W/m·K (479.72 K)<ref>{{cite web|title = Thermal Conductivity of Naphthalene|url = http://www.ddbst.com/en/EED/PCP/TCN_C123.php|website = http://www.ddbst.com|publisher = DDBST GmbH|accessdate = 2014-06-21}}</ref>
| Viscosity = 0.964 cP (80 °C) 0.761 cP (100 °C) 0.217 cP (150 °C)<ref>{{cite web|title = Dynamic Viscosity of Naphthalene|url = http://www.ddbst.com/en/EED/PCP/VIS_C123.php|website = http://www.ddbst.com|publisher = DDBST GmbH|accessdate = 2014-06-21}}</ref>
}}
|Section3={{Chembox Structure
| CrystalStruct = [[monoclinic crystal system|Monoclinic]]<ref name=sccs>{{cite book|url = http://books.google.com/books?id=hYRCAAAAQBAJ&pg=PA288|title = Structure and Chemistry of Crystalline Solids|last = Douglas|first = Bodie E.|last2 = Ho|first2 = Shih-Ming|publisher = Springer Science+Business Media, Inc.|year = 2007|isbn = 0-387-26147-8|place = New York|page = 288}}</ref>
| SpaceGroup = P21/b<ref name=sccs />
| PointGroup = C{{sup sub|5|2h}}<ref name=sccs />
| LattConst_a = 8.235 Å
| LattConst_b = 6.003 Å
| LattConst_c = 8.658 Å<ref name=sccs />
| LattConst_alpha =
| LattConst_beta = 122.92
| LattConst_gamma =
}}
|Section4={{Chembox Thermochemistry
| HeatCapacity = 165.72 J/mol·K<ref name=crc />
| Entropy = 167.39 J/mol·K<ref name=crc /><ref name=nist />
| DeltaHf = 78.53 kJ/mol<ref name=crc />
| DeltaGf = 201.585 kJ/mol<ref name=crc />
| DeltaHc = 5156.3 kJ/mol<ref name=crc />
}}
|Section7={{Chembox Hazards
| MainHazards = [[Flammable]], [[wikt:sensitizer|sensitizer]], possible [[carcinogen]]. Dust can form [[explosive]] mixtures with [[air]]
| GHSPictograms = {{GHS02}}{{GHS07}}{{GHS08}}{{GHS09}}<ref name="sigma">{{Sigma-Aldrich|id=147141|name=Naphthalene|accessdate=2014-06-21}}</ref>
| GHSSignalWord = Danger
| HPhrases = {{H-phrases|228|302|351|410}}<ref name="sigma" />
| PPhrases = {{P-phrases|210|273|281|501}}<ref name="sigma" />
| EUClass = {{Hazchem Xn}} {{Hazchem N}}
| NFPA-H = 2
| NFPA-F = 2
| NFPA-R = 0
| FlashPtC = 80
| FlashPt_ref = <ref name="sigma" />
| AutoignitionPtC = 525
| AutoignitionPt_ref = <ref name="sigma" />
| RPhrases = {{R22}}, {{R40}}, {{R50/53}}
| SPhrases = {{S2}}, {{S36/37}}, {{S46}}, {{S60}}, {{S61}}
| ExploLimits = 5.9%<ref name="sigma" />
| TLV-TWA = 10 ppm<ref name=crc>{{CRC90}}</ref>
| TLV-STEL = 15 ppm<ref name=crc />
| LD50 = 1800 mg/kg (rat, oral) 490 mg/kg (rat, oral) 1200 mg/kg (guinea pig, oral) 533 mg/kg (mouse, oral)<ref>{{IDLH|91203|Naphthalene}}</ref>
| IDLH = 250 ppm<ref name=PGCH>{{PGCH|0439}}</ref>
| REL = TWA 10 ppm (50 mg/m3) ST 15 ppm (75 mg/m3)<ref name=PGCH/>
| PEL = TWA 10 ppm (50 mg/m3)<ref name=PGCH/>
}}
}}

'''Naphthalene''' is an [[organic compound]] with [[chemical formula|formula]] {{chem|[[carbon|C]]|10|[[hydrogen|H]]|8}}. It is the simplest [[polycyclic aromatic hydrocarbon]], and is a white [[crystal|crystalline solid]] with a characteristic odor that is detectable at concentrations as low as 0.08 [[parts per million|ppm by mass]].<ref>{{cite journal
| title=Odor as an aid to chemical safety: Odor thresholds compared with threshold limit values and volatiles for 214 industrial chemicals in air and water dilution
| author=Amoore J E and Hautala E
| journal=J Appl Toxicology
| volume=3
| issue=6
| pages=272–290
| year=1983
| doi=10.1002/jat.2550030603 }}</ref> As an [[aromaticity|aromatic]] [[hydrocarbon]], naphthalene's structure consists of a fused pair of [[benzene]] rings. It is best known as the main ingredient of traditional [[mothball]]s.

==History==
In the early 1820s, two separate reports described a white solid with a pungent odor derived from the distillation of [[coal tar]]. In 1821, [[John Kidd (chemist)|John Kidd]] cited these two disclosures and then described many of this substance's properties and the means of its production. He proposed the name ''naphthaline'', as it had been derived from a kind of [[naphtha]] (a broad term encompassing any volatile, flammable liquid hydrocarbon mixture, including coal tar).<ref>{{cite journal | author = John Kidd | year = 1821 | title = Observations on Naphthalene, a peculiar substance resembling a concrete essential oil, which is produced during the decomposition of coal tar, by exposure to a red heat | journal = Philosophical Transactions | volume = 111 | pages = 209–221 | doi = 10.1098/rstl.1821.0017}}</ref> Naphthalene's chemical formula was determined by [[Michael Faraday]] in 1826. The structure of two fused benzene rings was proposed by [[Emil Erlenmeyer]] in 1866,<ref>{{cite journal
| title = Studien über die s. g. aromatischen Säuren
| author = Emil Erlenmeyer
| journal = [[Annalen der Chemie und Pharmacie]]
| volume = 137
| issue = 3
| pages = 327–359
| year = 1866
| doi = 10.1002/jlac.18661370309 }}</ref> and confirmed by [[Carl Gräbe]] three years later.<ref>C. Graebe (1869) [http://babel.hathitrust.org/cgi/pt?id=uva.x002457978;view=1up;seq=32 "Ueber die Constitution des Naphthalins"] (On the structure of naphthalene), ''Annalen der Chemie und Pharmacie'', '''149''' : 20-28.</ref>

==Structure and reactivity==
A naphthalene molecule can be viewed as the fusion of a pair of benzene rings. (In [[organic chemistry]], rings are ''fused'' if they share two or more atoms.) As such, naphthalene is classified as a benzenoid [[polycyclic aromatic hydrocarbon]] (PAH). There are two sets of equivalent hydrogen atoms: the ''alpha'' positions are positions 1, 4, 5, and 8 on the drawing below, and the ''beta'' positions are positions 2, 3, 6, and 7.

Unlike [[benzene]], the carbon–carbon bonds in naphthalene are not of the same length. The bonds C1–C2, C3–C4, C5–C6 and C7–C8 are about 1.37 Å (137 pm) in length, whereas the other carbon–carbon bonds are about 1.42 Å (142 pm) long. This difference, which was established by [[X-ray diffraction]],<ref>{{cite journal|last1=Cruickshank|first1=D. W. J.|last2=Sparks|first2=R. A.|title=Experimental and Theoretical Determinations of Bond Lengths in Naphthalene, Anthracene and Other Hydrocarbons|journal=Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences|date=18 October 1960|volume=258|issue=1293|pages=270–285|doi=10.1098/rspa.1960.0187}}</ref> is consistent with the [[valence bond theory|valence bond]] model of bonding in naphthalene and in particular the phenomenon of [[cross-conjugation]]. This theorem would describe naphthalene as consisting of an [[Aromaticity|aromatic]] benzene unit bonded to a [[diene]] but not extensively [[Conjugated system|conjugated]] to it (at least in the ground state). As such naphthalene possesses several resonance structures.

:[[Image:Naphthalene resonance structure.svg|400px|Resonance structures of naphthalene]]

Two [[isomer]]s are possible for mono-substituted naphthalenes, corresponding to substitution at an alpha or beta position.

===Reactions with electrophiles===
In electrophilic aromatic substitution reactions, naphthalene reacts faster than does benzene. For example, chlorination of naphthalene proceeds without a catalyst to give [[1-chloronaphthalene]]. Likewise, whereas both benzene and naphthalene can be alkylated using [[Friedel–Crafts reaction]]s, naphthalene can also be alkylated by reaction with [[alkene]]s or [[alcohol]]s, using [[sulfuric acid|sulfuric]] or [[phosphoric acid]] as the catalyst.

In terms of regiochemistry, [[electrophile]]s attack occurs at the alpha position. The selectivity for alpha over beta substitution can be rationalized in terms of the resonance structures of the intermediate: for the alpha substitution intermediate, seven resonance structures can be drawn, of which four preserve an aromatic ring. For beta substitution, the intermediate has only six resonance structures, and only two of these are aromatic. Sulfonation, however, gives a mixture of the "alpha" product 1-naphthalenesulfonic acid and the "beta" product 2-naphthalenesulfonic acid, with the ratio dependent on reaction conditions. The 1-isomer forms predominantly at 25 °C, and the 2-isomer at 160 °C.
[[Sulfonation]] to give the 1- and 2-sulfonic acid occurs readily:
: {{chem|H|2|SO|4}} + {{chem|C|10|H|8}} → {{chem|C|10|H|7|-SO|3|H}} + {{chem|H|2|O}}
Further sulfonation occurs to give di-, tri-, and tetrasulfonic acids.

===Reduction and oxidation===
Naphthalene can be [[hydrogenate]]d under high pressure in the presence of metal [[catalyst]]s to give 1,2,3,4-tetrahydronaphthalene or [[tetralin]] ({{chem|C|10|H|12}}). Further hydrogenation yields decahydronaphthalene or [[decalin]] ({{chem|C|10|H|18}}).

[[Oxidation]] with [[chromate]] or [[permanganate]], or oxidation with {{chem|O|2}} and a [[vanadium]] [[catalyst]], gives [[phthalic acid]].

==Production==
Most naphthalene is derived from [[coal tar]]. From the 1960s until the 1990s, significant amounts of naphthalene were also produced from heavy petroleum fractions during [[petroleum refining]], but today petroleum-derived naphthalene represents only a minor component of naphthalene production.

Naphthalene is the most abundant single component of coal tar. Although the composition of coal tar varies with the coal from which it is produced, typical coal tar is about 10% naphthalene by weight. In industrial practice, [[distillation]] of coal tar yields an oil containing about 50% naphthalene, along with twelve other [[aromatic compound]]s. This oil, after being washed with aqueous [[sodium hydroxide]] to remove [[acid]]ic components (chiefly various [[phenol]]s), and with sulfuric acid to remove [[base (chemistry)|basic]] components, undergoes [[fractional distillation]] to isolate naphthalene. The crude naphthalene resulting from this process is about 95% naphthalene by weight. The chief impurities are the sulfur-containing aromatic compound [[benzothiophene]] (< 2%), [[indane]] (0.2%), [[indene]] (< 2%), and methylnaphthalene (< 2%). Petroleum-derived naphthalene is usually purer than that derived from coal tar. Where required, crude naphthalene can be further purified by [[Recrystallization (chemistry)|recrystallization]] from any of a variety of solvents, resulting in 99% naphthalene by weight, referred to as 80 °C (melting point). Approximately 1.3M tons are produced annually.<ref name=Ullmann>Gerd Collin, Hartmut Höke, Helmut Greim "Naphthalene and Hydronaphthalenes" in ''Ullmann's Encyclopedia of Industrial Chemistry'', Wiley-VCH, Weinheim, 2003. {{doi|10.1002/14356007.a17_001.pub2}}. Article Online Posting Date: March 15, 2003.</ref>

In North America, coal tar producers are [[Koppers]] Inc., Ruetgers Canada Inc. and Recochem Inc., and petroleum-derived producer is Advanced Aromatics, L.P.
In Western Europe most known producers are Koppers, Ruetgers and Deza. In Eastern Europe, - variety of integrated metallurgy complexes (Severstal, Evraz, Mechel, MMK) in Russia. Dedicated naphthalene and phenol maker INKOR and Yenakievsky Metallurgy plant in Ukraine, and ArcelorMittal Temirtau in Kazakhstan.

===Other sources and occurrences===
Aside from coal tar, trace amounts of naphthalene are produced by [[magnolia]]s and certain species of [[deer]], as well as the [[Formosan subterranean termite]], possibly produced by the termite as a repellant against "ants, poisonous fungi and nematode worms."<ref>{{cite news |url=http://news.bbc.co.uk/1/hi/sci/tech/76115.stm |title=Termite 'mothball' keep insects at bay |publisher=BBC News |work=Sci/Tech |date=April 8, 1998}}</ref> Some strains of the [[endophytic]] fungus ''[[Muscodor albus]]'' produce naphthalene among a range of volatile organic compounds, while ''[[Muscodor vitigenus]]'' produces naphthalene almost exclusively.<ref>{{cite journal |vauthors=Daisy BH, Strobel GA, Castillo U, etal |title=Naphthalene, an insect repellent, is produced by ''Muscodor vitigenus'', a novel endophytic fungus |journal=Microbiology (Reading, Engl.) |volume=148 |issue=Pt 11 |pages=3737–41 |date=November 2002 |pmid=12427963 |url=http://mic.sgmjournals.org/cgi/content/abstract/148/11/3737 | doi = 10.1099/00221287-148-11-3737 }}</ref>

Naphthalene has been found in meteorites.: n {{chem|C|10|H|7|-SO|3|H}} + n {{chem|CH|2|}}=O → {{chem|SO|3|H-C|10|H|7|-(-CH|2|-C|10|H|7|-SO|3|H)|n}} + n {{chem|H|2|O|}}
*[[Neutralization (chemistry)|Neutralization]] Step (naphthalene sulfonic acid condensate plus sodium hydroxide):

===Naphthalene in the interstellar medium===
Naphthalene has been tentatively detected in the [[interstellar medium]] in the direction of the star [[Perseus (constellation)#Stars|Cernis 52]] in the constellation [[Perseus (constellation)|Perseus]].<ref>{{cite web |url=http://www.sciencedaily.com/releases/2008/09/080919075007.htm |title=Interstellar Space Molecules That Help Form Basic Life Structures Identified |work=Science Daily |date=September 2008}}</ref><ref name=apjl685>{{citation | display-authors=1 | last1=Iglesias-Groth | first1=S. | last2=Manchado | first2=A. | last3=García-Hernández | first3=D. A. | last4=González Hernández | first4=J. I. | last5=Lambert | first5=D. L. | title=Evidence for the Naphthalene Cation in a Region of the Interstellar Medium with Anomalous Microwave Emission | journal=The Astrophysical Journal Letters | date=2008-09-20 | volume=685 | pages=L55–L58 | doi=10.1086/592349 | bibcode=2008ApJ...685L..55I|arxiv = 0809.0778 }} - This spectral assignment has not been independently confirmed, and is described by the authors as "tentative" (page L58).</ref> More than 20% of the [[carbon]] in the universe may be associated with polyaromatic hydrocarbons, including naphthalene.<ref name="NASA-20140221">{{cite web |last=Hoover |first=Rachel |title=Need to Track Organic Nano-Particles Across the Universe? NASA's Got an App for That |url=http://www.nasa.gov/ames/need-to-track-organic-nano-particles-across-the-universe-nasas-got-an-app-for-that/ |date=February 21, 2014 |work=[[NASA]] |accessdate=February 22, 2014 }}</ref>

[[Protonated]] [[cation]]s of naphthalene ({{chem|C|10|H|9|+}}) are the source of part of the spectrum of the [[Unidentified Infrared Emission]]s (UIRs). Protonated naphthalene differs from neutral naphthalene (e.g. that used in [[mothballs]]) in that it has an additional hydrogen atom. The UIRs from
"[http://www.researchgate.net/publication/231024571_Searching_for_Naphthalene_Cation_Absorption_in_the_Interstellar_Medium naphthalene cation]" ({{chem|C|10|H|8|+}}) have been observed by astronomers. This research has been publicized as "mothballs in space."<ref>{{cite web | url=http://www.astrobio.net/pressrelease/3243/mothballs-in-space | title=Mothballs in Space|work = Astrobiology Magazine | accessdate=December 25, 2008}}</ref>

==Uses==
Naphthalene is used mainly as a precursor to other chemicals. The single largest use of naphthalene is the industrial production of [[phthalic anhydride]], although more phthalic anhydride is made from [[O-Xylene|''o''-xylene]].

The [[insecticide]] [[carbaryl|1-naphthyl-N-methylcarbamate (''carbaryl'')]]. Other useful agrichemicals include naphthoxyacetic acids.
[[File:Nadoxolol.svg|thumb|200px|left|[[Nadoxolol]] is a beta blocker.]].
===Naphthalenesulfonic acids and sulfonates===
Many naphthalenesulfonic acids and sulfonates are useful. Alkyl naphthalene sulfonate are [[surfactant]]s, The [[aminonaphthalenesulfonic acids]], naphthalenes substituted with [[amine]]s and [[sulfonic acid]]s, are intermediates in the preparation of many synthetic [[dye]]s. The hydrogenated naphthalenes tetrahydronaphthalene ([[tetralin]]) and decahydronaphthalene ([[decalin]]) are used as low-volatility [[solvents]]. Naphthalene sulfonic acids ae also used in the synthesis of [[1-naphthol]] and [[2-naphthol]], precursors for various dyestuffs, pigments, rubber processing chemicals and other chemicals and pharmaceuticals.<ref name=Ullmann/>

Naphthalene sulfonic acids are used in the manufacture of naphthalene sulfonate polymer [[plasticizers]] ([[dispersants]]), which are used to produce [[concrete]] and [[plasterboard]] ([[wallboard]] or [[drywall]]). They are also used as dispersants in synthetic and natural rubbers, and as [[tanning]] agents ([[syntan]]s) in leather industries, [[agricultural]] formulations (dispersants for [[pesticides]]), [[dyes]] and as a dispersant in [[lead–acid battery]] plates.

Naphthalene sulfonate polymers are produced by treating naphthalenesulfonic acid with [[formaldehyde]], followed by neutralization with [[sodium hydroxide]] or [[calcium hydroxide]]. These products are commercially sold in solution (water) or dry powder form.

===As a solvent for chemical reactions===
Molten naphthalene provides an excellent solubilizing medium for poorly soluble aromatic compounds. In many cases it is more efficient than other high-boiling solvents, such as [[dichlorobenzene]], [[benzonitrile]], [[nitrobenzene]] and [[durene]]. The reaction of [[Buckminsterfullerene|C60]] with anthracene is conveniently conducted in refluxing naphthalene to give the 1:1 [[Diels–Alder reaction|Diels-Alder]] adduct.<ref>{{ cite journal | author = K. Komatsua, Y. Murataa, N. Sugitaa, K. Takeuchib, T.S.M. Wan | title = Use of naphthalene as a solvent for selective formation of the 1:1 diels-alder adduct of C60 with anthracene | year = 1993 | journal = [[Tetrahedron Letters]] | volume = 34 | issue = 52 | pages = 8473–8476 | doi = 10.1016/S0040-4039(00)61362-X }}</ref> The aromatization of hydroporphyrins has been achieved using a solution of [[2,3-Dichloro-5,6-dicyano-1,4-benzoquinone|DDQ]] in naphthalene.<ref>{{ cite journal | author = M.A. Filatov, A.V. Cheprakov | title = The synthesis of new tetrabenzo- and tetranaphthoporphyrins via the addition reactions of 4,7-dihydroisoindole | year = 2011 |journal = [[Tetrahedron (journal)|Tetrahedron]] | volume = 67 | issue = 19 | pages = 3559–3566 | doi = 10.1016/j.tet.2011.01.052}}</ref>

===Wetting agent and surfactant===
Alkyl naphthalene sulfonates (ANS) are used in many industrial applications as nondetergent [[surfactant|wetting agents]] that effectively disperse colloidal systems in aqueous media. The major commercial applications are in the agricultural chemical industry, which uses ANS for wettable powder and wettable granular (dry-flowable) formulations, and the textile and fabric industry, which utilizes the wetting and defoaming properties of ANS for bleaching and dyeing operations.

===As a fumigant===
Naphthalene has been used as a household [[fumigant]]. It was once the primary ingredient in [[mothball]]s, though its use has largely been replaced in favor of alternatives such as [[1,4-Dichlorobenzene|1,4-dichlorobenzene]]. In a sealed container containing naphthalene pellets, naphthalene vapors build up to levels toxic to both the adult and larval forms of many [[moth]]s that attack textiles. Other fumigant uses of naphthalene include use in soil as a fumigant pesticide, in [[attic]] spaces to repel animals and insects, and in museum storage-drawers and cupboards to protect the contents from attack by insect pests.

Naphthalene is a repellent to [[opossum]]s and could be used to deter them from taking up residency in people's homes.<ref>{{Cite web|url = http://www.dse.vic.gov.au/plants-and-animals/native-plants-and-animals/problem-wildlife/possums/possums-repellent-study|title = Summary of Possum Repellent Study}}</ref><ref>"Removing a possums from your roof", NSW Department of the Environment and Heritage, http://www.environment.nsw.gov.au/animals/RemovingAPossumFromYourRoof.htm</ref>

===Niche applications===
It is used in pyrotechnic special effects such as the generation of black smoke and simulated explosions.  In the past, naphthalene was administered orally to kill parasitic worms in livestock. Naphthalene and its alkyl [[homology (chemistry)|homologs]] are the major constituents of [[creosote]]. Naphthalene is used in engineering to study heat transfer using mass sublimation.

==Health effects==
Exposure to large amounts of naphthalene may damage or destroy [[red blood cell]]s. Humans, in particular children, have developed this condition, known as [[hemolytic anemia]], after ingesting mothballs or deodorant blocks containing naphthalene. Symptoms include [[Fatigue (medical)|fatigue]], lack of appetite, restlessness, and pale skin. Exposure to large amounts of naphthalene may cause [[confusion]], [[nausea]], [[vomiting]], [[diarrhea]], [[blood]] in the [[urine]], and [[jaundice]] (yellow coloration of the skin).<ref>{{MedlinePlusEncyclopedia|002477|Naphthalene poisoning}}</ref> Over 400 million people have an inherited condition called [[glucose-6-phosphate dehydrogenase deficiency]]. Exposure to naphthalene is more harmful for these people and may cause hemolytic anemia at lower doses.<ref>{{cite journal | author = Santucci K, Shah B | date = Jan 2000 | title = Association of naphthalene with acute hemolytic anemia | url = | journal = Acad Emerg Med | volume = 7 | issue = 1| pages = 42–7 }}</ref>

When the US [[National Toxicology Program]] (NTP) exposed male and female rats and mice to naphthalene vapors on weekdays for two years,<ref>{{cite web | title=NTP Technical Reports 410 and 500 | work=NTP Technical Reports 410 and 500, available from NTP: Long-Term Abstracts & Reports| url=http://ntp.niehs.nih.gov/INDEX.CFM?OBJECTID=0847DDA0-F261-59BF-FAA04EB1EC032B61| accessdate=March 6, 2005}}</ref> male and female rats exhibited evidence of [[carcinogenic]] activity based on increased incidences of [[adenoma]] and [[neuroblastoma]] of the nose, female mice exhibited some evidence of carcinogenic activity based on increased incidences of alveolar and bronchiolar adenomas of the lung, and male mice exhibited no evidence of carcinogenic activity.

The [[International Agency for Research on Cancer]] (IARC)<ref>{{cite web | title=IARC Monographs on the Evaluation of Carcinogenic Risks to Humans | work=Monographs on the Evaluation of Carcinogenic Risks to Humans, Some Traditional Herbal Medicines, Some Mycotoxins, Naphthalene and Styrene, Vol. 82 (2002) (p. 367)| url=http://monographs.iarc.fr/ENG/Monographs/vol82/index.php | accessdate=December 25, 2008}}</ref> classifies naphthalene as possibly carcinogenic to humans and animals ([[List of IARC Group 2B carcinogens|Group 2B]]). The IARC also points out that acute exposure causes [[cataract]]s in humans, rats, rabbits, and mice; and that hemolytic anemia, described above, can occur in children and infants after oral or inhalation exposure or after maternal exposure during pregnancy. Under California's [[Proposition 65]], naphthalene is listed as "known to the State to cause cancer".<ref>[http://www.oehha.org/prop65.html Proposition 65], Office of Environmental Health Hazard Assessment</ref> A probable mechanism for the carcinogenic effects of mothballs and some types of air fresheners containing naphthalene has been identified.<ref>[http://www.physorg.com/news70042017.html "Scientists May Have Solved Mystery Of Carcinogenic Mothballs"], ''Physorg.com'', June 20, 2006.</ref><ref name=EHANS>{{cite web|title=Mothballs, air fresheners and cancer|url=http://www.environmentalhealth.ca/mothballsairfresh.htm|work=Environmental Health Association of Nova Scotia|publisher=Environmental Health Association of Nova Scotia|accessdate=24 May 2013}}</ref>

===Regulation===
US government agencies have set occupational exposure limits to naphthalene exposure. The [[Occupational Safety and Health Administration]] has set a [[permissible exposure limit]] at 10 ppm (50 mg/m3) over an eight hour time-weighted average. The [[National Institute for Occupational Safety and Health]] has set a [[recommended exposure limit]] at 10 ppm (50 mg/m3) over an eight hour time-weighted average, as well as a [[short-term exposure limit]] at 15 ppm (75 mg/m3).<ref>[http://www.cdc.gov/niosh/npg/npgd0439.html CDC - NIOSH Pocket Guide to Chemical Hazards]</ref>

Mothballs and other products containing naphthalene have been banned within the EU since 2008.<ref name=Alderson>{{cite news|last=Alderson|first=Andrew|title=Holy straight bananas – now the Eurocrats are banning moth balls|url=http://www.telegraph.co.uk/news/newstopics/howaboutthat/3463893/Holy-straight-bananas-now-the-Eurocrats-are-banning-moth-balls.html|accessdate=2013-11-23|newspaper=The Telegraph|date=15 Nov 2008}}</ref><ref name=Gray>{{cite news|last=Gray|first=Kerrina|title=Council warned against use of poisonous moth balls|url=http://www.yourlocalguardian.co.uk/news/10813745.Council_warns_against_use_of_poisonous_mothballs/|work=Your Local Guardian|publisher=Newsquest (London) Ltd.|accessdate=2012-11-23|date=17 November 2013}}</ref>

In [[China]], the use of naphthalene in mothballs is forbidden.<ref>{{citation | title=国务院经贸办、卫生部关于停止生产和销售萘丸提倡使用樟脑制品的通知（国经贸调（1993）64号）}}</ref> It is due partly to the health effects as well as the wide use of natural [[camphor]] as replacement. However naphthalene is widely produced for moth balls and currently exported from China.<ref>[http://www.alibaba.com/countrysearch/CN/moth-ball.html] Search of Chinese online shop</ref>

==See also==
*[[Camphor]]
*[[Dialin]], [[Tetralin]], [[Octalin]], [[Decalin]]
*[[List of interstellar and circumstellar molecules]]
*[[Mothballs]]
*[[1-Naphthol]], [[2-Naphthol]]
*[[Sodium naphthalenide]]
*[[Wagner-Jauregg reaction]] (classic naphthalene synthesis)

==References==
{{reflist|30em}}

==External links==
{{Commons category|Naphthalene}}
*[http://npic.orst.edu/capro/Mothballs1.pdf Mothballs Case Profile]—National Pesticide Information Center
*[http://www.epa.gov/ttn/atw/hlthef/naphthal.html Naphthalene]—EPA Air Toxics Web Site
*[http://www.inchem.org/documents/pims/chemical/pim363.htm Naphthalene (PIM 363)]—mostly on toxicity of naphthalene
*[http://www.cdc.gov/niosh/npg/npgd0439.html Naphthalene]—CDC – NIOSH Pocket Guide to Chemical Hazards
*{{PPDB|1312}}

{{Hydrocarbons}}
{{PAHs}}
{{Molecules detected in outer space}}

{{Authority control}}
[[Category:Naphthalenes]]
[[Category:Antiseptics]]
[[Category:Hazardous air pollutants]]
[[Category:IARC Group 2B carcinogens]]
[[Category:Insecticides]]
[[Category:Simple aromatic rings]]

Benzoyl peroxide

2016-02-07T08:16:33Z

71.109.148.145: /* Synthesis, structure and physical properties */ direct import from the benzoyl chloride page.

{{chembox
| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 477313648
| ImageFile_Ref = {{chemboximage|correct|??}}
| ImageFile = Benzoyl-peroxide.svg
| ImageName = Skeletal formula
| ImageFile1 = Benzoyl-peroxide-3D-balls.png
| ImageName1 = Ball-and-stick model
| IUPACName = dibenzoyl peroxide
| OtherNames = Benzoyl peroxide (BPO) 
Benzoperoxide 
Dibenzoyl peroxide (DBPO)

|Section1={{Chembox Identifiers
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = W9WZN9A0GM
| ChEMBL_Ref = {{ebicite|changed|EBI}}
| ChEMBL = 1200370
| KEGG_Ref = {{keggcite|correct|kegg}}
| KEGG = D03093
| InChI =1/C14H10O4/c15-13(11-7-3-1-4-8-11)17-18-14(16)12-9-5-2-6-10-12/h1-10H
| InChIKey = OMPJBNCRMGITSC-UHFFFAOYAV
| SMILES = c1ccc(cc1)C(=O)OOC(=O)c2ccccc2
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C14H10O4/c15-13(11-7-3-1-4-8-11)17-18-14(16)12-9-5-2-6-10-12/h1-10H
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = OMPJBNCRMGITSC-UHFFFAOYSA-N
| CASNo = 94-36-0
| CASNo_Ref = {{cascite|correct|CAS}}
| EC_number = 202-327-6
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 6919
| PubChem = 7187
| RTECS = DM8575000
}}
|Section2={{Chembox Properties
| C=14 | H=10 | O=4
| Appearance = colourless solid
| Density = 1.334 g/cm3
| MeltingPtC = 103 to 105
| MeltingPt_notes = decomposes
| Solubility = poor
}}
|Section6={{Chembox Pharmacology
| ATCCode_prefix = D10
| ATCCode_suffix = AE01
| ATC_Supplemental = {{ATCvet|D11|AX90}}
}}
|Section7={{Chembox Hazards
| EUClass = {{Hazchem E}} ('''E''') {{Hazchem Xi}} ('''Xi''')
| RPhrases = {{R3}}, {{R7}}, {{R36}}, {{R43}}
| SPhrases = {{S2}}, {{S3/7}}, {{S14}}, {{S36/37/39}}
| NFPA-H = 3
| NFPA-F = 1
| NFPA-R = 3
| NFPA-S = OX
| AutoignitionPtC = 80
| AutoignitionPt_notes =
| PEL = TWA 5 mg/m3<ref name=PGCH>{{PGCH|0052}}</ref>
| FlashPtF = 176
| FlashPt_ref = <ref name=PGCH/>
| REL = TWA 5 mg/m3<ref name=PGCH/>
| IDLH = 1500 mg/m3<ref name=PGCH/>
| MainHazards = irritant, explosive<ref name=PGCH/>
| LC50 = 7000 mg/m3 (mouse, 4 hr)<ref name=IDLH>{{IDLH|94360|Benzoyl peroxide}}</ref>
| LD50 = 7710 mg/kg (mouse, oral)<ref name=IDLH/>
}}
}}

'''Benzoyl peroxide (BPO)''' is an [[organic compound]] in the [[organic peroxide|peroxide]] family. It consists of two [[benzoyl]] groups bridged by a [[peroxide]] link. Its [[structural formula]] is [C6H5C(O)]2O2. It is one of the most important organic peroxides in terms of applications and the scale of its production. Benzoyl peroxide is used as an [[Acne vulgaris|acne treatment]], for bleaching flour, hair and teeth, for cross-linking polyester resins, and for many other purposes.


It is on the [[World Health Organization's List of Essential Medicines]], the most important medications needed in a basic [[health system]].<ref>{{cite web|title=WHO Model List of EssentialMedicines|url=http://apps.who.int/iris/bitstream/10665/93142/1/EML_18_eng.pdf?ua=1|work=World Health Organization|accessdate=22 April 2014|date=October 2013}}</ref>

== Uses ==
Most benzoyl peroxide is used as a [[radical initiator]] to induce [[Polymerization|polymerizations]].<ref>{{Ullmann | first1 = Herbert | last1 = Klenk | first2 = Peter H. | last2 = Götz | first3 = Rainer | last3 = Siegmeier | first4 = Wilfried | last4 = Mayr | title = Peroxy Compounds, Organic | doi = 10.1002/14356007.a19_199}}</ref> Other major applications include its [[antiseptic]] and bleaching properties.

===Acne treatment===
[[Image:Benzoyl peroxide gel.jpg|thumb|right|Tube of a water-based 5% benzoyl peroxide preparation for the treatment of [[Acne vulgaris|acne]].]]

Benzoyl peroxide (BPO) is effective for reducing the number and severity of [[Acne vulgaris|acne lesions]]. BPO has a [[bactericidal]] effect on ''[[Propionibacterium acnes]]'' bacteria associated with acne and does not induce [[antibiotic resistance]].<ref name="Simonart2012">{{Cite journal|author=Simonart T|title=Newer approaches to the treatment of acne vulgaris|journal=Am J Clin Dermatol|volume=13|issue=6|pages=357–64|date=December 2012|pmid=22920095|doi=10.2165/11632500-000000000-00000}}</ref><ref name="Seidler2010"/> It may be combined with [[salicylic acid]], [[sulfur]], [[erythromycin]] or [[clindamycin]] ([[antibiotics]]), or [[adapalene]] (a synthetic [[retinoid]]). Two common [[combination drug]]s include [[benzoyl peroxide/clindamycin]] and [[adapalene/benzoyl peroxide]], an unusual formulation considering most [[retinoids]] are deactivated by peroxides. Combination products such as benzoyl peroxide/clindamycin and benzoyl peroxide/salicylic acid appear to be slightly more effective than benzoyl peroxide alone for the treatment of acne lesions.<ref name="Seidler2010">{{Cite journal|author=Seidler EM, Kimball AB|title=Meta-analysis comparing efficacy of benzoyl peroxide, clindamycin, benzoyl peroxide with salicylic acid, and combination benzoyl peroxide/clindamycin in acne|journal=J Am Acad Dermatol|volume=63|issue=1|pages=52–62|date=July 2010|pmid=20488582|doi=10.1016/j.jaad.2009.07.052}}</ref>

Benzoyl peroxide for acne treatment is typically applied to the affected areas in gel or cream form, in concentrations of 2.5% increasing through 5.0%, and up to 10%.<ref name="Simonart2012"/> No strong evidence supports the idea that higher concentrations of benzoyl peroxide are more effective than lower concentrations.<ref name="Simonart2012"/>

Benzoyl peroxide commonly causes initial dryness and sometimes irritation, although the [[skin]] develops [[Drug tolerance|tolerance]] after a week or so. A small percentage of people are much more [[Hypersensitivity|sensitive]] to it and liable to suffer burning, [[itching]], peeling, and possibly [[Swelling (medical)|swelling]].{{citation needed|date=December 2012}} It is sensible to apply the lowest concentration and build up as appropriate. Once tolerance is achieved, increasing the quantity or concentration and gaining tolerance at a higher level may give better subsequent acne clearance.<ref name="ReferenceA">{{cite book|last1=al.]|first1=edited by Brian K. Alldredge ... [et|title=Applied therapeutics : the clinical use of drugs.|date=2013|publisher=Wolters Kluwer Health/Lippincott Williams & Wilkins|location=Baltimore|isbn=978-1609137137|page=949|edition=10th}}</ref> Irritation can also be reduced by avoiding harsh facial cleansers and wearing [[sunscreen]] prior to sun exposure.<ref name="ReferenceA"/>

===Other uses===

Other common uses for benzoyl peroxide include
* [[hair bleach|Bleaching hair]]
* [[Tooth whitening]] systems
* The preparation of [[bleached flour]]
* A [[Radical initiator|initiator]] and [[catalyst]] for [[polyester]] [[thermoset]] resins, as an alternative to the much more hazardous [[methyl ethyl ketone peroxide]].{{Citation needed|date=April 2009}}
* A hardener in order to start the polymerization process in resins. For instance, [[Poly(methyl methacrylate)|PMMA]] resins can be polymerized with benzoyl peroxide.<ref>http://www.degaroute.com/sites/dc/Downloadcenter/Evonik/Product/DEGAROUTE/en/Degaroute%20Brosch%C3%BCre.pdf</ref>
* Removing ink and dye stains on [[polyvinyl chloride|vinyl]] [[doll]]s and other playscale figures.<ref name="Stevens">{{cite web|url=http://www.prillycharmin.com/restore/1oxy10.htm|title=Oxy10 for vinyl stains. Benzoyl Peroxide removes stain from Vinyl. Restore Dolls|last=Stevens|first=Cynthia|work=Prilly Charmin Dolls|accessdate=9 February 2015}}</ref>

In the U.S., the typical concentration for benzoyl peroxide is 2.5% to 10% for both [[Prescription drug|prescription]] and [[over-the-counter drug]] preparations that are used in treatment for acne. Higher concentrations are used for hair bleach and teeth whitening. Benzoyl peroxide, like most [[peroxide]]s, is a powerful [[bleach|bleaching agent]]. Contact with [[fabric]]s or [[hair]] can cause permanent color dampening almost immediately. Even secondary contact can cause bleaching; for example, contact with a towel that has been used to wash off benzoyl peroxide-containing hygiene products.<ref>{{citation | first1 = RA | last1 = Bojar | first2 = William | last2 = Cunliffe | first3 = KT | last3 = Holland | year = 1995 | title = The short-term treatment of acne vulgaris with benzoyl peroxide: effects on the surface and follicular cutaneous microflora. | volume = 132 | pages = 204–8 | doi = 10.1111/j.1365-2133.1995.tb05014.x| pmid=7888356 | journal = Br J Dermatol}}</ref>

==Side effects ==
Concentrated benzoyl peroxide is potentially explosive,<ref>{{cite web|last=Cartwright|first=Hugh|title=Chemical Safety Data: Benzoyl peroxide|url=http://cartwright.chem.ox.ac.uk/hsci/chemicals/benzoyl_peroxide.html|publisher=Oxford University|accessdate=13 August 2011|date=17 March 2005}}</ref> and can cause fires without external ignition. The hazard is acute for the pure material, so the compound is generally used as a solution or a paste. For example, cosmetics contain only a small percent of benzoyl peroxide and pose no explosion risk.

Studies have highlighted the [[carcinogenic]] potential of benzoyl peroxide. A 1981 study from the journal ''Science'' concluded, "caution should be recommended in the use of this and other free radical-generating compounds".<ref>{{cite web|url=http://www.ncbi.nlm.nih.gov/pubmed/6791284 |title=Skin tumor-promoting activity of benzoyl peroxide, a... [Science. 1981] - PubMed - NCBI |publisher=Ncbi.nlm.nih.gov |date=2012-05-24 |accessdate=2012-09-08}}</ref>

In a 1977 study using a human maximization test, 76% of subjects acquired a contact sensitization to benzoyl peroxide. Formulations of 5% and 10% were used.<ref>{{citation | first1 = James J. | last1 = Leyden | first2 = Albert M. | last2 = Kligman | year = 1977 | title = Contact sensitization to benzoyl peroxide | volume = 3 | issue = 5 | pages = 273–75 | doi = 10.1111/j.1600-0536.1977.tb03674.x | journal = Contact Dermatitis}}</ref>

<gallery>
Image:BenzoperoxideRx.JPG|Skin irritation due to benzoyl peroxide
Image:Benzoyl peroxide stain.jpg|A bleached fabric stain caused by contact with benzoyl peroxide.
</gallery>

== Synthesis, structure and physical properties ==
Benzoyl peroxide was the first organic peroxide prepared by intentional synthesis. It was prepared by treating [[benzoyl chloride]] with [[barium peroxide]],<ref>{{citation | first = B. C. | last = Brodie | title = Ueber die Bildung der Hyperoxyde organischer Säureradicale | journal = Justus Liebigs Ann. Chem. | year = 1858 | volume = 108 | pages = 79–83 | doi = 10.1002/jlac.18581080117}}</ref> a reaction that probably follows this equation:
:2 C6H5C(O)Cl + BaO2 → [C6H5C(O)]2O2 + BaCl2
Benzoyl peroxide is usually prepared by [[chemical reaction|treating]] [[hydrogen peroxide]] with [[benzoyl chloride]].
:2 C6H5COCl + H2O2 + 2 NaOH → (C6H5CO)2O2 + 2 NaCl + 2 H2O
The oxygen-oxygen bond in peroxides is weak. Thus benzoyl peroxide readily undergoes [[homolysis (chemistry)|homolysis]] (symmetrical fission), forming [[radical (chemistry)|free radicals]]:
:[C6H5C(O)]2O2 → 2 C6H5CO2•
The symbol • indicates that the products are radicals; i.e., they contain at least one unpaired electron. Such species are highly reactive. The homolysis is usually induced by heating. The [[half-life]] of benzoyl peroxide is one hour at 92 °C. At 131 °C, the half-life is one minute.<ref>{{citation | first = Hui, III | last = Li | title = Synthesis, Characterization and Properties of Vinyl Ester Matrix Resins | url = http://scholar.lib.vt.edu/theses/available/etd-42198-113329/unrestricted/ch2.pdf | series = Ph.D. Dissertation, University of Vermont | volume = Chapter 2 | year = 1998}}</ref>

Benzoyl peroxide breaks down in contact with skin, producing [[benzoic acid]] and oxygen, neither of which is significantly toxic.<ref>{{SIDS-ref | title = Benzoyl peroxide | id = BENZOYLPER | date = April 2004}}</ref>

== References ==
{{reflist|2}}

== External links ==
*{{ICSC|0225|02}}
*{{PGCH|0052}}
*{{SIDS | title = Benzoyl peroxide | id = BENZOYLPER}}
*{{citation | contribution = Benzoyl peroxide | url = http://monographs.iarc.fr/ENG/Monographs/vol71/mono71-13.pdf | pages = 345–58 | title = Re-evaluation of Some Organic Chemicals, Hydrazine and Hydrogen Peroxide | series = IARC Monographs on the Evaluation of Carcinogenic Risks to Humans 71 | publisher = International Agency for Research on Cancer | location = Lyon, France | year = 1999 | isbn = 92-832-1271-1}}.

{{E number infobox 920-929}}
{{Acne Agents}}

{{DEFAULTSORT:Benzoyl Peroxide}}
[[Category:Anti-acne preparations]]
[[Category:IARC Group 3 carcinogens]]
[[Category:Organic peroxides]]
[[Category:Radical initiators]]
[[Category:World Health Organization essential medicines]]

Talk:Standard enthalpy of formation

2016-02-07T07:04:37Z

71.109.148.145: /* Sign wrong? */

{{physics|class=start|importance=low}}
{{chemistry|class=Start|importance=High}}

== equation incorrect ==

equation for standard enthalpy change of reaction should be changed to reflect that fact that the stoichiometric numbers of reactants are already negative, thus there is no need for to have separate reactant and product terms in the equation. It also needs general cleanup; words like "products" do not belong in equations, and "reaction" should be simply "r" according to convention. Use the equation on the standard enthalpy change of reaction as a model.
[[Special:Contributions/71.121.232.215|71.121.232.215]] ([[User talk:71.121.232.215|talk]]) 05:13, 7 April 2009 (UTC)

Also, aren't the stoichiometric values wrong?

CH4 + 3 O2 → CO2 + 2 H2O

On left: 1C, 4H, 6O
On Right 1C, 4H, 4O

I'm assuming the eqn should be: CH4 + 2 O2 → CO2 + 2 H2O but I'm still a little new to enthalpy so will leave it to somebody else! :-) (Chris Fletcher) —Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[User:Chris Fletcher|Chris Fletcher]] ([[User talk:Chris Fletcher|talk]] • [[Special:Contributions/Chris Fletcher|contribs]]) 13:14, 2 June 2010 (UTC) 

This article states what it is and how to use it. But fails to define the origin of the tables or how the individual molecules enthalpy change of formation are derived. Does there exist a known mathematical way in which to come up with these numbers? [[Special:Contributions/96.2.120.230|96.2.120.230]] ([[User talk:96.2.120.230|talk]]) 18:32, 6 August 2010 (UTC)

== NaOH data wrong ==

Standard heat of formation is listed in table here as 426 kJ/mol while wikipedia article on Sodium Hydroxide claims it is 735 kJ/mol. Both can not be right.[[Special:Contributions/71.31.146.16|71.31.146.16]] ([[User talk:71.31.146.16|talk]]) 07:00, 20 June 2012 (UTC)
:Atkins and de Paula list -425.61 for NaOH(s) and the NIST webbook gives -425.93, so I have corrected the NaOH article. The value in this article is close. However the table does need reformatting - the minus sign for this value (and a few others) is hidden on the preceding line because the columns are too narrow. [[User:Dirac66|Dirac66]] ([[User talk:Dirac66|talk]]) 14:37, 20 June 2012 (UTC)
::OK, formatting fixed. [[User:Dirac66|Dirac66]] ([[User talk:Dirac66|talk]]) 19:21, 20 June 2012 (UTC)

== Isotopic differences in elements ==

Are there some differences in the values of this enthalpy for elements in various isotopic mixtures similar to those that exist in different allotropic states of various elements (for example the diamond and graphite for carbon, where the diamond has a non-zero enthalpy of formation)? What isotopic mixture should have the zero value? I think this is a useful content addition to article--[[Special:Contributions/5.15.53.219|5.15.53.219]] ([[User talk:5.15.53.219|talk]]) 12:26, 16 June 2015 (UTC)

:I see that editor 5.2.200.163 added two sentences yesterday on isotopic differences, which imply that the standard state corresponds to a definite isotopic composition for each element. Although this does seem plausible in principle, it would be better to have a source which confirms the statement and which specifies how the standard-state isotopic composition is determined for each element.
:Also, the second sentence refers to the enthalpy of atomization of hetero-isotopic diatomic ''molecules''. I would question whether individual molecules actually have enthalpies, since enthalpy is a thermodynamic property of macroscopic amounts of matter. Again a source would help. [[User:Dirac66|Dirac66]] ([[User talk:Dirac66|talk]]) 02:06, 9 October 2015 (UTC)
::The second aspect could be easily fixed by a different wording, instead of ''molecules'' we can say ''coumpounds'' or ''hetero-isotopic diatomic molecules compounds'' which underlines the macroscopic view.--[[Special:Contributions/5.2.200.163|5.2.200.163]] ([[User talk:5.2.200.163|talk]]) 12:00, 9 October 2015 (UTC)
::Surely source(s) for these assertions would help. I wonder though what is the probability that the ''standard-state isotopic composition for each element enthalpy of formation'' issue could have gone unnoticed in sources until now, could it be higher than the default 50%-50% assigning?--[[Special:Contributions/5.2.200.163|5.2.200.163]] ([[User talk:5.2.200.163|talk]]) 12:08, 9 October 2015 (UTC)
:::Compounds is a better word provided the example is actually a compound. The present example 35Cl-36Cl is actually an element and not a compound, so the enthalpy of formation is zero, at least without worrying about isotopes. A better example would be HDO or perhaps CH3D. [[User:Dirac66|Dirac66]] ([[User talk:Dirac66|talk]]) 00:18, 10 October 2015 (UTC)
::::Perhaps ''element'' would be a better choice. But isn't this diatomic molecule from two different isotopes (of chlorine, oxigen, nitrogen, etc) like [[hydrogen deuteride]] technically a compound molecule/substance ([[isotopologue]])?--[[Special:Contributions/5.2.200.163|5.2.200.163]] ([[User talk:5.2.200.163|talk]]) 13:40, 13 October 2015 (UTC)
:I have now found a source which contradicts the claim that ''Also isotopes of an element other than the standard state have non-zero standard enthalpies of formation, differing from the stardard state isotope or isotopic mixture by the energy of neutron capture for one or more neutrons.'' The NIST thermochemical table [http://webbook.nist.gov/cgi/cbook.cgi?ID=C14940637&Units=SI&Mask=1#Thermo-Gas here] gives the value of ΔHf°(HDO, g) = -245.37 kJ/mol, compared to -241.83 kJ/mol for ΔHf°(H2O, g). The difference of 3.54 kJ/mol is many orders of magnitude too small to be an ''energy of neutron capture'' which is a nuclear reaction. In fact the energy of neutron capture is not included because ΔHf°(HDO, g) is the enthalpy of the reaction 1/2 H2 + 1/2 D2 + 1/2 O2 → HDO, with D in both reactants and products so that no nuclear reaction is involved. Instead the 3.54 kJ/mol corresponds to a difference in zero-point vibrational energy between reactants and products, which is very much smaller.
:This illustrates the dangers of adding unsourced material. I will remove the reference to isotopic differences in the Key Concepts section. It is true that many other statements in the article are also unsourced and should eventually be sourced, but I will leave them alone since they appear to be generally correct.[[User:Dirac66|Dirac66]] ([[User talk:Dirac66|talk]]) 18:32, 14 October 2015 (UTC)
::I don't see exactly what is the exact contradiction you claim, the issue is still needing further details to be solved. The difference in the heat of formation of water and semi-deuterated water is inconclusive about the differences heat of atomization and of formation of different isotopes as it is clear that transition from one isotope to another requires a nuclear reaction of at least one neutron capture or beta decay such as in the tritiation of heavy water moderator due to neutron flux or similarly to the deuteration of light water. It is clear that some paradoxical/anomalous situation is involved requiring further investigation. Of course statements should be backed by sources in order to be a verified information in wikiarticles.
::Does the source you mention contain the heat of atomization of deuterium, tritium and hydrogen deuteride to be compared with that of hydrogen to see where the anomaly comes from? It is clear that there must be a difference of some sort between isotopes, the exact nature and numerical value has to be determined. So about the wording I'd leave out the statement about neutron capture difference but clearly the difference between isotopes should be mentioned with the specification that is of an unspecified nature.--[[Special:Contributions/5.2.200.163|5.2.200.163]] ([[User talk:5.2.200.163|talk]]) 12:55, 15 October 2015 (UTC)
::An important aspect of this discussion involves the measured energy of a neutron capture reaction. Are there some tables with such measurements to be checked? Surely the neutron capture is or must be included in some [[thermochemical cycle]]. Is then the heat of formation of molecular deuterium D2 considered zero like that of molecular protium H2? This seems to be a suggested answer, but if so something does not add up here. Where dissapears the heat of neutron capture involved in transforming H2 into D2?--[[Special:Contributions/5.2.200.163|5.2.200.163]] ([[User talk:5.2.200.163|talk]]) 09:45, 19 October 2015 (UTC)
::How about the heat of atomization of D2 (aka deuterium bond energy)? What is the difference from the case of H2?--[[Special:Contributions/5.2.200.163|5.2.200.163]] ([[User talk:5.2.200.163|talk]]) 09:48, 19 October 2015 (UTC)
::The NIST tables display a difference of 3.72 kj/mol between heat of atomizations.--[[Special:Contributions/5.2.200.163|5.2.200.163]] ([[User talk:5.2.200.163|talk]]) 09:56, 19 October 2015 (UTC)

:Perhaps the following thoughts may be useful. They concern the "minus-oneth" law of thermodynamics, a presupposition of the subject, that for a system, there exist states of internal thermodynamic equilibrium.
:According to Münster:
::::::... We shall now give this concept a precise form by means of the ''definition'':
::::::      An isolated system is in thermodynamic equilibrium when, in the system, no changes of state are occurring at a measurable rate.
::::::...
::::::      The proviso 'at a measurable rate' implies that we can consider an equilibrium only with respect to specified processes and defined experimental conditions.
::::::...
::::::... This can, however, be completely ignored since thermonuclear processes do not occur at a measurable rate under conditions usually considered in thermodynamics.
::::::      The concept 'absolute equilibrium' or 'equilibrium with respect to all imaginable processes', has, therefore, no physical significance.<ref>Münster, A. (1970). ''Classical Thermodynamics'', translated by E.S. Halberstadt, Wiley–Interscience, London, ISBN 0-471-62430-6, pp. 52–53.</ref>

:According to Callen:
::::::      In actuality, few systems are in absolute and true equilibrium. In absolute equilibrium, all radioactive materials would have decayed completely and nuclear reactions would have transmuted all nuclei to the most stable of isotopes. Such processes, which would take cosmic times to complete, generally can be ignored.<ref>[[Herbert Callen|Callen, H.B.]] (1960/1985). ''Thermodynamics and an Introduction to Thermostatistics'', (1st edition 1960) 2nd edition 1985, Wiley, New York, ISBN 0-471-86256-8, p. 15.</ref>
{{Reflist}}
:I think it important that Münster implies that one must presuppose and explicitly prescribe the range of processes that one will admit as relevant.[[User:Chjoaygame|Chjoaygame]] ([[User talk:Chjoaygame|talk]]) 13:14, 19 October 2015 (UTC)
::I agree with Chjoaygame's explanation of the reason for ignoring nuclear reactions, but I will add a note about the meaning of the NIST value. For HD, the value given for ΔHf is ΔH of the reaction 1/2 H2 + 1/2 D2 → HD, so that neutron capture is not included. (As for HDO explained above, but without the oxygen.) The neutron capture would be included if one considered the reaction H2 + n → HD, but as Chjoaygame has explained this is of no practical interest on any useful timescale so it is ignored. [[User:Dirac66|Dirac66]] ([[User talk:Dirac66|talk]]) 14:39, 19 October 2015 (UTC)
:::I think the most important aspect when discussing about the synthesis of HD from H2 and D2 to mention explicitly what is the heat of formation of D2. Is it considered zero by default like in the case of H2? This assumption seems problematic. Another approach should be considered by applying [[Hess's law]], similarly to the case of NaCl which is mentioned in the article and involves heats of atomization, sublimation, ionization, etc. The synthesis of HD from H2 and D2 involves only heats of atomization (and eventually neutron capture, depending on the absence or presence of initial deuterium). But the neutron capture ''cannot be omitted'' when considering the initial reactant only hydrogen and neutron and not deuterium which is not present.
:::Timescales are not to be taken into consideration when applying Hess law. The heat of a reaction does not depend on its reaction rate, so timescales, a kinetic factor, is relevant only in thermokinetic reasonings which are not the object of this discussion. The formation of deuterium from hydrogen could not ignor neutron capture which is esential for formation of an isotope from the lightest isotope of an element. The heat of formation of isotopes reference is the subject of this discussion, no reason to ignor neutron capture and to assume that the heat of formation of D2 is zero.--[[Special:Contributions/5.2.200.163|5.2.200.163]] ([[User talk:5.2.200.163|talk]]) 13:17, 20 October 2015 (UTC)

::::In my limited reading of this section of the talk page, I see it as discussing a proposal to add information about isotopic mixtures. The question is asked "What isotopic mixture should have the zero value?" and the comment added "I think this is a useful content addition to article". Perhaps this topic should be added to the article, depending on factors that I do not pretend to comprehend. But if it is to be added, it needs far more than editorial chatter; it needs a fair survey of reliable sources. I suppose that in some quarters, such as perhaps nuclear physics, neutron capture will be part of the array of presupposed reactions, while in other quarters, such as perhaps ordinary chemistry, it will not? To bring it into the article, I suppose a fair survey of reliable sources would extend to perhaps five standard textbooks on nuclear physics with specific interest in such reactions; and a check on standard ordinary chemistry texts to see what they have to say on the subject. If those sources are in fair agreement, they should be cited for that in the relevant section of the article. The section should make it clear that its topic assumes interest in those reactions. This talk page is not a general discussion page. It is about editing the article.[[User:Chjoaygame|Chjoaygame]] ([[User talk:Chjoaygame|talk]]) 14:45, 20 October 2015 (UTC)
:::::I agree about the survey of sources needed both in nuclear physical chemistry and engineering and ordinary physical chemistry focused on chemical thermodynamics. The problem is where should the search for sources be started? There is a possibility that some sources not contain the topic mentioned. In this case, when to end the search? This seemed at first a rather trivial chemical thermodynamics textbook/seminary problem which has turned out not so trivial as expected initially. Also some extra-wiki discussions with knowledgeable people in both domains could point to some sources to be checked.--[[Special:Contributions/5.2.200.163|5.2.200.163]] ([[User talk:5.2.200.163|talk]]) 15:34, 20 October 2015 (UTC)
::::::Yes.[[User:Chjoaygame|Chjoaygame]] ([[User talk:Chjoaygame|talk]]) 15:47, 20 October 2015 (UTC)
::::::The NIST page for deuterium is [http://webbook.nist.gov/cgi/cbook.cgi?Name=d2&Units=SI&cTG=on#Thermo-Gas here] and shows a value for entropy but ''not'' enthalpy. I believe this is because, yes, it is considered zero by default. The NIST values only make sense if it is assumed that the standard state for each isotopic species is the elemental state for that isotopic species, so that H2 and D2 are both considered zero. Yes, this point could be mentioned in the article if someone can find an explicit source for it. [[User:Dirac66|Dirac66]] ([[User talk:Dirac66|talk]]) 16:01, 20 October 2015 (UTC)
:::::::Can NIST data assumption be mentioned without a source to explicitly state the assumption on D2?--[[Special:Contributions/5.2.200.163|5.2.200.163]] ([[User talk:5.2.200.163|talk]]) 15:44, 23 October 2015 (UTC)
===Bond energy calculation===
An equivalent method to calculate/check the heat effect of a reaction is that based on bond energy of products minus the bond energy of reactants. Applied to the reaction of interest in this case the formation of HD from H2 and D2 (whose heat is considered to be the heat of formation of HD considering D2 heat zero) involves the bond energy of HD. A key question is: Does the value of this bond energy appear in NIST tables?--[[Special:Contributions/5.2.200.163|5.2.200.163]] ([[User talk:5.2.200.163|talk]]) 10:36, 22 October 2015 (UTC)
:No, the NIST tables do not include bond energies. One can calculate them from the ΔHf values: E(H-D) = ΔHf(H) + ΔHf(D) - ΔHf(HD), although of course this will not serve as a check.
:I think the three of us have taken this discussion as far as is useful without additional sources. The situation is that the NIST values we have found only make sense if it is assumed that NIST excludes nuclear reactions from the ΔHf values, either for the reason given by Chjoaygame above or for some other reason. So in this article we can either say that nuclear reactions are excluded or we can just omit the point (which I favor), but we cannot say that they are included. [[User:Dirac66|Dirac66]] ([[User talk:Dirac66|talk]]) 01:12, 23 October 2015 (UTC)
::I agree that this talk section has gone far enough. I am favour of omitting mention because so far no suitable survey of reliable sources has emerged.[[User:Chjoaygame|Chjoaygame]] ([[User talk:Chjoaygame|talk]]) 01:58, 23 October 2015 (UTC)
:::I also agree about the length of this discussion. For the moment, lacking sources, we can omit the aspects discussed here. Perhaps we could bring other editors knowledgeable in nuclear engineering or/and chemical engineering thermodynamics to help searching for relevant sources.--[[Special:Contributions/5.2.200.163|5.2.200.163]] ([[User talk:5.2.200.163|talk]]) 15:33, 23 October 2015 (UTC)
:::There is one more aspect to be clarified at the present stage of the discussion: the one re NIST (default) assumption about D2 heat of formation. Could it or not be mentioned in article just by acces to NIST tables without other source to explicitly notice what NIST tables contain?--[[Special:Contributions/5.2.200.163|5.2.200.163]] ([[User talk:5.2.200.163|talk]]) 15:37, 23 October 2015 (UTC)

::::Above are two sources saying it is not considered in ordinary thermodynamics. I think that since you think it important enough to justify mention of the less ordinary case, you should think it important enough to find sources for that.[[User:Chjoaygame|Chjoaygame]] ([[User talk:Chjoaygame|talk]]) 18:24, 23 October 2015 (UTC)

== Sign wrong? ==

IANA physicist or chemist, but I believe that the values for acetylene(g) and benzene(l) should be negative, not positive, since that's their base phase at 25°C. I see that a lot of compound pages have had their numeric data swept off into a "data" page, presumably so it's easier for the cognoscenti to watch for malicious graffiti on the key data. Perhaps this page needs something/someone similar? Even (or maybe especially) if I'm wrong! :)

Oh, yeah... if the page is going to differentiate between subphases (C-graphite vs C-diamond and S vs S-monoclinic) perhaps the "phase" column could be renamed "allotrope".

--Chem Doormouse
— Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[Special:Contributions/71.109.148.145|71.109.148.145]] ([[User talk:71.109.148.145|talk]]) 06:59, 7 February 2016 (UTC)

Talk:Standard enthalpy of formation

2016-02-07T06:59:43Z

71.109.148.145: /* Sign wrong? */ new section

Clostridium acetobutylicum

2016-02-07T03:25:01Z

71.109.148.145: Cleanup

{{italic title}}
{{Taxobox
| color = lightgrey
| name = ''Clostridium acetobutylicum''
| regnum = [[Bacterium|Bacteria]]
| divisio = [[Firmicutes]]
| classis = [[Clostridia]]
| ordo = [[Clostridia]]le
| familia = [[Clostridiaceae]]
| genus = ''[[Clostridium]]''
| species = '''''C. acetobutylicum'''''
}}
[[File:Weizmann's passport photo.jpg|thumb|170px|[[Chaim Weizmann]]]]
'''''Clostridium acetobutylicum''''', [[American Type Culture Collection|ATCC]] 824, is a commercially valuable [[bacterium]] sometimes called the "'''Weizmann Organism'''", after Jewish-Russian-born [[Chaim Weizmann]]. A senior lecturer at the [[University of Manchester]], [[England]], he used them in 1916 as a bio-chemical tool to produce at the same time, jointly, [[acetone]], [[ethanol]], and [[butanol]] from [[starch]]. The method has been described since as the [[ABE process]], (Acetone Butanol Ethanol fermentation process), yielding 3 parts of [[acetone]], 6 of [[butanol]], and 1 of [[ethanol]]. Acetone was used in the important wartime task of casting [[cordite]]. The alcohols were used to produce vehicle fuels and [[synthetic rubber]].

Unlike [[yeast]], which can digest [[sugar]] only into [[alcohol]] and [[carbon dioxide]], ''C. acetobutylicum'' and other Clostridia can digest [[whey]], [[sugar]], [[starch]], [[cellulose]] and perhaps certain types of [[lignin]], yielding [[butanol]], [[propionic acid]], [[diethyl ether|ether]], and [[glycerin]].

==In genetic engineering==

In 2008, a strain of ''[[Escherichia coli]]'' was genetically engineered to synthesize butanol; the genes were derived from ''Clostridium acetobutylicum''.<ref>{{cite web | last1 = M. Goho | first1 = Alexandra | title = Better Bugs for Making Butanol | url = http://www.technologyreview.com/news/409400/better-bugs-for-making-butanol/ | website = MIT Technology Review | date = 2008-01-16}}</ref><ref>{{Cite journal | last1 = Atsumi | first1 = S. | last2 = Hanai | first2 = T. | last3 = Liao | first3 = JC. | title = Non-fermentative pathways for synthesis of branched-chain higher alcohols as biofuels. | journal = Nature | volume = 451 | issue = 7174 | pages = 86–9 |date = Jan 2008 | doi = 10.1038/nature06450 | PMID = 18172501 }}</ref> In 2013, the first microbial production of short-chain [[alkane]]s was reported<ref>{{Cite journal | last1 = Choi | first1 = YJ. | last2 = Lee | first2 = SY. | title = Microbial production of short-chain alkanes. | journal = Nature | volume = 502 | issue = 7472 | pages = 571–4 |date = Oct 2013 | doi = 10.1038/nature12536 | PMID = 24077097 }}</ref> - which is a considerable step toward the production of gasoline. One of the crucial [[enzyme]]s - a [[fatty acid|fatty]] [[acyl-CoA]] [[reductase]] - came from ''Clostridium acetobutylicum''.

== See also ==
* [[Acetone-butanol-ethanol fermentation|ABE]]
* [[Acetone]]
* [[Butanol]]
* [[Ethanol]]

==Further reading==
* {{cite journal |author=Nölling J |title=Genome sequence and comparative analysis of the solvent-producing bacterium Clostridium acetobutylicum |journal=J. Bacteriol. |volume=183 |issue=16 |pages=4823–38 |date=August 2001 |pmid=11466286 |pmc=99537 |doi=10.1128/JB.183.16.4823-4838.2001 |url= |name-list-format=vanc|author2=Breton G |author3=Omelchenko MV |display-authors=3 |last4=Makarova |first4=K. S. |last5=Zeng |first5=Q. |last6=Gibson |first6=R. |last7=Lee |first7=H. M. |last8=Dubois |first8=J. |last9=Qiu |first9=D.}}
* {{cite journal |author=Driessen AJ, Ubbink-Kok T, Konings WN |title=Amino acid transport by membrane vesicles of an obligate anaerobic bacterium, Clostridium acetobutylicum |journal=J. Bacteriol. |volume=170 |issue=2 |pages=817–20 |date=February 1988 |pmid=2828326 |pmc=210727 |doi= |url=http://jb.asm.org/cgi/pmidlookup?view=long&pmid=2828326}}
* {{cite journal |author=Zappe H, Jones WA, Jones DT, Woods DR |title=Structure of an endo-beta-1,4-glucanase gene from Clostridium acetobutylicum P262 showing homology with endoglucanase genes from Bacillus spp |journal=Appl. Environ. Microbiol. |volume=54 |issue=5 |pages=1289–92 |date=May 1988 |pmid=3389820 |pmc=202643 |doi= |url=http://aem.asm.org/cgi/pmidlookup?view=long&pmid=3389820}}
* {{cite journal |author=Bowles LK, Ellefson WL |title=Effects of butanol on Clostridium acetobutylicum |journal=Appl. Environ. Microbiol. |volume=50 |issue=5 |pages=1165–70 |date=November 1985 |pmid=2868690 |pmc=238718 |doi= |url=http://aem.asm.org/cgi/pmidlookup?view=long&pmid=2868690}}
* {{patent|US|1875536}}
* {{patent|US|1315585}}
* {{cite journal | last1 = Weber | first1 = Christian | last2 = Farwick | first2 = Alexander | last3 = Benisch | first3 = Feline | last4 = Brat | first4 = Dawid | last5 = Dietz | first5 = Heiko | last6 = Subtil | first6 = Thorsten | last7 = Boles | first7 = Eckhard | title = Trends and challenges in the microbial production of lignocellulosic bioalcohol fuels | journal = Applied Microbiology and Biotechnology | date = 10 June 2010 | volume = 87 | issue = 4 | pages = 1303–1315 | doi = 10.1007/s00253-010-2707-z | pmid = 20535464 | issn = 01757598}}
* {{cite journal | pmc = 373084 | pmid = 3540574 | year = 1986 | last1 = Jones | first1 = DT | last2 = Woods | first2 = DR | title = Acetone-butanol fermentation revisited | volume = 50 | issue = 4 | pages = 484–524 | journal = Microbiological reviews}}
* {{cite book | last1 = Bartha | first1 = Ronald M. Atlas & Richard | title = Microbial ecology : fundamentals and applications | date = 1993 | publisher = Benjamin/Cummings Pub. Co. | location = Redwood City, Calif. | isbn = 0-8053-0653-6 | page = 563 | edition = 3rd}}
* {{cite book | title = Microbial Processes: Promising Technologies for Developing Countries | year = 1979 | publisher = National Academy of Sciences | location = Washington | url = http://www.nap.edu/openbook.php?record_id=9544&page=R1 | accessdate = May 2011}}
* {{cite web | last1 = Wong Kromhout | first1 = Wileen | title = UCLA researchers engineer E. coli to produce record-setting amounts of alternative fuel | url = http://newsroom.ucla.edu/releases/ucla-engineers-drive-e-coli-to-197675 | website = UCLA Newsroom | date = 2011-03-16}}

== External links ==
* [http://www.atcc.org/ATCCAdvancedCatalogSearch/ProductDetails/tabid/452/Default.aspx?ATCCNum=824&Template=bacteria ATCC reference organism 824 C.Acetobutylicum.]
* [http://www.findarticles.com/p/articles/mi_m1272/is_n2593_v123/ai_15826295 findarticles.com: Bacteria speeds drug to tumors - use of Clostridium acetobutylicum enzyme to activate cancer drug CB 1954].
* [http://www.epa.gov/biotech_rule/pubs/fra/fra003.htm EPA Clostridium acetobutylicum Final Risk Assessment]
* [https://www2.carolina.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=10101&storeId=10151&productId=39315 Carolina Bio Supply Living Culture Order Page]
* [http://www.engr.psu.edu/h2e/Pub/Regan/Regan_etal_1.htm Genetic Engineering of Clostridium acetobutylicum for Enhanced Production of Hydrogen Gas]: [[Penn State University]].
* [http://pathema.tigr.org/tigr-scripts/Clostridium/PathemaHomePage.cgi Pathema-''Clostridium'' Resource]
* [http://www.encyclopedia.com/topic/Chaim_Weizmann.aspx Chaim Weizmann]

==References==
{{Reflist}}

[[Category:Clostridiaceae]]
[[Category:Biofuels]]
[[Category:Gram-positive bacteria]]

Clostridium acetobutylicum

2016-02-07T03:24:12Z

71.109.148.145: Move to correct section

{{italic title}}
{{Taxobox
| color = lightgrey
| name = ''Clostridium acetobutylicum''
| regnum = [[Bacterium|Bacteria]]
| divisio = [[Firmicutes]]
| classis = [[Clostridia]]
| ordo = [[Clostridia]]le
| familia = [[Clostridiaceae]]
| genus = ''[[Clostridium]]''
| species = '''''C. acetobutylicum'''''
}}
[[File:Weizmann's passport photo.jpg|thumb|170px|[[Chaim Weizmann]]]]
'''''Clostridium acetobutylicum''''', [[American Type Culture Collection|ATCC]] 824, is a commercially valuable [[bacterium]] sometimes called the "'''Weizmann Organism'''", after Jewish-Russian-born [[Chaim Weizmann]]. A senior lecturer at the [[University of Manchester]], [[England]], he used them in 1916 as a bio-chemical tool to produce at the same time, jointly, [[acetone]], [[ethanol]], and [[butanol]] from [[starch]]. The method has been described since as the [[ABE process]], (Acetone Butanol Ethanol fermentation process), yielding 3 parts of [[acetone]], 6 of [[butanol]], and 1 of [[ethanol]]. Acetone was used in the important wartime task of casting [[cordite]]. The alcohols were used to produce vehicle fuels and [[synthetic rubber]].

Unlike [[yeast]], which can digest [[sugar]] only into [[alcohol]] and [[carbon dioxide]], ''C. acetobutylicum'' and other Clostridia can digest [[whey]], [[sugar]], [[starch]], [[cellulose]] and perhaps certain types of [[lignin]], yielding [[butanol]], [[propionic acid]], [[diethyl ether|ether]], and [[glycerin]].

==In genetic engineering==

In 2008, a strain of ''[[Escherichia coli]]'' was genetically engineered to synthesize butanol; the genes were derived from ''Clostridium acetobutylicum''.<ref>{{cite web | last1 = M. Goho | first1 = Alexandra | title = Better Bugs for Making Butanol | url = http://www.technologyreview.com/news/409400/better-bugs-for-making-butanol/ | website = MIT Technology Review | date = 2008-01-16}}</ref><ref>{{Cite journal | last1 = Atsumi | first1 = S. | last2 = Hanai | first2 = T. | last3 = Liao | first3 = JC. | title = Non-fermentative pathways for synthesis of branched-chain higher alcohols as biofuels. | journal = Nature | volume = 451 | issue = 7174 | pages = 86–9 |date = Jan 2008 | doi = 10.1038/nature06450 | PMID = 18172501 }}</ref> In 2013, the first microbial production of short-chain [[alkane]]s was reported<ref>{{Cite journal | last1 = Choi | first1 = YJ. | last2 = Lee | first2 = SY. | title = Microbial production of short-chain alkanes. | journal = Nature | volume = 502 | issue = 7472 | pages = 571–4 |date = Oct 2013 | doi = 10.1038/nature12536 | PMID = 24077097 }}</ref> - which is a considerable step toward the production of gasoline. One of the crucial [[enzyme]]s - a [[fatty acid|fatty]] [[acyl-CoA]] [[reductase]] - came from ''Clostridium acetobutylicum''.

== See also ==
* [[Acetone-butanol-ethanol fermentation|ABE]]
* [[Acetone]]
* [[Butanol]]
* [[Ethanol]]

==References==
{{Reflist}}

==Further reading==
* {{cite journal |author=Nölling J |title=Genome sequence and comparative analysis of the solvent-producing bacterium Clostridium acetobutylicum |journal=J. Bacteriol. |volume=183 |issue=16 |pages=4823–38 |date=August 2001 |pmid=11466286 |pmc=99537 |doi=10.1128/JB.183.16.4823-4838.2001 |url= |name-list-format=vanc|author2=Breton G |author3=Omelchenko MV |display-authors=3 |last4=Makarova |first4=K. S. |last5=Zeng |first5=Q. |last6=Gibson |first6=R. |last7=Lee |first7=H. M. |last8=Dubois |first8=J. |last9=Qiu |first9=D.}}
* {{cite journal |author=Driessen AJ, Ubbink-Kok T, Konings WN |title=Amino acid transport by membrane vesicles of an obligate anaerobic bacterium, Clostridium acetobutylicum |journal=J. Bacteriol. |volume=170 |issue=2 |pages=817–20 |date=February 1988 |pmid=2828326 |pmc=210727 |doi= |url=http://jb.asm.org/cgi/pmidlookup?view=long&pmid=2828326}}
* {{cite journal |author=Zappe H, Jones WA, Jones DT, Woods DR |title=Structure of an endo-beta-1,4-glucanase gene from Clostridium acetobutylicum P262 showing homology with endoglucanase genes from Bacillus spp |journal=Appl. Environ. Microbiol. |volume=54 |issue=5 |pages=1289–92 |date=May 1988 |pmid=3389820 |pmc=202643 |doi= |url=http://aem.asm.org/cgi/pmidlookup?view=long&pmid=3389820}}
* {{cite journal |author=Bowles LK, Ellefson WL |title=Effects of butanol on Clostridium acetobutylicum |journal=Appl. Environ. Microbiol. |volume=50 |issue=5 |pages=1165–70 |date=November 1985 |pmid=2868690 |pmc=238718 |doi= |url=http://aem.asm.org/cgi/pmidlookup?view=long&pmid=2868690}}
* {{patent|US|1875536}}
* {{patent|US|1315585}}
* {{cite journal | last1 = Weber | first1 = Christian | last2 = Farwick | first2 = Alexander | last3 = Benisch | first3 = Feline | last4 = Brat | first4 = Dawid | last5 = Dietz | first5 = Heiko | last6 = Subtil | first6 = Thorsten | last7 = Boles | first7 = Eckhard | title = Trends and challenges in the microbial production of lignocellulosic bioalcohol fuels | journal = Applied Microbiology and Biotechnology | date = 10 June 2010 | volume = 87 | issue = 4 | pages = 1303–1315 | doi = 10.1007/s00253-010-2707-z | pmid = 20535464 | issn = 01757598}}
* {{cite journal | pmc = 373084 | pmid = 3540574 | year = 1986 | last1 = Jones | first1 = DT | last2 = Woods | first2 = DR | title = Acetone-butanol fermentation revisited | volume = 50 | issue = 4 | pages = 484–524 | journal = Microbiological reviews}}
* {{cite book | last1 = Bartha | first1 = Ronald M. Atlas & Richard | title = Microbial ecology : fundamentals and applications | date = 1993 | publisher = Benjamin/Cummings Pub. Co. | location = Redwood City, Calif. | isbn = 0-8053-0653-6 | page = 563 | edition = 3rd}}
* {{cite book | title = Microbial Processes: Promising Technologies for Developing Countries | year = 1979 | publisher = National Academy of Sciences | location = Washington | url = http://www.nap.edu/openbook.php?record_id=9544&page=R1 | accessdate = May 2011}}
* {{cite web | last1 = Wong Kromhout | first1 = Wileen | title = UCLA researchers engineer E. coli to produce record-setting amounts of alternative fuel | url = http://newsroom.ucla.edu/releases/ucla-engineers-drive-e-coli-to-197675 | website = UCLA Newsroom | date = 2011-03-16}}

== External links ==
* [http://www.atcc.org/ATCCAdvancedCatalogSearch/ProductDetails/tabid/452/Default.aspx?ATCCNum=824&Template=bacteria ATCC reference organism 824 C.Acetobutylicum.]
* [http://www.findarticles.com/p/articles/mi_m1272/is_n2593_v123/ai_15826295 findarticles.com: Bacteria speeds drug to tumors - use of Clostridium acetobutylicum enzyme to activate cancer drug CB 1954].
* [http://www.epa.gov/biotech_rule/pubs/fra/fra003.htm EPA Clostridium acetobutylicum Final Risk Assessment]
* [https://www2.carolina.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=10101&storeId=10151&productId=39315 Carolina Bio Supply Living Culture Order Page]
* [http://www.engr.psu.edu/h2e/Pub/Regan/Regan_etal_1.htm Genetic Engineering of Clostridium acetobutylicum for Enhanced Production of Hydrogen Gas]: [[Penn State University]].
* [http://pathema.tigr.org/tigr-scripts/Clostridium/PathemaHomePage.cgi Pathema-''Clostridium'' Resource]
* [http://www.encyclopedia.com/topic/Chaim_Weizmann.aspx Chaim Weizmann]

[[Category:Clostridiaceae]]
[[Category:Biofuels]]
[[Category:Gram-positive bacteria]]

Clostridium acetobutylicum

2016-02-07T03:23:41Z

71.109.148.145: Move to correct section

{{italic title}}
{{Taxobox
| color = lightgrey
| name = ''Clostridium acetobutylicum''
| regnum = [[Bacterium|Bacteria]]
| divisio = [[Firmicutes]]
| classis = [[Clostridia]]
| ordo = [[Clostridia]]le
| familia = [[Clostridiaceae]]
| genus = ''[[Clostridium]]''
| species = '''''C. acetobutylicum'''''
}}
[[File:Weizmann's passport photo.jpg|thumb|170px|[[Chaim Weizmann]]]]
'''''Clostridium acetobutylicum''''', [[American Type Culture Collection|ATCC]] 824, is a commercially valuable [[bacterium]] sometimes called the "'''Weizmann Organism'''", after Jewish-Russian-born [[Chaim Weizmann]]. A senior lecturer at the [[University of Manchester]], [[England]], he used them in 1916 as a bio-chemical tool to produce at the same time, jointly, [[acetone]], [[ethanol]], and [[butanol]] from [[starch]]. The method has been described since as the [[ABE process]], (Acetone Butanol Ethanol fermentation process), yielding 3 parts of [[acetone]], 6 of [[butanol]], and 1 of [[ethanol]]. Acetone was used in the important wartime task of casting [[cordite]]. The alcohols were used to produce vehicle fuels and [[synthetic rubber]].

Unlike [[yeast]], which can digest [[sugar]] only into [[alcohol]] and [[carbon dioxide]], ''C. acetobutylicum'' and other Clostridia can digest [[whey]], [[sugar]], [[starch]], [[cellulose]] and perhaps certain types of [[lignin]], yielding [[butanol]], [[propionic acid]], [[diethyl ether|ether]], and [[glycerin]].

==In genetic engineering==

In 2008, a strain of ''[[Escherichia coli]]'' was genetically engineered to synthesize butanol; the genes were derived from ''Clostridium acetobutylicum''.<ref>{{cite web | last1 = M. Goho | first1 = Alexandra | title = Better Bugs for Making Butanol | url = http://www.technologyreview.com/news/409400/better-bugs-for-making-butanol/ | website = MIT Technology Review | date = 2008-01-16}}</ref><ref>{{Cite journal | last1 = Atsumi | first1 = S. | last2 = Hanai | first2 = T. | last3 = Liao | first3 = JC. | title = Non-fermentative pathways for synthesis of branched-chain higher alcohols as biofuels. | journal = Nature | volume = 451 | issue = 7174 | pages = 86–9 |date = Jan 2008 | doi = 10.1038/nature06450 | PMID = 18172501 }}</ref> In 2013, the first microbial production of short-chain [[alkane]]s was reported<ref>{{Cite journal | last1 = Choi | first1 = YJ. | last2 = Lee | first2 = SY. | title = Microbial production of short-chain alkanes. | journal = Nature | volume = 502 | issue = 7472 | pages = 571–4 |date = Oct 2013 | doi = 10.1038/nature12536 | PMID = 24077097 }}</ref> - which is a considerable step toward the production of gasoline. One of the crucial [[enzyme]]s - a [[fatty acid|fatty]] [[acyl-CoA]] [[reductase]] - came from ''Clostridium acetobutylicum''.

== See also ==
* [[Acetone-butanol-ethanol fermentation|ABE]]
* [[Acetone]]
* [[Butanol]]
* [[Ethanol]]

==References==
{{Reflist}}
* {{cite journal | pmc = 373084 | pmid = 3540574 | year = 1986 | last1 = Jones | first1 = DT | last2 = Woods | first2 = DR | title = Acetone-butanol fermentation revisited | volume = 50 | issue = 4 | pages = 484–524 | journal = Microbiological reviews}}
* {{cite book | last1 = Bartha | first1 = Ronald M. Atlas & Richard | title = Microbial ecology : fundamentals and applications | date = 1993 | publisher = Benjamin/Cummings Pub. Co. | location = Redwood City, Calif. | isbn = 0-8053-0653-6 | page = 563 | edition = 3rd}}
* {{cite book | title = Microbial Processes: Promising Technologies for Developing Countries | year = 1979 | publisher = National Academy of Sciences | location = Washington | url = http://www.nap.edu/openbook.php?record_id=9544&page=R1 | accessdate = May 2011}}
* {{cite web | last1 = Wong Kromhout | first1 = Wileen | title = UCLA researchers engineer E. coli to produce record-setting amounts of alternative fuel | url = http://newsroom.ucla.edu/releases/ucla-engineers-drive-e-coli-to-197675 | website = UCLA Newsroom | date = 2011-03-16}}

==Further reading==
* {{cite journal |author=Nölling J |title=Genome sequence and comparative analysis of the solvent-producing bacterium Clostridium acetobutylicum |journal=J. Bacteriol. |volume=183 |issue=16 |pages=4823–38 |date=August 2001 |pmid=11466286 |pmc=99537 |doi=10.1128/JB.183.16.4823-4838.2001 |url= |name-list-format=vanc|author2=Breton G |author3=Omelchenko MV |display-authors=3 |last4=Makarova |first4=K. S. |last5=Zeng |first5=Q. |last6=Gibson |first6=R. |last7=Lee |first7=H. M. |last8=Dubois |first8=J. |last9=Qiu |first9=D.}}
* {{cite journal |author=Driessen AJ, Ubbink-Kok T, Konings WN |title=Amino acid transport by membrane vesicles of an obligate anaerobic bacterium, Clostridium acetobutylicum |journal=J. Bacteriol. |volume=170 |issue=2 |pages=817–20 |date=February 1988 |pmid=2828326 |pmc=210727 |doi= |url=http://jb.asm.org/cgi/pmidlookup?view=long&pmid=2828326}}
* {{cite journal |author=Zappe H, Jones WA, Jones DT, Woods DR |title=Structure of an endo-beta-1,4-glucanase gene from Clostridium acetobutylicum P262 showing homology with endoglucanase genes from Bacillus spp |journal=Appl. Environ. Microbiol. |volume=54 |issue=5 |pages=1289–92 |date=May 1988 |pmid=3389820 |pmc=202643 |doi= |url=http://aem.asm.org/cgi/pmidlookup?view=long&pmid=3389820}}
* {{cite journal |author=Bowles LK, Ellefson WL |title=Effects of butanol on Clostridium acetobutylicum |journal=Appl. Environ. Microbiol. |volume=50 |issue=5 |pages=1165–70 |date=November 1985 |pmid=2868690 |pmc=238718 |doi= |url=http://aem.asm.org/cgi/pmidlookup?view=long&pmid=2868690}}
* {{patent|US|1875536}}
* {{patent|US|1315585}}
* {{cite journal | last1 = Weber | first1 = Christian | last2 = Farwick | first2 = Alexander | last3 = Benisch | first3 = Feline | last4 = Brat | first4 = Dawid | last5 = Dietz | first5 = Heiko | last6 = Subtil | first6 = Thorsten | last7 = Boles | first7 = Eckhard | title = Trends and challenges in the microbial production of lignocellulosic bioalcohol fuels | journal = Applied Microbiology and Biotechnology | date = 10 June 2010 | volume = 87 | issue = 4 | pages = 1303–1315 | doi = 10.1007/s00253-010-2707-z | pmid = 20535464 | issn = 01757598}}

== External links ==
* [http://www.atcc.org/ATCCAdvancedCatalogSearch/ProductDetails/tabid/452/Default.aspx?ATCCNum=824&Template=bacteria ATCC reference organism 824 C.Acetobutylicum.]
* [http://www.findarticles.com/p/articles/mi_m1272/is_n2593_v123/ai_15826295 findarticles.com: Bacteria speeds drug to tumors - use of Clostridium acetobutylicum enzyme to activate cancer drug CB 1954].
* [http://www.epa.gov/biotech_rule/pubs/fra/fra003.htm EPA Clostridium acetobutylicum Final Risk Assessment]
* [https://www2.carolina.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=10101&storeId=10151&productId=39315 Carolina Bio Supply Living Culture Order Page]
* [http://www.engr.psu.edu/h2e/Pub/Regan/Regan_etal_1.htm Genetic Engineering of Clostridium acetobutylicum for Enhanced Production of Hydrogen Gas]: [[Penn State University]].
* [http://pathema.tigr.org/tigr-scripts/Clostridium/PathemaHomePage.cgi Pathema-''Clostridium'' Resource]
* [http://www.encyclopedia.com/topic/Chaim_Weizmann.aspx Chaim Weizmann]

[[Category:Clostridiaceae]]
[[Category:Biofuels]]
[[Category:Gram-positive bacteria]]

Clostridium acetobutylicum

2016-02-07T03:23:00Z

71.109.148.145: Move to correct section

{{italic title}}
{{Taxobox
| color = lightgrey
| name = ''Clostridium acetobutylicum''
| regnum = [[Bacterium|Bacteria]]
| divisio = [[Firmicutes]]
| classis = [[Clostridia]]
| ordo = [[Clostridia]]le
| familia = [[Clostridiaceae]]
| genus = ''[[Clostridium]]''
| species = '''''C. acetobutylicum'''''
}}
[[File:Weizmann's passport photo.jpg|thumb|170px|[[Chaim Weizmann]]]]
'''''Clostridium acetobutylicum''''', [[American Type Culture Collection|ATCC]] 824, is a commercially valuable [[bacterium]] sometimes called the "'''Weizmann Organism'''", after Jewish-Russian-born [[Chaim Weizmann]]. A senior lecturer at the [[University of Manchester]], [[England]], he used them in 1916 as a bio-chemical tool to produce at the same time, jointly, [[acetone]], [[ethanol]], and [[butanol]] from [[starch]]. The method has been described since as the [[ABE process]], (Acetone Butanol Ethanol fermentation process), yielding 3 parts of [[acetone]], 6 of [[butanol]], and 1 of [[ethanol]]. Acetone was used in the important wartime task of casting [[cordite]]. The alcohols were used to produce vehicle fuels and [[synthetic rubber]].

Unlike [[yeast]], which can digest [[sugar]] only into [[alcohol]] and [[carbon dioxide]], ''C. acetobutylicum'' and other Clostridia can digest [[whey]], [[sugar]], [[starch]], [[cellulose]] and perhaps certain types of [[lignin]], yielding [[butanol]], [[propionic acid]], [[diethyl ether|ether]], and [[glycerin]].

==In genetic engineering==

In 2008, a strain of ''[[Escherichia coli]]'' was genetically engineered to synthesize butanol; the genes were derived from ''Clostridium acetobutylicum''.<ref>{{cite web | last1 = M. Goho | first1 = Alexandra | title = Better Bugs for Making Butanol | url = http://www.technologyreview.com/news/409400/better-bugs-for-making-butanol/ | website = MIT Technology Review | date = 2008-01-16}}</ref><ref>{{Cite journal | last1 = Atsumi | first1 = S. | last2 = Hanai | first2 = T. | last3 = Liao | first3 = JC. | title = Non-fermentative pathways for synthesis of branched-chain higher alcohols as biofuels. | journal = Nature | volume = 451 | issue = 7174 | pages = 86–9 |date = Jan 2008 | doi = 10.1038/nature06450 | PMID = 18172501 }}</ref> In 2013, the first microbial production of short-chain [[alkane]]s was reported<ref>{{Cite journal | last1 = Choi | first1 = YJ. | last2 = Lee | first2 = SY. | title = Microbial production of short-chain alkanes. | journal = Nature | volume = 502 | issue = 7472 | pages = 571–4 |date = Oct 2013 | doi = 10.1038/nature12536 | PMID = 24077097 }}</ref> - which is a considerable step toward the production of gasoline. One of the crucial [[enzyme]]s - a [[fatty acid|fatty]] [[acyl-CoA]] [[reductase]] - came from ''Clostridium acetobutylicum''.

== See also ==
* [[Acetone-butanol-ethanol fermentation|ABE]]
* [[Acetone]]
* [[Butanol]]
* [[Ethanol]]

==References==
{{Reflist}}
* {{cite journal | pmc = 373084 | pmid = 3540574 | year = 1986 | last1 = Jones | first1 = DT | last2 = Woods | first2 = DR | title = Acetone-butanol fermentation revisited | volume = 50 | issue = 4 | pages = 484–524 | journal = Microbiological reviews}}
* {{cite book | last1 = Bartha | first1 = Ronald M. Atlas & Richard | title = Microbial ecology : fundamentals and applications | date = 1993 | publisher = Benjamin/Cummings Pub. Co. | location = Redwood City, Calif. | isbn = 0-8053-0653-6 | page = 563 | edition = 3rd}}
* {{cite book | title = Microbial Processes: Promising Technologies for Developing Countries | year = 1979 | publisher = National Academy of Sciences | location = Washington | url = http://www.nap.edu/openbook.php?record_id=9544&page=R1 | accessdate = May 2011}}
* {{cite web | last1 = Wong Kromhout | first1 = Wileen | title = UCLA researchers engineer E. coli to produce record-setting amounts of alternative fuel | url = http://newsroom.ucla.edu/releases/ucla-engineers-drive-e-coli-to-197675 | website = UCLA Newsroom | date = 2011-03-16}}

==Further reading==
* {{cite journal |author=Nölling J |title=Genome sequence and comparative analysis of the solvent-producing bacterium Clostridium acetobutylicum |journal=J. Bacteriol. |volume=183 |issue=16 |pages=4823–38 |date=August 2001 |pmid=11466286 |pmc=99537 |doi=10.1128/JB.183.16.4823-4838.2001 |url= |name-list-format=vanc|author2=Breton G |author3=Omelchenko MV |display-authors=3 |last4=Makarova |first4=K. S. |last5=Zeng |first5=Q. |last6=Gibson |first6=R. |last7=Lee |first7=H. M. |last8=Dubois |first8=J. |last9=Qiu |first9=D.}}
* {{cite journal |author=Driessen AJ, Ubbink-Kok T, Konings WN |title=Amino acid transport by membrane vesicles of an obligate anaerobic bacterium, Clostridium acetobutylicum |journal=J. Bacteriol. |volume=170 |issue=2 |pages=817–20 |date=February 1988 |pmid=2828326 |pmc=210727 |doi= |url=http://jb.asm.org/cgi/pmidlookup?view=long&pmid=2828326}}
* {{cite journal |author=Zappe H, Jones WA, Jones DT, Woods DR |title=Structure of an endo-beta-1,4-glucanase gene from Clostridium acetobutylicum P262 showing homology with endoglucanase genes from Bacillus spp |journal=Appl. Environ. Microbiol. |volume=54 |issue=5 |pages=1289–92 |date=May 1988 |pmid=3389820 |pmc=202643 |doi= |url=http://aem.asm.org/cgi/pmidlookup?view=long&pmid=3389820}}
* {{cite journal |author=Bowles LK, Ellefson WL |title=Effects of butanol on Clostridium acetobutylicum |journal=Appl. Environ. Microbiol. |volume=50 |issue=5 |pages=1165–70 |date=November 1985 |pmid=2868690 |pmc=238718 |doi= |url=http://aem.asm.org/cgi/pmidlookup?view=long&pmid=2868690}}

== External links ==
* [http://www.atcc.org/ATCCAdvancedCatalogSearch/ProductDetails/tabid/452/Default.aspx?ATCCNum=824&Template=bacteria ATCC reference organism 824 C.Acetobutylicum.]
* [http://www.findarticles.com/p/articles/mi_m1272/is_n2593_v123/ai_15826295 findarticles.com: Bacteria speeds drug to tumors - use of Clostridium acetobutylicum enzyme to activate cancer drug CB 1954].
* [http://www.epa.gov/biotech_rule/pubs/fra/fra003.htm EPA Clostridium acetobutylicum Final Risk Assessment]
* [https://www2.carolina.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=10101&storeId=10151&productId=39315 Carolina Bio Supply Living Culture Order Page]
* [http://www.engr.psu.edu/h2e/Pub/Regan/Regan_etal_1.htm Genetic Engineering of Clostridium acetobutylicum for Enhanced Production of Hydrogen Gas]: [[Penn State University]].
* [http://pathema.tigr.org/tigr-scripts/Clostridium/PathemaHomePage.cgi Pathema-''Clostridium'' Resource]
* [http://www.encyclopedia.com/topic/Chaim_Weizmann.aspx Chaim Weizmann]
* {{patent|US|1875536}}
* {{patent|US|1315585}}
* {{cite journal | last1 = Weber | first1 = Christian | last2 = Farwick | first2 = Alexander | last3 = Benisch | first3 = Feline | last4 = Brat | first4 = Dawid | last5 = Dietz | first5 = Heiko | last6 = Subtil | first6 = Thorsten | last7 = Boles | first7 = Eckhard | title = Trends and challenges in the microbial production of lignocellulosic bioalcohol fuels | journal = Applied Microbiology and Biotechnology | date = 10 June 2010 | volume = 87 | issue = 4 | pages = 1303–1315 | doi = 10.1007/s00253-010-2707-z | pmid = 20535464 | issn = 01757598}}

[[Category:Clostridiaceae]]
[[Category:Biofuels]]
[[Category:Gram-positive bacteria]]

Clostridium acetobutylicum

2016-02-07T03:20:30Z

71.109.148.145: /* References */ Cleanup. Cut and paste error or something.

{{italic title}}
{{Taxobox
| color = lightgrey
| name = ''Clostridium acetobutylicum''
| regnum = [[Bacterium|Bacteria]]
| divisio = [[Firmicutes]]
| classis = [[Clostridia]]
| ordo = [[Clostridia]]le
| familia = [[Clostridiaceae]]
| genus = ''[[Clostridium]]''
| species = '''''C. acetobutylicum'''''
}}
[[File:Weizmann's passport photo.jpg|thumb|170px|[[Chaim Weizmann]]]]
'''''Clostridium acetobutylicum''''', [[American Type Culture Collection|ATCC]] 824, is a commercially valuable [[bacterium]] sometimes called the "'''Weizmann Organism'''", after Jewish-Russian-born [[Chaim Weizmann]]. A senior lecturer at the [[University of Manchester]], [[England]], he used them in 1916 as a bio-chemical tool to produce at the same time, jointly, [[acetone]], [[ethanol]], and [[butanol]] from [[starch]]. The method has been described since as the [[ABE process]], (Acetone Butanol Ethanol fermentation process), yielding 3 parts of [[acetone]], 6 of [[butanol]], and 1 of [[ethanol]]. Acetone was used in the important wartime task of casting [[cordite]]. The alcohols were used to produce vehicle fuels and [[synthetic rubber]].

Unlike [[yeast]], which can digest [[sugar]] only into [[alcohol]] and [[carbon dioxide]], ''C. acetobutylicum'' and other Clostridia can digest [[whey]], [[sugar]], [[starch]], [[cellulose]] and perhaps certain types of [[lignin]], yielding [[butanol]], [[propionic acid]], [[diethyl ether|ether]], and [[glycerin]].

==In genetic engineering==

In 2008, a strain of ''[[Escherichia coli]]'' was genetically engineered to synthesize butanol; the genes were derived from ''Clostridium acetobutylicum''.<ref>{{cite web | last1 = M. Goho | first1 = Alexandra | title = Better Bugs for Making Butanol | url = http://www.technologyreview.com/news/409400/better-bugs-for-making-butanol/ | website = MIT Technology Review | date = 2008-01-16}}</ref><ref>{{Cite journal | last1 = Atsumi | first1 = S. | last2 = Hanai | first2 = T. | last3 = Liao | first3 = JC. | title = Non-fermentative pathways for synthesis of branched-chain higher alcohols as biofuels. | journal = Nature | volume = 451 | issue = 7174 | pages = 86–9 |date = Jan 2008 | doi = 10.1038/nature06450 | PMID = 18172501 }}</ref> In 2013, the first microbial production of short-chain [[alkane]]s was reported<ref>{{Cite journal | last1 = Choi | first1 = YJ. | last2 = Lee | first2 = SY. | title = Microbial production of short-chain alkanes. | journal = Nature | volume = 502 | issue = 7472 | pages = 571–4 |date = Oct 2013 | doi = 10.1038/nature12536 | PMID = 24077097 }}</ref> - which is a considerable step toward the production of gasoline. One of the crucial [[enzyme]]s - a [[fatty acid|fatty]] [[acyl-CoA]] [[reductase]] - came from ''Clostridium acetobutylicum''.

== See also ==
* [[Acetone-butanol-ethanol fermentation|ABE]]
* [[Acetone]]
* [[Butanol]]
* [[Ethanol]]

==References==
{{Reflist}}
* http://www.encyclopedia.com/topic/Chaim_Weizmann.aspx
* {{cite journal | pmc = 373084 | pmid = 3540574 | year = 1986 | last1 = Jones | first1 = DT | last2 = Woods | first2 = DR | title = Acetone-butanol fermentation revisited | volume = 50 | issue = 4 | pages = 484–524 | journal = Microbiological reviews}}
* {{cite book | last1 = Bartha | first1 = Ronald M. Atlas & Richard | title = Microbial ecology : fundamentals and applications | date = 1993 | publisher = Benjamin/Cummings Pub. Co. | location = Redwood City, Calif. | isbn = 0-8053-0653-6 | page = 563 | edition = 3rd}}
* {{cite book | title = Microbial Processes: Promising Technologies for Developing Countries | year = 1979 | publisher = National Academy of Sciences | location = Washington | url = http://www.nap.edu/openbook.php?record_id=9544&page=R1 | accessdate = May 2011}}
* {{cite web | last1 = Wong Kromhout | first1 = Wileen | title = UCLA researchers engineer E. coli to produce record-setting amounts of alternative fuel | url = http://newsroom.ucla.edu/releases/ucla-engineers-drive-e-coli-to-197675 | website = UCLA Newsroom | date = 2011-03-16}}

==Further reading==
* {{cite journal |author=Nölling J |title=Genome sequence and comparative analysis of the solvent-producing bacterium Clostridium acetobutylicum |journal=J. Bacteriol. |volume=183 |issue=16 |pages=4823–38 |date=August 2001 |pmid=11466286 |pmc=99537 |doi=10.1128/JB.183.16.4823-4838.2001 |url= |name-list-format=vanc|author2=Breton G |author3=Omelchenko MV |display-authors=3 |last4=Makarova |first4=K. S. |last5=Zeng |first5=Q. |last6=Gibson |first6=R. |last7=Lee |first7=H. M. |last8=Dubois |first8=J. |last9=Qiu |first9=D.}}
* {{cite journal |author=Driessen AJ, Ubbink-Kok T, Konings WN |title=Amino acid transport by membrane vesicles of an obligate anaerobic bacterium, Clostridium acetobutylicum |journal=J. Bacteriol. |volume=170 |issue=2 |pages=817–20 |date=February 1988 |pmid=2828326 |pmc=210727 |doi= |url=http://jb.asm.org/cgi/pmidlookup?view=long&pmid=2828326}}
* {{cite journal |author=Zappe H, Jones WA, Jones DT, Woods DR |title=Structure of an endo-beta-1,4-glucanase gene from Clostridium acetobutylicum P262 showing homology with endoglucanase genes from Bacillus spp |journal=Appl. Environ. Microbiol. |volume=54 |issue=5 |pages=1289–92 |date=May 1988 |pmid=3389820 |pmc=202643 |doi= |url=http://aem.asm.org/cgi/pmidlookup?view=long&pmid=3389820}}
* {{cite journal |author=Bowles LK, Ellefson WL |title=Effects of butanol on Clostridium acetobutylicum |journal=Appl. Environ. Microbiol. |volume=50 |issue=5 |pages=1165–70 |date=November 1985 |pmid=2868690 |pmc=238718 |doi= |url=http://aem.asm.org/cgi/pmidlookup?view=long&pmid=2868690}}

== External links ==
* [http://www.atcc.org/ATCCAdvancedCatalogSearch/ProductDetails/tabid/452/Default.aspx?ATCCNum=824&Template=bacteria ATCC reference organism 824 C.Acetobutylicum.]
* [http://www.findarticles.com/p/articles/mi_m1272/is_n2593_v123/ai_15826295 findarticles.com: Bacteria speeds drug to tumors - use of Clostridium acetobutylicum enzyme to activate cancer drug CB 1954].
* [http://www.epa.gov/biotech_rule/pubs/fra/fra003.htm EPA Clostridium acetobutylicum Final Risk Assessment]
* [https://www2.carolina.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=10101&storeId=10151&productId=39315 Carolina Bio Supply Living Culture Order Page]
* [http://www.engr.psu.edu/h2e/Pub/Regan/Regan_etal_1.htm Genetic Engineering of Clostridium acetobutylicum for Enhanced Production of Hydrogen Gas]: [[Penn State University]].
* [http://pathema.tigr.org/tigr-scripts/Clostridium/PathemaHomePage.cgi Pathema-''Clostridium'' Resource]
* {{patent|US|1875536}}
* {{patent|US|1315585}}
* {{cite journal | last1 = Weber | first1 = Christian | last2 = Farwick | first2 = Alexander | last3 = Benisch | first3 = Feline | last4 = Brat | first4 = Dawid | last5 = Dietz | first5 = Heiko | last6 = Subtil | first6 = Thorsten | last7 = Boles | first7 = Eckhard | title = Trends and challenges in the microbial production of lignocellulosic bioalcohol fuels | journal = Applied Microbiology and Biotechnology | date = 10 June 2010 | volume = 87 | issue = 4 | pages = 1303–1315 | doi = 10.1007/s00253-010-2707-z | pmid = 20535464 | issn = 01757598}}

[[Category:Clostridiaceae]]
[[Category:Biofuels]]
[[Category:Gram-positive bacteria]]

Clostridium acetobutylicum

2016-02-07T03:18:46Z

71.109.148.145: Increasing clarity.

{{italic title}}
{{Taxobox
| color = lightgrey
| name = ''Clostridium acetobutylicum''
| regnum = [[Bacterium|Bacteria]]
| divisio = [[Firmicutes]]
| classis = [[Clostridia]]
| ordo = [[Clostridia]]le
| familia = [[Clostridiaceae]]
| genus = ''[[Clostridium]]''
| species = '''''C. acetobutylicum'''''
}}
[[File:Weizmann's passport photo.jpg|thumb|170px|[[Chaim Weizmann]]]]
'''''Clostridium acetobutylicum''''', [[American Type Culture Collection|ATCC]] 824, is a commercially valuable [[bacterium]] sometimes called the "'''Weizmann Organism'''", after Jewish-Russian-born [[Chaim Weizmann]]. A senior lecturer at the [[University of Manchester]], [[England]], he used them in 1916 as a bio-chemical tool to produce at the same time, jointly, [[acetone]], [[ethanol]], and [[butanol]] from [[starch]]. The method has been described since as the [[ABE process]], (Acetone Butanol Ethanol fermentation process), yielding 3 parts of [[acetone]], 6 of [[butanol]], and 1 of [[ethanol]]. Acetone was used in the important wartime task of casting [[cordite]]. The alcohols were used to produce vehicle fuels and [[synthetic rubber]].

Unlike [[yeast]], which can digest [[sugar]] only into [[alcohol]] and [[carbon dioxide]], ''C. acetobutylicum'' and other Clostridia can digest [[whey]], [[sugar]], [[starch]], [[cellulose]] and perhaps certain types of [[lignin]], yielding [[butanol]], [[propionic acid]], [[diethyl ether|ether]], and [[glycerin]].

==In genetic engineering==

In 2008, a strain of ''[[Escherichia coli]]'' was genetically engineered to synthesize butanol; the genes were derived from ''Clostridium acetobutylicum''.<ref>{{cite web | last1 = M. Goho | first1 = Alexandra | title = Better Bugs for Making Butanol | url = http://www.technologyreview.com/news/409400/better-bugs-for-making-butanol/ | website = MIT Technology Review | date = 2008-01-16}}</ref><ref>{{Cite journal | last1 = Atsumi | first1 = S. | last2 = Hanai | first2 = T. | last3 = Liao | first3 = JC. | title = Non-fermentative pathways for synthesis of branched-chain higher alcohols as biofuels. | journal = Nature | volume = 451 | issue = 7174 | pages = 86–9 |date = Jan 2008 | doi = 10.1038/nature06450 | PMID = 18172501 }}</ref> In 2013, the first microbial production of short-chain [[alkane]]s was reported<ref>{{Cite journal | last1 = Choi | first1 = YJ. | last2 = Lee | first2 = SY. | title = Microbial production of short-chain alkanes. | journal = Nature | volume = 502 | issue = 7472 | pages = 571–4 |date = Oct 2013 | doi = 10.1038/nature12536 | PMID = 24077097 }}</ref> - which is a considerable step toward the production of gasoline. One of the crucial [[enzyme]]s - a [[fatty acid|fatty]] [[acyl-CoA]] [[reductase]] - came from ''Clostridium acetobutylicum''.

== See also ==
* [[Acetone-butanol-ethanol fermentation|ABE]]
* [[Acetone]]
* [[Butanol]]
* [[Ethanol]]

==References==
{{Reflist}}
* http://www.encyclopedia.com/topic/Chaim_Weizmann.aspx
* {{cite journal | pmc = 373084 | pmid = 3540574 | year = 1986 | last1 = Jones | first1 = DT | last2 = Woods | first2 = DR | title = Acetone-butanol fermentation revisited | volume = 50 | issue = 4 | pages = 484–524 | journal = Microbiological reviews}}
* {{cite book | last1 = Bartha | first1 = Ronald M. Atlas & Richard | title = Microbial ecology : fundamentals and applications | date = 1993 | publisher = Benjamin/Cummings Pub. Co. | location = Redwood City, Calif. | isbn = 0-8053-0653-6 | page = 563 | edition = 3rd}}
* {{cite book | title = Microbial Processes: Promising Technologies for Developing Countries | year = 1979 | publisher = National Academy of Sciences | location = Washington | url = http://www.nap.edu/openbook.php?record_id=9544&page=R1 | accessdate = May 2011}}
Probably, you can see, for immediate results: 
27 hits 6 Fuel and Energy 107-123 
42 hits 7 Waste Treatment and Utilization 124-141 
36 hits 8 Cellulose Conversion 142-157
* {{cite web | last1 = Wong Kromhout | first1 = Wileen | title = UCLA researchers engineer E. coli to produce record-setting amounts of alternative fuel | url = http://newsroom.ucla.edu/releases/ucla-engineers-drive-e-coli-to-197675 | website = UCLA Newsroom | date = 2011-03-16}}

==Further reading==
* {{cite journal |author=Nölling J |title=Genome sequence and comparative analysis of the solvent-producing bacterium Clostridium acetobutylicum |journal=J. Bacteriol. |volume=183 |issue=16 |pages=4823–38 |date=August 2001 |pmid=11466286 |pmc=99537 |doi=10.1128/JB.183.16.4823-4838.2001 |url= |name-list-format=vanc|author2=Breton G |author3=Omelchenko MV |display-authors=3 |last4=Makarova |first4=K. S. |last5=Zeng |first5=Q. |last6=Gibson |first6=R. |last7=Lee |first7=H. M. |last8=Dubois |first8=J. |last9=Qiu |first9=D.}}
* {{cite journal |author=Driessen AJ, Ubbink-Kok T, Konings WN |title=Amino acid transport by membrane vesicles of an obligate anaerobic bacterium, Clostridium acetobutylicum |journal=J. Bacteriol. |volume=170 |issue=2 |pages=817–20 |date=February 1988 |pmid=2828326 |pmc=210727 |doi= |url=http://jb.asm.org/cgi/pmidlookup?view=long&pmid=2828326}}
* {{cite journal |author=Zappe H, Jones WA, Jones DT, Woods DR |title=Structure of an endo-beta-1,4-glucanase gene from Clostridium acetobutylicum P262 showing homology with endoglucanase genes from Bacillus spp |journal=Appl. Environ. Microbiol. |volume=54 |issue=5 |pages=1289–92 |date=May 1988 |pmid=3389820 |pmc=202643 |doi= |url=http://aem.asm.org/cgi/pmidlookup?view=long&pmid=3389820}}
* {{cite journal |author=Bowles LK, Ellefson WL |title=Effects of butanol on Clostridium acetobutylicum |journal=Appl. Environ. Microbiol. |volume=50 |issue=5 |pages=1165–70 |date=November 1985 |pmid=2868690 |pmc=238718 |doi= |url=http://aem.asm.org/cgi/pmidlookup?view=long&pmid=2868690}}

== External links ==
* [http://www.atcc.org/ATCCAdvancedCatalogSearch/ProductDetails/tabid/452/Default.aspx?ATCCNum=824&Template=bacteria ATCC reference organism 824 C.Acetobutylicum.]
* [http://www.findarticles.com/p/articles/mi_m1272/is_n2593_v123/ai_15826295 findarticles.com: Bacteria speeds drug to tumors - use of Clostridium acetobutylicum enzyme to activate cancer drug CB 1954].
* [http://www.epa.gov/biotech_rule/pubs/fra/fra003.htm EPA Clostridium acetobutylicum Final Risk Assessment]
* [https://www2.carolina.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=10101&storeId=10151&productId=39315 Carolina Bio Supply Living Culture Order Page]
* [http://www.engr.psu.edu/h2e/Pub/Regan/Regan_etal_1.htm Genetic Engineering of Clostridium acetobutylicum for Enhanced Production of Hydrogen Gas]: [[Penn State University]].
* [http://pathema.tigr.org/tigr-scripts/Clostridium/PathemaHomePage.cgi Pathema-''Clostridium'' Resource]
* {{patent|US|1875536}}
* {{patent|US|1315585}}
* {{cite journal | last1 = Weber | first1 = Christian | last2 = Farwick | first2 = Alexander | last3 = Benisch | first3 = Feline | last4 = Brat | first4 = Dawid | last5 = Dietz | first5 = Heiko | last6 = Subtil | first6 = Thorsten | last7 = Boles | first7 = Eckhard | title = Trends and challenges in the microbial production of lignocellulosic bioalcohol fuels | journal = Applied Microbiology and Biotechnology | date = 10 June 2010 | volume = 87 | issue = 4 | pages = 1303–1315 | doi = 10.1007/s00253-010-2707-z | pmid = 20535464 | issn = 01757598}}

[[Category:Clostridiaceae]]
[[Category:Biofuels]]
[[Category:Gram-positive bacteria]]

Clostridium acetobutylicum

2016-02-07T03:16:36Z

71.109.148.145: Argh! The grammar! It hurts!

{{italic title}}
{{Taxobox
| color = lightgrey
| name = ''Clostridium acetobutylicum''
| regnum = [[Bacterium|Bacteria]]
| divisio = [[Firmicutes]]
| classis = [[Clostridia]]
| ordo = [[Clostridia]]le
| familia = [[Clostridiaceae]]
| genus = ''[[Clostridium]]''
| species = '''''C. acetobutylicum'''''
}}
[[File:Weizmann's passport photo.jpg|thumb|170px|[[Chaim Weizmann]]]]
'''''Clostridium acetobutylicum''''', [[American Type Culture Collection|ATCC]] 824, is a commercially valuable [[bacterium]] sometimes called the "'''Weizmann Organism'''", after Jewish-Russian-born [[Chaim Weizmann]]. A senior lecturer at the [[University of Manchester]], [[England]], he used them in 1916 as a bio-chemical tool to produce at the same time, jointly, [[acetone]], [[ethanol]], and [[butanol]] from [[starch]]. The method has been described since as the [[ABE process]], (Acetone Butanol Ethanol fermentation process), yielding 3 parts of [[acetone]], 6 of [[butanol]], and 1 of [[ethanol]], reducing the former difficulties to make [[cordite]], an explosive, from acetone and producing vehicle fuels and [[synthetic rubber]].

Unlike [[yeast]], which can digest [[sugar]] only into [[alcohol]] and [[carbon dioxide]], ''C. acetobutylicum'' and other Clostridia can digest [[whey]], [[sugar]], [[starch]], [[cellulose]] and perhaps certain types of [[lignin]], yielding [[butanol]], [[propionic acid]], [[diethyl ether|ether]], and [[glycerin]].

==In genetic engineering==

In 2008, a strain of ''[[Escherichia coli]]'' was genetically engineered to synthesize butanol; the genes were derived from ''Clostridium acetobutylicum''.<ref>{{cite web | last1 = M. Goho | first1 = Alexandra | title = Better Bugs for Making Butanol | url = http://www.technologyreview.com/news/409400/better-bugs-for-making-butanol/ | website = MIT Technology Review | date = 2008-01-16}}</ref><ref>{{Cite journal | last1 = Atsumi | first1 = S. | last2 = Hanai | first2 = T. | last3 = Liao | first3 = JC. | title = Non-fermentative pathways for synthesis of branched-chain higher alcohols as biofuels. | journal = Nature | volume = 451 | issue = 7174 | pages = 86–9 |date = Jan 2008 | doi = 10.1038/nature06450 | PMID = 18172501 }}</ref> In 2013, the first microbial production of short-chain [[alkane]]s was reported<ref>{{Cite journal | last1 = Choi | first1 = YJ. | last2 = Lee | first2 = SY. | title = Microbial production of short-chain alkanes. | journal = Nature | volume = 502 | issue = 7472 | pages = 571–4 |date = Oct 2013 | doi = 10.1038/nature12536 | PMID = 24077097 }}</ref> - which is a considerable step toward the production of gasoline. One of the crucial [[enzyme]]s - a [[fatty acid|fatty]] [[acyl-CoA]] [[reductase]] - came from ''Clostridium acetobutylicum''.

== See also ==
* [[Acetone-butanol-ethanol fermentation|ABE]]
* [[Acetone]]
* [[Butanol]]
* [[Ethanol]]

==References==
{{Reflist}}
* http://www.encyclopedia.com/topic/Chaim_Weizmann.aspx
* {{cite journal | pmc = 373084 | pmid = 3540574 | year = 1986 | last1 = Jones | first1 = DT | last2 = Woods | first2 = DR | title = Acetone-butanol fermentation revisited | volume = 50 | issue = 4 | pages = 484–524 | journal = Microbiological reviews}}
* {{cite book | last1 = Bartha | first1 = Ronald M. Atlas & Richard | title = Microbial ecology : fundamentals and applications | date = 1993 | publisher = Benjamin/Cummings Pub. Co. | location = Redwood City, Calif. | isbn = 0-8053-0653-6 | page = 563 | edition = 3rd}}
* {{cite book | title = Microbial Processes: Promising Technologies for Developing Countries | year = 1979 | publisher = National Academy of Sciences | location = Washington | url = http://www.nap.edu/openbook.php?record_id=9544&page=R1 | accessdate = May 2011}}
Probably, you can see, for immediate results: 
27 hits 6 Fuel and Energy 107-123 
42 hits 7 Waste Treatment and Utilization 124-141 
36 hits 8 Cellulose Conversion 142-157
* {{cite web | last1 = Wong Kromhout | first1 = Wileen | title = UCLA researchers engineer E. coli to produce record-setting amounts of alternative fuel | url = http://newsroom.ucla.edu/releases/ucla-engineers-drive-e-coli-to-197675 | website = UCLA Newsroom | date = 2011-03-16}}

==Further reading==
* {{cite journal |author=Nölling J |title=Genome sequence and comparative analysis of the solvent-producing bacterium Clostridium acetobutylicum |journal=J. Bacteriol. |volume=183 |issue=16 |pages=4823–38 |date=August 2001 |pmid=11466286 |pmc=99537 |doi=10.1128/JB.183.16.4823-4838.2001 |url= |name-list-format=vanc|author2=Breton G |author3=Omelchenko MV |display-authors=3 |last4=Makarova |first4=K. S. |last5=Zeng |first5=Q. |last6=Gibson |first6=R. |last7=Lee |first7=H. M. |last8=Dubois |first8=J. |last9=Qiu |first9=D.}}
* {{cite journal |author=Driessen AJ, Ubbink-Kok T, Konings WN |title=Amino acid transport by membrane vesicles of an obligate anaerobic bacterium, Clostridium acetobutylicum |journal=J. Bacteriol. |volume=170 |issue=2 |pages=817–20 |date=February 1988 |pmid=2828326 |pmc=210727 |doi= |url=http://jb.asm.org/cgi/pmidlookup?view=long&pmid=2828326}}
* {{cite journal |author=Zappe H, Jones WA, Jones DT, Woods DR |title=Structure of an endo-beta-1,4-glucanase gene from Clostridium acetobutylicum P262 showing homology with endoglucanase genes from Bacillus spp |journal=Appl. Environ. Microbiol. |volume=54 |issue=5 |pages=1289–92 |date=May 1988 |pmid=3389820 |pmc=202643 |doi= |url=http://aem.asm.org/cgi/pmidlookup?view=long&pmid=3389820}}
* {{cite journal |author=Bowles LK, Ellefson WL |title=Effects of butanol on Clostridium acetobutylicum |journal=Appl. Environ. Microbiol. |volume=50 |issue=5 |pages=1165–70 |date=November 1985 |pmid=2868690 |pmc=238718 |doi= |url=http://aem.asm.org/cgi/pmidlookup?view=long&pmid=2868690}}

== External links ==
* [http://www.atcc.org/ATCCAdvancedCatalogSearch/ProductDetails/tabid/452/Default.aspx?ATCCNum=824&Template=bacteria ATCC reference organism 824 C.Acetobutylicum.]
* [http://www.findarticles.com/p/articles/mi_m1272/is_n2593_v123/ai_15826295 findarticles.com: Bacteria speeds drug to tumors - use of Clostridium acetobutylicum enzyme to activate cancer drug CB 1954].
* [http://www.epa.gov/biotech_rule/pubs/fra/fra003.htm EPA Clostridium acetobutylicum Final Risk Assessment]
* [https://www2.carolina.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=10101&storeId=10151&productId=39315 Carolina Bio Supply Living Culture Order Page]
* [http://www.engr.psu.edu/h2e/Pub/Regan/Regan_etal_1.htm Genetic Engineering of Clostridium acetobutylicum for Enhanced Production of Hydrogen Gas]: [[Penn State University]].
* [http://pathema.tigr.org/tigr-scripts/Clostridium/PathemaHomePage.cgi Pathema-''Clostridium'' Resource]
* {{patent|US|1875536}}
* {{patent|US|1315585}}
* {{cite journal | last1 = Weber | first1 = Christian | last2 = Farwick | first2 = Alexander | last3 = Benisch | first3 = Feline | last4 = Brat | first4 = Dawid | last5 = Dietz | first5 = Heiko | last6 = Subtil | first6 = Thorsten | last7 = Boles | first7 = Eckhard | title = Trends and challenges in the microbial production of lignocellulosic bioalcohol fuels | journal = Applied Microbiology and Biotechnology | date = 10 June 2010 | volume = 87 | issue = 4 | pages = 1303–1315 | doi = 10.1007/s00253-010-2707-z | pmid = 20535464 | issn = 01757598}}

[[Category:Clostridiaceae]]
[[Category:Biofuels]]
[[Category:Gram-positive bacteria]]

Liquid metal

2016-02-07T01:36:14Z

71.109.148.145:

{{Other uses|Liquid metal (disambiguation)}}

'''Liquid metal''' consists of [[gallium]]-containing [[alloys]] with very low melting points which form a [[eutectic]] which is liquid at room temperature.<ref name=indalloy>[http://www.indium.com/_dynamo/download.php?docid=456 Indalloy Alloys Liquid at Room Temperature]</ref> The standard metal used to be [[mercury (element)|mercury]], but gallium-based alloys are being used as a replacement in various applications. Mercury is toxic, and has a high [[vapor pressure]] at room temperature.<ref name=tim>[http://www.indium.com/TIM/solutions/liquidmetal.php Thermal Interface Materials]</ref> Gallium alloys have reduced toxicity and a lower vapor pressure than mercury.

== Thermal and electrical conductivity ==
Alloy systems that are liquid at room [[temperature]] have a high degree of [[thermal conductivity]] far superior to ordinary non-metallic liquids.<ref name=kunquan>
{{cite book
|last1=Kunquan
|first1=Ma
|last2=Jing
|first2=Liu
|title=Liquid metal cooling in thermal management of computer chips
|format=Review Article
|volume=1
|number=4
|date=October 2007
|publisher=Higher Education Press, co-published with Springer-Verlag GmbH
|doi=10.1007/s11708-007-0057-3
|issn=1673-7504
|journal=Frontiers of Energy and Power Engineering in China
|pages=384–402
}}</ref> The high degree of thermal conductivity allows liquid metal to efficiently transfer energy from the heat source to the liquid. Alloy system's also has a high electrical conductivity compared to other non-metallic liquid. The property of high electrical conductivity allows the liquid to be pumped by more efficient, electromagnetic pumps.<ref>{{Cite journal|title = Cooling of high-power-density microdevices using liquid metal coolants|url = http://scitation.aip.org/content/aip/journal/apl/85/3/10.1063/1.1772862|journal = Applied Physics Letters|date = 2004-07-19|issn = 0003-6951|pages = 506-508|volume = 85|issue = 3|doi = 10.1063/1.1772862|first = A.|last = Miner|first2 = U.|last2 = Ghoshal}}</ref> This results in the use of these materials for specific heat conducting and/or dissipation applications. Other advantages of liquid alloy systems are their inherent high densities and electrical conductivities.

== Wetting to metallic and non-metallic surfaces ==
Once [[oxide]]s have been removed from the substrate surface, most liquid metals will wet to most metallic surfaces. Specifically though, room-temperature liquid metal can be very reactive with certain metals. Liquid metal can dissolve most metals; however, at moderate temperatures, only some are slightly soluble, such as [[sodium]], [[potassium]], [[gold]], [[magnesium]], [[lead]], [[nickel]] and interestingly [[Mercury (element)|mercury]].<ref>{{cite book
| title = The Chemistry of ALUMINUM, GALLIUM, INDIUM, and THALLIUM, Pergamon Texts in Inorganic Chemistry, {{ASIN|B0007AXLOA}}
| year = 1975
| volume = 12
| last1 = Wade
| first1 = K.
| last2 = Banister
| first2 = A. J.
}}</ref> Gallium is [[corrosive]] to all metals except [[tungsten]] and [[tantalum]], which have a high resistance to [[corrosion]]. [[Niobium]], [[titanium]] and [[molybdenum]] have resistance to corrosion, but less so than tungsten and tantalum.<ref>{{cite book
| title = Liquid Metals Handbook
| year = 1952
| edition = 2
| last1 = Lyon
| first1 = Richard N., ed.
| location = Washington, D.C.
}}</ref> Similar to [[indium]], gallium and gallium-containing alloys have the ability to wet to many non-metallic surfaces such as [[glass]] and [[quartz]].

Gently rubbing the gallium-containing alloy into the surface may help induce wetting. However, this observation of "wetting by rubbing into glass surface" has created a widely spread misconception that the gallium-based liquid metals wet glass surfaces, as if the liquid breaks free of the oxide skin and wets the glass surface. The reality is the opposite; the oxide makes the liquid wet the glass. In more details: as the liquid is rubbed into and spread onto the glass surface, the liquid oxidizes and coats the glass with a thin layer of oxide (solid) residues, on which the liquid metal wets. In other words, what is seen is a gallium-based liquid metal wetting its solid oxide, not glass. Apparently, the above misconception was caused by the super-fast oxidation of the liquid gallium in even a trace amount of oxygen, i.e., nobody observed the true behavior of a liquid gallium on glass, until C. J. Kim's group at UCLA debunked the above myth by testing [[Galinstan]], a gallium-based alloy that is liquid at room temperature, in a completely oxygen-free environment.<ref name=Liu>
{{cite book
|last1=Liu
|first1=T.
|last2=S.
|first2=Prosenjit
|last3=Kim
|first3=C.-J.
|title=Characterization of Nontoxic Liquid-Metal Alloy Galinstan for Applications in Microdevices
|format=Journal Article
|volume=21
|number=2
|date=April 2012
|publisher=IEEE
|doi=10.1109/JMEMS.2011.2174421
|journal=Journal of Microelectromechanical Systems
|pages=443–450
}}</ref> Note: These alloys form a thin dull looking oxide skin that is easily dispersed with mild [[Agitation (action)|agitation]]. The oxide-free surfaces are bright and lustrous.

== Applications ==
Typical applications for liquid metals include [[thermostats]], [[switches]], [[barometers]], [[heat transfer]] systems, and [[Thermal engineering|thermal cooling]] and heating designs.<ref>[http://www.indium.com/TIM/solutions/liquidmetal.php Liquid Metal Thermal Interface Materials]</ref> Uniquely, they can be used to conduct heat and/or electricity between non-metallic and metallic surfaces.

== Packaging ==
Liquid metal is usually packed in [[polyethylene]] bottles.

== Storage/shelf life ==
{{manual|section|date=April 2015}}
{{Unreferenced section|date=April 2015}}
Unopened bottles of liquid metal generally have a one-year shelf life. It is recommended that, as the liquid metal is removed from the bottle, the volume be replaced with dry [[argon]] gas. This will minimize the possibility of [[oxidation]] at the surface of the alloy. If the liquid metal has been stored below its [[melting point]] and has solidified, it should be re-melted and thoroughly shaken or mixed before use. Care should be taken in reheating the liquid metal in the original packaging provided. Temperatures should not exceed {{convert|65|°C|°F}}.

== General handling guidelines ==
{{manual|section|date=April 2015}}
{{Unreferenced section|date=April 2015}}
*Liquid metal may be frozen before shipping and shipped in a solid state, to avoid "sloshing" and uncontrolled movement.
*Liquid metal should be shipped in accordance with the applicable international regulations and reported as a [[corrosive]] liquid. Liquid metals are prohibited on most airlines. Due to their corrosive nature, they should not be put in contact with most other metals.
*Liquid metal may be stored at room temperatures, in a cool, dry area away from incompatible materials, including [[hydrogen peroxide]], [[hydrochloric acid]], and [[Halogenation|halogenated]] chemicals.
*Before use, liquid metal should be allowed to reach room temperature and liquefy. Shake or mix before use.
*Allow up to four hours for solidified liquid metal to reach room temperature. Remove from storage one day before use.
*Rapid warming of liquid metal on top of an oven or by any other method is not recommended, but a temperature-controlled water bath may be used. Gallium-containing alloys are very corrosive when hot; their temperature should not exceed {{convert|65|°C|°F}}.
*Gallium-contained alloys have a specific shelf life and should be managed as a first-in, first-out (FIFO) product. Packaging should be labeled with date and time of opening.
*Gallium may be absorbed through the skin. Rubber or vinyl gloves should be worn at all times when handling gallium-containing alloys.
*It is not recommended to repackage gallium-containing alloys from their original packaging.
*As the liquid metal is removed from the packaging, it is recommended that the volume be replaced with dry [[argon]] gas to minimize the possibility of [[oxidation]] on the surface of the alloy.

== In popular culture ==
A fictional "mimetic polyalloy" is a form of liquid metal consisting entirely of microscopic [[nanobot]]s, which are used for production of a [[T-1000|Series 1000 Terminator]] in ''[[Terminator 2: Judgment Day]]''.

== See also ==
*[[Electromagnetic pump]]
*[[NaK]], [[Mercury (element)|Quicksilver]] - other metals which are liquid at room temperature

== References ==
{{Reflist}}

[[Category:Fusible alloys]]
[[Category:Brazing and soldering]]

Tetracaine

2016-02-05T22:27:46Z

71.109.148.145: spelling

{{Drugbox
| verifiedrevid = 470603479
| IUPAC_name = 2-(dimethylamino)ethyl 4-(butylamino)benzoate
| image = Tetracaine2DCSD.svg

| tradename =
| Drugs.com = {{drugs.com|monograph|tetracaine}}
| MedlinePlus = a682640
| pregnancy_AU = 
| pregnancy_US = 
| pregnancy_category =
| legal_AU = 
| legal_CA = 
| legal_UK = 
| legal_US = 
| legal_status = Rx Only
| routes_of_administration = Topical, Epidural, Spinal

| bioavailability =
| protein_bound = 75.6
| metabolism =
| elimination_half-life =
| excretion =

| CAS_number_Ref = {{cascite|correct|??}}
| CAS_number = 94-24-6
| CAS_supplemental = {{CAS|136-47-0}} ([[hydrochloride]]) 
| ATC_prefix = C05
| ATC_suffix = AD02
| ATC_supplemental = {{ATC|D04|AB06}} {{ATC|N01|BA03}} {{ATC|S01|HA03}}
| PubChem = 5411
| DrugBank_Ref = {{drugbankcite|correct|drugbank}}
| DrugBank =
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 5218
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 0619F35CGV
| KEGG_Ref = {{keggcite|correct|kegg}}
| KEGG = D00551
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI = 9468
| ChEMBL_Ref = {{ebicite|correct|EBI}}
| ChEMBL = 698
| PDB_ligand = TE4

| C=15 | H=24 | N=2 | O=2
| molecular_weight = 264.363 g/mol
| smiles = O=C(OCCN(C)C)c1ccc(NCCCC)cc1
| InChI = 1/C15H24N2O2/c1-4-5-10-16-14-8-6-13(7-9-14)15(18)19-12-11-17(2)3/h6-9,16H,4-5,10-12H2,1-3H3
| InChIKey = GKCBAIGFKIBETG-UHFFFAOYAR
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C15H24N2O2/c1-4-5-10-16-14-8-6-13(7-9-14)15(18)19-12-11-17(2)3/h6-9,16H,4-5,10-12H2,1-3H3
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = GKCBAIGFKIBETG-UHFFFAOYSA-N
}}
'''Tetracaine''' ([[International Nonproprietary Name|INN]], also known as '''amethocaine'''; trade name '''Pontocaine'''. '''Ametop''' and '''Dicaine''') is a potent [[local anesthetic]] of the [[ester]] group. It is mainly used [[topical anesthetic|topically]] in [[ophthalmology]] and as an [[antipruritic]], and it has been used in [[spinal anesthesia]].

In [[biomedical research]], tetracaine is used to alter the function of calcium release channels ([[ryanodine receptor]]s) that control the release of calcium from intracellular stores. Tetracaine is an [[allosteric regulation|allosteric blocker]] of channel function. At low concentrations, tetracaine causes an initial inhibition of spontaneous calcium release events, while at high concentrations, tetracaine blocks release completely.<ref>{{cite journal|last=Györke|first=S|author2=Lukyanenko, V|title=Dual effects of tetracaine on spontaneous sodium release in rat ventricular myocytes|publisher=J Physiol|volume=500|issue=2|year=1997|pages=297–309|display-authors=etal}}</ref>

Tetracaine is the T in ''Tac'', a mixture of 5 to 12 per cent tetracaine, 0.05 per cent [[adrenaline]], and 4 or 10 per cent [[cocaine]] hydrochloride used in ear, nose & throat surgery and in the emergency department where numbing of the surface is needed rapidly, especially when children have been injured in the eye, ear, or other sensitive locations.<ref>Appleton's Nursing Manual - "Cocaine"</ref>


It is on the [[World Health Organization's List of Essential Medicines]], a list of the most important medication needed in a basic [[health system]].<ref>{{cite web|title=WHO Model List of EssentialMedicines|url=http://apps.who.int/iris/bitstream/10665/93142/1/EML_18_eng.pdf?ua=1|work=World Health Organization|accessdate=22 April 2014|date=October 2013}}</ref>

A [[systematic review]] investigated tetracaine for use in emergency departments, especially for IV cannulation in children, in view of its analgesic and cost-saving properties - however it did not find a statistically significant improvement in first attempt cannulations.<ref>{{cite journal|last=Pywell|first=A|author2=Xyrichis, A |title=Does topical Amethocaine cream increase first-time successful cannulation in children compared with a eutectic mixture of local anaesthetics (EMLA) cream? A systematic review and meta-analysis of randomised controlled trials|publisher=Emerg Med J|volume=0|issue=0|year=2014|pages=1–5|doi=10.1136/emermed-2014-204066}}</ref>

==References==
{{Reflist}}

==Further reading==
*O. Eisleb, {{US Patent|1889645}} (1932).

{{Vasoprotectives}}

{{nervous-system-drug-stub}}

[[Category:Local anesthetics]]
[[Category:Ethyl esters]]
[[Category:World Health Organization essential medicines]]

Tetracaine

2016-02-05T22:27:10Z

71.109.148.145: Four different orthographies of the same value in one sentence? No.

{{Drugbox
| verifiedrevid = 470603479
| IUPAC_name = 2-(dimethylamino)ethyl 4-(butylamino)benzoate
| image = Tetracaine2DCSD.svg

| tradename =
| Drugs.com = {{drugs.com|monograph|tetracaine}}
| MedlinePlus = a682640
| pregnancy_AU = 
| pregnancy_US = 
| pregnancy_category =
| legal_AU = 
| legal_CA = 
| legal_UK = 
| legal_US = 
| legal_status = Rx Only
| routes_of_administration = Topical, Epidural, Spinal

| bioavailability =
| protein_bound = 75.6
| metabolism =
| elimination_half-life =
| excretion =

| CAS_number_Ref = {{cascite|correct|??}}
| CAS_number = 94-24-6
| CAS_supplemental = {{CAS|136-47-0}} ([[hydrochloride]]) 
| ATC_prefix = C05
| ATC_suffix = AD02
| ATC_supplemental = {{ATC|D04|AB06}} {{ATC|N01|BA03}} {{ATC|S01|HA03}}
| PubChem = 5411
| DrugBank_Ref = {{drugbankcite|correct|drugbank}}
| DrugBank =
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 5218
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 0619F35CGV
| KEGG_Ref = {{keggcite|correct|kegg}}
| KEGG = D00551
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI = 9468
| ChEMBL_Ref = {{ebicite|correct|EBI}}
| ChEMBL = 698
| PDB_ligand = TE4

| C=15 | H=24 | N=2 | O=2
| molecular_weight = 264.363 g/mol
| smiles = O=C(OCCN(C)C)c1ccc(NCCCC)cc1
| InChI = 1/C15H24N2O2/c1-4-5-10-16-14-8-6-13(7-9-14)15(18)19-12-11-17(2)3/h6-9,16H,4-5,10-12H2,1-3H3
| InChIKey = GKCBAIGFKIBETG-UHFFFAOYAR
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C15H24N2O2/c1-4-5-10-16-14-8-6-13(7-9-14)15(18)19-12-11-17(2)3/h6-9,16H,4-5,10-12H2,1-3H3
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = GKCBAIGFKIBETG-UHFFFAOYSA-N
}}
'''Tetracaine''' ([[International Nonproprietary Name|INN]], also known as '''amethocaine'''; trade name '''Pontocaine'''. '''Ametop''' and '''Dicaine''') is a potent [[local anesthetic]] of the [[ester]] group. It is mainly used [[topical anesthetic|topically]] in [[ophthalmology]] and as an [[antipruritic]], and it has been used in [[spinal anesthesia]].

In [[biomedical research]], tetracaine is used to alter the function of calcium release channels ([[ryanodine receptor]]s) that control the release of calcium from intracellular stores. Tetracaine is an [[allosteric regulation|allosteric blocker]] of channel function. At low concentrations, tetracaine causes an initial inhibition of spontaneous calcium release events, while at high concentrations, tetracaine blocks release completely.<ref>{{cite journal|last=Györke|first=S|author2=Lukyanenko, V|title=Dual effects of tetracaine on spontaneous sodium release in rat ventricular myocytes|publisher=J Physiol|volume=500|issue=2|year=1997|pages=297–309|display-authors=etal}}</ref>

Tetracaine is the T in ''Tac'', a mixture of 5 to 12 per cent tetracaine, 0.05 per cent [[adrenaline]], and 4 or 10 per cent [[cocaine]] hydrochloride used in ear, nose & throat surgery and in the emergemcy department where numbing of the surface is needed rapidly, especially when children have been injured in the eye, ear, or other sensitive locations.<ref>Appleton's Nursing Manual - "Cocaine"</ref>


It is on the [[World Health Organization's List of Essential Medicines]], a list of the most important medication needed in a basic [[health system]].<ref>{{cite web|title=WHO Model List of EssentialMedicines|url=http://apps.who.int/iris/bitstream/10665/93142/1/EML_18_eng.pdf?ua=1|work=World Health Organization|accessdate=22 April 2014|date=October 2013}}</ref>

A [[systematic review]] investigated tetracaine for use in emergency departments, especially for IV cannulation in children, in view of its analgesic and cost-saving properties - however it did not find a statistically significant improvement in first attempt cannulations.<ref>{{cite journal|last=Pywell|first=A|author2=Xyrichis, A |title=Does topical Amethocaine cream increase first-time successful cannulation in children compared with a eutectic mixture of local anaesthetics (EMLA) cream? A systematic review and meta-analysis of randomised controlled trials|publisher=Emerg Med J|volume=0|issue=0|year=2014|pages=1–5|doi=10.1136/emermed-2014-204066}}</ref>

==References==
{{Reflist}}

==Further reading==
*O. Eisleb, {{US Patent|1889645}} (1932).

{{Vasoprotectives}}

{{nervous-system-drug-stub}}

[[Category:Local anesthetics]]
[[Category:Ethyl esters]]
[[Category:World Health Organization essential medicines]]

Talk:Cortisone

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{{WPPHARM|class=Start|importance=High}}
{{Chemicals|core|class=B|importance=Mid}}

== Cortisone != cortisol ==

Made by Calvin Donnell —Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[Special:Contributions/75.55.38.127|75.55.38.127]] ([[User talk:75.55.38.127|talk]]) 21:47, 16 September 2008 (UTC) 
As far as I can judge, this article describes the hormone [[cortisol]] not cortisone. Cortisone, in my vocabulary, is a medical substance acting like cortisol. I am however not [[Wikipedia:Be bold in updating pages|bold]] enough to go ahead mess around with this in English, not being a native English speaker - but if no objections arrive I will adjust this article according to my view on the subject. // [[User:Habj|Habj]] 19:59, 21 January 2006 (UTC)

AFAIK, cortisone is synthetic cortisol. Also, Corticosterone is refered to here as unimportant. Yes, in human health as humans do not express it: It is the rodent version of cortisol. The claim that cortisol/cortisone is responsible for stress/ill-health correlation is oversimplistic. 1. In chronic stress cort. becomes downregulated and AVP becomes the major driver of the HPA axis, and hence the major driver of immune inhibition; 2. The autonomic nervous system also plays a major role in damping down immune responses during stress; 3. Autoimmune diseases actually benefit from high cortisol levels. There are many other substances that mediate immune supression eg substance P, NF kappa beta etc. It seems to be a problem here that the chemistry project run pages on biological molecules are over-simplistic wrt to the biology. Is there no biochemistry/cellular biology project similar to the chemistry one? I support the above edit.[[User:Povmcdov|Povmcdov]] 15:47, 25 February 2007 (UTC)

[[Special:Contributions/116.199.208.54|116.199.208.54]] ([[User talk:116.199.208.54|talk]]) 19:48, 5 October 2008 (UTC)Cortisol? = cortisone??, also known as the stress hormone (steriod hormone). and clinical depression is influenced by the high levels of cortisol in the body/brian.
Effects memory. peoples ability to encode memory drop when levels of cortisol is elevated.
exercise can lower levels of cortisol[[Special:Contributions/116.199.208.54|116.199.208.54]] ([[User talk:116.199.208.54|talk]])

== Image found on commons ==

[[Image:Cortisone.png|thumb|200px|right|Differs in presentation from image currenly in article]] —The preceding [[Wikipedia:Sign your posts on talk pages|unsigned]] comment was added by [[User:Leonard G.|Leonard G.]] ([[User talk:Leonard G.|talk]] • [[Special:Contributions/Leonard G.|contribs]]) 06:45, 19 December 2006 (UTC).

Be careful! There is a mistake in the article: this is not a steroid-like structure on the picture!
Look on the right for the structure:

:Both the image in the article and the image on this page represent the same chemical compound - and they both have steroid structure. I don't see a mistake in either. The one in the article, however, is preferred because it contains additional stereochemical information that is not present in this one. --[[User:Edgar181|Ed]] ([[User talk:Edgar181|Edgar181]]) 14:52, 30 April 2007 (UTC)

== Uses? ==

Effects and Uses section is weak. What '''are''' the uses? It seems there are some paragraphs missing. The 3rd paragraph begins: "''One of cortisone's effects on''..." -- it seems the writer assumes we already know what cortisone is used for, when he starts talking about side-effects. But his previous 2 paragraphs have nothing to that effect.

All that he says (in the preceding para) is: "...''sometimes used as a drug to treat a variety of ailments''..." -- duh? Of course it is; but .. '''what''' ailments? And how? Details, details.

Very surprising that this is omitted; the largest part of any Wiki article about any drug should be what it is used for. I understand that cortisone is used for arthritis; can this be confirmed? There should be an entire section devoted to this, if so.

Lots of work needed to clean this article up, I'm afraid. —Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[User:Atikokan|Atikokan]] ([[User talk:Atikokan|talk]] • [[Special:Contributions/Atikokan|contribs]]) 01:04, 9 March 2008 (UTC) 

I am interested in potential side effects. Some years ago my doctor injected both my shoulders and elbows with cortisone because I had severe inflamation in the joints. Within weeks I gained about 60 pounds in weight and despite dieting I am unable to lose the extra weight. Yet doctors insist that my weight gain is not related to the injections. [[User:The Geologist|The Geologist]] ([[User talk:The Geologist|talk]]) 13:22, 11 March 2008 (UTC)

I am also interested in more detail on how cortisone is used and how it works. I'm most familiar with it in the context of getting a cortisone shot for muscular and joint problems; would like to know what it does to help these problems, as suppressing the immune system doesn't seem directly applicable!
[[User:Tlibson|Lyn]] ([[User talk:Tlibson|talk]]) 16:30, 20 October 2009 (UTC)

==Lewis Hastings Sarett==
Should [[Lewis Hastings Sarett]] be mentioned? He was th chemist at Merck doing the synthesis?--[[User:Stone|Stone]] ([[User talk:Stone|talk]]) 14:38, 24 May 2008 (UTC)

==Veterinary use==
The phrase ''"Because of cortisone's effect on the immune system, dogs treated with even moderate doses show an increase in thirst and urination frequency"'', doesn't make any sense.
Cortisone does have an effect on the immune system, but this has no direct effect on the kidneys.
It has some direct on the kidneys, and possibly, direct effects on thirst centres - hence the effects on urination and thirst —Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[User:Excelis4|Excelis4]] ([[User talk:Excelis4|talk]] • [[Special:Contributions/Excelis4|contribs]]) 08:58, 18 February 2010 (UTC) 

I agree. The reference is also probably incorrectly formatted, as it should refer to the actual paper in the Bonagura volume, where Bonagura is the editor. [[User:John Duncan|John Duncan]] ([[User talk:John Duncan|talk]]) 14:18, 17 July 2010 (UTC)

Agreed. This statement as presented is generally misleading and essentially incorrect (any effect on fluid balance is likely due to a minimal mineralcorticoid effect, which in some instances are suppressed by exogenous glucocorticoid), further this statement is unsourced. I will remove it. --[[Special:Contributions/140.198.200.21|140.198.200.21]] ([[User talk:140.198.200.21|talk]]) 16:10, 11 July 2011 (UTC)

== Could someone rewrite the first paragraph? ==

It reads really odd.[[Special:Contributions/94.234.170.2|94.234.170.2]] ([[User talk:94.234.170.2|talk]]) 13:28, 6 September 2011 (UTC)

== John F. Kennedy ==

Unknown at the time of the [[United States presidential election, 1960|1960 Presidential election]], President [[John F. Kennedy]] took Cortisone supplements to counter the adrenal deficiency symptoms of [[Addison's Disease]], which he denied having.<ref>http://www.pbs.org/newshour/character/essays/kennedy.html</ref><ref>{{cite news| url=http://www.nytimes.com/1992/10/06/health/the-doctor-s-world-disturbing-issue-of-kennedy-s-secret-illness.html?pagewanted=all&src=pm | work=The New York Times | first1=Lawrence K. | last1=Altman | title=THE DOCTOR'S WORLD; Disturbing Issue of Kennedy's Secret Illness | date=1992-10-06}}</ref>

This reference amounts to a bit of trivia added to the end of the history of the drug. If there is some reason why it belongs (Kennedy were to have been taking it as a test subject, etc., part of early research in the 1950s and so on, and the editor can establish this, and so on, then there is a place for it. Otherwise, it does not belong here in the main history section and in the absence of another section to which to relocate it, I am removing it. I am leaving it here in case someone wants to add a paragraph where this would be appropriate (list of famous people who have taken cortisone, or something like that). — Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[Special:Contributions/132.174.192.68|132.174.192.68]] ([[User talk:132.174.192.68|talk]]) 17:00, 30 January 2013 (UTC) 

== IUPAC name wrong? ==

I observe that the IUPAC name for [[Prednisone]] differs very substantially from [[Cortisone]] even though the only difference is a diene -> ene. IANAOC, and I know small changes in structure CAN lead to vastly different namings, but in this case, since the "front to back" nature of the molecule doesn't change, I am surprised by the profound difference. Can someone check this?

Talk:Prednisone

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{{talkheader}}
{{Reliable sources for medical articles}}
,
{{WikiProject Pharmacology|class=C|importance=high}}

==Used after heart valve transplants?==

Is this drug used to prevent rejection following cadaveric heart valve transplants? —Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[Special:Contributions/124.169.242.226|124.169.242.226]] ([[User talk:124.169.242.226|talk]]) 14:25, 7 August 2010 (UTC) 

== Correction ==

I'm just deleting a line within the article -

''Other side effects include osteoporosis,reduced immune response,hunger,emotional efects and gassiness.''

Osteoporosis is mentioned in the previous sentence, and immune suppression is discussed earlier in the article, so it's a redundant sentence.
Cheers, Dylan.

== Corticosteroid misconceptions ==

Personally, I read a wack of things from linguistics to anatomy. I don't just read the nice happy-bunny stuff, but I enjoy controversial things too that would make most people wince. Guess I'm weird. One funny internet myth that I detect from my google searches is a dangerous confusion between [[corticosteroids]] and [[anabolic steroids]].

While they are both types of "steroids", the name only refers to their chemical similarity, not their similarity vis-a-vis their functionality within the human body. There are many comical posts available online from people who unfortunately mistake these two very different chemicals. They honestly are mistaken in thinking that they are going to look like [[Arnold Schwarzennagger]] if they take [[prednisone]]. Yikes!

So I'm just thinking that since Wikipedia is meant to be NPOV in its information, it would be a positive move to add a section about popular myths and misconceptions like this one. (And I know, some may object to anyone taking steroids for bodybuilding because of many countries illegalizing its use for recreational purposes but again Wikipedia isn't about hasty puritanical judgement. It's just here to display facts to promote knowledge and education.) Dunno. Thoughts? --[[User:Glengordon01|Glengordon01]] 04:34, 18 August 2006 (UTC)

:There are generally misconceptions as to what the word "steroid" means. Plants produce steroids. Also, your talk page, and the "Arnold schwarzennagger" made me giggle. [[User:James.Spudeman|James.Spudeman]] 21:57, 24 February 2007 (UTC)

== Topical corticosteroids ==

Could topical corticosteroids cause adrenal suppresion? —The preceding [[Wikipedia:Sign your posts on talk pages|unsigned]] comment was added by [[User:Happathyapathy|Happathyapathy]] ([[User talk:Happathyapathy|talk]] • [[Special:Contributions/Happathyapathy|contribs]]) 03:39, 22 January 2007 (UTC).

==Increased sex drive ==

The article notes that prednisone can cause increased sex drive, which appears to be the opposite of what I find in a google search: [http://www.google.co.nz/search?hl=en&safe=off&q=prednisone+%22sex+drive%22&btnG=Search&meta= prednisone ''reduces'' sex drive]. I will edit accordingly. —The preceding [[Wikipedia:Sign your posts on talk pages|unsigned]] comment was added by [[User:Ppe42|Ppe42]] ([[User talk:Ppe42|talk]] • [[Special:Contributions/Ppe42|contribs]]) 02:05, 30 March 2007 (UTC).

==Side Effects List ==

For each side effect listed, major and minor, two parameters are of interest: (a) the fraction of patients who would experience this side effect, and (b) the severity of this side effect on quality of life. A debilitating side effect that affects only a few could be as undesirable as a benign side effect that affects a majority. I wish someone could provide such additional information. —Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[User:LoopTel|LoopTel]] ([[User talk:LoopTel|talk]] • [[Special:Contributions/LoopTel|contribs]]) 22:12, 10 November 2007 (UTC) 

== Is there a doctor in the house? ==

I'm a layman who requested a citation for a recently added statement in section ''Dependency'', "For those on chronic therapy, alternate-day dosing may preserve adrenal function, thereby reducing side effects", simply because I have not heard of this approach before. The citation offered was "(see [http://www.uspharmacist.com/NewLook/CE/glucocort/lesson.htm "Dosing Considerations"])." I'm still somewhat uncomfortable after reading the citation, so I'm asking for a professional opinion: Does the citation support the statement? No disrespect intended to the original submitter, but I get antsy about broad statements that might induce someone to change their drug regimen, even if this is only Wikipedia. --[[User:CliffC|CliffC]] 23:58, 8 May 2007 (UTC)
: Please see the [[Wikipedia:Medical disclaimer|disclaimer]]: you should not be using WikiPedia for medical information, you MUST see a doctor! --[[User:Pv7721|Vlad]]|[[User talk:Pv7721|->]] 22:01, 14 November 2007 (UTC)
::Stay calm, I'm not counting on Wikipedia for accuracy in ''anything''. As I say above, "No disrespect intended to the original submitter, but I get antsy about broad statements that might induce someone to change their drug regimen, even if this is only Wikipedia." It bothers me when I see postings where the poster repeats what he saw at some poorly-written source then can't come up with a decent citation, or worse yet, is just offering information based on personal belief. Thanks for responding. --[[User:CliffC|CliffC]] 00:42, 15 November 2007 (UTC)
:::I'm calm, but you're right about a point: this is WikiPedia, the free encyclopedia that ANYONE (including you! :D) can edit. So of course I guess that if you think something is wrong, the best thing to do is to fix it! All the best! --[[User:Pv7721|Vlad]]|[[User talk:Pv7721|->]] 20:36, 17 November 2007 (UTC)

== History ==
There may be a problem. My father, who died of Hodgkins Disease in 1962, was taking Prednisone (and later the generic hydrocortisone) for several years... and complaining bitterly about the high price of the former.
[[User:Dick Kimball|Dick Kimball]] 06:18, 15 October 2007 (UTC)

==new question==
Perhaps someone can answer this question! I take pred for my cluster headaches! I have been on several tapers, the last one in June of this year! If I go below 10 mg. my headaches come back! If I stay at 10 mg. I have few or none! My question is, if I stay on 10Mg. is that dose enough to still effect the other bad things that come in higher doses?InsertformulahereThanks, EOD
: Again, see my previous answer to a similar question: WikiPedia CAN NOT replace a real doctor! So only a doctor can give you an accurate answer to your question! --[[User:Pv7721|Vlad]]|[[User talk:Pv7721|->]] 22:04, 14 November 2007 (UTC)
: I agree with the above, you need to see a doctor. All I can tell you is my own experience - I have just re-started prednisone for a recurring erythema nodosum, and in my previous attempts to wean off the drug, if I ever went down below 5 or 10 mg/day, my condition sometimes would have a rebound flare-up. Even at 5 mg/day, there can be long-lasting side-effects, such as osteoporosis, and lingering Cushing's Sydrome. Talk to a doctor or a pharmacist. — Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[User:Shanninsky|Shanninsky]] ([[User talk:Shanninsky|talk]] • [[Special:Contributions/Shanninsky|contribs]]) 11:48, 25 July 2011 (UTC) 

== Capitalization ==

This article mainly uses P/prednisone at the beginnings of sentences. It's hard to tell whether it is a proper name or not ... I'll use a non-wiki source to figure it out. [[User:Boris B|Boris B]] ([[User talk:Boris B|talk]]) 23:11, 22 February 2008 (UTC)

:Good point. Prednisone isn't a proper name. I'll try to reword a sentence to illustrate this fact. [[User:WDavis1911|WDavis1911]] ([[User talk:WDavis1911|talk]]) 20:16, 24 February 2008 (UTC)

== History, again ==
Hate to nitpick, but this sentence:

"Prednisone was invented in the early 1950s when Arthur Nobile at Schering, strep throat demonstrated that the side-effects of cortisone, such as water retention, high blood pressure and muscle weakness, could be removed by oxidisation of the drug through exposure to microbes."

...just doesn't parse. Some words are needed between "Schering" and "strep throat," otherwise it
makes no sense. Thanks.
--User:Myles Callum —Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[User:MylesCallum|MylesCallum]] ([[User talk:MylesCallum|talk]] • [[Special:Contributions/MylesCallum|contribs]]) 06:22, 26 October 2008 (UTC) 

: You're not being picky - you just found an [http://en.wikipedia.org/w/index.php?title=Prednisone&diff=240317682&oldid=239280379 random nonsense edit] from a few weeks ago. Fixed now. -- [[User:MarcoTolo|MarcoTolo]] ([[User talk:MarcoTolo|talk]]) 20:22, 26 October 2008 (UTC)

== Ceruloplasmin ==
Can anyone confirm that Prednisone can increase Ceruloplasmin levels? —Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[User:Tradingbr|Tradingbr]] ([[User talk:Tradingbr|talk]] • [[Special:Contributions/Tradingbr|contribs]]) 17:49, 16 September 2009 (UTC) 

== Prednisone for the eyes ==

My eye doctor uses Prednisone for my PIC. I thought it was just to help with my Avastin injections in my eye, but according to this article it looks like he is trying to prevent the primary problem of the PIC-- which is my white blood cells destroying my retinas. Does anyone have any actual documented information about this? Thank you.
[[User:KatTrombone|KatTrombone]] ([[User talk:KatTrombone|talk]]) 16:22, 11 November 2009 (UTC)

;Prednisolone Acetate (produced as a 1% ophthalmic suspension by Allergan) is also used following cataract surgery in some cases.[[Special:Contributions/32.97.110.56|32.97.110.56]] ([[User talk:32.97.110.56|talk]]) 19:09, 30 April 2010 (UTC)Dave

Apparently it is also used to treat post-operative PRK eye surgery (e.g., brand name Pred Forte) as eye drops, to avoid scar tissue formation during healing. —Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[Special:Contributions/207.81.141.90|207.81.141.90]] ([[User talk:207.81.141.90|talk]]) 21:56, 1 October 2010 (UTC) 

== prednisone side effects ==

Prednisone taken for long periods &/or high doses has very serious side effects not emphasized in the general article.
My husband has both legs amputated above the knee [infected again], blind, impotent & internal damage such as an enlarged heart. The worse result was the masking of diabetes until it was too late.
prednisone diabetes coricosteroids cvro--[[User:Buddyboy999|Buddyboy999]] ([[User talk:Buddyboy999|talk]]) 16:30, 13 December 2009 (UTC)

What is considered "long term" use of prednisone? My husband has been on it for 2/12 - 3 months. This med causes brittle bones and my husband just broke a rib by cleaning the toilet. I've noticed mood swings as well as adema in his ankle. From discussing the matter with family members who are in the medical profession, a mild antidepressant is commonly prescribed with Prednisone. At what point in time is that supposed to happen?

Malia —Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[Special:Contributions/63.171.1.2|63.171.1.2]] ([[User talk:63.171.1.2|talk]]) 17:14, 11 May 2010 (UTC) 

== COPD ==

My Mother's Doctor insist that she has COPD and prescribes Prednisone to treat it, which in turn drives her blood sugar above 400. I have not seen anything that indicates Ped as a treatment for COPD. Is it used for COPD? —Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[Special:Contributions/71.203.157.54|71.203.157.54]] ([[User talk:71.203.157.54|talk]]) 01:24, 30 June 2010 (UTC) 

== New template added ==

I have added the expert template with hopes of getting some more eyes on this article to help clean it up and make it a better article. I came to this article for information as a reader not an editor and found it to be of no use to me as it is, sorry. I will also notify the wiki projects listed above that may have an interest in this article. Thanks, --[[User:Crohnie|'''Crohnie''''''Gal''']][[User talk:Crohnie|Talk]] 12:54, 11 August 2010 (UTC)

==Half-life of 1 hour?==
Who put that the half-life of prednisone is 1 hour? I don't think that is true, and it concerns me because 1-2 hours is the time of peak bio absorption. The half-life is 3.4 to 3.8 hours.<ref>[http://www.drugs.com/ppa/prednisone.html Drugs.com, Prednisone Professional Prescribing Info]</ref> This drug is active in humans for almost 36 hours: how could that be with a half-life of only 1 hour? Makes no sense to me. A physician or Ph.D biochemist care to comment? [[User:Jack B108|Jack B108]] ([[User talk:Jack B108|talk]]) 21:03, 11 September 2010 (UTC)

::OK, I should have checked more carefully before the above post, as it appears that 1 h is the '''biological''' half-life of this drug. Perhaps the confusion is in that prednisone is not the active drug: its metabolite prednisolone is the important agent, and it has a longer '''plasma''' half-life. [[User:Jack B108|Jack B108]] ([[User talk:Jack B108|talk]]) 21:17, 11 September 2010 (UTC)

OK, but the article should mention that the half-life of prednisolone is more important than the half-life of prednisone. Also, the wiki page for prednisolone says the half-life is 2-3 hours, yet my doctor and http://www.globalrph.com/corticocalc.htm both report that the half-life of "prednisone" (not specifying the active drug) is 18 to 36 hours. [[Special:Contributions/99.28.64.176|99.28.64.176]] ([[User talk:99.28.64.176|talk]]) 02:49, 23 December 2010 (UTC)Jack Schmidt (not Jack B108) 22 December 2010

==History again==
Is there a source for this?

"The patent though was stolen by Arthur Nobile and a patent war ensued, Nobile was fired from Schering Corporation, but the patenter name was never changed to Hershel Herzog and William Charney."

Pretty much everything I've found so far indicates that Nobile was the patenter and I've found no other mention of any "patent war" or other dispute. Could just be my failing at search engine navigation. Scott Stillwell, 26 May 2011 — Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[Special:Contributions/99.169.55.153|99.169.55.153]] ([[User talk:99.169.55.153|talk]]) 06:14, 26 May 2011 (UTC) 

== can high dose 40mg+ cause facial hair to grow on women? ==

need to know considering stopping asap. thanks
Vee[[Special:Contributions/71.11.163.246|71.11.163.246]] ([[User talk:71.11.163.246|talk]]) 22:21, 29 August 2011 (UTC)

:Please see our [[Wikipedia:Medical disclaimer|medical disclaimer]]: do '''not''' use Wikipedia to make medical decisions or for medical advice. -- [[User:John Broughton|John Broughton]] [[User talk:John Broughton |(♫♫)]] 23:32, 2 October 2012 (UTC)

== first time ==

one time user should I be worried about side effects? — Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[Special:Contributions/76.103.52.47|76.103.52.47]] ([[User talk:76.103.52.47|talk]]) 19:02, 14 October 2012 (UTC) 

== Micrograph context ==

The micrograph of a fatty liver is excellent, but is likely very difficult to interpret for those who are not used to studying histological sections of normal livers. The image would be more useful if a normal tissue section was included as a separate panel so that the reader can easily see the difference.

== IUPAC name wrong? ==

I observe that the IUPAC name for [[Prednisone]] differs very substantially from [[Cortisone]] even though the only difference is a diene -> ene. IANAOC, and I know small changes in structure CAN lead to vastly different namings, but in this case, since the "front to back" nature of the molecule doesn't change, I am surprised by the profound difference. Can someone check this?

Percy Lavon Julian

2016-02-02T10:35:12Z

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{{Use mdy dates|date=October 2011}}
{{Infobox person
| name = Percy Lavon Julian
| image = Percy Lavon Julian.jpg
| image_size = 250px
| caption = Julian circa 1940–1950
| birth_date = {{birth date|1899|4|11|mf=y}}
| birth_place = [[Montgomery, Alabama]]
| death_date = {{death date and age|1975|4|19|1899|4|11|mf=y}}
| death_place = [[Waukegan, Illinois]]
| occupation = [[Chemist]]
| nationality = American
| alma_mater = [[DePauw University]] (BA) [[Harvard University]] (MS) [[University of Vienna]] (PhD)
| spouse = Anna Roselle Johnson (1901-1994)
| parents = Elizabeth Lena Adams (1878–?) James Sumner Julian (1871–1951)
| children = Percy Lavon Julian, Jr. (1940–2008) Faith Roselle Julian (1944– )
| faith = Christian
}}

'''Percy Lavon Julian''' (April 11, 1899 – April 19, 1975) was an American research [[chemist]] and a pioneer in the [[chemical synthesis]] of medicinal [[medication|drugs]] from plants.<ref name="Stille" /> He was the first to synthesize the natural product [[physostigmine]], and a pioneer in the industrial large-scale chemical synthesis of the human hormones [[progesterone]] and [[testosterone]] from [[plant sterols]] such as [[stigmasterol]] and sitosterol. His work laid the foundation for the [[steroid]] drug industry's production of [[cortisone]], other [[corticosteroid]]s, and [[combined oral contraceptive pill|birth control pill]]s.<ref name="PBS.org" /><ref name="ChemHeritage.org" /><ref name="USDA-a" /><ref name="AOCS" />

He later started his own company to synthesize steroid intermediates from the wild [[Mexican yam]]. His work helped greatly reduce the cost of steroid intermediates to large multinational pharmaceutical companies, helping to significantly expand the use of several important drugs.<ref name="NOVA" /><ref name="JNMA" />

Julian received more than 130 chemical patents. He was one of the first [[African Americans]] to receive a doctorate in [[chemistry]]. He was the first African-American [[chemist]] inducted into the [[United States National Academy of Sciences|National Academy of Sciences]], and the second African-American scientist inducted (behind [[David Blackwell]]) from any field.<ref name="NOVA" />

== Early life and education ==

Percy Julian was born in [[Montgomery, Alabama]], as the first child of six born to James Sumner Julian and Elizabeth Lena Julian, née Adams. Both of his parents were graduates of what was to be [[Alabama State University]]. His father, James, whose own father had been a [[History of slavery in the United States|slave]], was employed as a clerk in the Railway Service of the [[United States Post Office]], while his mother, Elizabeth, worked as a schoolteacher.<ref name=1930census /><ref name="Time-1975.05.05" /><ref>[[Media:1900 census Julian.jpg|Julian family]] in the [[United States Census, 1900|1900 U.S. Census]]; [[Montgomery, Alabama]]; James lived with his wife's siblings: Mather P. Adams (1884–? ); George Adams (1886–? ); Carrie L. Adams (1891–? ); Ethel M. Adams (1893–? ). James is listed as a mail carrier.</ref> Percy Julian grew up in the time of racist [[Jim Crow laws|Jim Crow]] culture and legal regime in the southern United States. Among his childhood memories was finding a [[lynching|lynched]] man hanged from a tree while walking in the woods near his home. At a time when access to an education beyond the eighth grade was extremely rare for African-Americans, Julian's parents steered all of their children toward higher education.

Julian attended [[DePauw University]] in [[Greencastle, Indiana]]. The college accepted few African-American students. The segregated nature of the town forced social humiliations. Julian was not allowed to live in the college dormitories and first stayed in an off-campus boarding home, which refused to serve him meals. It took him days before Julian found an establishment where he could eat. He later found work firing the furnace, waiting tables, and doing other odd jobs in a fraternity house; in return, he was allowed to sleep in the attic and eat at the house. Julian graduated from DePauw in 1920 as a [[Phi Beta Kappa]] and [[valedictorian]].<ref name="DepauwNews&Media-2009.02.19" /> By 1930 Julian's father would move the entire family to [[Greencastle, Indiana|Greencastle]] so that all his children could attend college at DePauw. He still worked as a railroad postal clerk.<ref name=1930census>[[1930 US Census]]; [[Greencastle, Indiana]] with [[Media:1930 census Julian.jpg|Julians]]; James owned his own home valued at $3,000. Percy Julian's siblings were James Sumner Julian II (1903–?) (Honorary Depauw 1970); Mattie Julian Brown (c 1905–1992) (Depauw 1926); Elizabeth Julian White (c 1907–2007) (Depauw 1928); Irma D. Julian Raybon (1912–1990) (Depauw 1933); and Emerson R. Julian (1917–1978) (Depauw 1938).</ref>

After graduating from DePauw, Julian wanted to obtain his doctorate in chemistry, but learned it would be difficult for an African-American to do so. Instead he obtained a position as a chemistry instructor at [[Fisk University]]. In 1923 he received an Austin Fellowship in Chemistry, which allowed him to attend [[Harvard University]] to obtain his M.S. However, worried that Euro-American students would resent being taught by an African-American, Harvard withdrew Julian's [[teaching assistant]]ship, making it impossible for him to complete his Ph.D. at Harvard.

In 1929, while an instructor at Howard University, Julian received a [[Rockefeller Foundation]] fellowship to continue his graduate work at the [[University of Vienna]], where he earned his Ph.D. in 1931. He studied under [[Ernst Späth]] and was considered an impressive student. In Europe, he found freedom from the racial prejudices that had stifled him in the States. He freely participated in intellectual social gatherings, went to the opera and found greater acceptance among his peers.<ref>{{cite news |coauthors= |title=Percy L. Julian Is Awarded Doctorate in Chemistry. |url= |quote=Percy L. Julian, associate professor and acting head of the department of chemistry of Howard University, has been awarded his doctorate in chemistry at the [[University of Vienna]], his achievement being a combination of two years' residence abroad and the transfer of graduate credit from [[Harvard University]]. |work=Washington Post |date=August 2, 1931 |accessdate=February 14, 2007 }}</ref><ref>{{cite news |coauthors= |title=Julian Will Do Research in Chemistry in Austrian Universities. |quote=Nine members of the faculty of the college of liberal arts of Howard University have been granted leaves of absence for graduate study during 1929–1930, and one for two years beginning with the fall of 1929. Percy L. Julian will study organic chemistry and microanalysis at the [[University of Vienna]] and at [[Graz University]]. |work=Washington Post |date=June 9, 1929 |accessdate=February 14, 2007 }}</ref> Julian was one of the first African Americans to receive a Ph.D. in chemistry, after [[St. Elmo Brady]] and Dr. [[Edward M.A. Chandler]].<ref name="NOVA" /><ref name="UniversityOfIllinois" />


After returning from [[Vienna]], Julian taught for one year at [[Howard University]]. At Howard, in part due to his position as a department head, Julian became caught up in university politics, setting off an embarrassing chain of events. At university president [[Mordecai Wyatt Johnson]]'s request,<ref>{{cite web |url=http://www.pbs.org/wgbh/nova/physics/forgotten-genius.html |title=Nova 'Forgotten Genius' Transcript}}</ref> he goaded white Professor of chemistry, Jacob Shohan (Ph.D from Harvard <ref>[http://aad.archives.gov/aad/record-detail.jsp?dt=2153&mtch=60&cat=all&tf=F&q=syria&bc=&rpp=10&pg=3&rid=35283&rlst=26533,26567,29475,30114,33203,35163,35283,35356,40035,41 The National Archive.]</ref>), into resigning.<ref name="taa_june_4_1932">{{cite web |url=http://news.google.com/newspapers?nid=UBnQDr5gPskC&dat=19320604&printsec=frontpage&hl=en| title=Julian Letters Draw A Veil From H.U.|work=The Afro American|accessdate=April 14, 2014|page=1|date=June 4, 1932}}</ref><ref>Kenneth R. Manning, [http://books.google.com/books?id=a9ju9E2iah4C&pg=PA223&lpg=PA223&dq=jacob+shohan&source=bl&ots=kH4iQRlPY5&sig=erozMZqw08ML2wmAECG2nbBFf-U&hl=en&sa=X&ei=QTFNU5mmA6TjsATVioCQCA&ved=0CCYQ6AEwADgK#v=onepage&q=jacob%20shohan&f=false ''Black Apollo of Science: The Life of Ernest Everett Just''], Oxford University Press, 1983, pp. 223-24.</ref> In late May 1932, Shohan retaliated by releasing to the local African-American newspaper the letters Julian had written to him from Vienna. The letters described "a variety of subjects from wine, pretty Viennese women, music and dances, to chemical experiments and plans for the new chemical building."<ref name="taa_june_4_1932"/> In the letters, he spoke with familiarity, and with some derision, of specific members of the Howard University faculty, terming one well-known Dean, an "ass".<ref name="taa_june_4_1932"/><ref name="taa_june_18_1932">{{cite web |url=http://news.google.com/newspapers?nid=2211&dat=19320618&id=wUxGAAAAIBAJ&sjid=f-UMAAAAIBAJ&pg=2511,5176373| title=Howard University Officials Ask Letter Writing Dr. Julian To Resign|work=The Afro American|accessdate=April 14, 2014|page=1|date=June 18, 1932}}</ref>

Around this same time, Julian also became entangled in an interpersonal conflict with his laboratory assistant, Robert Thompson. Julian had recommended Thompson for dismissal in March 1932.<ref name="taa_june_18_1932_2nd">{{cite web |url=http://news.google.com/newspapers?nid=2211&dat=19320618&id=wUxGAAAAIBAJ&sjid=f-UMAAAAIBAJ&pg=2511,5176373| title=What Will Happen Next?|work=The Afro American|accessdate=April 14, 2014|page=1}}</ref> Thompson sued Julian for "[[Alienation of affections|alienating the affections]] of his wife",<ref name="taa_june_4_1932"/> Anna Roselle Thompson, stating he had seen them together in a sexual tryst. Julian counter-sued him for libel. When Thompson was fired, he too gave the paper intimate and personal letters which Julian had written to him from Vienna. Dr. Julian's letters revealed "how he fooled the [Howard] president into accepting his plans for the chemistry building"<ref name="taa_june_18_1932"/> and "how he bluffed his good friend into appointing" a professor of Julian's liking.<ref name="taa_june_18_1932"/> Through the summer of 1932, the ''[[Baltimore Afro-American]]'' published all of Julian's letters. Eventually, the scandal and accompanying pressure forced Julian to resign. He lost his position and everything he had worked for.<ref name="NOVA" />

Some happiness for Dr. Julian, however, was to come from this scandal. On December 24, 1935 he married Anna Roselle (Ph.D. in Sociology, 1937, University of Pennsylvania). They had two children: Percy Lavon Julian, Jr. (August 31, 1940 – February 24, 2008), who became a prestigious civil rights lawyer in [[Madison, Wisconsin]];<ref name="WashingtonPost-2008.03.26" /> and Faith Roselle Julian (1944– ), who still resides in their Oak Park home and often makes inspirational speeches about her father and his contributions to science.<ref name="DepauwArchive-b" />

At the lowest point in Julian's career, his former mentor, William Blanchard, threw him a much-needed lifeline. Blanchard offered Julian a position to teach [[organic chemistry]] at DePauw University in 1932. Julian then helped Josef Pikl, a fellow student at the University of Vienna, to come to the United States to work with him at DePauw. In 1935 Julian and Pikl completed the [[total synthesis]] of [[physostigmine]] and confirmed the structural formula assigned to it. [[Robert Robinson (organic chemist)|Robert Robinson]] of [[Oxford University]] in the U.K. had been the first to publish a synthesis of physostigmine, but Julian noticed that the melting point of Robinson's end product was wrong, indicating that he had not created it. When Julian completed his synthesis, the melting point matched the correct one for natural physostigmine from the [[calabar bean]].<ref name="NOVA" />

Julian also extracted [[stigmasterol]], which took its name from ''Physostigma venenosum'', the west African [[calabar bean]] that he hoped could serve as raw material for synthesis of human steroidal hormones. At about this time, in 1934, Butenandt and Fernholz, in Germany,<ref name="Butenandt" /><ref name="Fernholz" /> had shown that stigmasterol, isolated from soybean oil, could be converted to [[progesterone]] by synthetic organic chemistry.

== Private sector work: Glidden ==

In 1936 Julian was denied a professorship at DePauw for racial reasons. [[DuPont]] had offered a job to fellow chemist Josef Pikl but declined to hire Julian, despite his superlative qualifications as an organic chemist, apologizing that they were "unaware he was a Negro".<ref name="DepauwNews&Media-2009.02.19" /> Julian next applied for a job at the Institute of Paper Chemistry (IPC) in [[Appleton, Wisconsin]]. However, Appleton was a [[sundown town]], forbidding African Americans from staying overnight, stating directly: "No Negro should be bed or boarded overnight in Appleton."

Meanwhile, Julian had written to the [[Glidden (paints)|Glidden Company]], a supplier of soybean oil products, to request a five-gallon sample of the oil to use as his starting point for the synthesis of human steroidal sex hormones (in part because his wife was suffering from [[infertility]]).<ref name="ChemHeritage.org" /> After receiving the request, W. J. O'Brien, a vice-president at Glidden, made a telephone call to Julian, offering him the position of director of research at Glidden's Soya Products Division in Chicago. He was very likely offered the job by O'Brien because he was fluent in German, and Glidden had just purchased a modern continuous countercurrent solvent extraction plant from Germany for the extraction of vegetable oil from soybeans for paints and other uses.<ref name="NOVA" />

Julian supervised the assembly of the plant at Glidden when he arrived in 1936. He then designed and supervised construction of the world's first plant for the production of industrial-grade, isolated soy protein from oil-free soybean meal. Isolated [[soy protein]] could replace the more expensive milk casein in industrial applications such as coating and sizing of paper, glue for making Douglas fir plywood, and in the manufacture of water-based paints.

At the start of World War II, Glidden sent a sample of Julian's isolated soy protein to National Foam System Inc. (today a unit of [[Kidde|Kidde Fire Fighting]]), which used it to develop Aer-O-Foam,<ref name="SOSRubber" /><ref name="Time-1943.12.06" /> the U.S. Navy's beloved fire-fighting "bean soup." While it was not exactly Julian's brainchild, his meticulous care in the preparation of the soy protein made the [[fire fighting foam]] possible. When a [[hydrolysis|hydrolyzate]] of isolated soy protein was fed into a water stream, the mixture was converted into a foam by means of an aerating nozzle. The soy protein foam was used to smother oil and gasoline fires aboard ships and was particularly useful on aircraft carriers. It saved the lives of thousands of sailors and airmen.<ref name="Time-1943.12.06" /> Citing this achievement, in 1947 the [[NAACP]] awarded Julian the [[Spingarn Medal]], its highest honor.

== Steroids ==
Julian's research at [[Glidden (paints)|Glidden]] changed direction in 1940 when he began work on synthesizing [[progesterone]], [[estrogen]], and [[testosterone]] from the [[plant sterol]]s [[stigmasterol]] and [[sitosterol]], isolated from soybean oil by a [[foam]] technique he invented and patented.<ref name="PBS.org" /><ref name="ChemHeritage.org" /><ref>U.S. Patent 2,273,046</ref> At that time clinicians were discovering many uses for the newly discovered hormones. However, only minute quantities could be extracted from hundreds of pounds of the spinal cords of animals.

In 1940 Julian was able to produce 100 lb of mixed soy [[sterol]]s daily, which had a value of $10,000 (${{Inflation|US|10000|1961|r=-3|fmt=c}} today){{Inflation-fn|US}} as sex hormones. Julian was soon [[Ozonide|ozonizing]] 100 pounds daily of mixed [[sterol]] [[Bromide|dibromides]]. The soy stigmasterol was easily converted into commercial quantities of the female hormone [[progesterone]], and the first pound of progesterone he made, valued at $63,500 (${{Inflation|US|63500|1961|r=-3|fmt=c}} today),{{Inflation-fn|US}} was shipped to the buyer, [[Upjohn]],<ref>Bryan A. Wilson and Monte S. Willis, [http://labmed.ascpjournals.org/content/41/11/688.full "Percy Lavon Julian, Pioneer of Medicinal Chemistry Synthesis"], Lab Medicine.</ref> in an armored car.<ref name="AOCS" /> Production of other sex hormones soon followed.<ref name="Witkop" />

His work made possible the production of these hormones on a larger industrial scale, with the potential of reducing the cost of treating hormonal deficiencies. Julian and his co-workers obtained patents for Glidden on key processes for the preparation of progesterone and testosterone from soybean plant sterols. Product patents held by a former cartel of European pharmaceutical companies had prevented a significant reduction in wholesale and retail prices for clinical use of these hormones in the 1940s. He saved many lives with this discovery.<ref name="BusinessWeek-1945.12.22" /><ref name="Fortune-1951.05" /><ref name="Gereffi" />

On April 13, 1949, [[rheumatologist]] [[Philip Hench]] at the [[Mayo Clinic]] announced the dramatic effectiveness of [[cortisone]] in treating [[rheumatoid arthritis]]. The cortisone was produced by [[Merck & Co.|Merck]] at great expense using a complex 36-step synthesis developed by chemist [[Lewis Sarett]], starting with [[deoxycholic acid]] from cattle [[bile acid]]s. On September 30, 1949, Julian announced an improvement in the process of producing cortisone.<ref name="Gibbons 1949" /><ref name="CEN 1949" /><ref name="Lehman 1951" /><ref name="Applezweig 1962" /> This eliminated the need to use [[osmium tetroxide]], which was a rare and expensive chemical.<ref name="Gibbons 1949"/> By 1950, Glidden could begin producing closely related compounds which might have partial cortisone activity. Julian also announced the synthesis, starting with the cheap and readily available [[pregnenolone]] (synthesized from the soybean oil sterol [[stigmasterol]]) of the steroid [[cortexolone]] (also known as [[Cortodoxone|Reichstein's Substance S]]), a molecule that differed from cortisone by a single missing oxygen atom;  and possibly [[17-hydroxyprogesterone|17α-hydroxyprogesterone]] and pregnenetriolone, which he hoped might also be effective in treating rheumatoid arthritis,<ref name="Gibbons 1949"/><ref name="CEN 1949"/><ref name="Lehman 1951"/><ref name="Applezweig 1962" /><ref name="Nat.AcademyOfSciences-bio" /> but unfortunately they were not.<ref name="Applezweig 1962" />

On April 5, 1952, [[biochemist]] Durey Peterson and [[microbiologist]] Herbert Murray at [[Upjohn]] published the first report of a [[industrial fermentation|fermentation]] process for the microbial 11α-oxygenation of steroids in a single step (by common [[molds]] of the order [[Mucorales]]). Their fermentation process could produce 11α-hydroxyprogesterone or 11α-hydroxycortisone from progesterone or Compound S, respectively, which could then by further chemical steps be converted to cortisone or 11β-hydroxycortisone ([[cortisol]]).<ref name="Peterson" />

After two years, Glidden abandoned production of cortisone to concentrate on Substance S. Julian developed a multistep process for conversion of [[pregnenolone]], available in abundance from soybean oil sterols, to [[cortexolone]]. In 1952, Glidden, which had been producing progesterone and other steroids from soybean oil, shut down its own production and began importing them from Mexico through an arrangement with Diosynth (a small Mexican company founded in 1947 by [[Russell Marker]] after leaving [[Syntex]]). Glidden's cost of production of [[cortexolone]] was relatively high, so Upjohn decided to use progesterone, available in large quantity at low cost from Syntex, to produce cortisone and hydrocortisone.<ref name="Applezweig 1962"/>

In 1953, Glidden decided to leave the steroid business, which had been relatively unprofitable over the years despite Julian's innovative work.<ref name="Shurtleff" /> On December 1, 1953, Julian left Glidden after 18 years, giving up a salary of nearly $50,000 a year ({{Inflation|US|50000|1953|r=-4|fmt=eq}}){{Inflation-fn|US}} to found his own company, Julian Laboratories, Inc., taking over the small, concrete-block building of Suburban Chemical Company in [[Franklin Park, Illinois]].<ref name="ChicagoTribune-1953.12.02" /><ref name="ChicagoTribune-1963.01.06" />

On December 2, 1953, [[Pfizer]] acquired exclusive licenses of Glidden patents for the synthesis of Substance S. Pfizer had developed a fermentation process for microbial 11β-oxygenation of steroids in a single step that could convert Substance S directly to 11β-hydrocortisone (cortisol), with Syntex undertaking large-scale production of [[cortexolone]] at very low cost.<ref name="Applezweig 1962" />

== Oak Park and Julian Laboratories ==

Circa 1950, Julian moved his family to the [[Chicago]] suburb of [[Oak Park, Illinois|Oak Park]], becoming the first African-American family to reside there.<ref name="DuSableMuseum" /> Although some residents welcomed them into the community, there was also opposition. Before they even moved in, on [[Thanksgiving|Thanksgiving Day]], 1950, their home was fire-bombed. Later, after they moved in, the house was attacked with dynamite on June 12, 1951. The attacks galvanized the community, and a community group was formed to support the Julians.<ref name="NewYorkTimes-1950.11.23" /> Julian's son later recounted that during these times, he and his father often kept watch over the family's property by sitting in a tree with a shotgun.<ref name="NOVA" />

In 1953, Julian founded his own research firm, Julian Laboratories, Inc. He brought many of his best chemists, including African-Americans and women, from Glidden to his own company. Julian won a contract to provide Upjohn with $2 million worth of [[progesterone]] (equivalent to ${{Inflation|US|2|1961}} million today).{{Inflation-fn|US}} To compete against [[Syntex]], he would have to use the same [[Mexican yam]] [[Mexican barbasco trade]] as his starting material. Julian used his own money and borrowed from friends to build a processing plant in Mexico, but he could not get a permit from the government to harvest the yams. Abraham Zlotnik, a former Jewish University of Vienna classmate whom Julian had helped escape from the Nazi European holocaust, led a search to find a new source of the yam in Guatemala for the company.

In July 1956, Julian and executives of two other American companies trying to enter the Mexican steroid intermediates market appeared before a U.S. Senate subcommittee. They testified that Syntex was using undue influence to monopolize access to the Mexican yam.<ref name="Gereffi" /><ref name="U.S.SenateWonderDrugs-1957" /> The hearings resulted in Syntex signing a [[consent decree]] with the [[United States Department of Justice|U.S. Justice Department]]. While it did not admit to restraining trade, it promised not to do so in the future.<ref name="Gereffi"/> Within five years, large American [[multinational corporation|multinational]] [[Pharmaceutical company|pharmaceutical companies]] had acquired all six producers of steroid intermediates in Mexico, four of which had been Mexican-owned.<ref name="Gereffi" />

Syntex reduced the cost of steroid intermediates more than 250-fold over twelve years, from $80 per gram in 1943 to $0.31 per gram in 1955.<ref name="Gereffi" /><ref name="U.S.SenateWonderDrugs-1957" /> Competition from Upjohn and [[General Mills]], which had together made very substantial improvements in the production of progesterone from stigmasterol, forced the price of Mexican progesterone to less than $0.15 per gram in 1957. The price continued to fall, bottoming out at $0.08 per gram in 1968.<ref name="Gereffi" /><ref name="Applezweig 1962" />

In 1958, [[Upjohn]] purchased 6,900 kg of progesterone from Syntex at $0.135 per gram, 6,201 kg of progesterone from [[G. D. Searle & Company|Searle]] (who had acquired Pesa) at $0.143 per gram, 5,150 kg of progesterone from Julian Laboratories at $0.14 per gram, and 1,925 kg of progesterone from General Mills (who had acquired Protex) at $0.142 per gram.<ref name="AdministeredPrices" />

Despite continually falling bulk prices of steroid intermediates, an oligopoly of large American multinational pharmaceutical companies kept the wholesale prices of corticosteroid drugs fixed and unchanged into the 1960s. Cortisone was fixed at $5.48 per gram from 1954, [[hydrocortisone]] at $7.99 per gram from 1954, and [[prednisone]] at $35.80 per gram from 1956.<ref name="Gereffi" /><ref name="AdministeredPrices" /> [[Merck & Co.|Merck]] and [[Roussel Uclaf]] concentrated on improving the production of corticosteroids from cattle bile acids. In 1960 Roussel produced almost one-third of the world's corticosteroids from bile acids.<ref name="Applezweig 1962" />

Julian Laboratories chemists found a way to quadruple the yield on a product on which they were barely breaking even. Julian reduced their price for the product from $4,000 per kg to $400 per kg.<ref name="NOVA" /> He sold the company in 1961 for $2.3 million (equivalent to ${{Inflation|US|2.3|1961}} million today).{{Inflation-fn|US}} The U.S. and Mexico facilities were purchased by [[GlaxoSmithKline|Smith Kline]], and Julian's chemical plant in Guatemala was purchased by [[Upjohn]].

In 1964, Julian founded Julian Associates and Julian Research Institute, which he managed for the rest of his life.<ref name="DepauwArchive-c" />

== National Academy of Sciences ==

He was elected to the [[United States National Academy of Sciences|National Academy of Sciences]] in 1973 in recognition of his scientific achievements.<ref name="NOVA" /> He became the second African-American to be inducted, after [[David Blackwell]].

== Legacy and honors ==

*In 1950, the [[Chicago Sun-Times]] named Percy Julian the Chicagoan of the Year.<ref name="DepauwArchive-b" />
*Since 1975, the [[National Organization for the Professional Advancement of Black Chemists and Chemical Engineers]] has presented the Percy L. Julian Award for Pure and Applied Research in Science and Engineering.<ref name="NOBCCheAwards" />
*In 1975, [[Percy L. Julian High School]] was opened on the south side of Chicago, Illinois as a Chicago public high school.
* In 1980, the science and mathematics building on the DePauw University campus was rededicated as the Percy L. Julian Mathematics and Science Center. In [[Greencastle, Indiana]], where DePauw is located, a street was named after Julian.
* In 1985, Hawthorne School in [[Oak Park, Illinois]], was renamed [[Percy Julian Middle School]].<ref name="OPESD97" />
* Illinois State University, where Julian served on the board of trustees, named a hall after him.<ref name="JulianHighSchoolChicago" />
* A structure at [[Coppin State University]] is named the Percy Julian Science Building.
* In 1990, he was inducted into the [[National Inventors Hall of Fame]].<ref name="NationalInventorsHallOfFame" />
*In 1993 Julian was honored on a stamp issued by the [[United States Postal Service]].<ref name="USDoS-stamp" />
*In 1999, the [[American Chemical Society]] recognized Julian's synthesis of [[physostigmine]] as a [[National Historic Chemical Landmarks|National Historic Chemical Landmark]].<ref>{{cite web | title = Percy L. Julian and the Synthesis of Physostigmine | work = National Historic Chemical Landmarks | publisher = American Chemical Society | url = http://www.acs.org/content/acs/en/education/whatischemistry/landmarks/julian.html | accessdate = 2014-02-21 }}</ref>
*In 2002, scholar [[Molefi Kete Asante]] listed Percy Lavon Julian on his list of [[100 Greatest African Americans|100 Greatest African-Americans]].<ref>Asante, Molefi Kete (2002). ''100 Greatest African Americans: A Biographical Encyclopedia''. Amherst, New York. Prometheus Books. ISBN 1-57392-963-8.</ref>
*In 2011, the qualifying exam preparation committee at the Albert Einstein College of Medicine was named for Percy Julian.
*In 2014, Google honored him with a [[Google Doodle#Google Doodles|Doodle]].[http://www.google.com/doodles/percy-julians-115th-birthday][http://www.forbes.com/sites/davidkroll/2014/04/11/todays-google-doodle-honors-pioneering-medicinal-chemist/] [http://blogs.scientificamerican.com/urban-scientist/2014/04/11/google-doodle-honors-chemist-dr-percy-julian/]

=== ''Nova'' documentary ===

[[Ruben Santiago-Hudson]] portrayed Percy Julian in the [[PBS|Public Broadcasting Service]] [[Nova (TV series)|''Nova'' documentary]] about his life, called "Forgotten Genius". It was presented on the PBS network on February 6, 2007, with initial sponsorship by the [[Camille and Henry Dreyfus Foundation]] and further funding by the [[National Endowment for the Humanities]]. Approximately sixty of Julian's family members, friends, and work associates were interviewed for the docudrama.<ref name="NOVA" /><ref name="Humanities-2007.01-02" />

Production on the biopic began at [[DePauw University]]'s Greencastle campus in May 2002 and included video of Julian's bust on display in the atrium of the university's Percy Lavon Julian Science and Mathematics Center. Completion and broadcasting of the documentary program was delayed in order for ''Nova'' to commission and publish a matching book on Julian's life.<ref name="DepauwNews&Media-2004.06.22" />

According to [[University of Illinois]] historian James Anderson in the film, "His story is a story of great accomplishment, of heroic efforts and overcoming tremendous odds...a story about who we are and what we stand for and the challenges that have been there and the challenges that are still with us."<ref name="Humanities-2007.01-02" />

=== Archive ===

The Percy Lavon Julian family papers are archived at [[DePauw University]].<ref name="DepauwArchive-a" />

== Patents ==

* {{US patent|2218971}}, October 22, 1940, Recovery of sterols
* {{US patent|2373686}}, July 15, 1942, Phosphatide product and method of making
* {{US patent|2752339}}, June 26, 1956, Preparation of cortisone
* {{US patent|3149132}}, September 15, 1964, 16-aminomenthyl-17-alkyltestosterone derivatives
* {{US patent|3274178}}, September 20, 1966, Method for preparing 16(alpha)-hydroxypregnenes and intermediates obtained therein
* {{US patent|3761469}}, September 25, 1973, Process for the manufacture of steroid chlorohydrins; with Arnold Lippert Hirsch

== Publications ==
* [http://pubs.acs.org/cgi-bin/archive.cgi/jacsat/1933/55/i05/pdf/ja01332a054.pdf?sessid=4512 Studies in the Indole Series. I. The Synthesis of Alpha-Benzylindoles]; Percy L. Julian, Josef Pikl; J. Am. Chem. Soc. 1933, 55(5), pp 2105–2110.
* [http://pubs.acs.org/doi/abs/10.1021/ja01307a051 Studies in the Indole Series. V. The Complete Synthesis of Physostigmine (Eserine)]; Percy L. Julian, Josef Pikl; J. Am. Chem. Soc. 1935, 57(4), pp 755–757.

== See also ==
{{Portal|Pharmacy and Pharmacology}}

* [[List of African-American inventors and scientists]]

== References ==

{{Reflist|colwidth=30em|refs=

<ref name="AdministeredPrices">{{cite book |author=United States Senate |year=1960 |title=Administered prices : hearings before the Subcommittee on Antitrust and Monopoly of the Committee on the Judiciary, US Senate, 86th Congress, 1st session, pursuant to S. Res. 57; Part 14: Administered Prices in the Drug Industry (Corticosteroids). December 7, 8, 9, 10, 11, and 12, 1959.
|location=Washington | publisher=US Government Printing Office |pages=7884, 8296}}</ref>

<ref name="AOCS">{{cite web|url=http://lipidlibrary.aocs.org/history/Julian/index.htm|title=Lipid Library: Percy Lavon Julian (1899–1975)|publisher=American Oil Chemists' Society|accessdate=February 18, 2012}}</ref>

<ref name="Applezweig 1962">{{cite book |author=Applezweig, Norman |year=1962 |title=Steroid Drugs |location=New York |publisher=Blakiston Division, [[McGraw-Hill]] |pages=vii–xi, 9–83|quote= p. 26: The pregnenolone experience also served to show that the older hormone producers using cholesterol and stigmasterol could not hope to become suppliers of the vast new quantities of pregnane compounds which the cortical hormones might require. In 1952 the Glidden Co., which until then had been producing progesterone and other steroids from stigmasterol, shifted over to Mexican sources through an arrangement with Diosynth and closed down its own production. The Glidden research director, Percy Julian, and his staff had worked out an excellent synthesis for Compound "S" which started from 16-dehydropregnenolone. The latter compound was directly available from diosgenin but would have been of prohibitive cost if prepared from soya sterols. Since Compound "S" differed from cortisone only by the absence of an oxygen at 11, there were high hopes that Compound "S" would succeed where pregnenolone had failed, as a substitute for cortisone. Compound "S" also proved to be an ineffective precursor when fed to patients with arthritic disease; in fact, it aggravated rather than relieved their symptoms. p. 30: The Glidden Company also ventured further afield from its soya sterols to exploit some of the researches of Julian, which were designed to improve the conversion of desoxycholic acid to cortisone. After two years, Glidden decided to abandon the production of cortisone from bile acid and to concentrate instead on Compound "S," which now loomed as a competitor for progesterone in processes which could convert it via fermentation to cortisone and hydrocortisone. Since Glidden's cost of production of Compound "S" was still relatively high, the progesterone group won out, and progesterone [from diosgenin] still remains the raw material of choice at Upjohn.}}</ref>

<ref name="BusinessWeek-1945.12.22">{{cite journal |date=December 22, 1945 |title=Sex Hormones In Legal Battle |journal=''[[Business Week]]'' |pages=46–50}}</ref>

<ref name="Butenandt">A. Butenandt, U. Westphal and H.Cobler, Berichte Deutsche chemische Gesellschaft, Vol. 67, 1934, pp. 1611–1616, 2085–2087.</ref>

<ref name="CEN 1949">{{cite journal|author=.|date=October 10, 1949|title=News of the week: New cortisone synthesis|journal=[[Chemical & Engineering News]]|volume=27|issue=41|page=2936|quote=Quote: A new synthesis of cortisone, eliminating the need for expensive osmium tetroxide, and the synthesis of three other compounds related to cortisone, which may possible be useful in the treatment of arthritis, have been announced by Percy L. Julian, director of research of the soya products division of the Glidden Co., Chicago. No statement was made as to further details of the new synthesis, but it was revealed that soybean products were not involved...all three [other compounds] were made from soybean sterols.|doi=10.1021/cen-v027n041.p2936}}</ref>

<ref name="ChemHeritage.org">Chemical Heritage Foundation. [http://www.chemheritage.org/discover/online-resources/chemistry-in-history/themes/pharmaceuticals/restoring-and-regulating-the-bodys-biochemistry/julian--marker--djerassi.aspx Restoring And Regulating The Body's Biochemistry: Percy Lavon Julian, Russell Earl Marker, Carl Djerassi], Chemical Heritage Foundation website, 2010.</ref>

<ref name="ChicagoTribune-1953.12.02">{{cite news |date=December 2, 1953 |title=Julian leaves Glidden. Will Head Own Firm. |work=Chicago Tribune |pages=C6 |url=http://pqasb.pqarchiver.com/chicagotribune/access/504442072.html?dids=504442072:504442072&FMT=CITE&FMTS=CITE:AI&type=historic&date=Dec+2%2C+1953&author=&pub=Chicago+Daily+Tribune+(1872-1963)&edition=&startpage=C6&desc=JULIAN+LEAVES+GLIDDEN}}</ref>

<ref name="ChicagoTribune-1963.01.06">{{cite news |date=January 6, 1963 |title=Julian aids mankind with his knowledge |work=Chicago Tribune |pages=1 |url=http://pqasb.pqarchiver.com/chicagotribune/access/581177362.html?dids=581177362:581177362&FMT=ABS&FMTS=ABS:AI&type=historic&date=Jan+6%2C+1963&author=CLAY+GOWRAN&pub=Chicago+Daily+Tribune+(1872-1963)&edition=&startpage=1&desc=Julian+Aids+Mankind+with+His+Knowledge | first=Clay | last=Gowran}}</ref>

<ref name="DepauwArchive-a">{{cite web |url=http://www.depauw.edu/library/archives/dpuinventories/julian_percy_lavon_family.htm |title=Percy Lavon Julian (1899–1975) archive |accessdate=February 14, 2007 |publisher=[[Depauw University]] |archiveurl=http://web.archive.org/web/20070206173402/http://www.depauw.edu/library/archives/dpuinventories/julian_percy_lavon_family.htm  |archivedate=February 6, 2007 }}</ref>

<ref name="DepauwArchive-b">{{cite web|url=http://www.depauw.edu/library/archives/percyjulian/chronology.asp |title=Life Chronology |accessdate=February 14, 2007 |publisher=[[DePauw University]] |deadurl=yes |archiveurl=https://web.archive.org/20070207163119/http://www.depauw.edu:80/library/archives/percyjulian/chronology.asp |archivedate=February 7, 2007 }}</ref>

<ref name="DepauwArchive-c">{{cite web|url=http://www.depauw.edu/library/archives/percyjulian/biography.asp |title=DePauw Archives biography |accessdate=February 13, 2007 |publisher=[[Depauw University]] |deadurl=yes |archiveurl=https://web.archive.org/20070207162810/http://www.depauw.edu:80/library/archives/percyjulian/biography.asp |archivedate=February 7, 2007 }}</ref>

<ref name="DepauwNews&Media-2004.06.22">DePauw University [http://www.depauw.edu/news-media/latest-news/details/13527 NOVA Back on Campus as Work on Percy Julian Documentary Continues], Depauw University News & Media Office website, June 22, 2004. Retrieved February 22, 2013.</ref>

<ref name="DepauwNews&Media-2009.02.19">DePauw University. [http://www.depauw.edu/news-media/latest-news/details/22969/ The Life of Percy Lavon Julian '20]
DePauw University News & Media Office website, February 19, 2009. Retrieved February 22, 2013.</ref>

<ref name="DuSableMuseum">{{cite web |url= http://www.dusablemuseum.org |title= From Dreams to Determination: The Legacy of Doctors Percy and Anna Julian|accessdate=February 13, 2007 |publisher=Dusable Museum}}</ref>

<ref name="Fernholz">E. Fernholz. Berichte Deutsche chemische Gesellschaft, Vol. 67, 1934, pp. 2027–2031. {{De icon}}</ref>

<ref name="Fortune-1951.05">{{cite journal |date=May 1951 |title=Mexican hormones |journal=[[Fortune (magazine)|''Fortune'']] |volume=43 |pages=86–90, 161–2, 166, 168 |issue=5}}</ref>

<ref name="Gibbons 1949">{{cite news|author=Gibbons, Roy|date=September 30, 1949|title=Science gets synthetic key to rare drug; discovery is made in Chicago|newspaper=[[Chicago Tribune]]|page=1|url=http://pqasb.pqarchiver.com/chicagotribune/access/494372192.html?dids=494372192:494372192&FMT=ABS&FMTS=ABS:AI|quote=Dr. Julian's new method for synthesizing the anti-arthritis compound, cortisone, is less costly than present methods, because it eliminates the need for utilizing osmium tetroxide, a rare and expensive chemical, the Glidden company declared....But whether has Dr. Julian has also synthesized cortisone from soybeans neither he nor the Glidden company would reveal.}}</ref>

<ref name="Gereffi">{{cite book |author=Gereffi, Gary |year=1983 |title=The Pharmaceutical Industry and Dependency in the Third World |location=Princeton |publisher=Princeton University Press |isbn=0-691-09401-2 |pages=53–163}}</ref>

<ref name="Humanities-2007.01-02">Taylor, Percy. [http://www.neh.gov/humanities/2007/januaryfebruary/feature/percy-julian "Percy Julian: Against the Odds"], ''Humanities'', published by the [[National Endowment for the Humanities]], January–February 2007, Vol. 28, No. 1.</ref>

<ref name="JNMA">Cobb, W. M. [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2609845/pdf/jnma00504-0097.pdf "Medical History: Percy Lavon Julian, Ph.D., Sc.D., LL.D., L.H.H.D., 1899– "], ''Journal of the National Medical Association'', March 1971; Vol. 63, No. 2, pp. 143–150, PMCID: PMC2609845.</ref>

<ref name="JulianHighSchoolChicago">{{cite web |url= http://www.pljulianhs.net|title= Percy L. Julian High School, Chicago|accessdate=February 13, 2007}}</ref>

<ref name="Lehman 1951">{{cite book|author=Lehman, R.W.; Embree, N.D.|year=1951|chapter=Soybean oil by-products|editor=Markley, Klare S. (ed.)|title=Soybeans and Soybean Products, vol. 2|location=New York|publisher=[[John Wiley & Sons|Interscience Publishers]]|page=846|oclc=1573228|quote=Cortisone has been synthesized81''d'' from bile acids having unsaturation or oxygenation in ring "C" which can give rise to a keto group at C11. Its synthesis from soybean oil sterols has not been reported, but the preparation from these sterols of closely related compounds which may have partial activity has been announced by Julian.81''e''}}</ref>

<ref name="Nat.AcademyOfSciences-bio">Witkop, Bernhard. [http://www.nap.edu/html/biomems/pjulian.html "Percy Lavon Julian: April 11, 1899 – April 19, 1975"] (Biographical Memoir), [[National Academy Press]], [[National Academy of Sciences]], (undated). Retrieved February 23, 2013.</ref>

<ref name="NationalInventorsHallOfFame">[http://www.invent.org/hall_of_fame/84.html National Inventors Hall of Fame]</ref>

<ref name="NewYorkTimes-1950.11.23">{{cite news |coauthors= |title=Arson Fails at Home of Negro Scientist. |url= |quote=Chicago, November 22, 1950. Quote: An attempt was made tonight to burn down the expensive home that Dr. Percy Julian, 51 years old, internationally known Negro research chemist, recently purchased in one of the most exclusive sections in suburban Oak Park. |work=New York Times |date=November 23, 1950 |accessdate=February 14, 2007 }}</ref>

<ref name="NewYorkTimes-1975.04.21">{{cite news |coauthors= |title=Dr. Percy Julian, Chemist, 76, Dies. |url= |quote=Leader in the Fight for Civil Rights Was Synthesizer of Cortisone Drugs. Dr. Percy L. Julian, an internationally known research chemist and a leader in the fight for civil rights, died Saturday in St. Theresa's Hospital, [[Waukegan, Illinois]]. He was 76 years old and lived in [[Oak Park, Illinois]]. |work=[[New York Times]] |date=April 21, 1975 |accessdate=February 14, 2007 }}</ref>

<ref name="NOBCCheAwards">NOBCChE. [http://www.nobcche.org/membership/professional/awards_Julian.asp NOBCChe ''Percy L. Julian Award Recipients''] (not awarded every year), National Organization for the Professional Advancement of Black Chemists and Chemical Engineers (NOBCChE) website.</ref>

<ref name="NOVA">{{cite web |url= http://www.pbs.org/wgbh/nova/transcripts/3402_julian.html |title= NOVA: Forgotten Genius |accessdate=February 13, 2007 |publisher=[[NOVA (TV series)]]}}</ref>

<ref name="OPESD97">[http://www.op97.org/julian/History.cfm History of Percy Julian Middle School], Oak Park, Illinois: Oak Park Elementary School District 97.</ref>

<ref name="Peterson">{{cite journal |author=Peterson, D. H., Murray, H .C. |year=1952 |title=Microbiological Oxygenation of Steroids At Carbon11 |journal=''[[Journal of the American Chemical Society]]'' |volume=74 |issue=7 |pages=1871–2 |url=http://pubs.acs.org/cgi-bin/abstract.cgi/jacsat/1952/74/i07/f-pdf/f_ja01127a531.pdf |format=PDF|doi=10.1021/ja01127a531}}</ref>

<ref name="Shurtleff">{{cite web |author=Shurtleff, William; Aoyagi, Akiko |year=2004 |title=History of the Glidden Company's Soya Products / Chemurgy Division |location=Lafayette, Calif. |publisher=SoyInfo Center |url=http://www.soyinfocenter.com/HSS/glidden.php |accessdate=February 24, 2007}}</ref>

<ref name="Stille">Stille, Darlene R. [http://books.google.com/books?id=4dbhjEkO_1QC&printsec=frontcover&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=true ''Percy Lavon Julian: Pioneering Chemist'' (Signature Lives series)], Capstone, 2009, ISBN 0756540895, ISBN 978-0756540890.</ref>

<ref name="Time-1943.12.06">{{cite news| url=http://www.time.com/time/magazine/article/0,9171,850791,00.html | work=Time | title=Production: Navy Bean Soup | date=December 6, 1943 | accessdate=May 22, 2010}}</ref>

<ref name="Time-1975.05.05">{{cite news |date=May 5, 1975 |title=Milestones |url=http://www.time.com/time/magazine/article/0,9171,913041,00.html |publisher=[[Time (magazine)|''Time'']] |quote=Died. Percy L. Julian, 76, prolific black research chemist; of Harvard and the University of Vienna on his way to garnering over 130 chemical patents. |accessdate=February 14, 2007 }}</ref>

<ref name="PBS.org">WGBH-PBS. [http://www.pbs.org/wgbh/aso/databank/entries/bmjuli.html People and Discoveries: Percy Julian, 1899–1975], WGBH-PBS, 1998. Retrieved from PBS.org website.</ref>

<ref name="SOSRubber">[http://www.sosrubberintl.com/pdf/NMS120-aofxl-3.pdf Aer-O-Foam MSDS], S.O.S. Rubber International website.</ref>

<ref name="U.S.SenateWonderDrugs-1957">{{cite book |author=United States Senate |year=1957 |title=Wonder drugs : Hearings Before the Subcommittee on Patents, Trademarks, and Copyrights of the Committee on the Judiciary, U.S. Senate, 84th Congress, 2nd session, pursuant to S. Res. 167, on licensing of United States Government owned patents; removal of obstacles to the production of essential materials from the cheapest source for the manufacture of cortisone and other hormones. July 5 and 6, 1956.
|location=Washington | publisher=US Government Printing Office |pages=114–5}}</ref>

<ref name="UniversityOfIllinois">{{cite web |url=http://chemistry.uiuc.edu/bios/brady.html |title=St. Elmo Brady | publisher=[[University of Illinois at Urbana-Champaign|University of Illinois]]|accessdate=February 14, 2007 |archiveurl = http://web.archive.org/web/20060903230903/http://www.chemistry.uiuc.edu/bios/brady.html  |archivedate = September 3, 2006}}</ref>

<ref name="USDA-a">{{cite web|url=http://www.ars.usda.gov/research/publications/publications.htm?seq_no_115=215771|title=Giants of the Past: Percy Lavon Julian (1899–1975). A Forgotten Pioneer in Soy|publisher=United States Department of Agriculture|accessdate=February 18, 2012}}</ref>

<ref name="USDoS-stamp">{{cite web | coauthors = | year = 2005 | url = http://usinfo.state.gov/usa/blackhis/stamps.htm | title = Black Heritage Stamps | work=International Information Programs | publisher=U.S. Department of State | accessdate =February 18, 2007}}</ref>

<ref name="WashingtonPost-1975.04.22">{{Cite news
| title = Dr. Percy Julian, Chemist, Dies |url=
| quote = Dr. Percy Lavon Julian, 76, an internationally known organic chemist and noted civil rights leader, died Saturday in St. Theresa's Hospital in [[Waukegan, Illinois]].
| work = [[The Washington Post]]
| date = April 22, 1975
| accessdate = February 14, 2007 }}</ref>

<ref name="WashingtonPost-2008.03.26">{{Cite news
| last = Lamb
| first = Yvonne Shinhoster
| title = Civil Rights Lawyer Percy Julian Jr., 67
| newspaper= [[The Washington Post]]
| date = March 26, 2008
| url = http://www.washingtonpost.com/wp-dyn/content/article/2008/03/25/AR2008032503563.html
| accessdate =November 15, 2009
}}</ref>

<ref name="Witkop">Bernhard Witkop. "Percy Lavon Julian. 1899–1975." in Biographical Memoirs. [[National Academy of Sciences]], 1980, Vol. 52, pp. 223–266.</ref>

}}

== Further reading ==

* Arora, Namit et al. [http://blog.shunya.net/shunyas_blog/2007/06/percy-julian-ch.html "Percy Julian, Chemist Extraordinaire" (biography)], Shunya's Notes website, June 24, 2007.
*{{Cite news
| pmid = 4928023
| last = Cobb | first = W.M.
| publication-date = March 1971
| year = 1971
| title = Percy Lavon Julian, PhD, Sc.D., LL.D., L.H.D., 1899–
| volume = 63
| issue = 2
| periodical = Journal of the National Medical Association
| pages = 143–50
| pmc = 2609845
}}
* Glidden Co. [http://www.soyinfocenter.com/HSS/glidden.php Soy Information Center], Glidden Company.
* Cullen, Katherine E. [http://books.google.com/books?id=sTZ19DVTHt0C&printsec=frontcover&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=true ''Chemistry: The People Behind the Science'' (Pioneers In Science)], Chapter 8: Percy Julian (1899–1975): Synthesis of Glaucoma Drug and Sterols from Natural Plant Products, Infobase Publishing, 2006, pp. 103–114, ISBN 0816072221, ISBN 978-0816072224.
* {{Cite news
|pmid = 8945489
|last=Kyle
|first=R A
|last2=Shampo
|first2=M A
|publication-date=Dec 1996
|year=1996
|title=Stamp vignette on medical science. Percy Lavon Julian—industrial chemist
|volume=71
|issue=12
|periodical=Mayo Clin. Proc.
|pages=1170
}}
*{{Cite news
|pmid = 15792073
|last=Weissmann
|first=Gerald
|publication-date=2005
|year=2005
|title=Cortisone and the burning cross. The story of Percy Julian
|volume=68
|issue=1
|periodical=The Pharos of Alpha Omega Alpha-Honor Medical Society. Alpha Omega Alpha
|pages=13–6
}}

== External links ==
* [http://www.teachersdomain.org/exhibits/pj07-ex/index.html Percy Julian Chemistry and Civil Rights]. Resources from Teachers' Domain
* [http://www.chemheritage.org/percy-julian/history/1.html "The Life and Science of Percy Julian"], Teacher's Guide from the [[Chemical Heritage Foundation]]
* [http://www.nap.edu/html/biomems/pjulian.html Percy Lavon Julian] by Bernhard Witkop (memoir of Julian)
* [http://www.blackinventor.com/pages/percyjulian.html Profile of Percy Julian] – The Black Inventor Online Museum
* [http://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GRid=6460402 Percy Julian] at Find-A-Grave
* [http://my.depauw.edu/library/archives/ehistory/chapter4/Julian.html Percy Julian Archives] at DePauw University
* [http://www.pbs.org/wgbh/nova/julian/ ''Forgotten Genius''], PBS Nova documentary and video
* [http://osulibrary.oregonstate.edu/specialcollections/events/2007paulingconference/video-s2-4-lyons.html Video: “Bringing Chemistry to Prime Time”], a talk by Nova producer Steve Lyons on the creation of the Percy Julian PBS documentary
* {{cite web | url = http://www.fundinguniverse.com/company-histories/The-Glidden-Company-Company-History.html |title=Glidden Company History |accessdate=February 14, 2007 |publisher=[[Glidden Company]]}}

{{Authority control}}

{{good article}}

{{Persondata
|NAME= Percy Lavon Julian
|ALTERNATIVE NAMES=
|SHORT DESCRIPTION=African-American chemist
|DATE OF BIRTH= April 11, 1899
|PLACE OF BIRTH= Montgomery, Alabama, United States
|DATE OF DEATH= April 19, 1975
|PLACE OF DEATH= Waukegan, Illinois, United States
}}
{{DEFAULTSORT:Julian, Percy Lavon}}
[[Category:1899 births]]
[[Category:1975 deaths]]
[[Category:African-American academics]]
[[Category:African-American scientists]]
[[Category:American chemists]]
[[Category:DePauw University alumni]]
[[Category:Fisk University faculty]]
[[Category:Harvard University alumni]]
[[Category:Howard University faculty]]
[[Category:Members of the United States National Academy of Sciences]]
[[Category:Organic chemists]]
[[Category:People from Oak Park, Illinois]]
[[Category:People from Montgomery, Alabama]]
[[Category:Spingarn Medal winners]]
[[Category:University of Vienna alumni]]

Manganese

2016-02-01T19:30:24Z

71.109.148.145: /* Occurrence and production */ Better to break azorian story out into something more relevant.

{{Hatnote|Manganese ''('''Mn''')'' is not to be confused with [[magnesium]] ''('''Mg''')''.}}
{{other uses}}
{{Infobox manganese}}
'''Manganese''' is a [[chemical element]] with symbol '''Mn''' and [[atomic number]] 25. It is not found as a [[free element]] in nature; it is often found in combination with [[iron]], and in many [[minerals]]. Manganese is a metal with important industrial metal [[alloy]] uses, particularly in [[stainless steels]].

Historically, manganese is named for various black minerals (such as [[pyrolusite]]) from the same region of [[Magnesia (regional unit)|Magnesia]] in Greece which gave names to similar-sounding [[magnesium]], Mg, and [[magnetite]], an ore of the element [[iron]], Fe. By the mid-18th century, [[Sweden|Swedish]] [[chemist]] [[Carl Wilhelm Scheele]] had used pyrolusite to produce [[chlorine]]. Scheele and others were aware that pyrolusite (now known to be [[manganese dioxide]]) contained a new element, but they were unable to isolate it. [[Johan Gottlieb Gahn]] was the first to isolate an impure sample of manganese metal in 1774, by [[reduction-oxidation|reducing]] the dioxide with [[carbon]].

[[Phosphate conversion coating|Manganese phosphating]] is used as a treatment for rust and corrosion prevention on [[steel]]. Depending on their [[oxidation state]], manganese [[ions]] have various colors and are used industrially as [[pigment]]s. The [[permanganate]]s of [[alkali metal|alkali]] and [[alkaline earth metals]] are powerful oxidizers. Manganese dioxide is used as the [[cathode]] (electron acceptor) material in [[Zinc-carbon battery|zinc-carbon]] and [[Alkaline battery|alkaline batteries]].

In biology, manganese(II) ions function as [[cofactor (biochemistry)|cofactors]] for a large variety of [[enzymes]] with many functions.<ref>{{cite book
|last1=Roth |first1=Jerome |last2=Ponzoni |first2=Silvia |last3=Aschner |first3=Michael
|editor1-first=Lucia |editor1-last=Banci |series=Metal Ions in Life Sciences |volume=12
|chapter= Chapter 6 Manganese Homeostasis and Transport
|title=Metallomics and the Cell |date=2013 |publisher=Springer |isbn=978-94-007-5560-4|doi=10.1007/978-94-007-5561-1_6}} electronic-book ISBN 978-94-007-5561-1 {{issn|1559-0836}} electronic-{{issn|1868-0402}}
</ref> Manganese enzymes are particularly essential in detoxification of [[superoxide]] free radicals in organisms that must deal with elemental [[oxygen]]. Manganese also functions in the oxygen-evolving complex of photosynthetic [[plants]]. The element is a required trace mineral for all known living organisms but is a [[neurotoxin]]. In larger amounts, and apparently with far greater effectiveness through inhalation, it can cause a [[manganism|poisoning syndrome]] in mammals, with neurological damage which is sometimes irreversible.

==Characteristics==

===Physical properties===
[[File:Manganese electrolytic and 1cm3 cube.jpg|thumb|left|200px|Electrolytically refined manganese chips and 1 cm3 cube]]
Manganese is a silvery-gray [[metal]] that resembles iron. It is hard and very brittle, difficult to fuse, but easy to oxidize.<ref name="Holl">{{cite book|publisher = Walter de Gruyter|date = 1985|edition = 91–100| pages = 1110–1117|isbn = 3-11-007511-3|title = Lehrbuch der Anorganischen Chemie|first = Arnold F.|last = Holleman|author2 = Wiberg, Egon|author3 = Wiberg, Nils|language = German|chapter=Mangan}}</ref> Manganese metal and its common ions are [[paramagnetic]].<ref name=magnet>{{cite book| url =https://web.archive.org/web/20110303222309/http://www-d0.fnal.gov/hardware/cal/lvps_info/engineering/elementmagn.pdf|title = Magnetic susceptibility of the elements and inorganic compounds, in Handbook of Chemistry and Physics| publisher = CRC press| isbn = 0-8493-0485-7|first = David R. |last = Lide|date = 2004}}</ref> Manganese tarnishes slowly in air and "rusts" like iron, in water containing dissolved oxygen.

===Isotopes===
{{Main|Isotopes of manganese}}
Naturally occurring manganese is composed of one stable [[isotope]], 55Mn. Eighteen [[radioisotope]]s have been characterized, with the most stable being 53Mn with a [[half-life]] of 3.7 million years, 54Mn with a [[half-life]] of 312.3 days, and 52Mn with a half-life of 5.591 days. All of the remaining [[radioactive]] isotopes have half-lives that are less than three hours and the majority of these have half-lives that are less than one minute. This element also has three [[meta state]]s.<ref name="Audi">{{cite journal| last = Audi|first = Georges|title = The NUBASE Evaluation of Nuclear and Decay Properties|journal = Nuclear Physics A|volume = 729|pages = 3–128| publisher = Atomic Mass Data Center|date = 2003|doi=10.1016/j.nuclphysa.2003.11.001|bibcode=2003NuPhA.729....3A| last2 = Bersillon| first2 = O.| last3 = Blachot| first3 = J.| last4 = Wapstra| first4 = A.H.}}</ref>
Manganese is part of the [[iron]] group of elements, which are thought to be synthesized in large [[star]]s shortly before the [[supernova]] explosion. 53Mn decays to 53[[chromium|Cr]] with a [[half-life]] of 3.7 million years. Because of its relatively short half-life, 53Mn occurs only in tiny amounts due to the action of [[cosmic rays]] on [[iron]] in rocks.<ref>{{cite journal| last = Schaefer| first = Jeorg|last2=Faestermann |first2=Thomas| title = Terrestrial manganese-53 – A new monitor of Earth surface processes| journal = Earth and Planetary Science Letters|volume = 251|issue = 3–4| pages =334–345|date = 2006|doi=10.1016/j.epsl.2006.09.016| bibcode=2006E&PSL.251..334S| last3 = Herzog| first3 = Gregory F.| last4 = Knie| first4 = Klaus| last5 = Korschinek| first5 = Gunther| last6 = Masarik| first6 = Jozef| last7 = Meier| first7 = Astrid| last8 = Poutivtsev| first8 = Michail| last9 = Rugel| first9 = Georg| last10 = Schlüchter| first10 = Christian| last11 = Serifiddin| first11 = Feride| last12 = Winckler| first12 = Gisela}}</ref> Manganese isotopic contents are typically combined with [[chromium]] isotopic contents and have found application in [[isotope geology]] and [[radiometric dating]]. Mn–Cr isotopic ratios reinforce the evidence from 26[[Aluminium|Al]] and 107[[Palladium|Pd]] for the early history of the [[solar system]]. Variations in 53Cr/52Cr and Mn/Cr ratios from several [[meteorite]]s indicate an initial 53Mn/55Mn ratio that suggests Mn–Cr isotopic composition must result from ''in situ'' decay of 53Mn in differentiated planetary bodies. Hence 53Mn provides additional evidence for [[nucleosynthesis|nucleosynthetic]] processes immediately before coalescence of the [[solar system]].<ref name="Audi"/>
The isotopes of manganese range in [[atomic weight]] from 46 [[atomic mass unit|u]] (46Mn) to 65 u (65Mn). The primary [[decay mode]] before the most abundant stable isotope, 55Mn, is [[electron capture]] and the primary mode after is [[beta decay]].<ref name="Audi"/>

===Chemical properties===
[[File:Chlorid manganatý.JPG|thumb|left|125px|[[Manganese(II) chloride]] crystals – the pale pink color of Mn(II) salts is due to a spin-forbidden 3d transition.<ref>{{cite book|title=Shriver and Atkins' Inorganic Chemistry|date=2010|publisher=Oxford University Press|isbn=978-0-19-923617-6|chapter=Ch. 20}}</ref>]]

The most common [[oxidation state]]s of manganese are +2, +3, +4, +6, and +7, though all oxidation states from −3 to +7 have been observed. Mn2+ often competes with Mg2+ in biological systems. Manganese compounds where manganese is in oxidation state +7, which are restricted to the unstable oxide Mn2O7 and compounds of the intensely purple permanganate anion MnO4−, are powerful [[oxidation|oxidizing agents]].<ref name="Holl"/> Compounds with oxidation states +5 (blue) and +6 (green) are strong oxidizing agents and are vulnerable to [[disproportionation]].

[[File:KMnO4 in H2O.jpg|thumb|left|125px|Aqueous solution of KMnO4 illustrating the deep purple of Mn(VII) as it occurs in permanganate]]
The most stable oxidation state for manganese is +2, which has a pale pink color, and many manganese(II) compounds are known, such as [[manganese(II) sulfate]] (MnSO4) and [[manganese(II) chloride]] (MnCl2). This oxidation state is also seen in the mineral rhodochrosite ([[manganese(II) carbonate]]). The +2 oxidation of Mn results from removal of the two '''4s''' electrons, leaving a "high spin" ion in which all five of the '''3d''' orbitals contain a single electron. Absorption of visible light by this ion is accomplished only by a spin-forbidden transition in which one of the d electrons must pair with another, to give the atom a change in spin of two units. The unlikeliness of such a transition is seen in the uniformly pale and almost colorless nature of Mn(II) compounds relative to other oxidation states of manganese.<ref>Rayner-Canham, Geoffrey and Overton, Tina (2003) ''Descriptive Inorganic Chemistry'', Macmillan, p. 491, ISBN 0-7167-4620-4.</ref>
<div style="float:right; margin:5px;">
{|class="wikitable"
|-
! colspan=2|Oxidation states of manganese<ref name="Schmidt">{{cite book|title = Anorganische Chemie II.|chapter = VII. Nebengruppe|pages = 100–109|first = Max|last = Schmidt|publisher = Wissenschaftsverlag|date = 1968|language = German}}</ref>
|-
| '''0''' || [[Dimanganese decacarbonyl|{{chem|Mn|2|(CO)|10}}]]
|-
| +1 || [[Methylcyclopentadienyl manganese tricarbonyl|{{chem|MnC|5|H|4|CH|3|(CO)|3}}]]
|-
| '''+2''' || [[Manganese(II) chloride|{{chem|MnCl|2}}]], [[Manganese(II) carbonate|{{chem|MnCO|3}}]], [[Manganese(II) oxide|{{chem|MnO}}]]
|-
| +3 || [[Manganese(III) fluoride|{{chem|MnF|3}}]], [[Manganese(III) acetate|{{chem|Mn(OAc)|3}}]], [[Manganese(III) oxide|{{chem|Mn|2|O|3}}]]
|-
| +4 || [[Manganese dioxide|{{chem|MnO|2}}]]
|-
| +5 || [[Potassium hypomanganate|{{chem|K|3|MnO|4}}]]
|-
| '''+6''' || [[Potassium manganate|{{chem|K|2|MnO|4}}]]
|-
| '''+7''' || [[Potassium permanganate|{{chem|KMnO|4}}]], [[Manganese heptoxide|{{chem|Mn|2|O|7}}]]
|-
|colspan=2|<center>Common oxidation states are in bold.</center>
|}</div>
The +3 oxidation state is known in compounds like [[manganese(III) acetate]], but these are quite powerful [[Redox|oxidizing agents]] and also prone to [[disproportionation]] in solution to manganese(II) and manganese(IV). Solid compounds of manganese(III) are characterized by their preference for distorted octahedral coordination due to the [[Jahn-Teller effect]] and its strong purple-red color.
The oxidation state 5+ can be obtained if manganese dioxide is dissolved in molten [[sodium nitrite]].<ref>{{cite journal|first = R. B.|last = Temple|author2=Thickett, G. W.|title = The formation of manganese(v) in molten sodium nitrite|url = http://www.publish.csiro.au/?act=view_file&file_id=CH9720655.pdf|journal = Australian Journal of Chemistry|date = 1972|volume = 25|page=55|doi = 10.1071/CH9720655|issue = 3}}</ref> Manganate (VI) salts can also be produced by dissolving Mn compounds, such as [[manganese dioxide]], in molten alkali while exposed to air.
Permanganate (+7 oxidation state) compounds are purple, and can give glass a violet color. [[Potassium permanganate]], [[sodium permanganate]] and [[barium permanganate]] are all potent oxidizers. Potassium permanganate, also called Condy's crystals, is a commonly used laboratory [[reagent]] because of its oxidizing properties and finds use as a topical medicine (for example, in the treatment of fish diseases). Solutions of potassium permanganate were among the first stains and fixatives to be used in the preparation of biological cells and tissues for electron microscopy.<ref>{{cite journal |doi=10.1083/jcb.2.6.799 |last=Luft |first=J. H.|date=1956|title=Permanganate – a new fixative for electron microscopy |journal=Journal of Biophysical and Biochemical Cytology |volume=2|pages=799–802 |pmid=13398447 |issue=6 |pmc=2224005}}</ref>

==History==
The origin of the name manganese is complex. In ancient times, two black minerals from [[Magnesia (regional unit)|Magnesia]] in what is now modern Greece, were both called ''magnes'' from their place of origin, but were thought to differ in gender. The male ''magnes'' attracted iron, and was the iron ore now known as [[lodestone]] or [[magnetite]], and which probably gave us the term [[magnet]]. The female ''magnes'' ore did not attract iron, but was used to decolorize glass. This feminine ''magnes'' was later called ''magnesia'', known now in modern times as [[pyrolusite]] or [[manganese dioxide]]. Neither this mineral nor manganese itself is magnetic. In the 16th century, manganese dioxide was called ma'''n'''ga'''n'''esum (note the two n's instead of one) by glassmakers, possibly as a corruption and concatenation of two words, since alchemists and glassmakers eventually had to differentiate a ''mag'''n'''esia '''n'''egra'' (the black ore) from ''mag'''n'''esia alba'' (a white ore, also from Magnesia, also useful in glassmaking). [[Michele Mercati]] called magnesia negra ''manganesa'', and finally the metal isolated from it became known as ''manganese'' (German: ''Mangan''). The name ''magnesia'' eventually was then used to refer only to the white [[magnesia alba]] (magnesium oxide), which provided the name [[magnesium]] for that free element, when it was eventually isolated, much later.<ref>{{cite web|last=Calvert|first=J.B.|url = http://www.du.edu/~jcalvert/phys/chromang.htm|title = Chromium and Manganese|accessdate = 2009-04-30|date = 2003-01-24}}</ref>

[[File:Lascaux painting.jpg|thumb| left |alt=A drawing of a left-facing bull, in black, on a cave wall |Some of the cave paintings in [[Lascaux]], [[France]], use manganese-based pigments.<ref name="Lascaux">{{cite journal|doi = 10.1088/0957-0233/14/9/310|title = Analysis of rock art painting and technology of Palaeolithic painters|date = 2003|last = Chalmin|first = Emilie |author2 = Menu, Michel |author3=Vignaud, Colette|journal = Measurement Science and Technology|volume = 14|pages = 1590–1597|issue = 9}}</ref>]]

Several oxides of manganese, for example [[Manganese(IV) oxide|manganese dioxide]], are abundant in nature, and owing to their color, these oxides have been used as pigments since the [[Stone Age]]. The cave paintings in [[Gargas, Haute-Garonne|Gargas]] contain manganese as pigments and these cave paintings are 30,000 to 24,000 years old.<ref>{{cite journal|doi = 10.1007/s00339-006-3510-7|title = Minerals discovered in paleolithic black pigments by transmission electron microscopy and micro-X-ray absorption near-edge structure|date = 2006|last1 = Chalmin|first1 = E|last2= Vignaud|first2=C.|last3=Salomon|first3=H.|last4=Farges|first4=F.|last5=Susini|first5=J. |last6= Menu|first6=M.| journal = Applied Physics A|volume = 83|pages = 213–218|issue = 12|bibcode = 2006ApPhA..83..213C}}</ref>

Manganese compounds were used by Egyptian and Roman glassmakers, to either remove color from glass or add color to it.<ref>{{cite journal|doi = 10.1126/science.133.3467.1824|date = 1961|last = Sayre|first = E. V.|author2=Smith, R. W.|title = Compositional Categories of Ancient Glass|volume = 133|issue = 3467|pages = 1824–1826|journal = Science|pmid = 17818999|bibcode = 1961Sci...133.1824S}}</ref> The use as "glassmakers soap" continued through the [[Middle Ages]] until modern times and is evident in 14th-century glass from [[Venice]].<ref name="ItGlass"/>

[[File:Gahn Johan Gottlieb.jpg|thumb|Credit for first isolating manganese is usually given to [[Johan Gottlieb Gahn]].]]

Because of the use in glassmaking, [[Manganese(IV) oxide|manganese dioxide]] was available to alchemists, the first chemists, and was used for experiments. [[Ignatius Gottfried Kaim]] (1770) and [[Johann Glauber]] (17th century) discovered that manganese dioxide could be converted to [[permanganate]], a useful laboratory reagent.<ref>{{cite journal|journal = Centaurus|volume = 19|issue = 4|title = The Discovery of an Element|first = E.|last = Rancke-Madsen|doi = 10.1111/j.1600-0498.1975.tb00329.x|pages = 299–313|date = 1975|bibcode = 1975Cent...19..299R}}</ref> By the mid-18th century, the Swedish chemist [[Carl Wilhelm Scheele]] used manganese dioxide to produce [[chlorine]]. First, [[hydrochloric acid]], or a mixture of dilute [[sulfuric acid]] and [[sodium chloride]] was made to react with manganese dioxide, later hydrochloric acid from the [[Leblanc process]] was used and the manganese dioxide was recycled by the [[Weldon process]]. The production of chlorine and [[hypochlorite]] containing [[bleach]]ing agents was a large consumer of manganese ores.

Scheele and other chemists were aware that manganese dioxide contained a new element, but they were not able to isolate it. [[Johan Gottlieb Gahn]] was the first to isolate an impure sample of manganese metal in 1774, by [[reduction-oxidation|reducing]] the dioxide with [[carbon]].

The manganese content of some iron ores used in Greece led to the speculations that the steel produced from that ore contains inadvertent amounts of manganese, making the [[Sparta]]n steel exceptionally hard.<ref>{{cite journal|doi = 10.1002/ajim.20524|date = 2007|title = From lead to manganese through mercury: mythology, science, and lessons for prevention|volume = 50|issue = 11|pages = 779–787 |journal = American journal of industrial medicine|pmid = 17918211|last1 = Alessio|first1 = L|last2 = Campagna|first2 = M|last3 = Lucchini|first3 = R}}</ref> Around the beginning of the 19th century, manganese was used in steelmaking and several patents were granted. In 1816, it was noted that adding manganese to iron made it harder, without making it any more brittle. In 1837, British academic [[James Couper (academic)|James Couper]] noted an association between heavy exposures to manganese in mines with a form of [[Parkinson's disease]].<ref name="Couper 1837 41–42"/> In 1912, manganese phosphating electrochemical conversion coatings for protecting firearms against rust and corrosion were patented in the United States, and have seen widespread use ever since.<ref>{{cite book|title = Production of Manganese Ferroalloys|publisher = Tapir Academic Press|date = 2007|isbn = 978-82-519-2191-6|chapter = History of manganese|pages = 11–12|author = Olsen, Sverre E.|author2 = Tangstad, Merete|author3 = Lindstad, Tor}}</ref>

The invention of the [[Leclanché cell]] in 1866 and the subsequent improvement of the batteries containing manganese dioxide as cathodic [[depolarizer]] increased the demand of manganese dioxide. Until the introduction of the [[nickel-cadmium battery]] and lithium-containing batteries, most batteries contained manganese. The [[zinc-carbon battery]] and the [[alkaline battery]] normally use industrially produced manganese dioxide, because natural occurring manganese dioxide contains impurities. In the 20th century, [[manganese(IV) oxide|manganese dioxide]] has seen wide commercial use as the chief cathodic material for commercial disposable dry cells and dry batteries of both the standard (zinc-carbon) and alkaline types.<ref name="ChiuZMnO2">{{cite journal|doi = 10.1002/ciuz.19800140502|title = Moderne Verfahren der Großchemie: Braunstein|date = 1980|last = Preisler|first = Eberhard|journal = Chemie in unserer Zeit|language=German|volume = 14|pages = 137–148|issue = 5}}</ref>

==Occurrence and production==
{{See also|Category:Manganese minerals}}
Manganese makes up about 1000 [[Parts per million|ppm]] (0.1%) of the [[Earth's crust]], making it the 12th most abundant element there.<ref name="Emsley2001">{{cite book |title = Nature's Building Blocks: An A-Z Guide to the Elements|last = Emsley|first = John|publisher = Oxford University Press|date = 2001|location = Oxford, UK |isbn = 0-19-850340-7|chapter = Manganese|pages = 249–253|url = https://books.google.com/?id=j-Xu07p3cKwC}}</ref> Soil contains 7–9000 ppm of manganese with an average of 440 ppm.<ref name="Emsley2001"/> Seawater has only 10 [[Parts per million|ppm]] manganese and the atmosphere contains 0.01 µg/m3.<ref name="Emsley2001"/> Manganese occurs principally as [[pyrolusite]] ([[manganese(IV) oxide|MnO2]]), [[braunite]], (Mn2+Mn3+6)(SiO12),<ref>{{cite journal|pages = 65–71|journal = Contributions to Mineralogy and Petrology|title = Geochemistry of braunite and associated phases in metamorphosed non-calcareous manganese ores of India|first = P. K.|last = Bhattacharyya|author2 = Dasgupta, Somnath |author3=Fukuoka, M. |author4=Roy Supriya |doi = 10.1007/BF00371403|date = 1984|volume = 87|issue = 1|bibcode=1984CoMP...87...65B}}</ref> [[psilomelane]] (Ba,H2O)2Mn5O10, and to a lesser extent as [[rhodochrosite]] ([[manganese(II) carbonate|MnCO3]]).

{|class="wikitable"
|[[File:ManganeseOreUSGOV.jpg|center|120px]]
|[[File:Mineraly.sk - psilomelan.jpg|center|160px]]
|[[File:Spiegeleisen.jpg|center|185px]]
|[[File:Dendrites01.jpg|center|144px]]
|[[File:The Searchlight Rhodochrosite Crystal.jpg|center|152px]]
|-
|Manganese ore
|Psilomelane (manganese ore)
|[[Spiegeleisen]] is an iron alloy with a manganese content of approximately 15%
|Manganese oxide dendrites on limestone from [[Solnhofen]], Germany – a kind of [[pseudofossil]]. Scale is in mm
|Mineral rhodochrosite ([[manganese(II) carbonate]])
|}
[[File:World Manganese Production 2006.svg|thumb|350px|Percentage of manganese output in 2006 by countries<ref name=USGSMCS2009/>]]

The most important manganese ore is pyrolusite ([[manganese(IV) oxide|MnO2]]). Other
economically important manganese ores usually show a close spatial relation to the iron ores.<ref name="Holl"/> Land-based resources are large but irregularly distributed. About 80% of the known world manganese resources are found in South Africa; other important manganese deposits are in Ukraine, Australia, India, China, [[Gabon]] and Brazil.<ref name=USGSMCS2009/> In 1978, 500 billion tons of [[manganese nodule]]s were estimated to exist on the [[ocean floor]].<ref>{{cite journal|doi = 10.1016/j.micron.2008.10.005|pages = 350–358|date = 2009|title = Manganese/polymetallic nodules: micro-structural characterization of exolithobiontic- and endolithobiontic microbial biofilms by scanning electron microscopy|volume = 40|issue = 3|pmid = 19027306|journal = Micron |author1 = Wang, X|author2 = Schröder, HC|author3 = Wiens, M|author4 = Schlossmacher, U|author5 = Müller, WEG}}</ref> Attempts to find economically viable methods of harvesting manganese nodules were abandoned in the 1970s.<ref>{{cite book|title = Manganese Nodules: Dimensions and Perspectives|publisher = Springer|date = 1978|isbn =978-90-277-0500-6|author = United Nations Ocean Economics and Technology Office, Technology Branch, United Nations}}</ref>

In South Africa most identified deposits are located near [[Hotazel]] in the [[Northern Cape Province]] with an estimated 15 billion tons in 2011. In 2011 South Africa was the world's largest producer of manganese producing 3.4 million tons.<ref name="Mbendi">{{cite web | url=http://www.mbendi.com/indy/ming/mang/af/sa/p0005.htm | title=Manganese Mining in South Africa – Overview | publisher=MBendi.com | accessdate=2014-01-04}}</ref>

Manganese is mined in South Africa, Australia, China, Brazil, Gabon, Ukraine, India, Fiji and Ghana and [[Kazakhstan]]. US Import Sources (1998–2001): Manganese ore: Gabon, 70%; South Africa, 10%; Australia, 9%; Mexico, 5%; and other, 6%. Ferromanganese: South Africa, 47%; France, 22%; Mexico, 8%; Australia, 8%; and other, 15%. Manganese contained in all manganese imports: South Africa, 31%; Gabon, 21%; Australia, 13%; Mexico, 8%; and other, 27%.<ref name=USGSMCS2009>{{cite web| last= Corathers|first = Lisa A. |date = 2009|url = http://minerals.usgs.gov/minerals/pubs/commodity/manganese/mcs-2009-manga.pdf|publisher = United States Geological Survey|accessdate = 2009-04-30|title = Mineral Commodity Summaries 2009: Manganese |format = PDF}}</ref><ref name="MangUSGS2006">{{cite web|last= Corathers|first = Lisa A.|url = http://minerals.usgs.gov/minerals/pubs/commodity/manganese/myb1-2006-manga.pdf|title = 2006 Minerals Yearbook: Manganese|publisher = United States Geological Survey|location = Washington, D.C.|date = June 2008|accessdate = 2009-04-30|format = PDF}}</ref>

For the production of [[ferromanganese]], the manganese ore is mixed with iron ore and carbon, and then reduced either in a blast furnace or in an electric arc furnace.<ref name="IndMin">{{cite book|title =Industrial Minerals & Rocks: Commodities, Markets, and Uses|edition = 7th|publisher = SME|date = 2006|isbn = 978-0-87335-233-8|chapter = Manganese|first = L. A.|last = Corathers |author2=Machamer, J. F.|url = https://books.google.com/?id=zNicdkuulE4C&pg=PA631|pages = 631–636}}
</ref> The resulting [[ferromanganese]] has a manganese content of 30 to 80%.<ref name="Holl"/> Pure manganese used for the production of iron-free alloys is produced by [[Leaching (metallurgy)|leaching]] manganese ore with [[sulfuric acid]] and a subsequent [[electrowinning]] process.<ref name="hydrometI">{{cite journal|doi = 10.1016/j.hydromet.2007.08.010 |title = Manganese metallurgy review. Part I: Leaching of ores/secondary materials and recovery of electrolytic/chemical manganese dioxide|date = 2007|last = Zhang|first = Wensheng|author2=Cheng, Chu Yong|journal = Hydrometallurgy|volume = 89|pages = 137–159|issue = 3–4}}</ref>

[[File:Manganese Process Flow Diagram.jpg|left|thumb|alt=Contains reactions and temperatures, as well as showing advanced processes such as the heat exchanger and milling process.|Process flow diagram for a manganese refining circuit.]]
A more progressive extraction process involves directly reducing manganese ore in a heap leach. This is done by percolating natural gas through the bottom of the heap; the natural gas provides the heat (needs to be at least 850 °C) and the reducing agent (carbon monoxide). This reduces all of the manganese ore to manganese oxide (MnO), which is a leachable form. The ore then travels through a grinding circuit to reduce the particle size of the ore to between 150–250 μm, this increases the surface area to aid in the leaching process. The ore is then added to a leach tank, which contains [[sulfuric acid]] and ferrous iron (Fe2+) in a 1.6:1 ratio. The iron reacts with the manganese dioxide to form iron hydroxide and elemental manganese.{{cn}} This process yields approximately 92% recovery of the manganese. For further purification, the manganese can then be sent to an electrowinning facility.<ref name="ManganeseRecovery">{{cite web|url = http://www.americanmanganeseinc.com/wp-content/uploads/2011/08/American-Manganese-Phase-II-August-19-2010-Final-Report-Internet-Version-V2.pdf |title = The Recovery of Manganese from low grade resources: bench scale metallurgical test program completed|date = 2010|author = Chow, Norman|author2 = Nacu, Anca|author3 = Warkentin, Doug|author4 = Aksenov, Igor|author5 = Teh, Hoe|last-author-amp = yes|publisher=Kemetco Research Inc.}}</ref>

==Manganese in Popular Culture==
* In 1972 the [[Central Intelligence Agency|CIA]]'s [[Project Azorian]], through billionaire [[Howard Hughes]], commissioned the ship ''[[Hughes Glomar Explorer]]'' with the cover story of harvesting manganese nodules from the sea floor. That triggered a rush of activity to attempt to collect manganese nodules, which was not actually practical. The real mission of ''Hughes Glomar Explorer'' was to raise a sunken [[Union of Soviet Socialist Republics|Soviet]] submarine, the [[Soviet submarine K-129 (1960)|K-129]], with the goal of retrieving Soviet code books.<ref name="azorian">{{cite web
| url= http://www2.gwu.edu/~nsarchiv/nukevault/ebb305/index.htm
| title= Project Azorian: The CIA's Declassified History of the Glomar Explorer
| publisher= National Security Archive at George Washington University
| date= 2010-02-12
| accessdate= 2013-09-18
}}</ref>
* In the movie [[Caddyshack]], [[Bill Murray]]'s character makes reference to Manganese in an attempt to impress Ty with the seriousness of Murray's plan to become head greenskeeper.

==Applications==
Manganese has no satisfactory substitute in its major applications, which are related to metallurgical alloy use.<ref name=USGSMCS2009/> In minor applications, (e.g., manganese phosphating), [[zinc]] and sometimes [[vanadium]] are viable substitutes.

===Steel===
[[File:M1917helmet.jpg|thumb|right|US Marine Corps [[Brodie helmet|steel helmet]]]]
Manganese is essential to iron and [[steelmaking|steel production]] by virtue of its sulfur-fixing, [[deoxidized steel|deoxidizing]], and [[alloying]] properties. [[Steelmaking]],<ref>{{cite book|isbn = 978-0-87170-858-8|pages = 56–57|first = John D.|last = Verhoeven|date = 2007|publisher = ASM International|location = Materials Park, Ohio|title = Steel metallurgy for the non-metallurgist}}</ref> including its ironmaking component, has accounted for most manganese demand, presently in the range of 85% to 90% of the total demand.<ref name="hydrometI"/> Among a variety of other uses, manganese is a key component of low-cost [[stainless steel]] formulations.<ref name="MangUSGS2006"/><ref>{{cite journal|doi = 10.1007/BF02648339|title = Mechanism of work hardening in Hadfield manganese steel|date = 1981|last = Dastur|first = Y. N.|journal = Metallurgical Transactions A|volume = 12|pages = 749|last2 = Leslie|first2 = W. C.|issue = 5|bibcode = 1981MTA....12..749D}}</ref>

Small amounts of manganese improve the workability of steel at high temperatures, because it forms a high-melting sulfide and therefore prevents the formation of a liquid [[iron sulfide]] at the grain boundaries. If the manganese content reaches 4%, the embrittlement of the steel becomes a dominant feature. The embrittlement decreases at higher manganese concentrations and reaches an acceptable level at 8%. Steel containing 8 to 15% of manganese can have a high [[tensile strength]] of up to 863 MPa.<ref>{{cite book|isbn = 978-1-4086-2616-0|pages = 351–352|title = Iron and Steel|first = John Henry|last = Stansbie|publisher = Read Books|url = https://books.google.com/?id=FyogLqUxW1cC&pg=PA351|date = 2007
}}</ref><ref>{{cite book|isbn = 978-0-07-136076-0|pages = 585–587|last = Brady|first = George S.|author2 = Clauser, Henry R. |author3=Vaccari. John A. |date = 2002|publisher = McGraw-Hill|location = New York, NY|title = Materials handbook: an encyclopedia for managers, technical professionals, purchasing and production managers, technicians, and supervisors|url = https://books.google.com/?id=vIhvSQLhhMEC&pg=PA585}}</ref> Steel with 12% manganese was used for British [[Brodie helmet|steel helmets]]. This steel composition was discovered in 1882 by [[Robert Hadfield]] and is still known as [[Hadfield steel]].<ref>{{cite journal|title = Sir Robert Abbott Hadfield F.R.S. (1858–1940), and the Discovery of Manganese Steel Geoffrey Tweedale|journal = Notes and Records of the Royal Society of London|volume = 40|issue = 1 |date = 1985|pages = 63–74|doi = 10.1098/rsnr.1985.0004|first = Geoffrey|last = Tweedale|jstor = 531536}}</ref>

===Aluminium alloys===
{{Main|Aluminium alloy}}
The second large application for manganese is as an alloying agent for [[aluminium]]. Aluminium with a manganese content of roughly 1.5% has an increased resistance against corrosion due to the formation of grains absorbing impurities which would lead to [[galvanic corrosion]].<ref>{{cite web|url = http://www.suppliersonline.com/propertypages/2024.asp|title = Chemical properties of 2024 aluminum allow|accessdate = 2009-04-30|publisher = Metal Suppliers Online, LLC.}}</ref> The corrosion-resistant [[aluminium alloy]]s 3004 and 3104 with a manganese content of 0.8 to 1.5% are the alloys used for most of the [[beverage can]]s.<ref name="Al3004">{{cite book |title = Introduction to aluminum alloys and tempers|first = John Gilbert|last = Kaufman|publisher = ASM International|date = 2000|isbn = 978-0-87170-689-8|chapter = Applications for Aluminium Alloys and Tempers|pages = 93–94|url = https://books.google.com/?id=idmZIDcwCykC&pg=PA93}}</ref> Before year 2000, more than 1.6 million [[tonne]]s have been used of those alloys; with a content of 1% manganese, this amount would need 16,000 tonnes of manganese.<ref name="Al3004"/>

===Other uses===
[[Methylcyclopentadienyl manganese tricarbonyl]] is used as an additive in [[unleaded gasoline]] to boost [[octane rating]] and reduce [[engine knocking]]. The manganese in this unusual organometallic compound is in the +1 oxidation state.<ref>{{cite journal|author=Leigh A. Graham|author2=Alison R. Fout|author3=Karl R. Kuehne|author4=Jennifer L. White|author5=Bhaskar Mookherji|author6=Fred M. Marks|author7=Glenn P. A. Yap|author8=Lev N. Zakharov|author9=Arnold L. Rheingold|author10=Daniel Rabinovich|last-author-amp=yes |title=Manganese(I) poly(mercaptoimidazolyl)borate complexes: spectroscopic and structural characterization of MnH–B interactions in solution and in the solid state|journal=[[Dalton Transactions]]|issue=1|date=2005|pages=171–180|pmid=15605161|doi=10.1039/b412280a }}</ref>

[[Manganese(IV) oxide]] (manganese dioxide, MnO2) is used as a reagent in [[organic chemistry]] for the [[oxidation]] of benzylic [[alcohol]]s (i.e. adjacent to an [[aromatic ring]]). Manganese dioxide has been used since antiquity to oxidatively neutralize the greenish tinge in glass caused by trace amounts of iron contamination.<ref name="ItGlass">{{cite journal|doi = 10.1007/s11837-998-0024-0|title = Glassmaking in renaissance Italy: The innovation of venetian cristallo|date = 1998|last = Mccray|first = W. Patrick|journal = Journal of the Minerals, Metals and Materials Society|volume = 50|pages = 14|issue = 5|bibcode = 1998JOM....50e..14M}}</ref> MnO2 is also used in the manufacture of oxygen and chlorine, and in drying black paints. In some preparations, it is a brown [[pigment]] that can be used to make [[paint]] and is a constituent of natural [[umber]].

[[Manganese(IV) oxide]] was used in the original type of dry cell [[Battery (electricity)|battery]] as an electron acceptor from zinc, and is the blackish material found when opening carbon–zinc type flashlight cells. The manganese dioxide is reduced to the manganese oxide-hydroxide MnO(OH) during discharging, preventing the formation of hydrogen at the anode of the battery.<ref name="BattHist"/>

:MnO2 + H2O + {{chem|e|-}} → MnO(OH) + {{chem|OH|-}}

The same material also functions in newer [[alkaline batteries]] (usually battery cells), which use the same basic reaction, but a different electrolyte mixture. In 2002, more than 230,000 tons of manganese dioxide was used for this purpose.<ref name="ChiuZMnO2"/><ref name="BattHist">{{cite journal|doi = 10.1016/S0167-2738(00)00722-0|title = Batteries fifty years of materials development|date = 2000|last = Dell|first = R. M.|journal = Solid State Ionics|volume = 134|pages = 139–158}}</ref>

[[File:1945-P-Jefferson-War-Nickel-Reverse.JPG|150px|right|thumb|World-War-II-era 5-cent coin (1942-5 identified by mint mark P,D or S above dome) made from a 56% copper-35% silver-9% manganese alloy]]

The metal is occasionally used in coins; until 2000, the only United States coin to use manganese was the [[Jefferson nickel#1938–1945: Early minting; World War II changes|"wartime" nickel]] from 1942 to 1945.<ref>{{cite journal|journal = Western Journal of Medicine|date = 2001|volume = 175|issue = 2|pages = 112–114|first = Raymond T.|last = Kuwahara|author2 = Skinner III, Robert B. |author3=Skinner Jr., Robert B. |title = Nickel coinage in the United States|doi = 10.1136/ewjm.175.2.112|pmid = 11483555|pmc = 1071501}}</ref> An alloy of 75% copper and 25% nickel was traditionally used for the production of nickel coins. However, because of shortage of nickel metal during the war, it was substituted by more available silver and manganese, thus resulting in an alloy of 56% copper, 35% silver and 9% manganese. Since 2000, [[Dollar (United States coin)|dollar coins]], for example the [[Sacagawea dollar]] and the [[Presidential $1 Coin Program|Presidential $1 coins]], are made from a brass containing 7% of manganese with a pure copper core.<ref>{{cite journal|url = http://www.usmint.gov/mint_programs/golden_dollar_coin/index.cfm?action=sacDesign|title = Design of the Sacagawea dollar|publisher = United States Mint|accessdate = 2009-05-04}}</ref> In both cases of nickel and dollar, the use of manganese in the coin was to duplicate the electromagnetic properties of a previous identically sized and valued coin, for vending purposes. In the case of the later U.S. dollar coins, the manganese alloy was an attempt to duplicate properties of the copper/nickel alloy used in the previous [[Susan B. Anthony dollar]]. 

Manganese compounds have been used as pigments and for the coloring of ceramics and glass. The brown color of ceramic is sometimes based on manganese compounds.<ref>{{cite book|title =Ceramics for the archaeologist| first = Anna Osler|last = Shepard|publisher = Carnegie Institution of Washington|date = 1956|pages = 40–42|isbn = 978-0-87279-620-1|chapter = Manganese and Iron–Manganese Paints}}</ref> In the glass industry, manganese compounds are used for two effects. Manganese(III) reacts with iron(II) to induce a strong green color in glass by forming less-colored iron(III) and slightly pink manganese(II), compensating for the residual color of the iron(III).<ref name="ItGlass"/> Larger amounts of manganese are used to produce pink colored glass.

==Biological role==
[[File:Arginase.jpeg|thumb|right|400px|Reactive center of arginase with boronic acid [[Enzyme inhibitor|inhibitor]] – the manganese atoms are shown in yellow.]]
Manganese is an important metal for human health, being absolutely necessary for development, metabolism, and the antioxidant system. Nevertheless, excessive exposure or intake may lead to a condition known as manganism, a neurodegenerative disorder that causes dopaminergic neuronal death and parkinsonian- like symptoms.<ref name="Emsley2001"/><ref>
{{cite book
|first1=Daiana
|last1=Silva Avila
|first2=Robson
|last2=Luiz Puntel
|first3=Michael
|last3=Aschner
|editor=Astrid Sigel|editor2=Helmut Sigel|editor3=Roland K. O. Sigel
|title=Interrelations between Essential Metal Ions and Human Diseases
|series=Metal Ions in Life Sciences
|volume=13
|date=2013
|publisher=Springer
|pages=199–227
|chapter=Chapter 7. Manganese in Health and Disease
|doi=10.1007/978-94-007-7500-8_7
}}
</ref> The classes of enzymes that have manganese [[Cofactor (biochemistry)|cofactors]] are very broad, and include [[oxidoreductase]]s, [[transferase]]s, [[hydrolase]]s, [[lyase]]s, [[isomerase]]s, [[ligase]]s, [[lectin]]s, and [[integrin]]s. The [[reverse transcriptase]]s of many [[retrovirus]]es (though not [[lentivirus]]es such as [[HIV]]) contain manganese. The best-known manganese-containing [[polypeptides]] may be [[arginase]], the [[diphtheria toxin]], and Mn-containing [[superoxide dismutase]] ([[Mn-SOD]]).<ref name="Mnzym">{{cite journal|doi = 10.1016/S0898-8838(08)60152-X|title = Manganese Redox Enzymes and Model Systems: Properties, Structures, and Reactivity|date = 1998|last = Law|first = N.|volume = 46|page= 305|last2 = Caudle|first2 = M|last3 = Pecoraro|first3 = V|series = Advances in Inorganic Chemistry|isbn = 9780120236466}}</ref>

Mn-SOD is the type of SOD present in eukaryotic [[mitochondria]], and also in most bacteria (this fact is in keeping with the bacterial-origin theory of mitochondria). The Mn-SOD enzyme is probably one of the most ancient, for nearly all organisms living in the presence of oxygen use it to deal with the toxic effects of [[superoxide]] ({{chem|O|2|-}}), formed from the 1-electron reduction of dioxygen. Exceptions include a few kinds of bacteria, such as ''[[Lactobacillus plantarum]]'' and related [[lactobacillus|lactobacilli]], which use a different nonenzymatic mechanism, involving manganese (Mn2+) ions complexed with polyphosphate directly for this task, indicating how this function possibly evolved in aerobic life.

The manganese [[dietary reference intake]] for a 44 y.o. human male is 2.3 mg per day from food, with 11 mg estimated as the tolerable upper limit for daily intake to avoid toxicity. Estimates for females and children are generally less.<ref name=IOM>{{citation
| title = Dietary Reference Intakes (DRIs): Recommended Intakes for Individuals
| publisher = Food and Nutrition Board, Institute of Medicine, National Academies
| date = 2004
| url = http://www.iom.edu/Global/News%20Announcements/~/media/Files/Activity%20Files/Nutrition/DRIs/DRI_Summary_Listing.pdf
| accessdate = 2009-06-09 }}
</ref> The essential minimum intake is unknown since [[manganese deficiency (medicine)|manganese deficiency]] is so rare.<ref>''See'' {{cite web|url=http://lpi.oregonstate.edu/mic/minerals/manganese|title=Manganese|work=Micronutrient Information Center|publisher=[[Oregon State University]] [[Linus Pauling Institute]]}}</ref><ref>''Cf''. {{cite web|title=Manganese (CASRN 7439-96-5)|url=http://www.epa.gov/iris/subst/0373.htm#reforal|at=sec. __I.A.4., Additional Studies/Comments (Oral RfD)|quote=Because of the ubiquitous nature of manganese in foodstuffs, actual manganese deficiency has not been observed in the general population. There are, however, only two reports in the literature of experimentally induced manganese deficiency in humans....While an outright manganese deficiency has not been observed in the general human population, suboptimal manganese status may be more of a concern.|publisher=[[Environmental Protection Agency]]|work=Integrated Risk Information System}}</ref> The human body contains about 12 mg of manganese, which is stored mainly in the bones. The remaining manganese in soft tissue is mostly concentrated in the liver and kidneys.<ref name="Emsley2001"/> In the human brain, the manganese is bound to manganese [[metalloprotein]]s, most notably [[glutamine synthetase]] in [[astrocyte]]s.<ref>{{cite journal|doi = 10.1016/S0165-0173(02)00234-5|title = Manganese action in brain function|date = 2003|last = Takeda| first = A.|journal = Brain Research Reviews|volume = 41|issue = 1|pmid=12505649|pages = 79–87}}</ref>

Manganese is also important in photosynthetic [[oxygen evolution]] in [[chloroplast]]s in plants. The [[oxygen-evolving complex]] (OEC) is a part of photosystem II contained in the thylakoid membranes of chloroplasts; it is responsible for the terminal [[Oxygen evolution|photooxidation of water]] during the [[light reactions]] of [[photosynthesis]], and has a metalloenzyme core containing four atoms of manganese.<ref>{{cite encyclopedia|last= Dismukes|first = G. Charles|author2=Willigen, Rogier T. van|date = 2006|title = Manganese: The Oxygen-Evolving Complex & Models|encyclopedia = Encyclopedia of Inorganic Chemistry|doi = 10.1002/0470862106.ia128|chapter= Manganese: The Oxygen-Evolving Complex & Models|isbn= 0470860782}}</ref> For this reason, most broad-spectrum plant fertilizers contain manganese.

==Precautions==
Manganese compounds are less toxic than those of other widespread metals, such as [[nickel]] and [[copper]].<ref>{{cite book|pages = 31|title = Manganese|first = Heather|last = Hasan|publisher = The Rosen Publishing Group|date = 2008|isbn = 978-1-4042-1408-8|url = https://books.google.com/?id=nRmpEaudmTYC&pg=PA31}}</ref> However, exposure to manganese dusts and fumes should not exceed the ceiling value of 5 mg/m3 even for short periods because of its toxicity level.<ref>{{cite web|url = https://web.archive.org/web/20120425170847/http://www.environmentwriter.org/resources/backissues/chemicals/manganese.htm|title = Manganese Chemical Background|accessdate = 2008-04-30|publisher = Metcalf Institute for Marine and Environmental Reporting University of Rhode Island |date = April 2006}}</ref>  Manganese poisoning has been linked to impaired motor skills and cognitive disorders.<ref>{{cite web| url=http://rais.ornl.gov/tox/profiles/mn.html|publisher=Oak Ridge National Laboratory|title=Risk Assessment Information System Toxicity Summary for Manganese|accessdate=2008-04-23}}</ref>

The permanganate exhibits a higher toxicity than the manganese(II) compounds. The fatal dose is about 10 g, and several fatal intoxications have occurred. The strong oxidative effect leads to necrosis of the [[mucous membrane]]. For example, the [[esophagus]] is affected if the permanganate is swallowed. Only a limited amount is absorbed by the intestines, but this small amount shows severe effects on the kidneys and on the liver.<ref>{{cite journal|doi = 10.1136/emj.14.1.43|title = Potassium permanganate poisoning – a rare cause of fatal self poisoning|date = 1997|last = Ong|first = K. L.|journal = Emergency Medicine Journal|volume = 14|pages = 43–5|pmid = 9023625|last2 = Tan|last3 = Cheung|issue = 1|first2 = TH|first3 = WL|pmc = 1342846}}</ref><ref>{{cite journal|doi =10.1177/096032719601500313|title =Fatal acute hepatorenal failure following potassium permanganate ingestion|date =1996|last = Young|first = R.|journal = Human & Experimental Toxicology|volume = 15|pages = 259–61|pmid =8839216|last2 =Critchley|last3 =Young|last4 =Freebairn|last5 =Reynolds|last6 =Lolin|issue =3|first2 =JA|first3 =KK|first4 =RC|first5 =AP|first6 =YI}}</ref>


In 2005, a study suggested a possible link between manganese inhalation and central nervous system toxicity in rats.<ref name=elsner>{{cite journal|date=2005|title=Neurotoxicity of inhaled manganese: Public health danger in the shower? |journal=Medical Hypotheses|volume=65 |issue=3 |pages=607–616 |doi=10.1016/j.mehy.2005.01.043 |pmid=15913899 |last1=Elsner |first1=Robert J. F. |last2=Spangler |first2=John G.}}</ref>

Manganese exposure in [[United States]] is regulated by the [[Occupational Safety and Health Administration]] (OSHA).<ref name="osha.gov">{{cite web|title=Safety and Health Topics: Manganese Compounds (as Mn)|url=https://www.osha.gov/dts/chemicalsampling/data/CH_250190.html}}</ref> People can be exposed to manganese in the workplace by breathing it in or swallowing it. OSHA has set the legal limit ([[permissible exposure limit]]) for manganese exposure in the workplace as 5 mg/m3 over an 8-hour workday. The [[National_Institute_for_Occupational_Safety_and_Health]] (NIOSH) has set a [[recommended exposure limit]] (REL) of 1 mg/m3 over an 8-hour workday and a short term limit of 3 mg/m3. At levels of 500 mg/m3, manganese is [[IDLH|immediately dangerous to life and health]].<ref>{{Cite web|title = CDC - NIOSH Pocket Guide to Chemical Hazards -
Manganese compounds and fume (as Mn)|url = http://www.cdc.gov/niosh/npg/npgd0379.html|website = www.cdc.gov|accessdate = 2015-11-19}}</ref>

Generally, exposure to ambient Mn air concentrations in excess of 5 μg Mn/m3 can lead to Mn-induced symptoms. Increased [[ferroportin]] protein expression in human embryonic kidney (HEK293) cells is associated with decreased intracellular Mn concentration and attenuated cytotoxicity, characterized by the reversal of Mn-reduced [[glutamate]] uptake and diminished [[lactate dehydrogenase]] leakage.<ref>{{cite journal|pmid=20002294|last1=Yin|first1=Z|date=2010|pages=1190–8|issue=5|volume=112|last2=Jiang|first2=H|journal=Journal of Neurochemistry|last3=Lee|first3=ES|last4=Ni|first4=M|last5=Erikson|first5=KM|last6=Milatovic|first6=D|last7=Bowman|first7=AB|last8=Aschner|first8=M|title=Ferroportin is a manganese-responsive protein that decreases manganese cytotoxicity and accumulation|url=http://libres.uncg.edu/ir/uncg/f/K_Erickson_Ferroportin_2009.pdf|pmc=2819584|doi=10.1111/j.1471-4159.2009.06534.x}}</ref>

== Environmental health concerns ==

=== Manganese in drinking water ===
Waterborne manganese has a greater bioavailability than dietary manganese. According to results from a 2010 study,<ref name="Bouchard 138–143">{{cite journal | last=Bouchard|first=Maryse F. | author2=Sébastien Sauvé | author3=Benoit Barbeau | author4=Melissa Legrand| author5=Marie-Ève Brodeur | author6=Thérèse Bouffard| author7=Elyse Limoges | author8=David C. Bellinger | author9=Donna Mergler | last-author-amp=yes|title=Intellectual Impairment in School-Age Children | journal=Environmental Health Perspectives | date=20 September 2010 | doi=10.1289/ehp.1002321 | url=http://www.cityofmadison.com/water/waterQuality/documents/EHP.20100920.MnIQ.pdf | accessdate=2010-12-11 | volume=119|pages=138–143| pmid=20855239 | issue=1 | pmc=3018493}}</ref> higher levels of exposure to manganese in [[drinking water]] are associated with increased [[intellectual impairment]] and reduced [[intelligence quotient]]s in school-age children. It is hypothesized that long-term exposure to the naturally occurring manganese in shower water puts up to 8.7 million Americans at risk.<ref name=elsner/><ref>{{cite journal|doi =10.1002/biof.5520100102|title =Manganese deficiency and toxicity: Are high or low dietary amounts of manganese cause for concern?|pmid=10475586|date = 1999|author = Finley, John Weldon|journal = BioFactors|volume = 10|issue =1|pages =15–24|last2 =Davis|first2 =Cindy D.}}</ref><ref>{{cite journal|doi =10.1081/CLT-100102427|title =Manganese|date =1999|author =Barceloux, Donald|journal = Clinical Toxicology|volume =37|page=293|last2 =Barceloux|first2 =Donald|issue =2}}</ref> However, data indicates that the human body can recover from certain adverse effects of overexposure to manganese if the exposure is stopped and the body can clear the excess.<ref>{{Devenyi, A.G., T.F. Barron, and A.C. Mamourian. 1994. Dystonia, hyperintense basal ganglia, and high whole blood manganese levels in Alagille's syndrome. Gastroenterol. 106(4):1068-
1071}}</ref>

=== Manganese in gasoline ===
[[File:Methylcyclopentadienyl manganese tricarbonyl.tif|thumb|right|MMT]]
[[Methylcyclopentadienyl manganese tricarbonyl]] (MMT) is a gasoline additive used to replace lead compounds for unleaded gasolines, to improve the octane number in low octane number petrol distillates. It functions as an antiknock agent by the action of the carbonyl groups. Fuels containing manganese tend to form manganese carbides, which damage exhaust valves. The need to use lead or manganese compounds is merely historic, as the availability of reformation processes which create high-octane rating fuels increased. The use of such fuels directly or in mixture with non-reformed distillates is universal in developed countries (EU, Japan, etc.). In USA the imperative to provide the lowest possible price per volume on motor fuels (low fuel taxation rate) and lax legislation of fuel content (before 2000) caused refineries to use MMT. Compared to 1953, levels of manganese in air have dropped.<ref>Agency for Toxic Substances and Disease Registry (2012) [http://www.atsdr.cdc.gov/toxprofiles/tp151-c6.pdf 6. Potential for human exposure], in [http://www.atsdr.cdc.gov/ToxProfiles/tp.asp?id=102&tid=23 ''Toxicological Profile for Manganese''], Atlanta, GA: U.S. Department of Health and Human Services.</ref> Many racing competitions specifically ban manganese compounds in racing fuel (cart, minibike). MMT contains 24.4–25.2% manganese. There is strong correlation between elevated atmospheric manganese concentrations and automobile traffic density.

== Role in neurological disorders ==

=== Manganism ===
{{Main|Manganism}}
Manganese overexposure is most frequently associated with [[manganism]], a rare neurological disorder associated with excessive manganese ingestion or inhalation. Historically, persons employed in the production or processing of manganese alloys<ref>Baselt, R. (2008) ''Disposition of Toxic Drugs and Chemicals in Man'', 8th edition, Biomedical Publications, Foster City, CA, pp. 883–886, ISBN 0-9626523-7-7.</ref><ref>{{cite journal|doi = 10.1023/A:1021970120965|date = 2002|author = Normandin, Louise|journal = Metabolic Brain Disease|volume = 17|pages = 375–87|pmid = 12602514|last2 = Hazell|first2 = AS|title = Manganese neurotoxicity: an update of pathophysiologic mechanisms|issue = 4}}</ref> have been at risk for developing manganism; however, current health and safety regulations protect workers in developed nations.<ref name="osha.gov"/> The disorder was first described in 1837 by British academic John Couper, who studied two patients who were manganese grinders.<ref name="Couper 1837 41–42">{{cite journal|last=Couper|first=John|title=On the effects of black oxide of manganese when inhaled into the lungs|journal=Br. Ann. Med. Pharm. Vital. Stat. Gen. Sci.|date=1837|volume=1|pages=41–42}}</ref>

Manganism is a biphasic disorder. In its early stages, an intoxicated person may experience depression, mood swings, compulsive behaviors, and psychosis. Early neurological symptoms give way to late-stage manganism, which resembles [[Parkinson's disease]]. Symptoms include weakness, monotone and slowed speech, an expressionless face, tremor, forward-leaning gait, inability to walk backwards without falling, rigidity, and general problems with dexterity, gait and balance.<ref name="Couper 1837 41–42"/><ref name="Cersosimo 2007 340–346">{{cite journal|last=Cersosimo|first=M.G.|author2=Koller, W.C.|title=The diagnosis of manganese-induced parkinsonism|journal=NeuroToxicology|date=2007|volume=27|pages=340–346|doi=10.1016/j.neuro.2005.10.006|pmid=16325915|issue=3}}</ref> Unlike [[Parkinson's disease]], manganism is not associated with loss of smell and patients are typically unresponsive to treatment with [[L-DOPA]].<ref>{{cite journal|last=Lu|first=C.S.|author2=Huang, C.C |author3=Chu, N.S. |author4=Calne, D.B. |title=Levodopa failure in chronic manganism|journal=Neurology|date=1994|volume=44|pages=1600–1602|doi=10.1212/WNL.44.9.1600|pmid=7936281|issue=9}}</ref> Symptoms of late-stage manganism become more severe over time even if the source of exposure is removed and brain manganese levels return to normal.<ref name="Cersosimo 2007 340–346"/>

=== Childhood developmental disorders ===
Several recent studies attempt to examine the effects of chronic low-dose manganese overexposure on development in children. The earliest study of this kind was conducted in the Chinese province of Shanxi. Drinking water there had been contaminated through improper sewage irrigation and contained 240–350 µg Mn/L. Although WMn concentrations at or below 300 µg Mn/L were considered safe at the time of the study by the US EPA and 400 µg Mn/L by the [[World Health Organization]], the 92 children sampled (between 11 and 13 years of age) from this province displayed lower performance on tests of manual dexterity and rapidity, short-term memory, and visual identification when compared to children from an uncontaminated area. More recently, a study of 10-year-old children in Bangladesh showed a relationship between WMn concentration in well water and diminished IQ scores. A third study conducted in Quebec examined school children between the ages of 6 and 15 living in homes that received water from a well containing 610 µg Mn/L; controls lived in homes that received water from a 160 µg Mn/L well. Children in the experimental group showed increased hyperactive and oppositional behaviors.<ref name="Bouchard 138–143"/>

The EPA currently states less than 50 µg Mn/L are considered safe.<ref name="EPA drinking water">{{cite web|title=Drinking Water Contaminants|url=http://water.epa.gov/drink/contaminants/index.cfm|website=water.epa.gov|publisher=US EPA|accessdate=2 February 2015}}</ref>

=== Neurodegenerative diseases ===
A protein called [[DMT1]] is the major transporter involved in manganese absorption from the intestine, and may be the major transporter of manganese across the [[blood–brain barrier]]. [[DMT1]] also transports inhaled manganese across the nasal epithelium. The putative mechanism of action is that manganese overexposure and/or dysregulation lead to oxidative stress, mitochondrial dysfunction, glutamate-mediated excitoxicity, and aggregation of proteins.

==See also==
* [[Parkerizing]]

==References==
{{Reflist|colwidth=30em}}

==External links==
{{Sister project links|wikt=manganese|n=no|q=no|s=no}}
* [http://www.npi.gov.au/substances/manganese/index.html National Pollutant Inventory – Manganese and compounds Fact Sheet]
* [http://www.manganese.org International Manganese Institute]
* [http://www.cdc.gov/niosh/topics/manganese/ NIOSH Manganese Topic Page]
* [http://www.periodicvideos.com/videos/025.htm Manganese] at ''[[The Periodic Table of Videos]]'' (University of Nottingham)
* [http://www.iom-world.org/pubs/IOM_TM1004.pdf Development of a Standardised Method for Measuring Manganese Exposure] by A Sánchez Jiménez and others. [[Institute of Occupational Medicine]] Research Report TM/10/04. (This study compares the concentrations of inhalable and respirable Manganese collected with three airborne samples: the CIS (Conical Inhalable Sampler), IOM ( the Institute of Occupational Medicine) and the Higgins Dewell cyclone.)
{{clear}}
{{Compact periodic table}}
{{Manganese compounds}}
{{Manganese minerals}}

{{good article}}
{{Use dmy dates|date=September 2011}}

{{Authority control}}

[[Category:Chemical elements]]
[[Category:Dietary minerals]]
[[Category:Transition metals]]
[[Category:Manganese| ]]
[[Category:Deoxidizers]]
[[Category:Occupational safety and health]]
[[Category:Biology and pharmacology of chemical elements]]
[[Category:Reducing agents]]

Manganese

2016-02-01T19:22:49Z

71.109.148.145: /* Occurrence and production */

{{Hatnote|Manganese ''('''Mn''')'' is not to be confused with [[magnesium]] ''('''Mg''')''.}}
{{other uses}}
{{Infobox manganese}}
'''Manganese''' is a [[chemical element]] with symbol '''Mn''' and [[atomic number]] 25. It is not found as a [[free element]] in nature; it is often found in combination with [[iron]], and in many [[minerals]]. Manganese is a metal with important industrial metal [[alloy]] uses, particularly in [[stainless steels]].

Historically, manganese is named for various black minerals (such as [[pyrolusite]]) from the same region of [[Magnesia (regional unit)|Magnesia]] in Greece which gave names to similar-sounding [[magnesium]], Mg, and [[magnetite]], an ore of the element [[iron]], Fe. By the mid-18th century, [[Sweden|Swedish]] [[chemist]] [[Carl Wilhelm Scheele]] had used pyrolusite to produce [[chlorine]]. Scheele and others were aware that pyrolusite (now known to be [[manganese dioxide]]) contained a new element, but they were unable to isolate it. [[Johan Gottlieb Gahn]] was the first to isolate an impure sample of manganese metal in 1774, by [[reduction-oxidation|reducing]] the dioxide with [[carbon]].

[[Phosphate conversion coating|Manganese phosphating]] is used as a treatment for rust and corrosion prevention on [[steel]]. Depending on their [[oxidation state]], manganese [[ions]] have various colors and are used industrially as [[pigment]]s. The [[permanganate]]s of [[alkali metal|alkali]] and [[alkaline earth metals]] are powerful oxidizers. Manganese dioxide is used as the [[cathode]] (electron acceptor) material in [[Zinc-carbon battery|zinc-carbon]] and [[Alkaline battery|alkaline batteries]].

In biology, manganese(II) ions function as [[cofactor (biochemistry)|cofactors]] for a large variety of [[enzymes]] with many functions.<ref>{{cite book
|last1=Roth |first1=Jerome |last2=Ponzoni |first2=Silvia |last3=Aschner |first3=Michael
|editor1-first=Lucia |editor1-last=Banci |series=Metal Ions in Life Sciences |volume=12
|chapter= Chapter 6 Manganese Homeostasis and Transport
|title=Metallomics and the Cell |date=2013 |publisher=Springer |isbn=978-94-007-5560-4|doi=10.1007/978-94-007-5561-1_6}} electronic-book ISBN 978-94-007-5561-1 {{issn|1559-0836}} electronic-{{issn|1868-0402}}
</ref> Manganese enzymes are particularly essential in detoxification of [[superoxide]] free radicals in organisms that must deal with elemental [[oxygen]]. Manganese also functions in the oxygen-evolving complex of photosynthetic [[plants]]. The element is a required trace mineral for all known living organisms but is a [[neurotoxin]]. In larger amounts, and apparently with far greater effectiveness through inhalation, it can cause a [[manganism|poisoning syndrome]] in mammals, with neurological damage which is sometimes irreversible.

==Characteristics==

===Physical properties===
[[File:Manganese electrolytic and 1cm3 cube.jpg|thumb|left|200px|Electrolytically refined manganese chips and 1 cm3 cube]]
Manganese is a silvery-gray [[metal]] that resembles iron. It is hard and very brittle, difficult to fuse, but easy to oxidize.<ref name="Holl">{{cite book|publisher = Walter de Gruyter|date = 1985|edition = 91–100| pages = 1110–1117|isbn = 3-11-007511-3|title = Lehrbuch der Anorganischen Chemie|first = Arnold F.|last = Holleman|author2 = Wiberg, Egon|author3 = Wiberg, Nils|language = German|chapter=Mangan}}</ref> Manganese metal and its common ions are [[paramagnetic]].<ref name=magnet>{{cite book| url =https://web.archive.org/web/20110303222309/http://www-d0.fnal.gov/hardware/cal/lvps_info/engineering/elementmagn.pdf|title = Magnetic susceptibility of the elements and inorganic compounds, in Handbook of Chemistry and Physics| publisher = CRC press| isbn = 0-8493-0485-7|first = David R. |last = Lide|date = 2004}}</ref> Manganese tarnishes slowly in air and "rusts" like iron, in water containing dissolved oxygen.

===Isotopes===
{{Main|Isotopes of manganese}}
Naturally occurring manganese is composed of one stable [[isotope]], 55Mn. Eighteen [[radioisotope]]s have been characterized, with the most stable being 53Mn with a [[half-life]] of 3.7 million years, 54Mn with a [[half-life]] of 312.3 days, and 52Mn with a half-life of 5.591 days. All of the remaining [[radioactive]] isotopes have half-lives that are less than three hours and the majority of these have half-lives that are less than one minute. This element also has three [[meta state]]s.<ref name="Audi">{{cite journal| last = Audi|first = Georges|title = The NUBASE Evaluation of Nuclear and Decay Properties|journal = Nuclear Physics A|volume = 729|pages = 3–128| publisher = Atomic Mass Data Center|date = 2003|doi=10.1016/j.nuclphysa.2003.11.001|bibcode=2003NuPhA.729....3A| last2 = Bersillon| first2 = O.| last3 = Blachot| first3 = J.| last4 = Wapstra| first4 = A.H.}}</ref>
Manganese is part of the [[iron]] group of elements, which are thought to be synthesized in large [[star]]s shortly before the [[supernova]] explosion. 53Mn decays to 53[[chromium|Cr]] with a [[half-life]] of 3.7 million years. Because of its relatively short half-life, 53Mn occurs only in tiny amounts due to the action of [[cosmic rays]] on [[iron]] in rocks.<ref>{{cite journal| last = Schaefer| first = Jeorg|last2=Faestermann |first2=Thomas| title = Terrestrial manganese-53 – A new monitor of Earth surface processes| journal = Earth and Planetary Science Letters|volume = 251|issue = 3–4| pages =334–345|date = 2006|doi=10.1016/j.epsl.2006.09.016| bibcode=2006E&PSL.251..334S| last3 = Herzog| first3 = Gregory F.| last4 = Knie| first4 = Klaus| last5 = Korschinek| first5 = Gunther| last6 = Masarik| first6 = Jozef| last7 = Meier| first7 = Astrid| last8 = Poutivtsev| first8 = Michail| last9 = Rugel| first9 = Georg| last10 = Schlüchter| first10 = Christian| last11 = Serifiddin| first11 = Feride| last12 = Winckler| first12 = Gisela}}</ref> Manganese isotopic contents are typically combined with [[chromium]] isotopic contents and have found application in [[isotope geology]] and [[radiometric dating]]. Mn–Cr isotopic ratios reinforce the evidence from 26[[Aluminium|Al]] and 107[[Palladium|Pd]] for the early history of the [[solar system]]. Variations in 53Cr/52Cr and Mn/Cr ratios from several [[meteorite]]s indicate an initial 53Mn/55Mn ratio that suggests Mn–Cr isotopic composition must result from ''in situ'' decay of 53Mn in differentiated planetary bodies. Hence 53Mn provides additional evidence for [[nucleosynthesis|nucleosynthetic]] processes immediately before coalescence of the [[solar system]].<ref name="Audi"/>
The isotopes of manganese range in [[atomic weight]] from 46 [[atomic mass unit|u]] (46Mn) to 65 u (65Mn). The primary [[decay mode]] before the most abundant stable isotope, 55Mn, is [[electron capture]] and the primary mode after is [[beta decay]].<ref name="Audi"/>

===Chemical properties===
[[File:Chlorid manganatý.JPG|thumb|left|125px|[[Manganese(II) chloride]] crystals – the pale pink color of Mn(II) salts is due to a spin-forbidden 3d transition.<ref>{{cite book|title=Shriver and Atkins' Inorganic Chemistry|date=2010|publisher=Oxford University Press|isbn=978-0-19-923617-6|chapter=Ch. 20}}</ref>]]

The most common [[oxidation state]]s of manganese are +2, +3, +4, +6, and +7, though all oxidation states from −3 to +7 have been observed. Mn2+ often competes with Mg2+ in biological systems. Manganese compounds where manganese is in oxidation state +7, which are restricted to the unstable oxide Mn2O7 and compounds of the intensely purple permanganate anion MnO4−, are powerful [[oxidation|oxidizing agents]].<ref name="Holl"/> Compounds with oxidation states +5 (blue) and +6 (green) are strong oxidizing agents and are vulnerable to [[disproportionation]].

[[File:KMnO4 in H2O.jpg|thumb|left|125px|Aqueous solution of KMnO4 illustrating the deep purple of Mn(VII) as it occurs in permanganate]]
The most stable oxidation state for manganese is +2, which has a pale pink color, and many manganese(II) compounds are known, such as [[manganese(II) sulfate]] (MnSO4) and [[manganese(II) chloride]] (MnCl2). This oxidation state is also seen in the mineral rhodochrosite ([[manganese(II) carbonate]]). The +2 oxidation of Mn results from removal of the two '''4s''' electrons, leaving a "high spin" ion in which all five of the '''3d''' orbitals contain a single electron. Absorption of visible light by this ion is accomplished only by a spin-forbidden transition in which one of the d electrons must pair with another, to give the atom a change in spin of two units. The unlikeliness of such a transition is seen in the uniformly pale and almost colorless nature of Mn(II) compounds relative to other oxidation states of manganese.<ref>Rayner-Canham, Geoffrey and Overton, Tina (2003) ''Descriptive Inorganic Chemistry'', Macmillan, p. 491, ISBN 0-7167-4620-4.</ref>
<div style="float:right; margin:5px;">
{|class="wikitable"
|-
! colspan=2|Oxidation states of manganese<ref name="Schmidt">{{cite book|title = Anorganische Chemie II.|chapter = VII. Nebengruppe|pages = 100–109|first = Max|last = Schmidt|publisher = Wissenschaftsverlag|date = 1968|language = German}}</ref>
|-
| '''0''' || [[Dimanganese decacarbonyl|{{chem|Mn|2|(CO)|10}}]]
|-
| +1 || [[Methylcyclopentadienyl manganese tricarbonyl|{{chem|MnC|5|H|4|CH|3|(CO)|3}}]]
|-
| '''+2''' || [[Manganese(II) chloride|{{chem|MnCl|2}}]], [[Manganese(II) carbonate|{{chem|MnCO|3}}]], [[Manganese(II) oxide|{{chem|MnO}}]]
|-
| +3 || [[Manganese(III) fluoride|{{chem|MnF|3}}]], [[Manganese(III) acetate|{{chem|Mn(OAc)|3}}]], [[Manganese(III) oxide|{{chem|Mn|2|O|3}}]]
|-
| +4 || [[Manganese dioxide|{{chem|MnO|2}}]]
|-
| +5 || [[Potassium hypomanganate|{{chem|K|3|MnO|4}}]]
|-
| '''+6''' || [[Potassium manganate|{{chem|K|2|MnO|4}}]]
|-
| '''+7''' || [[Potassium permanganate|{{chem|KMnO|4}}]], [[Manganese heptoxide|{{chem|Mn|2|O|7}}]]
|-
|colspan=2|<center>Common oxidation states are in bold.</center>
|}</div>
The +3 oxidation state is known in compounds like [[manganese(III) acetate]], but these are quite powerful [[Redox|oxidizing agents]] and also prone to [[disproportionation]] in solution to manganese(II) and manganese(IV). Solid compounds of manganese(III) are characterized by their preference for distorted octahedral coordination due to the [[Jahn-Teller effect]] and its strong purple-red color.
The oxidation state 5+ can be obtained if manganese dioxide is dissolved in molten [[sodium nitrite]].<ref>{{cite journal|first = R. B.|last = Temple|author2=Thickett, G. W.|title = The formation of manganese(v) in molten sodium nitrite|url = http://www.publish.csiro.au/?act=view_file&file_id=CH9720655.pdf|journal = Australian Journal of Chemistry|date = 1972|volume = 25|page=55|doi = 10.1071/CH9720655|issue = 3}}</ref> Manganate (VI) salts can also be produced by dissolving Mn compounds, such as [[manganese dioxide]], in molten alkali while exposed to air.
Permanganate (+7 oxidation state) compounds are purple, and can give glass a violet color. [[Potassium permanganate]], [[sodium permanganate]] and [[barium permanganate]] are all potent oxidizers. Potassium permanganate, also called Condy's crystals, is a commonly used laboratory [[reagent]] because of its oxidizing properties and finds use as a topical medicine (for example, in the treatment of fish diseases). Solutions of potassium permanganate were among the first stains and fixatives to be used in the preparation of biological cells and tissues for electron microscopy.<ref>{{cite journal |doi=10.1083/jcb.2.6.799 |last=Luft |first=J. H.|date=1956|title=Permanganate – a new fixative for electron microscopy |journal=Journal of Biophysical and Biochemical Cytology |volume=2|pages=799–802 |pmid=13398447 |issue=6 |pmc=2224005}}</ref>

==History==
The origin of the name manganese is complex. In ancient times, two black minerals from [[Magnesia (regional unit)|Magnesia]] in what is now modern Greece, were both called ''magnes'' from their place of origin, but were thought to differ in gender. The male ''magnes'' attracted iron, and was the iron ore now known as [[lodestone]] or [[magnetite]], and which probably gave us the term [[magnet]]. The female ''magnes'' ore did not attract iron, but was used to decolorize glass. This feminine ''magnes'' was later called ''magnesia'', known now in modern times as [[pyrolusite]] or [[manganese dioxide]]. Neither this mineral nor manganese itself is magnetic. In the 16th century, manganese dioxide was called ma'''n'''ga'''n'''esum (note the two n's instead of one) by glassmakers, possibly as a corruption and concatenation of two words, since alchemists and glassmakers eventually had to differentiate a ''mag'''n'''esia '''n'''egra'' (the black ore) from ''mag'''n'''esia alba'' (a white ore, also from Magnesia, also useful in glassmaking). [[Michele Mercati]] called magnesia negra ''manganesa'', and finally the metal isolated from it became known as ''manganese'' (German: ''Mangan''). The name ''magnesia'' eventually was then used to refer only to the white [[magnesia alba]] (magnesium oxide), which provided the name [[magnesium]] for that free element, when it was eventually isolated, much later.<ref>{{cite web|last=Calvert|first=J.B.|url = http://www.du.edu/~jcalvert/phys/chromang.htm|title = Chromium and Manganese|accessdate = 2009-04-30|date = 2003-01-24}}</ref>

[[File:Lascaux painting.jpg|thumb| left |alt=A drawing of a left-facing bull, in black, on a cave wall |Some of the cave paintings in [[Lascaux]], [[France]], use manganese-based pigments.<ref name="Lascaux">{{cite journal|doi = 10.1088/0957-0233/14/9/310|title = Analysis of rock art painting and technology of Palaeolithic painters|date = 2003|last = Chalmin|first = Emilie |author2 = Menu, Michel |author3=Vignaud, Colette|journal = Measurement Science and Technology|volume = 14|pages = 1590–1597|issue = 9}}</ref>]]

Several oxides of manganese, for example [[Manganese(IV) oxide|manganese dioxide]], are abundant in nature, and owing to their color, these oxides have been used as pigments since the [[Stone Age]]. The cave paintings in [[Gargas, Haute-Garonne|Gargas]] contain manganese as pigments and these cave paintings are 30,000 to 24,000 years old.<ref>{{cite journal|doi = 10.1007/s00339-006-3510-7|title = Minerals discovered in paleolithic black pigments by transmission electron microscopy and micro-X-ray absorption near-edge structure|date = 2006|last1 = Chalmin|first1 = E|last2= Vignaud|first2=C.|last3=Salomon|first3=H.|last4=Farges|first4=F.|last5=Susini|first5=J. |last6= Menu|first6=M.| journal = Applied Physics A|volume = 83|pages = 213–218|issue = 12|bibcode = 2006ApPhA..83..213C}}</ref>

Manganese compounds were used by Egyptian and Roman glassmakers, to either remove color from glass or add color to it.<ref>{{cite journal|doi = 10.1126/science.133.3467.1824|date = 1961|last = Sayre|first = E. V.|author2=Smith, R. W.|title = Compositional Categories of Ancient Glass|volume = 133|issue = 3467|pages = 1824–1826|journal = Science|pmid = 17818999|bibcode = 1961Sci...133.1824S}}</ref> The use as "glassmakers soap" continued through the [[Middle Ages]] until modern times and is evident in 14th-century glass from [[Venice]].<ref name="ItGlass"/>

[[File:Gahn Johan Gottlieb.jpg|thumb|Credit for first isolating manganese is usually given to [[Johan Gottlieb Gahn]].]]

Because of the use in glassmaking, [[Manganese(IV) oxide|manganese dioxide]] was available to alchemists, the first chemists, and was used for experiments. [[Ignatius Gottfried Kaim]] (1770) and [[Johann Glauber]] (17th century) discovered that manganese dioxide could be converted to [[permanganate]], a useful laboratory reagent.<ref>{{cite journal|journal = Centaurus|volume = 19|issue = 4|title = The Discovery of an Element|first = E.|last = Rancke-Madsen|doi = 10.1111/j.1600-0498.1975.tb00329.x|pages = 299–313|date = 1975|bibcode = 1975Cent...19..299R}}</ref> By the mid-18th century, the Swedish chemist [[Carl Wilhelm Scheele]] used manganese dioxide to produce [[chlorine]]. First, [[hydrochloric acid]], or a mixture of dilute [[sulfuric acid]] and [[sodium chloride]] was made to react with manganese dioxide, later hydrochloric acid from the [[Leblanc process]] was used and the manganese dioxide was recycled by the [[Weldon process]]. The production of chlorine and [[hypochlorite]] containing [[bleach]]ing agents was a large consumer of manganese ores.

Scheele and other chemists were aware that manganese dioxide contained a new element, but they were not able to isolate it. [[Johan Gottlieb Gahn]] was the first to isolate an impure sample of manganese metal in 1774, by [[reduction-oxidation|reducing]] the dioxide with [[carbon]].

The manganese content of some iron ores used in Greece led to the speculations that the steel produced from that ore contains inadvertent amounts of manganese, making the [[Sparta]]n steel exceptionally hard.<ref>{{cite journal|doi = 10.1002/ajim.20524|date = 2007|title = From lead to manganese through mercury: mythology, science, and lessons for prevention|volume = 50|issue = 11|pages = 779–787 |journal = American journal of industrial medicine|pmid = 17918211|last1 = Alessio|first1 = L|last2 = Campagna|first2 = M|last3 = Lucchini|first3 = R}}</ref> Around the beginning of the 19th century, manganese was used in steelmaking and several patents were granted. In 1816, it was noted that adding manganese to iron made it harder, without making it any more brittle. In 1837, British academic [[James Couper (academic)|James Couper]] noted an association between heavy exposures to manganese in mines with a form of [[Parkinson's disease]].<ref name="Couper 1837 41–42"/> In 1912, manganese phosphating electrochemical conversion coatings for protecting firearms against rust and corrosion were patented in the United States, and have seen widespread use ever since.<ref>{{cite book|title = Production of Manganese Ferroalloys|publisher = Tapir Academic Press|date = 2007|isbn = 978-82-519-2191-6|chapter = History of manganese|pages = 11–12|author = Olsen, Sverre E.|author2 = Tangstad, Merete|author3 = Lindstad, Tor}}</ref>

The invention of the [[Leclanché cell]] in 1866 and the subsequent improvement of the batteries containing manganese dioxide as cathodic [[depolarizer]] increased the demand of manganese dioxide. Until the introduction of the [[nickel-cadmium battery]] and lithium-containing batteries, most batteries contained manganese. The [[zinc-carbon battery]] and the [[alkaline battery]] normally use industrially produced manganese dioxide, because natural occurring manganese dioxide contains impurities. In the 20th century, [[manganese(IV) oxide|manganese dioxide]] has seen wide commercial use as the chief cathodic material for commercial disposable dry cells and dry batteries of both the standard (zinc-carbon) and alkaline types.<ref name="ChiuZMnO2">{{cite journal|doi = 10.1002/ciuz.19800140502|title = Moderne Verfahren der Großchemie: Braunstein|date = 1980|last = Preisler|first = Eberhard|journal = Chemie in unserer Zeit|language=German|volume = 14|pages = 137–148|issue = 5}}</ref>

==Occurrence and production==
{{See also|Category:Manganese minerals}}
Manganese makes up about 1000 [[Parts per million|ppm]] (0.1%) of the [[Earth's crust]], making it the 12th most abundant element there.<ref name="Emsley2001">{{cite book |title = Nature's Building Blocks: An A-Z Guide to the Elements|last = Emsley|first = John|publisher = Oxford University Press|date = 2001|location = Oxford, UK |isbn = 0-19-850340-7|chapter = Manganese|pages = 249–253|url = https://books.google.com/?id=j-Xu07p3cKwC}}</ref> Soil contains 7–9000 ppm of manganese with an average of 440 ppm.<ref name="Emsley2001"/> Seawater has only 10 [[Parts per million|ppm]] manganese and the atmosphere contains 0.01 µg/m3.<ref name="Emsley2001"/> Manganese occurs principally as [[pyrolusite]] ([[manganese(IV) oxide|MnO2]]), [[braunite]], (Mn2+Mn3+6)(SiO12),<ref>{{cite journal|pages = 65–71|journal = Contributions to Mineralogy and Petrology|title = Geochemistry of braunite and associated phases in metamorphosed non-calcareous manganese ores of India|first = P. K.|last = Bhattacharyya|author2 = Dasgupta, Somnath |author3=Fukuoka, M. |author4=Roy Supriya |doi = 10.1007/BF00371403|date = 1984|volume = 87|issue = 1|bibcode=1984CoMP...87...65B}}</ref> [[psilomelane]] (Ba,H2O)2Mn5O10, and to a lesser extent as [[rhodochrosite]] ([[manganese(II) carbonate|MnCO3]]).

{|class="wikitable"
|[[File:ManganeseOreUSGOV.jpg|center|120px]]
|[[File:Mineraly.sk - psilomelan.jpg|center|160px]]
|[[File:Spiegeleisen.jpg|center|185px]]
|[[File:Dendrites01.jpg|center|144px]]
|[[File:The Searchlight Rhodochrosite Crystal.jpg|center|152px]]
|-
|Manganese ore
|Psilomelane (manganese ore)
|[[Spiegeleisen]] is an iron alloy with a manganese content of approximately 15%
|Manganese oxide dendrites on limestone from [[Solnhofen]], Germany – a kind of [[pseudofossil]]. Scale is in mm
|Mineral rhodochrosite ([[manganese(II) carbonate]])
|}
[[File:World Manganese Production 2006.svg|thumb|350px|Percentage of manganese output in 2006 by countries<ref name=USGSMCS2009/>]]

The most important manganese ore is pyrolusite ([[manganese(IV) oxide|MnO2]]). Other
economically important manganese ores usually show a close spatial relation to the iron ores.<ref name="Holl"/> Land-based resources are large but irregularly distributed. About 80% of the known world manganese resources are found in South Africa; other important manganese deposits are in Ukraine, Australia, India, China, [[Gabon]] and Brazil.<ref name=USGSMCS2009/> In 1978, 500 billion tons of [[manganese nodule]]s were estimated to exist on the [[ocean floor]].<ref>{{cite journal|doi = 10.1016/j.micron.2008.10.005|pages = 350–358|date = 2009|title = Manganese/polymetallic nodules: micro-structural characterization of exolithobiontic- and endolithobiontic microbial biofilms by scanning electron microscopy|volume = 40|issue = 3|pmid = 19027306|journal = Micron |author1 = Wang, X|author2 = Schröder, HC|author3 = Wiens, M|author4 = Schlossmacher, U|author5 = Müller, WEG}}</ref> Attempts to find economically viable methods of harvesting manganese nodules were abandoned in the 1970s.<ref>{{cite book|title = Manganese Nodules: Dimensions and Perspectives|publisher = Springer|date = 1978|isbn =978-90-277-0500-6|author = United Nations Ocean Economics and Technology Office, Technology Branch, United Nations}}</ref>

In South Africa most identified deposits are located near [[Hotazel]] in the [[Northern Cape Province]] with an estimated 15 billion tons in 2011. In 2011 South Africa was the world's largest producer of manganese producing 3.4 million tons.<ref name="Mbendi">{{cite web | url=http://www.mbendi.com/indy/ming/mang/af/sa/p0005.htm | title=Manganese Mining in South Africa – Overview | publisher=MBendi.com | accessdate=2014-01-04}}</ref>

Manganese is mined in South Africa, Australia, China, Brazil, Gabon, Ukraine, India, Fiji and Ghana and [[Kazakhstan]]. US Import Sources (1998–2001): Manganese ore: Gabon, 70%; South Africa, 10%; Australia, 9%; Mexico, 5%; and other, 6%. Ferromanganese: South Africa, 47%; France, 22%; Mexico, 8%; Australia, 8%; and other, 15%. Manganese contained in all manganese imports: South Africa, 31%; Gabon, 21%; Australia, 13%; Mexico, 8%; and other, 27%.<ref name=USGSMCS2009>{{cite web| last= Corathers|first = Lisa A. |date = 2009|url = http://minerals.usgs.gov/minerals/pubs/commodity/manganese/mcs-2009-manga.pdf|publisher = United States Geological Survey|accessdate = 2009-04-30|title = Mineral Commodity Summaries 2009: Manganese |format = PDF}}</ref><ref name="MangUSGS2006">{{cite web|last= Corathers|first = Lisa A.|url = http://minerals.usgs.gov/minerals/pubs/commodity/manganese/myb1-2006-manga.pdf|title = 2006 Minerals Yearbook: Manganese|publisher = United States Geological Survey|location = Washington, D.C.|date = June 2008|accessdate = 2009-04-30|format = PDF}}</ref>

For the production of [[ferromanganese]], the manganese ore is mixed with iron ore and carbon, and then reduced either in a blast furnace or in an electric arc furnace.<ref name="IndMin">{{cite book|title =Industrial Minerals & Rocks: Commodities, Markets, and Uses|edition = 7th|publisher = SME|date = 2006|isbn = 978-0-87335-233-8|chapter = Manganese|first = L. A.|last = Corathers |author2=Machamer, J. F.|url = https://books.google.com/?id=zNicdkuulE4C&pg=PA631|pages = 631–636}}
</ref> The resulting [[ferromanganese]] has a manganese content of 30 to 80%.<ref name="Holl"/> Pure manganese used for the production of iron-free alloys is produced by [[Leaching (metallurgy)|leaching]] manganese ore with [[sulfuric acid]] and a subsequent [[electrowinning]] process.<ref name="hydrometI">{{cite journal|doi = 10.1016/j.hydromet.2007.08.010 |title = Manganese metallurgy review. Part I: Leaching of ores/secondary materials and recovery of electrolytic/chemical manganese dioxide|date = 2007|last = Zhang|first = Wensheng|author2=Cheng, Chu Yong|journal = Hydrometallurgy|volume = 89|pages = 137–159|issue = 3–4}}</ref>

[[File:Manganese Process Flow Diagram.jpg|left|thumb|alt=Contains reactions and temperatures, as well as showing advanced processes such as the heat exchanger and milling process.|Process flow diagram for a manganese refining circuit.]]
A more progressive extraction process involves directly reducing manganese ore in a heap leach. This is done by percolating natural gas through the bottom of the heap; the natural gas provides the heat (needs to be at least 850 °C) and the reducing agent (carbon monoxide). This reduces all of the manganese ore to manganese oxide (MnO), which is a leachable form. The ore then travels through a grinding circuit to reduce the particle size of the ore to between 150–250 μm, this increases the surface area to aid in the leaching process. The ore is then added to a leach tank, which contains [[sulfuric acid]] and ferrous iron (Fe2+) in a 1.6:1 ratio. The iron reacts with the manganese dioxide to form iron hydroxide and elemental manganese.{{cn}} This process yields approximately 92% recovery of the manganese. For further purification, the manganese can then be sent to an electrowinning facility.<ref name="ManganeseRecovery">{{cite web|url = http://www.americanmanganeseinc.com/wp-content/uploads/2011/08/American-Manganese-Phase-II-August-19-2010-Final-Report-Internet-Version-V2.pdf |title = The Recovery of Manganese from low grade resources: bench scale metallurgical test program completed|date = 2010|author = Chow, Norman|author2 = Nacu, Anca|author3 = Warkentin, Doug|author4 = Aksenov, Igor|author5 = Teh, Hoe|last-author-amp = yes|publisher=Kemetco Research Inc.}}</ref>

In 1972 the [[Central Intelligence Agency|CIA]]'s [[Project Azorian]], through billionaire [[Howard Hughes]], commissioned the ship ''[[Hughes Glomar Explorer]]'' with the cover story of harvesting manganese nodules from the sea floor. That triggered a rush of activity to attempt to collect manganese nodules, which was not actually practical. The real mission of ''Hughes Glomar Explorer'' was to raise a sunken [[Union of Soviet Socialist Republics|Soviet]] submarine, the [[Soviet submarine K-129 (1960)|K-129]], with the goal of retrieving Soviet code books.<ref name="azorian">{{cite web
| url= http://www2.gwu.edu/~nsarchiv/nukevault/ebb305/index.htm
| title= Project Azorian: The CIA's Declassified History of the Glomar Explorer
| publisher= National Security Archive at George Washington University
| date= 2010-02-12
| accessdate= 2013-09-18
}}</ref>

==Applications==
Manganese has no satisfactory substitute in its major applications, which are related to metallurgical alloy use.<ref name=USGSMCS2009/> In minor applications, (e.g., manganese phosphating), [[zinc]] and sometimes [[vanadium]] are viable substitutes.

===Steel===
[[File:M1917helmet.jpg|thumb|right|US Marine Corps [[Brodie helmet|steel helmet]]]]
Manganese is essential to iron and [[steelmaking|steel production]] by virtue of its sulfur-fixing, [[deoxidized steel|deoxidizing]], and [[alloying]] properties. [[Steelmaking]],<ref>{{cite book|isbn = 978-0-87170-858-8|pages = 56–57|first = John D.|last = Verhoeven|date = 2007|publisher = ASM International|location = Materials Park, Ohio|title = Steel metallurgy for the non-metallurgist}}</ref> including its ironmaking component, has accounted for most manganese demand, presently in the range of 85% to 90% of the total demand.<ref name="hydrometI"/> Among a variety of other uses, manganese is a key component of low-cost [[stainless steel]] formulations.<ref name="MangUSGS2006"/><ref>{{cite journal|doi = 10.1007/BF02648339|title = Mechanism of work hardening in Hadfield manganese steel|date = 1981|last = Dastur|first = Y. N.|journal = Metallurgical Transactions A|volume = 12|pages = 749|last2 = Leslie|first2 = W. C.|issue = 5|bibcode = 1981MTA....12..749D}}</ref>

Small amounts of manganese improve the workability of steel at high temperatures, because it forms a high-melting sulfide and therefore prevents the formation of a liquid [[iron sulfide]] at the grain boundaries. If the manganese content reaches 4%, the embrittlement of the steel becomes a dominant feature. The embrittlement decreases at higher manganese concentrations and reaches an acceptable level at 8%. Steel containing 8 to 15% of manganese can have a high [[tensile strength]] of up to 863 MPa.<ref>{{cite book|isbn = 978-1-4086-2616-0|pages = 351–352|title = Iron and Steel|first = John Henry|last = Stansbie|publisher = Read Books|url = https://books.google.com/?id=FyogLqUxW1cC&pg=PA351|date = 2007
}}</ref><ref>{{cite book|isbn = 978-0-07-136076-0|pages = 585–587|last = Brady|first = George S.|author2 = Clauser, Henry R. |author3=Vaccari. John A. |date = 2002|publisher = McGraw-Hill|location = New York, NY|title = Materials handbook: an encyclopedia for managers, technical professionals, purchasing and production managers, technicians, and supervisors|url = https://books.google.com/?id=vIhvSQLhhMEC&pg=PA585}}</ref> Steel with 12% manganese was used for British [[Brodie helmet|steel helmets]]. This steel composition was discovered in 1882 by [[Robert Hadfield]] and is still known as [[Hadfield steel]].<ref>{{cite journal|title = Sir Robert Abbott Hadfield F.R.S. (1858–1940), and the Discovery of Manganese Steel Geoffrey Tweedale|journal = Notes and Records of the Royal Society of London|volume = 40|issue = 1 |date = 1985|pages = 63–74|doi = 10.1098/rsnr.1985.0004|first = Geoffrey|last = Tweedale|jstor = 531536}}</ref>

===Aluminium alloys===
{{Main|Aluminium alloy}}
The second large application for manganese is as an alloying agent for [[aluminium]]. Aluminium with a manganese content of roughly 1.5% has an increased resistance against corrosion due to the formation of grains absorbing impurities which would lead to [[galvanic corrosion]].<ref>{{cite web|url = http://www.suppliersonline.com/propertypages/2024.asp|title = Chemical properties of 2024 aluminum allow|accessdate = 2009-04-30|publisher = Metal Suppliers Online, LLC.}}</ref> The corrosion-resistant [[aluminium alloy]]s 3004 and 3104 with a manganese content of 0.8 to 1.5% are the alloys used for most of the [[beverage can]]s.<ref name="Al3004">{{cite book |title = Introduction to aluminum alloys and tempers|first = John Gilbert|last = Kaufman|publisher = ASM International|date = 2000|isbn = 978-0-87170-689-8|chapter = Applications for Aluminium Alloys and Tempers|pages = 93–94|url = https://books.google.com/?id=idmZIDcwCykC&pg=PA93}}</ref> Before year 2000, more than 1.6 million [[tonne]]s have been used of those alloys; with a content of 1% manganese, this amount would need 16,000 tonnes of manganese.<ref name="Al3004"/>

===Other uses===
[[Methylcyclopentadienyl manganese tricarbonyl]] is used as an additive in [[unleaded gasoline]] to boost [[octane rating]] and reduce [[engine knocking]]. The manganese in this unusual organometallic compound is in the +1 oxidation state.<ref>{{cite journal|author=Leigh A. Graham|author2=Alison R. Fout|author3=Karl R. Kuehne|author4=Jennifer L. White|author5=Bhaskar Mookherji|author6=Fred M. Marks|author7=Glenn P. A. Yap|author8=Lev N. Zakharov|author9=Arnold L. Rheingold|author10=Daniel Rabinovich|last-author-amp=yes |title=Manganese(I) poly(mercaptoimidazolyl)borate complexes: spectroscopic and structural characterization of MnH–B interactions in solution and in the solid state|journal=[[Dalton Transactions]]|issue=1|date=2005|pages=171–180|pmid=15605161|doi=10.1039/b412280a }}</ref>

[[Manganese(IV) oxide]] (manganese dioxide, MnO2) is used as a reagent in [[organic chemistry]] for the [[oxidation]] of benzylic [[alcohol]]s (i.e. adjacent to an [[aromatic ring]]). Manganese dioxide has been used since antiquity to oxidatively neutralize the greenish tinge in glass caused by trace amounts of iron contamination.<ref name="ItGlass">{{cite journal|doi = 10.1007/s11837-998-0024-0|title = Glassmaking in renaissance Italy: The innovation of venetian cristallo|date = 1998|last = Mccray|first = W. Patrick|journal = Journal of the Minerals, Metals and Materials Society|volume = 50|pages = 14|issue = 5|bibcode = 1998JOM....50e..14M}}</ref> MnO2 is also used in the manufacture of oxygen and chlorine, and in drying black paints. In some preparations, it is a brown [[pigment]] that can be used to make [[paint]] and is a constituent of natural [[umber]].

[[Manganese(IV) oxide]] was used in the original type of dry cell [[Battery (electricity)|battery]] as an electron acceptor from zinc, and is the blackish material found when opening carbon–zinc type flashlight cells. The manganese dioxide is reduced to the manganese oxide-hydroxide MnO(OH) during discharging, preventing the formation of hydrogen at the anode of the battery.<ref name="BattHist"/>

:MnO2 + H2O + {{chem|e|-}} → MnO(OH) + {{chem|OH|-}}

The same material also functions in newer [[alkaline batteries]] (usually battery cells), which use the same basic reaction, but a different electrolyte mixture. In 2002, more than 230,000 tons of manganese dioxide was used for this purpose.<ref name="ChiuZMnO2"/><ref name="BattHist">{{cite journal|doi = 10.1016/S0167-2738(00)00722-0|title = Batteries fifty years of materials development|date = 2000|last = Dell|first = R. M.|journal = Solid State Ionics|volume = 134|pages = 139–158}}</ref>

[[File:1945-P-Jefferson-War-Nickel-Reverse.JPG|150px|right|thumb|World-War-II-era 5-cent coin (1942-5 identified by mint mark P,D or S above dome) made from a 56% copper-35% silver-9% manganese alloy]]

The metal is occasionally used in coins; until 2000, the only United States coin to use manganese was the [[Jefferson nickel#1938–1945: Early minting; World War II changes|"wartime" nickel]] from 1942 to 1945.<ref>{{cite journal|journal = Western Journal of Medicine|date = 2001|volume = 175|issue = 2|pages = 112–114|first = Raymond T.|last = Kuwahara|author2 = Skinner III, Robert B. |author3=Skinner Jr., Robert B. |title = Nickel coinage in the United States|doi = 10.1136/ewjm.175.2.112|pmid = 11483555|pmc = 1071501}}</ref> An alloy of 75% copper and 25% nickel was traditionally used for the production of nickel coins. However, because of shortage of nickel metal during the war, it was substituted by more available silver and manganese, thus resulting in an alloy of 56% copper, 35% silver and 9% manganese. Since 2000, [[Dollar (United States coin)|dollar coins]], for example the [[Sacagawea dollar]] and the [[Presidential $1 Coin Program|Presidential $1 coins]], are made from a brass containing 7% of manganese with a pure copper core.<ref>{{cite journal|url = http://www.usmint.gov/mint_programs/golden_dollar_coin/index.cfm?action=sacDesign|title = Design of the Sacagawea dollar|publisher = United States Mint|accessdate = 2009-05-04}}</ref> In both cases of nickel and dollar, the use of manganese in the coin was to duplicate the electromagnetic properties of a previous identically sized and valued coin, for vending purposes. In the case of the later U.S. dollar coins, the manganese alloy was an attempt to duplicate properties of the copper/nickel alloy used in the previous [[Susan B. Anthony dollar]]. 

Manganese compounds have been used as pigments and for the coloring of ceramics and glass. The brown color of ceramic is sometimes based on manganese compounds.<ref>{{cite book|title =Ceramics for the archaeologist| first = Anna Osler|last = Shepard|publisher = Carnegie Institution of Washington|date = 1956|pages = 40–42|isbn = 978-0-87279-620-1|chapter = Manganese and Iron–Manganese Paints}}</ref> In the glass industry, manganese compounds are used for two effects. Manganese(III) reacts with iron(II) to induce a strong green color in glass by forming less-colored iron(III) and slightly pink manganese(II), compensating for the residual color of the iron(III).<ref name="ItGlass"/> Larger amounts of manganese are used to produce pink colored glass.

==Biological role==
[[File:Arginase.jpeg|thumb|right|400px|Reactive center of arginase with boronic acid [[Enzyme inhibitor|inhibitor]] – the manganese atoms are shown in yellow.]]
Manganese is an important metal for human health, being absolutely necessary for development, metabolism, and the antioxidant system. Nevertheless, excessive exposure or intake may lead to a condition known as manganism, a neurodegenerative disorder that causes dopaminergic neuronal death and parkinsonian- like symptoms.<ref name="Emsley2001"/><ref>
{{cite book
|first1=Daiana
|last1=Silva Avila
|first2=Robson
|last2=Luiz Puntel
|first3=Michael
|last3=Aschner
|editor=Astrid Sigel|editor2=Helmut Sigel|editor3=Roland K. O. Sigel
|title=Interrelations between Essential Metal Ions and Human Diseases
|series=Metal Ions in Life Sciences
|volume=13
|date=2013
|publisher=Springer
|pages=199–227
|chapter=Chapter 7. Manganese in Health and Disease
|doi=10.1007/978-94-007-7500-8_7
}}
</ref> The classes of enzymes that have manganese [[Cofactor (biochemistry)|cofactors]] are very broad, and include [[oxidoreductase]]s, [[transferase]]s, [[hydrolase]]s, [[lyase]]s, [[isomerase]]s, [[ligase]]s, [[lectin]]s, and [[integrin]]s. The [[reverse transcriptase]]s of many [[retrovirus]]es (though not [[lentivirus]]es such as [[HIV]]) contain manganese. The best-known manganese-containing [[polypeptides]] may be [[arginase]], the [[diphtheria toxin]], and Mn-containing [[superoxide dismutase]] ([[Mn-SOD]]).<ref name="Mnzym">{{cite journal|doi = 10.1016/S0898-8838(08)60152-X|title = Manganese Redox Enzymes and Model Systems: Properties, Structures, and Reactivity|date = 1998|last = Law|first = N.|volume = 46|page= 305|last2 = Caudle|first2 = M|last3 = Pecoraro|first3 = V|series = Advances in Inorganic Chemistry|isbn = 9780120236466}}</ref>

Mn-SOD is the type of SOD present in eukaryotic [[mitochondria]], and also in most bacteria (this fact is in keeping with the bacterial-origin theory of mitochondria). The Mn-SOD enzyme is probably one of the most ancient, for nearly all organisms living in the presence of oxygen use it to deal with the toxic effects of [[superoxide]] ({{chem|O|2|-}}), formed from the 1-electron reduction of dioxygen. Exceptions include a few kinds of bacteria, such as ''[[Lactobacillus plantarum]]'' and related [[lactobacillus|lactobacilli]], which use a different nonenzymatic mechanism, involving manganese (Mn2+) ions complexed with polyphosphate directly for this task, indicating how this function possibly evolved in aerobic life.

The manganese [[dietary reference intake]] for a 44 y.o. human male is 2.3 mg per day from food, with 11 mg estimated as the tolerable upper limit for daily intake to avoid toxicity. Estimates for females and children are generally less.<ref name=IOM>{{citation
| title = Dietary Reference Intakes (DRIs): Recommended Intakes for Individuals
| publisher = Food and Nutrition Board, Institute of Medicine, National Academies
| date = 2004
| url = http://www.iom.edu/Global/News%20Announcements/~/media/Files/Activity%20Files/Nutrition/DRIs/DRI_Summary_Listing.pdf
| accessdate = 2009-06-09 }}
</ref> The essential minimum intake is unknown since [[manganese deficiency (medicine)|manganese deficiency]] is so rare.<ref>''See'' {{cite web|url=http://lpi.oregonstate.edu/mic/minerals/manganese|title=Manganese|work=Micronutrient Information Center|publisher=[[Oregon State University]] [[Linus Pauling Institute]]}}</ref><ref>''Cf''. {{cite web|title=Manganese (CASRN 7439-96-5)|url=http://www.epa.gov/iris/subst/0373.htm#reforal|at=sec. __I.A.4., Additional Studies/Comments (Oral RfD)|quote=Because of the ubiquitous nature of manganese in foodstuffs, actual manganese deficiency has not been observed in the general population. There are, however, only two reports in the literature of experimentally induced manganese deficiency in humans....While an outright manganese deficiency has not been observed in the general human population, suboptimal manganese status may be more of a concern.|publisher=[[Environmental Protection Agency]]|work=Integrated Risk Information System}}</ref> The human body contains about 12 mg of manganese, which is stored mainly in the bones. The remaining manganese in soft tissue is mostly concentrated in the liver and kidneys.<ref name="Emsley2001"/> In the human brain, the manganese is bound to manganese [[metalloprotein]]s, most notably [[glutamine synthetase]] in [[astrocyte]]s.<ref>{{cite journal|doi = 10.1016/S0165-0173(02)00234-5|title = Manganese action in brain function|date = 2003|last = Takeda| first = A.|journal = Brain Research Reviews|volume = 41|issue = 1|pmid=12505649|pages = 79–87}}</ref>

Manganese is also important in photosynthetic [[oxygen evolution]] in [[chloroplast]]s in plants. The [[oxygen-evolving complex]] (OEC) is a part of photosystem II contained in the thylakoid membranes of chloroplasts; it is responsible for the terminal [[Oxygen evolution|photooxidation of water]] during the [[light reactions]] of [[photosynthesis]], and has a metalloenzyme core containing four atoms of manganese.<ref>{{cite encyclopedia|last= Dismukes|first = G. Charles|author2=Willigen, Rogier T. van|date = 2006|title = Manganese: The Oxygen-Evolving Complex & Models|encyclopedia = Encyclopedia of Inorganic Chemistry|doi = 10.1002/0470862106.ia128|chapter= Manganese: The Oxygen-Evolving Complex & Models|isbn= 0470860782}}</ref> For this reason, most broad-spectrum plant fertilizers contain manganese.

==Precautions==
Manganese compounds are less toxic than those of other widespread metals, such as [[nickel]] and [[copper]].<ref>{{cite book|pages = 31|title = Manganese|first = Heather|last = Hasan|publisher = The Rosen Publishing Group|date = 2008|isbn = 978-1-4042-1408-8|url = https://books.google.com/?id=nRmpEaudmTYC&pg=PA31}}</ref> However, exposure to manganese dusts and fumes should not exceed the ceiling value of 5 mg/m3 even for short periods because of its toxicity level.<ref>{{cite web|url = https://web.archive.org/web/20120425170847/http://www.environmentwriter.org/resources/backissues/chemicals/manganese.htm|title = Manganese Chemical Background|accessdate = 2008-04-30|publisher = Metcalf Institute for Marine and Environmental Reporting University of Rhode Island |date = April 2006}}</ref>  Manganese poisoning has been linked to impaired motor skills and cognitive disorders.<ref>{{cite web| url=http://rais.ornl.gov/tox/profiles/mn.html|publisher=Oak Ridge National Laboratory|title=Risk Assessment Information System Toxicity Summary for Manganese|accessdate=2008-04-23}}</ref>

The permanganate exhibits a higher toxicity than the manganese(II) compounds. The fatal dose is about 10 g, and several fatal intoxications have occurred. The strong oxidative effect leads to necrosis of the [[mucous membrane]]. For example, the [[esophagus]] is affected if the permanganate is swallowed. Only a limited amount is absorbed by the intestines, but this small amount shows severe effects on the kidneys and on the liver.<ref>{{cite journal|doi = 10.1136/emj.14.1.43|title = Potassium permanganate poisoning – a rare cause of fatal self poisoning|date = 1997|last = Ong|first = K. L.|journal = Emergency Medicine Journal|volume = 14|pages = 43–5|pmid = 9023625|last2 = Tan|last3 = Cheung|issue = 1|first2 = TH|first3 = WL|pmc = 1342846}}</ref><ref>{{cite journal|doi =10.1177/096032719601500313|title =Fatal acute hepatorenal failure following potassium permanganate ingestion|date =1996|last = Young|first = R.|journal = Human & Experimental Toxicology|volume = 15|pages = 259–61|pmid =8839216|last2 =Critchley|last3 =Young|last4 =Freebairn|last5 =Reynolds|last6 =Lolin|issue =3|first2 =JA|first3 =KK|first4 =RC|first5 =AP|first6 =YI}}</ref>


In 2005, a study suggested a possible link between manganese inhalation and central nervous system toxicity in rats.<ref name=elsner>{{cite journal|date=2005|title=Neurotoxicity of inhaled manganese: Public health danger in the shower? |journal=Medical Hypotheses|volume=65 |issue=3 |pages=607–616 |doi=10.1016/j.mehy.2005.01.043 |pmid=15913899 |last1=Elsner |first1=Robert J. F. |last2=Spangler |first2=John G.}}</ref>

Manganese exposure in [[United States]] is regulated by the [[Occupational Safety and Health Administration]] (OSHA).<ref name="osha.gov">{{cite web|title=Safety and Health Topics: Manganese Compounds (as Mn)|url=https://www.osha.gov/dts/chemicalsampling/data/CH_250190.html}}</ref> People can be exposed to manganese in the workplace by breathing it in or swallowing it. OSHA has set the legal limit ([[permissible exposure limit]]) for manganese exposure in the workplace as 5 mg/m3 over an 8-hour workday. The [[National_Institute_for_Occupational_Safety_and_Health]] (NIOSH) has set a [[recommended exposure limit]] (REL) of 1 mg/m3 over an 8-hour workday and a short term limit of 3 mg/m3. At levels of 500 mg/m3, manganese is [[IDLH|immediately dangerous to life and health]].<ref>{{Cite web|title = CDC - NIOSH Pocket Guide to Chemical Hazards -
Manganese compounds and fume (as Mn)|url = http://www.cdc.gov/niosh/npg/npgd0379.html|website = www.cdc.gov|accessdate = 2015-11-19}}</ref>

Generally, exposure to ambient Mn air concentrations in excess of 5 μg Mn/m3 can lead to Mn-induced symptoms. Increased [[ferroportin]] protein expression in human embryonic kidney (HEK293) cells is associated with decreased intracellular Mn concentration and attenuated cytotoxicity, characterized by the reversal of Mn-reduced [[glutamate]] uptake and diminished [[lactate dehydrogenase]] leakage.<ref>{{cite journal|pmid=20002294|last1=Yin|first1=Z|date=2010|pages=1190–8|issue=5|volume=112|last2=Jiang|first2=H|journal=Journal of Neurochemistry|last3=Lee|first3=ES|last4=Ni|first4=M|last5=Erikson|first5=KM|last6=Milatovic|first6=D|last7=Bowman|first7=AB|last8=Aschner|first8=M|title=Ferroportin is a manganese-responsive protein that decreases manganese cytotoxicity and accumulation|url=http://libres.uncg.edu/ir/uncg/f/K_Erickson_Ferroportin_2009.pdf|pmc=2819584|doi=10.1111/j.1471-4159.2009.06534.x}}</ref>

== Environmental health concerns ==

=== Manganese in drinking water ===
Waterborne manganese has a greater bioavailability than dietary manganese. According to results from a 2010 study,<ref name="Bouchard 138–143">{{cite journal | last=Bouchard|first=Maryse F. | author2=Sébastien Sauvé | author3=Benoit Barbeau | author4=Melissa Legrand| author5=Marie-Ève Brodeur | author6=Thérèse Bouffard| author7=Elyse Limoges | author8=David C. Bellinger | author9=Donna Mergler | last-author-amp=yes|title=Intellectual Impairment in School-Age Children | journal=Environmental Health Perspectives | date=20 September 2010 | doi=10.1289/ehp.1002321 | url=http://www.cityofmadison.com/water/waterQuality/documents/EHP.20100920.MnIQ.pdf | accessdate=2010-12-11 | volume=119|pages=138–143| pmid=20855239 | issue=1 | pmc=3018493}}</ref> higher levels of exposure to manganese in [[drinking water]] are associated with increased [[intellectual impairment]] and reduced [[intelligence quotient]]s in school-age children. It is hypothesized that long-term exposure to the naturally occurring manganese in shower water puts up to 8.7 million Americans at risk.<ref name=elsner/><ref>{{cite journal|doi =10.1002/biof.5520100102|title =Manganese deficiency and toxicity: Are high or low dietary amounts of manganese cause for concern?|pmid=10475586|date = 1999|author = Finley, John Weldon|journal = BioFactors|volume = 10|issue =1|pages =15–24|last2 =Davis|first2 =Cindy D.}}</ref><ref>{{cite journal|doi =10.1081/CLT-100102427|title =Manganese|date =1999|author =Barceloux, Donald|journal = Clinical Toxicology|volume =37|page=293|last2 =Barceloux|first2 =Donald|issue =2}}</ref> However, data indicates that the human body can recover from certain adverse effects of overexposure to manganese if the exposure is stopped and the body can clear the excess.<ref>{{Devenyi, A.G., T.F. Barron, and A.C. Mamourian. 1994. Dystonia, hyperintense basal ganglia, and high whole blood manganese levels in Alagille's syndrome. Gastroenterol. 106(4):1068-
1071}}</ref>

=== Manganese in gasoline ===
[[File:Methylcyclopentadienyl manganese tricarbonyl.tif|thumb|right|MMT]]
[[Methylcyclopentadienyl manganese tricarbonyl]] (MMT) is a gasoline additive used to replace lead compounds for unleaded gasolines, to improve the octane number in low octane number petrol distillates. It functions as an antiknock agent by the action of the carbonyl groups. Fuels containing manganese tend to form manganese carbides, which damage exhaust valves. The need to use lead or manganese compounds is merely historic, as the availability of reformation processes which create high-octane rating fuels increased. The use of such fuels directly or in mixture with non-reformed distillates is universal in developed countries (EU, Japan, etc.). In USA the imperative to provide the lowest possible price per volume on motor fuels (low fuel taxation rate) and lax legislation of fuel content (before 2000) caused refineries to use MMT. Compared to 1953, levels of manganese in air have dropped.<ref>Agency for Toxic Substances and Disease Registry (2012) [http://www.atsdr.cdc.gov/toxprofiles/tp151-c6.pdf 6. Potential for human exposure], in [http://www.atsdr.cdc.gov/ToxProfiles/tp.asp?id=102&tid=23 ''Toxicological Profile for Manganese''], Atlanta, GA: U.S. Department of Health and Human Services.</ref> Many racing competitions specifically ban manganese compounds in racing fuel (cart, minibike). MMT contains 24.4–25.2% manganese. There is strong correlation between elevated atmospheric manganese concentrations and automobile traffic density.

== Role in neurological disorders ==

=== Manganism ===
{{Main|Manganism}}
Manganese overexposure is most frequently associated with [[manganism]], a rare neurological disorder associated with excessive manganese ingestion or inhalation. Historically, persons employed in the production or processing of manganese alloys<ref>Baselt, R. (2008) ''Disposition of Toxic Drugs and Chemicals in Man'', 8th edition, Biomedical Publications, Foster City, CA, pp. 883–886, ISBN 0-9626523-7-7.</ref><ref>{{cite journal|doi = 10.1023/A:1021970120965|date = 2002|author = Normandin, Louise|journal = Metabolic Brain Disease|volume = 17|pages = 375–87|pmid = 12602514|last2 = Hazell|first2 = AS|title = Manganese neurotoxicity: an update of pathophysiologic mechanisms|issue = 4}}</ref> have been at risk for developing manganism; however, current health and safety regulations protect workers in developed nations.<ref name="osha.gov"/> The disorder was first described in 1837 by British academic John Couper, who studied two patients who were manganese grinders.<ref name="Couper 1837 41–42">{{cite journal|last=Couper|first=John|title=On the effects of black oxide of manganese when inhaled into the lungs|journal=Br. Ann. Med. Pharm. Vital. Stat. Gen. Sci.|date=1837|volume=1|pages=41–42}}</ref>

Manganism is a biphasic disorder. In its early stages, an intoxicated person may experience depression, mood swings, compulsive behaviors, and psychosis. Early neurological symptoms give way to late-stage manganism, which resembles [[Parkinson's disease]]. Symptoms include weakness, monotone and slowed speech, an expressionless face, tremor, forward-leaning gait, inability to walk backwards without falling, rigidity, and general problems with dexterity, gait and balance.<ref name="Couper 1837 41–42"/><ref name="Cersosimo 2007 340–346">{{cite journal|last=Cersosimo|first=M.G.|author2=Koller, W.C.|title=The diagnosis of manganese-induced parkinsonism|journal=NeuroToxicology|date=2007|volume=27|pages=340–346|doi=10.1016/j.neuro.2005.10.006|pmid=16325915|issue=3}}</ref> Unlike [[Parkinson's disease]], manganism is not associated with loss of smell and patients are typically unresponsive to treatment with [[L-DOPA]].<ref>{{cite journal|last=Lu|first=C.S.|author2=Huang, C.C |author3=Chu, N.S. |author4=Calne, D.B. |title=Levodopa failure in chronic manganism|journal=Neurology|date=1994|volume=44|pages=1600–1602|doi=10.1212/WNL.44.9.1600|pmid=7936281|issue=9}}</ref> Symptoms of late-stage manganism become more severe over time even if the source of exposure is removed and brain manganese levels return to normal.<ref name="Cersosimo 2007 340–346"/>

=== Childhood developmental disorders ===
Several recent studies attempt to examine the effects of chronic low-dose manganese overexposure on development in children. The earliest study of this kind was conducted in the Chinese province of Shanxi. Drinking water there had been contaminated through improper sewage irrigation and contained 240–350 µg Mn/L. Although WMn concentrations at or below 300 µg Mn/L were considered safe at the time of the study by the US EPA and 400 µg Mn/L by the [[World Health Organization]], the 92 children sampled (between 11 and 13 years of age) from this province displayed lower performance on tests of manual dexterity and rapidity, short-term memory, and visual identification when compared to children from an uncontaminated area. More recently, a study of 10-year-old children in Bangladesh showed a relationship between WMn concentration in well water and diminished IQ scores. A third study conducted in Quebec examined school children between the ages of 6 and 15 living in homes that received water from a well containing 610 µg Mn/L; controls lived in homes that received water from a 160 µg Mn/L well. Children in the experimental group showed increased hyperactive and oppositional behaviors.<ref name="Bouchard 138–143"/>

The EPA currently states less than 50 µg Mn/L are considered safe.<ref name="EPA drinking water">{{cite web|title=Drinking Water Contaminants|url=http://water.epa.gov/drink/contaminants/index.cfm|website=water.epa.gov|publisher=US EPA|accessdate=2 February 2015}}</ref>

=== Neurodegenerative diseases ===
A protein called [[DMT1]] is the major transporter involved in manganese absorption from the intestine, and may be the major transporter of manganese across the [[blood–brain barrier]]. [[DMT1]] also transports inhaled manganese across the nasal epithelium. The putative mechanism of action is that manganese overexposure and/or dysregulation lead to oxidative stress, mitochondrial dysfunction, glutamate-mediated excitoxicity, and aggregation of proteins.

==See also==
* [[Parkerizing]]

==References==
{{Reflist|colwidth=30em}}

==External links==
{{Sister project links|wikt=manganese|n=no|q=no|s=no}}
* [http://www.npi.gov.au/substances/manganese/index.html National Pollutant Inventory – Manganese and compounds Fact Sheet]
* [http://www.manganese.org International Manganese Institute]
* [http://www.cdc.gov/niosh/topics/manganese/ NIOSH Manganese Topic Page]
* [http://www.periodicvideos.com/videos/025.htm Manganese] at ''[[The Periodic Table of Videos]]'' (University of Nottingham)
* [http://www.iom-world.org/pubs/IOM_TM1004.pdf Development of a Standardised Method for Measuring Manganese Exposure] by A Sánchez Jiménez and others. [[Institute of Occupational Medicine]] Research Report TM/10/04. (This study compares the concentrations of inhalable and respirable Manganese collected with three airborne samples: the CIS (Conical Inhalable Sampler), IOM ( the Institute of Occupational Medicine) and the Higgins Dewell cyclone.)
{{clear}}
{{Compact periodic table}}
{{Manganese compounds}}
{{Manganese minerals}}

{{good article}}
{{Use dmy dates|date=September 2011}}

{{Authority control}}

[[Category:Chemical elements]]
[[Category:Dietary minerals]]
[[Category:Transition metals]]
[[Category:Manganese| ]]
[[Category:Deoxidizers]]
[[Category:Occupational safety and health]]
[[Category:Biology and pharmacology of chemical elements]]
[[Category:Reducing agents]]

Ferrous metallurgy

2016-02-01T03:32:14Z

71.109.148.145: /* Ancient Near East */ {{cn}} might be more friendly, but this sentence contradicts many (internal and external) sources

[[File:Bas fourneau.png|thumb|upright|[[Bloomery]] [[smelting]] during the [[Middle Ages]].]]
'''Ferrous metallurgy''' involves processes and [[alloy]]s based on [[iron]]. It began far back in [[prehistory]]. The earliest surviving [[iron]] artifacts, from the 4th millennium BC in [[Egypt]],<ref>{{cite journal | last1 = Rehren | first1 = T | display-authors = 1 | last2 = et al | year = 2013 | title = 5,000 years old Egyptian iron beads made from hammered meteoritic iron | url = http://www.sciencedirect.com/science/article/pii/S0305440313002057 | journal = Journal of Archaeological Science | volume = 40| issue = | pages = 4785–4792| doi=10.1016/j.jas.2013.06.002}}</ref> were made from [[meteorite|meteoritic]] [[Iron–nickel alloy|iron-nickel]].<ref name=ephotos /> It is not known when or where the [[smelting]] of iron from [[ore]]s began, but by the end of the 2nd millennium BC iron was being produced from [[iron ore]]s from China to Africa south of the Sahara.<ref name=miller>{{cite journal | last1 = Miller | first1 = Duncan E. | last2 = Der Merwe | first2 = N.J. Van | year = 1994 | title = Early Metal Working in Sub-Saharan Africa: A Review of Recent Research| journal = Journal of African History | volume = 35 | issue = | pages = 1–36 | doi=10.1017/s0021853700025949}}</ref><ref name=Stuiver>{{cite journal | last1 = Stuiver | first1 = Minze | last2 = Der Merwe | first2 = N.J. Van | year = 1968 | title = Radiocarbon Chronology of the Iron Age in Sub-Saharan Africa | journal = Current Anthropology | volume = 9| issue = | pages = 54–58| doi=10.1086/200878}}</ref> The use of [[wrought iron]] (worked iron) was known by the 1st millennium BC. During the medieval period, means were found in Europe of producing wrought iron from [[cast iron]] (in this context known as [[pig iron]]) using [[finery forge]]s. For all these processes, [[charcoal]] was required as fuel.

[[Steel]] (with a carbon content between pig iron and wrought iron) was first produced in antiquity as an alloy. Its process of production, [[Wootz]], was exported before the 4th century BC to ancient China, Africa, the Middle East and Europe. Archaeological evidence of [[cast iron]] appears in 5th century BC China.<ref name="Wagner" /> New methods of producing it by [[carburizing]] bars of iron in the [[cementation process]] were devised in the 17th century. During the [[Industrial Revolution]], new methods of producing bar iron without charcoal were devised and these were later applied to produce steel. In the late 1850s, [[Henry Bessemer]] invented a [[Bessemer process|new steelmaking process]], that involved blowing air through molten pig iron to burn off carbon, and so to produce mild steel. This and other 19th-century and later processes have displaced the use of wrought iron. Today, wrought iron is no longer produced.

== Meteoric iron ==
[[File:Willamette Meteorite AMNH.jpg|thumb|upright|[[Willamette Meteorite]], the sixth largest in the world, is an [[iron-nickel meteorite]]]]
[[File:Widmanstatten IronMet.JPG|thumb|Iron meteorites consist overwhelmingly of nickel-iron alloys. The metal taken from these meteorites is known as meteoric iron and was one of the earliest sources of usable iron available to humans.]]

Iron was extracted from [[iron-nickel meteorite]]s, which comprise about 6% of all meteorites that fall on the earth. That source can often be identified with certainty because of the unique [[crystal]]line features ("[[Widmanstatten figures]]") of that material, which are preserved when the metal is worked cold or at low temperature. Those artifacts include, for example, a [[bead]] from the 5th millennium BC found in [[Iran]]<ref name=ephotos /> and spear tips and ornaments from [[Ancient Egypt]] and [[Sumer]] around 4000 BC.<ref>R. F. Tylecote, ''A History of Metallurgy'' (2nd edn, 1992), 3</ref> [[Meteoric iron]] has been identified also in a [[China|Chinese]] axe head from the middle of the 2nd millennium BC.

These early uses appear to have been largely ceremonial or ornamental. Meteoritic iron is very rare, and the metal was probably very expensive, perhaps more expensive than [[gold]]. The early [[Hittites]] are known to have [[barter]]ed iron (meteoritic or smelted) for [[silver]], at a rate of 40 times the iron's weight, with [[Assyria]].<ref name=Veenhof>{{cite book|title=Mesopotamia: The Old Assyrian Period: The Old Assyrian Period. Orbis Biblicus et Orientalis|year=2008|publisher=Vandenhoeck & Ruprecht GmbH & Co KG|location=German|isbn=3525534523|page=84|url=http://books.google.co.uk/books?id=vYMmrenUywQC&pg=PA84&dq=the+old+assyrian+letters+amutum+silver&hl=en&sa=X&ei=VbB3UpHkOYKVhQfG1oHoDA&ved=0CEsQ6AEwAg#v=onepage&q=the%20old%20assyrian%20letters%20amutum%20silver&f=false|author=Klass R Veenhof|author2=Jesper Eidem|accessdate=4 November 2013}}</ref>

Meteoric iron was also fashioned into tools in the [[Arctic]], about the year 1000, when the [[Thule people]] of [[Greenland]] began making [[harpoon]]s, knives, [[Ulu|ulos]] and other edged tools from pieces of the [[Cape York meteorite]]. Typically pea-size bits of metal were cold-hammered into disks and fitted to a bone handle.<ref name=ephotos /> These artifacts were also used as trade goods with other Arctic peoples: tools made from the Cape York meteorite have been found in archaeological sites more than 1,000 miles (1,600 km) distant. When the [[United States|American]] polar explorer [[Robert Peary]] shipped the largest piece of the meteorite to the [[American Museum of Natural History]] in [[New York City]] in 1897, it still weighed over 33 [[ton]]s. Another example of a late use of meteoritic iron is an [[adze]] from around 1000 AD found in [[Sweden]].<ref name=ephotos />

{{commonscat inline|Objects made from meteoritic iron}}

== Native iron ==
[[Native metal|Native]] iron in the metallic state occurs rarely as small inclusions in certain [[basalt]] rocks. Besides meteoritic iron, Thule people of Greenland have used native iron from the [[Disko Island|Disko]] region.<ref name=ephotos />

== Iron smelting and the Iron Age ==
Iron smelting—the extraction of usable metal from [[oxidation|oxidized]] iron ores—is more difficult than [[tin]] and [[copper]] smelting. While these metals and their alloys can be cold-worked or melted in relatively simple furnaces (such as the kilns used for [[pottery]]) and cast into molds, smelted iron requires hot-working and can be melted only in specially designed furnaces. Thus it is not surprising that humans only mastered the technology of smelted iron after several millennia of [[bronze|bronze metallurgy]].

The place and time for the discovery of iron smelting is not known, partly because of the difficulty of distinguishing metal extracted from nickel-containing ores from hot-worked meteoritic iron.<ref name=ephotos /> The archaeological evidence seems to point to the Middle East area, during the [[Bronze Age]] in the 3rd millennium BC. However iron artifacts remained a rarity until the 12th century BC.

The [[Iron Age]] is conventionally defined by the widespread replacement of [[bronze]] weapons and tools with those of steel.<ref name=waldbaum>Waldbaum, Jane C. ''From Bronze to Iron''. Göteburg: Paul Astöms Förlag (1978): 56–58.</ref> That transition happened at different times in different places, as the technology spread.. Mesopotamia was fully into the Iron Age by 900 BC. Although Egypt produced iron artifacts, bronze remained dominant until its conquest by Assyria in 663 BC. The Iron Age began in Central Europe about 500 BC, and in India and China between 1200 and 500 BC.<ref name=Ceccarelli /> Around 500 BC, the [[Nubia]]ns who had learned from the Assyrians the use of iron and were expelled from Egypt, became major manufacturers and exporters of iron.<ref>Collins, Rober O. and Burns, James M. The History of Sub-Saharan Africa. New York:Cambridge University Press, p. 37. ISBN 978-0-521-68708-9.</ref>

=== Ancient Near East ===
[[File:Metal production in Ancient Middle East.svg|thumb|400px|left|Mining areas of the ancient [[Middle East]]. Boxes colors: [[arsenic]] is in brown, [[copper]] in red, [[tin]] in grey, iron in reddish brown, gold in yellow, silver in white and [[lead]] in black. Yellow area stands for [[arsenic bronze]], while grey area stands for tin [[bronze]]]]

One of the earliest smelted iron artifacts, a dagger with an iron blade found in a [[Hattians|Hattic]] tomb in [[Anatolia]], dated from 2500 BC.<ref name=cowen>Richard Cowen () ''The Age of Iron'' Chapter 5 in a series of essays on Geology, History, and People prepares for a course of the University of California at Davis. [http://mygeologypage.ucdavis.edu/cowen/~GEL115/115CH5.html Online version] accessed on 2010-02-11.</ref> About 1500 BC, increasing numbers of non-meteoritic, smelted iron objects appeared in [[Mesopotamia]], Anatolia, and Egypt.<ref name=ephotos>{{cite journal | last1 = Photos | first1 = E. | year = 1989 | title = The Question of Meteoritic versus Smelted Nickel-Rich Iron: Archaeological Evidence and Experimental Results | journal = World Archaeology | volume = 20 | issue = 3| pages = 403–421 | doi=10.1080/00438243.1989.9980081 | jstor=124562}}</ref> Nineteen iron objects were found in the [[tomb]] of [[Egypt]]ian ruler [[Tutankhamun]], died in 1323 BC, including an iron dagger with a golden hilt, an [[Eye of Horus]], the mummy's head-stand and sixteen models of an artisan's tools.<ref>''The Tomb of Tut-Ankh-Amen: Discovered by the Late Earl of Carnarvon and Howard Carter, Volume 3''</ref> An [[Ancient Egyptian]] [[sword]] bearing the name of [[pharaoh]] [[Merneptah]] as well as a [[battle axe]] with an iron blade and gold-decorated bronze shaft were both found in the excavation of [[Ugarit]].<ref name=cowen />

Although iron objects dating from the [[Bronze Age]] have been found across the Eastern Mediterranean, bronzework appears to have greatly predominated during this period.<ref name="Waldbaum 1978: 23">Waldbaum 1978: 23.</ref> By the 12th century BC, iron smelting and forging, of weapons and tools, was common from [[Sub-Saharan Africa]] through [[India]]. As the technology spread, iron came to replace bronze as the dominant metal used for tools and weapons across the Eastern Mediterranean (the [[Levant]], [[Cyprus]], [[Greece]], [[Crete]], Anatolia, and Egypt).<ref name=waldbaum />

Iron was originally smelted in [[bloomery|bloomeries]], furnaces where [[bellows]] were used to force air through a pile of iron ore and burning [[charcoal]]. The [[carbon monoxide]] produced by the charcoal reduced the [[iron oxide]] from the ore to metallic iron. The bloomery, however, was not hot enough to melt the iron, so the metal collected in the bottom of the furnace as a spongy mass, or ''bloom''. Workers then repeatedly beat and folded it to force out the molten slag. This laborious, time-consuming process produced [[wrought iron]], a malleable but fairly soft alloy.

Concurrent with the transition from bronze to iron was the discovery of [[carburization]], the process of adding carbon to wrought iron. While the iron bloom contained some carbon, the subsequent hot-working [[oxidation|oxidized]] most of it. Smiths in the Middle East discovered that wrought iron could be turned into a much harder product by heating the finished piece in a bed of charcoal, and then [[quench]]ing it in water or oil. This procedure turned the outer layers of the piece into [[steel]], an alloy of iron and [[iron carbide]]s, with an inner core of less brittle iron.

==== Theories on the origin of iron smelting ====
The development of iron smelting was traditionally attributed to the [[Hittites]] of Anatolia of the Late [[Bronze Age]].<ref name=mulhy>Muhly, James D. 'Metalworking/Mining in the Levant' pp. 174-183 in ''Near Eastern Archaeology'' ed. Suzanne Richard (2003), pp. 179-180.</ref> It was believed that they maintained a monopoly on iron working, and that their empire had been based on that advantage. According to that theory, the ancient [[Sea Peoples]], who invaded the Eastern Mediterranean and destroyed the Hittite empire at the end of the Late Bronze Age, were responsible for spreading the knowledge through that region. This theory is no longer held in the mainstream of scholarship,<ref name=mulhy /> since there is no archaeological evidence of the alleged Hittite monopoly. While there are some iron objects from Bronze Age Anatolia, the number is comparable to iron objects found in Egypt and other places of the same time period, and only a small number of those objects were weapons.<ref name="Waldbaum 1978: 23" />

A more recent theory claims that the development of iron technology was driven by the disruption of the [[copper]] and [[tin]] trade routes, due to the collapse of the empires at the end of the Late Bronze Age.<ref name=mulhy /> These metals, especially tin, were not widely available and metal workers had to transport them over long distances, whereas iron ores were widely available. However, no known archaeological evidence suggests a shortage of bronze or tin in the Early Iron Age.<ref>Muhly 2003:180.</ref> Bronze objects remained abundant, and these objects have the same percentage of tin as those from the Late Bronze Age.

=== Indian Sub-Continent ===
[[File:QtubIronPillar.JPG|thumb|180px|right|The [[Iron pillar of Delhi]]]]
The [[History of metallurgy in the Indian subcontinent]] began in the 2nd millennium BC. Archaeological sites in [[Gangetic plains]] have yielded iron implements dated between 1800 – 1200 BC.<ref name=Tewari>{{cite journal |last=Tewari |first=Rakesh |authorlink=Rakesh Tewari |title=The origins of iron-working in India: new evidence from the Central Ganga Plain and the Eastern Vindhyas |journal=Antiquity |volume=77 |number=297 |year=2003 |pp=536–544. |url=http://antiquity.ac.uk/projgall/tewari/tewari.pdf |doi=10.1017/s0003598x00092590}}</ref> By the early 13th century BC, iron smelting was practiced on a large scale in India.<ref name=Tewari /> In [[Southern India]] (present day [[Mysore]]) iron was in use 12th to 11th centuries BC.<ref name=UCP /> The technology of iron metallurgy advanced in the politically stable [[Maurya Empire|Maurya]] period.<ref>[[J. F. Richards]] et al. (2005).''[[The New Cambridge History of India]]''. Cambridge University Press. ISBN 0-521-36424-8. pp 64</ref> and during a period of peaceful settlements in the 1st millennium BC.<ref name=UCP>I. M. Drakonoff (1991). ''Early Antiquity''. University of Chicago Press. ISBN 0-226-14465-8. pp 372</ref>

Iron artifacts such as [[nail (fastener)|spikes]], [[knife|knives]], [[dagger]]s, [[arrow]]-heads, [[bowl (vessel)|bowls]], [[spoon]]s, [[saucepan]]s, [[axe]]s, [[chisel]]s, [[tongs]], door fittings etc., dated from 600 to 200 BC, have been discovered at several archaeological sites of India.<ref name=Ceccarelli>Marco Ceccarelli (2000). ''International Symposium on History of Machines and Mechanisms: Proceedings HMM Symposium''. Springer. ISBN 0-7923-6372-8. pp 218</ref> The Greek historian [[Herodotus]] wrote the first [[Western world|western]] account of the use of iron in India.<ref name=Ceccarelli /> The Indian mythological texts, the [[Upanishad]]s, have mentions of weaving, pottery, and metallurgy as well.<ref>[[Patrick Olivelle]] (1998). ''Upanisads''. Oxford University Press. ISBN 0-19-283576-9. pp xxix</ref> The [[Roman Empire|Romans]] had high regard for the excellence of steel from India in the time of the [[Gupta Empire]].<ref name=durant />

[[File:Dagger India Louvre MR13434.jpg|left|150px|thumb|Dagger and its scabbard, India, 17th–18th century. Blade: [[Damascus steel]] inlaid with gold; hilt: jade; scabbard: steel with engraved, chased and gilded decoration]]

Perhaps as early as 500 BC, although certainly by 200 AD, high quality steel was produced in southern India by the [[crucible steel|crucible technique]]. In this system, high-purity wrought iron, charcoal, and glass were mixed in a crucible and heated until the iron melted and absorbed the carbon.<ref name=Juleff /> Iron chain was used in Indian [[suspension bridge]]s as early as the 4th century.<ref>[http://www.britannica.com/eb/article-9070493/suspension-bridge Suspension bridge. (2007). In Encyclopædia Britannica. Retrieved April 5, 2007, from Encyclopædia Britannica Online]</ref>

[[Wootz steel]] was produced in India and [[Sri Lanka]] from around 300 BC.<ref name=Juleff>{{cite journal|author=G. Juleff|title=An ancient wind powered iron smelting technology in Sri Lanka|journal=[[Nature (journal)|Nature]]|volume=379|issue=3|pages=60–63|year=1996|doi=10.1038/379060a0|ref=harv|bibcode = 1996Natur.379...60J }}</ref> Wootz steel is famous from [[Classical Antiquity]] for its durability and ability to hold an edge. When asked by [[King Porus]] to select a gift, [[Alexander the Great|Alexander]] is said to have chosen, over [[gold]] or [[silver]], thirty pounds of steel.<ref name=durant /> Wootz steel was originally a complex alloy with iron as its main component together with various [[trace element]]s. Recent studies have suggested that its qualities may have been due to the formation of [[carbon nanotubes]] in the metal.<ref>{{cite news | url = http://nature.com/news/2006/061113/full/061113-11.html | title = Sharpest cut from nanotube sword: Carbon nanotech may have given swords of Damascus their edge | first = Katharine | last = Sanderson| publisher = Nature | date = 2006-11-15 | accessdate = 2006-11-17 }}</ref> According to [[Will Durant]], the technology passed to the [[Persian people|Persians]] and from them to [[Arab]]s who spread it through the Middle East.<ref name=durant>Will Durant (), ''[[The Story of Civilization]] I: Our Oriental Heritage''</ref> In the 16th century, the [[Dutch Empire|Dutch]] carried the technology from South India to Europe, where it was mass-produced.<ref>Roy Porter (2003). ''The Cambridge History of Science''. Cambridge University Press. ISBN 0-521-57199-5. pp 684</ref>

Steel was produced in [[Sri Lanka]] from 300 BC<ref name=Juleff /> by furnaces blown by the [[Monsoon of Indian subcontinent|monsoon winds]]. The furnaces were dug into the crests of hills, and the wind was diverted into the [[air vents]] by long trenches. This arrangement created a zone of high pressure at the entrance, and a zone of low pressure at the top of the furnace. The flow is believed to have allowed higher temperatures than bellows-driven furnaces could produce, resulting in better-quality iron.<ref name="Juleff1">{{cite journal|author=Juleff, G.|title=An ancient wind powered iron smelting technology in Sri Lanka|journal=[[Nature (journal)|Nature]]|volume=379|issue=3|pages=60–63|year=1996|doi=10.1038/379060a0|ref=harv|bibcode = 1996Natur.379...60J }}</ref><ref>http://www.fluent.com/about/news/newsletters/04v13i1/a27.htm</ref><ref>Simulation of air flows through a Sri Lankan wind driven furnace, submitted to J. Arch. Sci, 2003.</ref> Steel made in Sri Lanka was traded extensively within the region and in the [[Islamic world]]. ''See also [[Steel#Wootz steel and Damascus steel]]''

One of the world's foremost metallurgical curiosities is an [[iron pillar of Delhi|iron pillar]] located in the [[Qutb complex]], [[Delhi]]. The pillar is made of wrought iron (98% [[iron|Fe]]), is almost seven meters high and weighs more than six tonnes.<ref>R. Balasubramaniam (2002), ''Delhi Iron Pillar: New Insights''. Aryan Books International, Delhi ISBN 81-7305-223-9. [http://www.infinityfoundation.com/mandala/t_rv/t_rv_agraw_delhi_frameset.htm] [http://home.iitk.ac.in/~bala/journalpaper/journal/index.htm]</ref> The pillar was erected by [[Chandragupta II]] Vikramaditya and has withstood 1,600 years of exposure to heavy rains with relatively little [[corrosion]].

=== Iron Age Europe ===
[[File:Axe of iron from Swedish Iron Age, found at Gotland, Sweden.jpg|thumb|left|180px|[[Axe]] made of iron, dating from Swedish [[Iron Age]], found at [[Gotland Island|Gotland]], [[Sweden]]]]

Iron working was introduced to [[Greece]] in the late 10th century BC.<ref>Riederer, Josef; Wartke, Ralf-B.: "Iron", Cancik, Hubert; Schneider, Helmuth (eds.): [[Brill's New Pauly]], Brill 2009</ref> The earliest marks of [[Iron Age Europe|Iron Age in Central Europe]] are artifacts from the [[Hallstatt C]] culture (8th century BC). Throughout the 7th to 6th centuries BC, iron artifacts remained luxury items reserved for an elite. This changed dramatically shortly after 500 BC with the rise of the [[La Tène culture]], from which time iron metallurgy also became common in [[Nordic Iron Age|Northern Europe]] and [[Iron Age Britain|Britain]]. The spread of ironworking in Central and Western Europe is associated with [[Celts|Celtic]] expansion. By the 1st century BC, [[Noric steel]] was famous for its quality and sought-after by the [[Roman military]].

The annual iron output of the [[Roman Empire]] is estimated at 84,750 [[Tonnes|t]],<ref>Craddock, Paul T. (2008): "Mining and Metallurgy", in: [[John Peter Oleson|Oleson, John Peter]] (ed.): ''The Oxford Handbook of Engineering and Technology in the Classical World'', Oxford University Press, ISBN 978-0-19-518731-1, p. 108</ref> while the similarly populous Han China produced around 5,000 t.<ref>Wagner, Donald B.: "The State and the Iron Industry in Han China", NIAS Publishing, Copenhagen 2001, ISBN 87-87062-77-1, p. 73</ref>

=== China ===
[[File:Chinese Fining and Blast Furnace.jpg|thumb|right|250px|The process of fining iron [[ore]] to make wrought iron from pig iron, with the right illustration displaying men working a [[blast furnace]], from the ''[[Song Yingxing|Tiangong Kaiwu]]'' encyclopedia, 1637]]
Historians debate whether bloomery-based ironworking ever spread to China from the Middle East. One theory suggests that metallurgy was introduced through Central Asia.<ref name="pigott">Pigott, Vincent C. (1999). ''The Archaeometallurgy of the Asian Old World''. Philadelphia: University of Pennsylvania Museum of Archaeology and Anthropology. ISBN 0-924171-34-0, p. 8.</ref> The earliest [[cast iron]] artifacts, dating to 5th century BC, were discovered by archaeologists in what is now modern [[Luhe County]], [[Jiangsu]] in China. Cast iron was used in [[History of China#Ancient China|ancient China]] for warfare, agriculture, and architecture.<ref name="Wagner">{{cite book|author=Donald B. Wagner|title=Iron and Steel in Ancient China|accessdate=28 September 2012|year=1993|publisher=BRILL|isbn=978-90-04-09632-5|pages=335–340}}</ref> Around 500 BC, metalworkers in the southern [[state of Wu]] achieved a temperature of 1130 °C. At this temperature, iron combines with 4.3% carbon and melts. The liquid iron can be [[casting|cast]] into [[molding (process)|molds]], a method far less laborious than individually forging each piece of iron from a bloom. This technology would be known in Europe from early medieval times on.<ref>Giannichedda, Enrico (2007): "Metal production in Late Antiquity", in ''Technology in Transition AD 300-650'' L. Lavan E.Zanini & A. Sarantis Brill, eds., Leiden; p. 200</ref>

Cast iron is rather brittle and unsuitable for striking implements. It can, however, be ''decarburized'' to steel or wrought iron by heating it in air for several days. In China, these iron working methods spread northward, and by 300 BC, iron was the material of choice throughout China for most tools and weapons. A mass grave in [[Hebei]] province, dated to the early 3rd century BC, contains several soldiers buried with their weapons and other equipment. The artifacts recovered from this grave are variously made of wrought iron, cast iron, malleabilized cast iron, and quench-hardened steel, with only a few, probably ornamental, bronze weapons.

[[File:Yuan Dynasty - waterwheels and smelting.png|thumb|left|260px|An illustration of furnace bellows operated by waterwheels, from the ''Nong Shu'', by [[Wang Zhen (official)|Wang Zhen]], 1313 AD, during the [[Yuan Dynasty]] in China]]

During the [[Han Dynasty]] (202 BC–220 AD), the government established ironworking as a state monopoly (repealed during the latter half of the dynasty and returned to private entrepreneurship) and built a series of large blast furnaces in [[Henan]] province, each capable of producing several tons of iron per day. By this time, Chinese metallurgists had discovered how to fine molten pig iron, stirring it in the open air until it lost its carbon and could be hammered (wrought). (In modern Mandarin-[[Chinese language|Chinese]], this process is now called ''chao'', literally, [[stir frying]].) By the 1st century BC, Chinese metallurgists had found that wrought iron and cast iron could be melted together to yield an alloy of intermediate carbon content, that is, steel.<ref name="needham volume 4 part 3 197">Needham, Volume 4, Part 3, 197.</ref><ref name="needham volume 4 part 3 277">Needham, Volume 4, Part 3, 277.</ref><ref name="needham volume 4 part 3 563g">Needham, Volume 4, Part 3, 563 g</ref> According to legend, the sword of [[Liu Bang]], the first Han emperor, was made in this fashion. Some texts of the era mention "harmonizing the hard and the soft" in the context of ironworking; the phrase may refer to this process. The ancient city of Wan ([[Nanyang, Henan|Nanyang]]) from the Han period forward was a major center of the iron and steel industry.<ref name="needham volume 4 part 3 86">Needham, Volume 4, Part 3, 86.</ref> Along with their original methods of forging steel, the Chinese had also adopted the production methods of creating Wootz steel, an idea imported from India to China by the 5th century AD.<ref name="needham volume 4 part 1 282">Needham, Volume 4, Part 1, 282.</ref> During Han Dynasty, the Chinese were also the first to apply [[hydraulic]] power (i.e. a [[waterwheel]]) in working the bellows of the blast furnace. This was recorded in the year 31 AD, as an innovation of the [[engineer]] [[Du Shi]], [[Prefect]] of Nanyang.<ref name="needham volume 4 part 2 3701">Needham, Volume 4, Part 2, 370</ref> Although Du Shi was the first to apply water power to bellows in metallurgy, the first drawn and printed illustration of its operation with water power appeared in 1313 AD, in the Yuan Dynasty era text called the ''Nong Shu''.<ref name="needham volume 4 part 2">Needham, Volume 4, Part 2, 371.</ref> In the 11th century, there is evidence of the production of steel in [[Song Dynasty|Song China]] using two techniques: a "berganesque" method that produced inferior, heterogeneous steel and a precursor to the modern Bessemer process that utilized partial decarbonization via repeated forging under a cold blast.<ref>{{cite journal | last1 = Hartwell | first1 = Robert | year = 1966 | title = Markets, Technology and the Structure of Enterprise in the Development of the Eleventh Century Chinese Iron and Steel Industry | url = | journal = Journal of Economic History | volume = 26 | issue = | pages = 53–54 }}</ref> By the 11th century, there was a large amount of deforestation in China due to the iron industry's demands for charcoal.<ref name="ebrey 158">Ebrey, 158.</ref> By this time however, the Chinese had learned to use [[Coke (fuel)|bituminous coke]] to replace charcoal, and with this switch in resources many acres of prime timberland in China were spared.<ref name="ebrey 158" /> The change of fuel resources from charcoal to [[coal]] was pioneered in [[Roman Britain]] by the 2nd century AD, although it was also practiced in the Germanic [[Rhineland]] at the time.<ref>{{cite journal | last1 = Smith | first1 = A. H. V. | year = 1997 | title = Provenance of Coals from Roman Sites in England and Wales | url = | journal = [[Britannia (journal)|Britannia]] | volume = 28 | issue = | pages = 297–324 (322–324) | doi=10.2307/526770}}</ref>

{{See also|Early Japanese iron-working techniques|l1=Early Japanese Ironworking}}

=== Africa south of the Sahara ===
[[File:East&southern africa early iron age.png|thumb|upright|Iron Age finds in East and Southern Africa, corresponding to the early 1st millennium AD Bantu expansion]]
{{Main|Iron metallurgy in Africa}}
Inhabitants at Termit, in eastern [[Niger]] became the first iron smelting people in West Africa around 1500 BC.<ref>[http://portal.unesco.org/en/ev.php-URL_ID=3432&URL_DO=DO_TOPIC&URL_SECTION=201.html Iron in Africa: Revisiting the History] – Unesco (2002)</ref> Iron and copper working spread southward through the continent, reaching the [[Cape of Good Hope|Cape]] around AD 200.<ref name=miller/><ref name=Stuiver/> The widespread use of iron revolutionized the [[Bantu languages|Bantu]]-speaking farming communities who adopted it, driving out and absorbing the rock tool using hunter-gatherer societies they encountered as they expanded to farm wider areas of [[savanna]]. The technologically superior Bantu-speakers spread across southern Africa and became wealthy and powerful, producing iron for tools and weapons in large, industrial quantities.<ref name=miller /><ref name=Stuiver/>

In the region of the [[Aïr Mountains]] in [[Niger]] there are signs of independent copper smelting between 2500–1500 BC. The process was not in a developed state, indicating smelting was not foreign. It became mature about the 1500 BC.<ref>Ehret, Christopher (2002). The Civilizations of Africa. Charlottesville: University of Virginia, pp. 136, 137 ISBN 0-8139-2085-X.</ref>

Similarly, smelting in bloomery-type furnaces in [[West Africa]] and [[forging]] for tools appear in the [[Nok culture]] in Africa by 500 BC.<ref name=miller/><ref name=Stuiver/><ref>Tylecote 1975 (see below)</ref> The earliest records of bloomery-type furnaces in [[East Africa]] are discoveries of smelted iron and carbon in [[Nubia]] and [[Axum]] that date back between 1,000-500 BCE.<ref>[http://books.google.com/books?id=PZcX2jQFTRcC&pg=PA61&lpg=PA61&dq=Nubia,+iron,+furnace&source=web&ots=WJzolQaCH5&sig=VPOhOXewQAF5hSLwuZ8QWh0NLwQ&hl=en&ei=_cCKSaDqBYqhtweSn-yeBw&sa=X&oi=book_result&resnum=8&ct=result#PPA61,M1 A History of Sub-Saharan Africa]</ref><ref>[http://books.google.com/books?id=6tsaBtp0WrMC&pg=PA173&lpg=PA173&dq=Nubia,+iron,+furnace&source=web&ots=ZnEjQi52NG&sig=WRvnLo72eW1qNGPQtid36tcAttM&hl=en&ei=_cCKSaDqBYqhtweSn-yeBw&sa=X&oi=book_result&resnum=11&ct=result The Nubian Past]</ref> Particularly in [[Meroe]], there are known to have been ancient bloomeries that produced metal tools for the Nubians and Kushites and produced surplus for their economy.

In the regions of [[Tanzania]] inhabited by the [[Haya people]], carbon dating has shown that blast furnaces were as old as 2000 years, whereas steel of this calibre did not appear in [[Europe]] until several centuries later.<ref>{{cite news |url=http://www.time.com/time/magazine/article/0,9171,912179,00.html?iid=chix-sphere |title=Africa's Ancient Steelmakers |accessdate=2007-09-21 |work= Time magazine | date=1978-09-25}}</ref>

=== Medieval Islamic world ===
Iron technology was further advanced by several [[inventions in medieval Islam]], during the so-called [[Islamic Golden Age]]. These included a variety of [[Watermill|water-powered]] and [[Windmill|wind-powered]] industrial [[Mill (factory)|mills]] for metal production, including geared [[gristmill]]s and [[forge]]s. By the 11th century, every province throughout the [[Muslim world]] had these industrial mills in operation, from [[Al-Andalus|Islamic Spain]] and [[North Africa]] in the west to the [[Middle East]] and [[Central Asia]] in the east.<ref name=Lucas-10>Adam Robert Lucas (2005), "Industrial Milling in the Ancient and Medieval Worlds: A Survey of the Evidence for an Industrial Revolution in Medieval Europe", ''Technology and Culture'' '''46''' (1): 1-30 [10-1 & 27]</ref> There are also 10th-century references to [[cast iron]], as well as archeological evidence of [[blast furnace]]s being used in the [[Ayyubid]] and [[Mamluk]] empires from the 11th century, thus suggesting a diffusion of Chinese metal technology to the Islamic world.<ref>{{cite journal|title=Ahmad Y. Al-Hassan and Donald R. Hill, ''Islamic technology: an illustrated history''|author=R. L. Miller|journal=Medical History|volume=32|issue=4|date=October 1988|pages=466–7|ref=harv|doi=10.1017/s0025727300048602}}</ref>

[[Gear]]ed gristmills<ref>Donald Routledge Hill (1996), "Engineering", p. 781, in {{Harv|Rashed|Morelon|1996|pp=751–95}}</ref> were invented by Muslim engineers, and were used for crushing metallic ores before extraction. Gristmills in the Islamic world were often made from both [[watermill]]s and windmills. In order to adapt [[water wheel]]s for gristmilling purposes, [[cam]]s were used for raising and releasing [[trip hammer]]s.<ref name=Hill2>Donald Routledge Hill, "Mechanical Engineering in the Medieval Near East", ''Scientific American'', May 1991, p. 64-69. ([[cf.]] Donald Routledge Hill, [http://home.swipnet.se/islam/articles/HistoryofSciences.htm Mechanical Engineering])</ref> The first [[forge]] driven by a [[hydropower]]ed water mill rather than manual labour was invented in the 12th century Islamic Spain.<ref name=Lucas-65>Adam Lucas (2006), ''Wind, Water, Work: Ancient and Medieval Milling Technology'', p. 65. BRILL, ISBN 90-04-14649-0.</ref><ref name="Lucas-65" />

One of the most famous steels produced in the medieval Near East was [[Damascus steel]] used for [[swordmaking]], and mostly produced in [[Damascus]], [[Syria]], in the period from 900 to 1750. This was produced using the [[crucible steel]] method, based on the earlier Indian [[wootz steel]]. This process was adopted in the Middle East using locally produced steels. The exact process remains unknown, but it allowed [[carbide]]s to precipitate out as micro particles arranged in sheets or bands within the body of a blade. Carbides are far harder than the surrounding low carbon steel, so swordsmiths could produce an edge that cut hard materials with the precipitated carbides, while the bands of softer steel let the sword as a whole remain tough and flexible. A team of researchers based at the [[Technische Universität Dresden|Technical University]] of [[Dresden]] that uses [[X-ray]]s and [[electron microscopy]] to examine Damascus steel discovered the presence of [[cementite]] [[nanowires]]<ref>{{cite journal | first = W. | last = Kochmann | coauthors = Reibold M., Goldberg R., Hauffe W., Levin A. A., Meyer D. C., Stephan T., Müller H., Belger A., Paufler P. | year = 2004 | title = Nanowires in ancient Damascus steel | quotes = | journal = Journal of Alloys and Compounds | volume = 372 | pages = L15–L19 | issn = 0925-8388 | doi = 10.1016/j.jallcom.2003.10.005 | ref = harv }} {{cite journal | first = A. A. | last = Levin | coauthors = Meyer D. C., Reibold M., Kochmann W., Pätzke N., Paufler P. | year = 2005 | title = Microstructure of a genuine Damascus sabre | journal = Crystal Research and Technology | volume = 40 | issue = 9 | pages = 905–916 | doi =10.1002/crat.200410456 | url = http://www.crystalresearch.com/crt/ab40/905_a.pdf | ref = harv }}</ref> and [[carbon nanotube]]s.<ref>{{cite journal | first = M. | last = Reibold | coauthors = Levin A. A., Kochmann W., Pätzke N., Meyer D. C. | date= 16 November 2006 | title = Materials:Carbon nanotubes in an ancient Damascus sabre | journal = Nature | volume = 444 | pages = 286 | doi =10.1038/444286a | pmid = 17108950 | issue = 7117 | ref = harv | bibcode=2006Natur.444..286R}}</ref> Peter Paufler, a member of the Dresden team, says that these nanostructures give Damascus steel its distinctive properties<ref name="jmrefs">[http://news.nationalgeographic.com/news/2006/11/061116-nanotech-swords.html Legendary Swords' Sharpness, Strength From Nanotubes, Study Says]</ref> and are a result of the [[forging]] process.<ref name="jmrefs" /><ref>{{cite news | url = http://www.nature.com/news/2006/061113/full/061113-11.html | title = Sharpest cut from nanotube sword: Carbon nanotech may have given swords of Damascus their edge | first = Katharine | last = Sanderson| publisher = Nature (journal) | date = 2006-11-15 | accessdate = 2006-11-17 }}</ref>

== Medieval and Early Modern Europe ==
There was no fundamental change in the technology of iron production in Europe for many centuries. European metal workers continued to produce iron in bloomeries. However, the [[Medieval]] period brought two developments—the use of water power in the bloomery process in various places (outlined above), and the first European production in cast iron.

=== Powered bloomeries ===
{{Main|Bloomery}}
Sometime in the medieval period, water power was applied to the bloomery process. It is possible that this was at the [[Cistercian]] Abbey of [[Clairvaux Abbey|Clairvaux]] as early as 1135, but it was certainly in use in early 13th century [[France]] and Sweden.<ref>{{cite journal | last1 = Lucas | first1 = A. R. | year = 2005 | title = Industrial milling in the ancient and Medieval Worlds | url = | journal = Technology and Culture | volume = 46 | issue = | page = 19 | doi=10.1353/tech.2005.0026}}</ref> In [[England]], the first clear documentary evidence for this is the accounts of a forge of the [[Bishop of Durham]], near [[Bedburn]] in 1408,<ref>R. F. Tylecote, ''A History of Metallurgy'', 76.</ref> but that was certainly not the first such ironworks. In the [[Furness]] district of England, powered bloomeries were in use into the beginning of the 18th century, and near [[Garstang]] until about 1770.

The Catalan Forge was a variety of powered bloomery. Bloomeries with [[hot blast]] were used in upstate [[New York State|New York]] in the mid-19th century.

=== Blast furnace ===
[[File:Iron-Making.jpg|thumb|350|right|Ironmaking described in "[[The Popular Encyclopedia; or, Conversations Lexicon|The Popular Encyclopedia]]" vol.VII, published 1894]]
{{Main|blast furnace}}
Cast iron development lagged in Europe, as the smelters could only achieve temperatures of about 1000 C; or perhaps they did not want hotter temperatures, as they were seeking to produce [[Bloomery|blooms]] as a precursor of wrought iron, not cast iron. Through a good portion of the Middle Ages, in Western Europe, iron was still being made by the working of iron blooms into wrought iron. Some of the earliest casting of iron in Europe occurred in Sweden, in two sites, [[Lapphyttan]] and Vinarhyttan, between 1150 and 1350. Some scholars have speculated the practice followed the [[Mongol]]s across [[Russia]] to these sites, but there is no clear proof of this hypothesis, and it would certainly not explain the pre-Mongol datings of many of these iron-production centres. In any event, by the late 14th century, a market for cast iron goods began to form, as a demand developed for cast iron cannonballs.

=== Osmond process ===
Iron from furnaces such as Lapphyttan was refined into wrought iron by the [[osmond iron|osmond process]]. The pig iron from the furnace was melted in front of a blast of air and the droplets caught on a staff (which was spun). This formed a ball of iron, known as an osmond. This was probably a traded commodity by c. 1200.

=== Finery process ===
An alternative method of decarburising pig iron was the [[finery forge|finery process]], which seems to have been devised in the region around [[Namur (city)|Namur]] in the 15th century. By the end of that century, this [[Wallonia|Walloon]] process spread to the ''Pay de Bray'' on the eastern boundary of [[Normandy]], and then to England, where it became the main method of making wrought iron by 1600. It was introduced to Sweden by [[Louis De Geer (1587–1652)|Louis de Geer]] in the early 17th century and was used to make the [[oregrounds iron]] favoured by English steelmakers.

A variation on this was the [[German process]]. This became the main method of producing [[bar iron]] in Sweden.

=== Cementation steel ===
In the early 17th century, ironworkers in Western Europe had developed the [[cementation process]] for carburizing wrought iron. Wrought iron bars and charcoal were packed into stone boxes, then held at a red heat for up to a week. During this time, carbon diffused into the iron, producing a product called ''cement steel'' or ''blister steel''. One of the earliest places where this was used in England was at [[Coalbrookdale]], where Sir Basil Brooke had two cementation furnaces (recently excavated). For a time in the 1610s, he owned a patent on the process, but had to surrender this in 1619. He probably used [[Forest of Dean]] iron as his raw material, but it was soon found that oregrounds iron was more suitable. The quality of the steel could be improved by [[faggoting (metalworking)|faggoting]], producing the so-called shear steel.

=== Crucible steel ===
In the 1740s, [[Benjamin Huntsman]] found a means of melting blister steel, made by the cementation process, in crucibles. The resulting [[crucible steel]], usually cast in ingots, was more homogeneous than blister steel.

== Transition to coke in England ==

=== Beginnings ===
Early iron smelting used charcoal as both the heat source and the reducing agent. By the 18th century, the availability of wood for making charcoal was limiting the expansion of iron production, so that England became increasingly dependent for a considerable part of the iron required by its industry, on Sweden (from the mid-17th century) and then from about 1725 also on Russia.{{citation needed|date=January 2015}}

Smelting with coal (or its derivative [[coke (fuel)|coke]]) was a long sought objective. The production of pig iron with coke was probably achieved by [[Dud Dudley]] in the 1620s, and with a mixed fuel made from coal and wood again in the 1670s. However this was probably only a technological rather than a commercial success. [[Shadrach Fox]] may have smelted iron with coke at Coalbrookdale in [[Shropshire]] in the 1690s, but only to make cannonballs and other cast iron products such as shells. However, in the peace after the [[Nine Years War]], there was no demand for these.<ref>{{cite journal | last1 = King | first1 = P. W. | year = 2002 | title = Dud Dudley's contribution to metallurgy | url = | journal = Historical Metallurgy | volume = 36 | issue = 1| pages = 43–53 }}</ref><ref>{{cite journal | last1 = King | first1 = P. W. | year = 2001 | title = Sir Clement Clerke and the adoption of coal in metallurgy | url = | journal = Trans. Newcomen Soc. | volume = 73 | issue = 1| pages = 33–52 | doi=10.1179/tns.2001.002}}</ref>

=== Abraham Darby and his successors ===
{{Main|Abraham Darby I}}
In 1707, [[Abraham Darby I|Abraham Darby]] patented a method of making cast iron pots. His pots were thinner and hence cheaper than those of his rivals. Needing a larger supply of pig iron he leased the blast furnace at Coalbrookdale in 1709. There, he made iron using coke, thus establishing the first successful business in Europe to do so. His products were all of cast iron, though his immediate successors attempted (with little commercial success) to fine this to bar iron.<ref>A. Raistrick, ''A dynasty of Ironfounders'' (1953; 1989); N. Cox, 'Imagination and innovation of an industrial pioneer: The first Abraham Darby' ''Industrial Archaeology Review'' 12(2) (1990), 127-144.</ref>

[[Wrought iron|Bar iron]] thus continued normally to be made with charcoal pig iron until the mid-1750s. In 1755 [[Abraham Darby II]] (with partners) opened a new coke-using furnace at [[Horsehay]] in Shropshire, and this was followed by others. These supplied coke pig iron to finery forges of the traditional kind for the production of [[wrought iron|bar iron]]. The reason for the delay remains controversial.<ref>A. Raistrick, ''Dynasty''; C. K. Hyde, ''Technological change and the British iron industry 1700–1870'' (Princeton, 1977), 37-41; P. W. King, 'The Iron Trade in England and Wales 1500–1815' (Ph.D. thesis, Wolverhampton University, 2003), 128-41.</ref>

=== New forge processes ===
[[File:Puddling furnace.jpg|thumb|250px|Schematic drawing of a puddling furnace]]
It was only after this that economically viable means of converting pig iron to bar iron began to be devised. A process known as [[potting and stamping]] was devised in the 1760s and improved in the 1770s, and seems to have been widely adopted in the [[West Midlands (region)|West Midlands]] from about 1785. However, this was largely replaced by [[Henry Cort]]'s puddling process, patented in 1784, but probably only made to work with grey pig iron in about 1790. These processes permitted the great expansion in the production of iron that constitutes the Industrial Revolution for the iron industry.<ref>G. R. Morton and N. Mutton, 'The transition to Cort's puddling process' ''Journal of Iron and Steel Institute'' 205(7) (1967), 722-8; R. A. Mott (ed. P. Singer), ''Henry Cort: The great finer: creator of puddled iron'' (1983); P. W. King, 'Iron Trade', 185-93.</ref>

In the early 19th century, Hall discovered that the addition of iron oxide to the charge of the puddling furnace caused a violent reaction, in which the pig iron was [[decarburization|decarburised]], this became known as 'wet puddling'. It was also found possible to produce steel by stopping the [[puddling (metallurgy)|puddling process]] before decarburisation was complete.

== Hot blast ==
{{Main|Hot blast}}

The efficiency of the blast furnace was improved by the change to [[hot blast]], patented by [[James Beaumont Neilson]] in Scotland in 1828. This further reduced production costs. Within a few decades, the practice was to have a 'stove' as large as the furnace next to it into which the waste gas (containing CO) from the furnace was directed and burnt. The resultant heat was used to preheat the air blown into the furnace.<ref>A. Birch, ''Economic History of the British Iron and Steel Industry'' , 181-9; C. K. Hyde, ''Technological Change and the British iron industry'' (Princeton 1977), 146-59.</ref>

== Industrial steelmaking ==
[[File:Bessemer converter.jpg|thumb|right|Schematic drawing of a Bessemer converter]]

Apart from some production of puddled steel, English steel continued to be made by the cementation process, sometimes followed by remelting to produce crucible steel. These were batch-based processes whose raw material was bar iron, particularly Swedish oregrounds iron.

The problem of mass-producing cheap steel was solved in 1855 by Henry Bessemer, with the introduction of the [[Bessemer process|Bessemer converter]] at his steelworks in [[Sheffield]], England. (An early converter can still be seen at the city's [[Kelham Island Museum]]). In the Bessemer process, molten pig iron from the blast furnace was charged into a large crucible, and then air was blown through the molten iron from below, igniting the dissolved carbon from the coke. As the carbon burned off, the melting point of the mixture increased, but the heat from the burning carbon provided the extra energy needed to keep the mixture molten. After the carbon content in the melt had dropped to the desired level, the air draft was cut off: a typical Bessemer converter could convert a 25-ton batch of pig iron to steel in half an hour.

Finally, the [[Basic oxygen steelmaking|basic oxygen process]] was introduced at the Voest-Alpine works in 1952; a modification of the basic Bessemer process, it lances oxygen from above the steel (instead of bubbling air from below), reducing the amount of nitrogen uptake into the steel. The basic oxygen process is used in all modern steelworks; the last Bessemer converter in the U.S. was retired in 1968. Furthermore, the last three decades have seen a massive increase in the mini-mill business, where scrap steel only is melted with an [[electric arc furnace]]. These mills only produced bar products at first, but have since expanded into flat and heavy products, once the exclusive domain of the integrated steelworks.

Until these 19th-century developments, steel was an expensive commodity and only used for a limited number of purposes where a particularly hard or flexible metal was needed, as in the cutting edges of tools and springs. The widespread availability of inexpensive steel powered the [[Second Industrial Revolution]] and modern society as we know it. Mild steel ultimately replaced wrought iron for almost all purposes, and wrought iron is no longer commercially produced. With minor exceptions, alloy steels only began to be made in the late 19th century. [[Stainless steel]] was developed on the eve of the [[First World War]] and was not widely used until the 1920s.

== See also ==
* [[Damascus Steel]]
* [[Wootz steel]]
* [[Steel#History of steelmaking|History of steelmaking]]
* [[Iron Age]]
* [[Nok culture]]
* [[Non-ferrous extractive metallurgy]]
* [[Roman metallurgy]]

== Notes ==
{{reflist|2}}

== References ==
* Ebrey, Walthall, Palais, (2006). ''East Asia: A Cultural, Social, and Political History''. Boston: Houghton Mifflin Company.
* Knowles, Anne Kelly. (2013) ''Mastering Iron: The Struggle to Modernize an American Industry, 1800–1868'' (University of Chicago Press) 334 pages
* Needham, Joseph (1986). ''Science and Civilization in China: Volume 4, Part 2''; Needham, Joseph (1986). ''Science and Civilization in China: Volume 4, Part 3''.
* Pleiner, R. (2000) ''Iron in Archaeology. The European Bloomery Smelters'', Praha, Archeologický Ústav Av Cr.
* Wagner, Donald (1996). ''Iron and Steel in Ancient China''. Leiden: E. J. Brill.
* Woods, Michael and Mary B. Woods (2000). ''Ancient Machines: From Wedges to Waterwheels. Minneapolis'': Twenty-First Century Books.

{{Prehistoric technology}}
{{Iron and steel production| state=expanded}}

{{DEFAULTSORT:History Of Ferrous Metallurgy}}
[[Category:History of metallurgy]]
[[Category:Steelmaking]]
[[Category:4th-millennium BC establishments]]

Cristallo

2016-01-31T22:36:35Z

71.109.148.145: /* Materials */

'''Cristallo''' is a [[glass]] which is totally clear (like [[rock crystal]]), without the slight yellow or greenish color originating from [[iron oxide]] impurities. This effect is achieved through small additions of [[manganese oxide]].<ref name=douglas>R. W. Douglas: ''A history of glassmaking'', G T Foulis & Co Ltd, Henley-on-Thames, 1972, ISBN 0-85429-117-2.</ref> Often Cristallo has a low [[calcium oxide|lime]] content which makes it prone to glass corrosion (otherwise known as [[glass disease]]).

The invention of Cristallo glass is attributed to [[Angelo Barovier]] around 1450.<ref>Carl I. Gable, ''Murano Magic: Complete Guide to Venetian Glass, its History and Artists'' (Schiffer, 2004), p. 24. ISBN 0-7643-1946-9.</ref>

==Materials==

In addition to common glass making materials [[manganese]], [[quartz]] pebbles, and [[soda ash|alume catino]] are used in the making of cristallo glass.

Rather than using common sand, crushed quartz pebbles were used instead. The quartz pebbles were typically from the [[Ticino]] and the [[Adige]] rivers. The quartz pebbles went through a rigorous screening process before being selected for use in cristallo production. The quartz pebbles had to be free of yellow and black veins and also had to be able to produce sparks when struck with steel.

If the quartz pebbles passed the selection process then the pebbles were heated to the point where the stones began to glow and then placed into cold water. Then the pebbles were crushed and ground.

The typical flux was used in the production of cristallo was called alume catino. Alume catino was derived from the ash of the [[salsola soda]] and salsola kali bushes that grew in the Levantine coastal region.

The ash of the plants was then carefully sieved and then placed into water to be gently boiled with constant mixing. Then the ashen mixture was placed into shallow pans to be dried. Once dried the alume catino would repeat the boiling and drying process until all of the salt was extracted from the ashes.

==Process==

The crushed and ground quartz was mixed with the purified alume catino and constantly mixed at high temperatures. The top of the molten batch would then be skimmed off. By skimming the top of the molten glass, unreacted and undissolved chlorides and sulfates in the mixture were removed.

The molten glass would then be ladled into vats of water. The water removed chloride and sulfate impurities from the mixture. The process of remelting and placing the molten mixture into vats of water was repeated several times until the glass-makers were satisfied.

Next the glass was placed into a furnace that was heated to the highest temperature possible and left there for several days. The material was stirred continually to eliminate defects, such as bubbles.

Then the refined mixture was taken, heated and shaped into blocks called frit. The frit was then taken and remelted and skimmed once again in order to remove impurities. The batch then had manganese added to the mixture at this time. The addition of manganese helps to rid the cristallo of any color tints. This step is repeated until the glass-maker is satisfied.

Now the molten mixture is ready to be shaped by glass-makers into pieces of cristalloware.

==References==
{{reflist}}
* {{cite journal
| last = McCray
| first = W. Patrick
| authorlink = W. Patrick McCray
| title = Glassmaking in Renaissance Italy: The innovation of Venetian cristallo
|date=May 1998
| journal = Journal of the Minerals, Metals and Materials Society
| volume = 50
| issue = 5
| pages = 14–19
| doi = 10.1007/s11837-998-0024-0
}}
* {{cite web
| last = Austin
| first = Jamie Sue
| title = A History of Murano Glass- II
| work = Life in Italy
| url = http://www.lifeinitaly.com/murano/murano-history-2.asp}}

{{Glass makers and brands}}

[[Category:Glass trademarks and brands]]

Cristallo

2016-01-31T22:35:42Z

71.109.148.145: /* Materials */

'''Cristallo''' is a [[glass]] which is totally clear (like [[rock crystal]]), without the slight yellow or greenish color originating from [[iron oxide]] impurities. This effect is achieved through small additions of [[manganese oxide]].<ref name=douglas>R. W. Douglas: ''A history of glassmaking'', G T Foulis & Co Ltd, Henley-on-Thames, 1972, ISBN 0-85429-117-2.</ref> Often Cristallo has a low [[calcium oxide|lime]] content which makes it prone to glass corrosion (otherwise known as [[glass disease]]).

The invention of Cristallo glass is attributed to [[Angelo Barovier]] around 1450.<ref>Carl I. Gable, ''Murano Magic: Complete Guide to Venetian Glass, its History and Artists'' (Schiffer, 2004), p. 24. ISBN 0-7643-1946-9.</ref>

==Materials==

In addition to common glass making materials [[manganese]], [[quartz]] pebbles, and [[soda ash|alume catino]] are used in the making of cristallo glass.

Rather than using common sand, crushed quartz pebbles were used instead. The quartz pebbles were typically from the [[Ticino]] and the [[Adige]] rivers. The quartz pebbles went through a rigorous screening process before being selected for use in cristallo production. The quartz pebbles had to be free of yellow and black veins and also had to be able to produce sparks when struck with steel.

If the quartz pebbles passed the selection process then the pebbles were heated to the point where the stones began to glow and then paced into cold water. Then the pebbles were crushed and ground.

The typical flux was used in the production of cristallo was called alume catino. Alume catino was derived from the ash of the [[salsola soda]] and salsola kali bushes that grew in the Levantine coastal region.

The ash of the plants was then carefully sieved and then placed into water to be gently boiled with constant mixing. Then the ashen mixture was placed into shallow pans to be dried. Once dried the alume catino would repeat the boiling and drying process until all of the salt was extracted from the ashes.

==Process==

The crushed and ground quartz was mixed with the purified alume catino and constantly mixed at high temperatures. The top of the molten batch would then be skimmed off. By skimming the top of the molten glass, unreacted and undissolved chlorides and sulfates in the mixture were removed.

The molten glass would then be ladled into vats of water. The water removed chloride and sulfate impurities from the mixture. The process of remelting and placing the molten mixture into vats of water was repeated several times until the glass-makers were satisfied.

Next the glass was placed into a furnace that was heated to the highest temperature possible and left there for several days. The material was stirred continually to eliminate defects, such as bubbles.

Then the refined mixture was taken, heated and shaped into blocks called frit. The frit was then taken and remelted and skimmed once again in order to remove impurities. The batch then had manganese added to the mixture at this time. The addition of manganese helps to rid the cristallo of any color tints. This step is repeated until the glass-maker is satisfied.

Now the molten mixture is ready to be shaped by glass-makers into pieces of cristalloware.

==References==
{{reflist}}
* {{cite journal
| last = McCray
| first = W. Patrick
| authorlink = W. Patrick McCray
| title = Glassmaking in Renaissance Italy: The innovation of Venetian cristallo
|date=May 1998
| journal = Journal of the Minerals, Metals and Materials Society
| volume = 50
| issue = 5
| pages = 14–19
| doi = 10.1007/s11837-998-0024-0
}}
* {{cite web
| last = Austin
| first = Jamie Sue
| title = A History of Murano Glass- II
| work = Life in Italy
| url = http://www.lifeinitaly.com/murano/murano-history-2.asp}}

{{Glass makers and brands}}

[[Category:Glass trademarks and brands]]

Redemption Maddie

2016-01-31T00:05:24Z

71.109.148.145:

{{Infobox Film
| name = Redemption Maddie
| image = Redemptionmaddie.jpg
| image_size =
| caption = Film Poster
| director = [http://www.imdb.com/name/nm1683676/ Aaron King]
| producer = [http://www.imdb.com/name/nm2105583/ Yoshi Tsuji]
| writer = Rachel Morrison Aaron King [http://www.imdb.com/name/nm0561617/ Harry Maxon]
| narrator =
| starring = [http://www.imdb.com/name/nm1270095/ Allison Scagliotti]
| music = [http://www.imdb.com/name/nm1869376/ Kristin Øhrn Dyrud]
| cinematography = [http://www.imdb.com/name/nm1121126/ Rachel Morrison]
| editing = [http://www.imdb.com/name/nm1827917/ MIchael Darrow]
| distributor = American Film Institute
| released = February 4, 2007
| runtime = 25 minutes
| country = [[United States]]
| language = [[English language|English]]
| budget =
| gross =
| preceded_by =
| followed_by =
}}

'''''Redemption Maddie''''' is a [[2007 in film|2007]] short film directed by [[Aaron King (film)|Aaron King]][http://www.imdb.com/name/nm1683676/] and starring [[Allison Scagliotti]][http://www.imdb.com/name/nm1270095/]. The film was completed as part of the American Film Institute Conservatory's MFA Program.

The film began touring the festival circuit in 2007, premiering at the 22nd Annual [[Santa Barbara International Film Festival]]. It has won several awards including a Grand Jury Prize for Student Shorts at the AFI Dallas International Film Festival,<ref>[http://afidallas.blogspot.com/2007/04/redemption-maddie-wins-jury-prize-best.html REDEMPTION MADDIE Wins Jury Prize Best Student Film at AFI DALLAS (April 23, 2007)]</ref> Best Short Film and Best Actress at [[BendFilm Festival]],<ref>[http://www.bendfilm.org/who-we-are/past-festivals/2007-bend-film-festival/2007-Bend-Film-Winners/default.aspx 2007 Bend Film Winners]</ref> and Best Screenplay at the Hollyshorts Film Festival. After completing its festival run, Maddie was distributed by Reframe <ref>[http://reframecollection.org/films/film?Id=1768 Tribeca Film Institute Reframe collection]</ref> and Amazon <ref>[http://www.amazon.com/Redemption-Maddie/dp/B004LAPSPM/ref=sr_1_1?ie=UTF8&qid=1354120887&sr=8-1&keywords=redemption+maddie Redemption Maddie (Amazon.com)]</ref> for DVD and digital purchase.

The film's official website provides the following description: ''In the wake of tragedy, 14 year old Maddie Clifford employs sex, insulin syringes, and an ill-fated rabbit in her disquietingly poignant search for salvation.''

The synopsis highlights an aspect of the film's plot which revolves around the so-called [[rabbit test]], a disturbing (misunderstanding of) the practice employed to detect pregnancy used in the early twentieth century.

==References==
{{Reflist}}

==External links==
*{{IMDb title|0890881}}
*[http://www.vimeo.com/175647 AFI Dallas 2007 Award Reception]
*[http://www.redemptionmaddie.com Redemption Maddie Official Website]

[[Category:2007 films]]
[[Category:American short films]]
[[Category:American films]]
[[Category:Independent films]]
[[Category:2000s drama films]]
[[Category:English-language films]]

{{short-drama-film-stub}}

Urushibara nickel

2016-01-30T23:58:33Z

71.109.148.145: /* Preparation */

'''Urushibara nickel''' is a [[nickel]] based [[hydrogenation]] [[catalyst]], named after Yoshiyuki Urushibara.<ref name=Original>{{cite journal|last1=Urushibara|first1=Yoshiyuki|title=A New Method of Catalytic Hydrogenation|journal=Bulletin of the Chemical Society of Japan|date=1952|volume=25|issue=4|page=280|doi=10.1246/bcsj.25.280}}</ref><ref name=Shigeo>{{cite book|last1=Nishimura|first1=Shigeo|title=Handbook of Heterogeneous Catalytic Hydrogenation for Organic Synthesis|date=2001|publisher=Wiley-Interscience|location=Newyork|isbn=9780471396987|pages=19, 36, 94, 123, 166, 204-205|edition=1st|url=https://books.google.com/books?id=RjZRAAAAMAAJ&q=0471396982&dq=0471396982&hl=en&sa=X&ei=BCacVMTgN5LmoASd34KQCQ&ved=0CB8Q6AEwAA}}</ref><ref>{{cite book|last1=Hata|first1=Kazuo|title=New Hydrogenating Catalysts: Urushibara Catalysts|date=1972|publisher=Wiley|location=Oakland, CA|isbn=9780470358900|edition=1st|url=https://books.google.com/books?id=5-FEAQAAIAAJ&q=0470358904&dq=0470358904&hl=en&sa=X}}</ref>

==History==
It was discovered by Yoshiyuki Urushibara in 1951, while doing research on the reduction of [[estrone]] to [[estradiol]].<ref name=Original></ref>

==Preparation==
First nickel is precipitated in [[metal]]lic form by reacting a solution of a nickel salt with an excess of [[zinc]].<ref name=Shigeo></ref><ref name=prep1>{{cite journal|last1=Urushibara|first1=Yoshiyuki|last2=Nishimura|first2=Shigeo|title=Procedure for the Preparation of the New Nickel Catalyst|journal=Bulletin of the Chemical Society of Japan|date=1954|volume=27|issue=7|page=480|doi=10.1246/bcsj.27.480}}</ref> This precipitated nickel contains relatively large amounts of zinc and [[zinc oxide]]. Then the catalyst is activated by digesting with either [[Base (chemistry)|base]] or [[acid]]. There is different designations for differently prepared Urushibara nickel catalysts.<ref>{{cite journal|last1=Urushibara|first1=Yoshiyuki|last2=Nishimura|first2=Shigeo|last3=Uehara|first3=Hideo|title=A New Preparation of Catalytic Nickel|journal=Bulletin of the Chemical Society of Japan|date=1955|volume=28|issue=6|page=446|doi=10.1246/bcsj.28.446}}</ref> The most common is U-Ni-A and U-Ni-B. U-Ni-A is prepared by digesting the precipitated nickel with an acid such as [[acetic acid]]. U-Ni-B is prepared by digesting with a base such as [[sodium hydroxide]]. After the digestion with acid most of the zinc and zinc oxide is dissolved from the catalyst, while after digestion with base it still contains considerable amounts of zinc and zinc oxide. It is also possible to precipitate the nickel using [[aluminium]] or [[magnesium]].

==Properties==
Urushibara nickel is not [[pyrophoric]]. It can be used for most hydrogenations where [[Raney nickel]] can be used.<ref name=prep1></ref>

==Variations==
[[Cobalt]] or [[iron]] can substitute for nickel to form different hydrogenation catalysts with different properties, these catalysts are respectively termed Urushibara Cobalt<ref>{{cite journal|last1=Taira|first1=Shinichi|title=Reduction of Organic Compounds with Urushibara Catalysts under High Pressure. VII. Feature of Various Urushibara Catalysts as Revealed in the Reduction of Benzophenone|journal=Bulletin of the Chemical Society of Japan|date=1961|volume=34|issue=2|pages=261-270|doi=10.1246/bcsj.34.261}}</ref> and Urushibara Iron.<ref>{{cite journal|last1=Taira|first1=Shinichi|title=Reduction of Organic Compounds with Urushibara Catalysts under High Pressure. X. Hydrogenation of 2-Butyne-1,4-diol to cis-2-Butene-1,4-diol with Various Urushibara Catalysts|journal=Bulletin of the Chemical Society of Japan|date=1962|volume=35|issue=5|pages=840-844|doi=10.1246/bcsj.35.840}}</ref> As a hydrogenation catalyst, Urushibara Cobalt is used for [[nitrile reduction]] where it serves as a superior catalyst for the production of [[Primary (chemistry)|primary]] [[amine]]s.<ref name=Shigeo></ref> Urushibara Iron is limited as a catalyst due to its relatively low activity toward most [[functional group]]s, however; it does finds some use in the partial hydrogenation of [[alkyne]]s to [[alkene]]s.

==References==
{{Reflist}}

[[Category:Catalysts]]
[[Category:Hydrogenation catalysts]]
[[Category:Named alloys]]
[[Category:Nickel alloys]]
[[Category:Zinc alloys]]

The Thing (listening device)

2016-01-29T02:13:04Z

71.109.148.145: Section was renamed and edited

[[Image:Bugged-great-seal-open.jpg|thumbnail|280px|Replica of the [[Great Seal of the United States|Great Seal]] which contained a Soviet bugging device, on display at the [[NSA]]'s [[National Cryptologic Museum]].]]
'''The Thing''', also known as '''the Great Seal bug''', was one of the first [[covert listening device]]s (or "bugs") to use passive techniques to transmit an audio signal. It was concealed inside a gift given by the Soviets to the US Ambassador to Moscow on August 4, 1945. Because it was passive, being energized and activated by electromagnetic energy from an outside source, it is considered a predecessor of [[RFID]] technology.<ref>{{cite book |author= |title=Hacking Exposed Linux: Linux Security Secrets & Solutions |publisher=McGraw-Hill Osborne Media |edition=third |year=2008 |page=298 |isbn=978-0-07-226257-5}}</ref>

== Creation ==
The Thing was designed by Soviet Russian inventor [[Léon Theremin]],<ref>Glinsky, Albert, ''Theremin: Ether Music and Espionage, University of Illinois Press, Urbana, 2000</ref> whose best-known invention is the electronic musical instrument the [[theremin]].

The principle used by The Thing, of a resonant cavity microphone, had been patented by Winfield R. Koch of the [[Radio Corporation of America]] (RCA) in 1941. In US patent 2,238,117 he describes the principle of a sound-modulated resonant cavity. High-frequency energy is [[Inductive coupling|inductively coupled]] to the cavity. The resonant frequency is varied by the change in capacitance resulting from the displacement of the acoustic diaphragm.<ref name=USpatent2238117A >{{cite patent
| country = US | number=2238117 | status = Patent
| title = Ultra high frequency modulator
| pubdate = 1941-04-15 | gdate = | fdate =1940-01-31 | pridate =1938-09-30
| inventor =Koch, Winfield R | assign1 = [[Radio Corporation of America]](RCA).
| class = | }} Retrieved 24 September 2013. "[https://www.google.com.au/patents/US2238117?dq=US+2238117+A&hl=en&sa=X&ei=AjtBUuXUAs2ekgWKvICIBA&ved=0CEEQ6AEwAQ US 2238117 A]" Google Patent Search</ref>

== Installation and use ==
The device was used by the [[Soviet Union]] to spy on the [[United States]]. It was embedded in a carved wooden plaque of the [[Great Seal of the United States]]. On August 4, 1945, a delegation from the [[Young Pioneer organization of the Soviet Union]] presented the bugged carving to U.S. [[Ambassador]] [[W. Averell Harriman]], as a "gesture of friendship" to the USSR's [[World War II]] [[Allies of World War II|ally]]. It hung in the ambassador's [[Spaso House|Moscow residential study]] for seven years, until it was exposed in 1952 during the tenure of Ambassador [[George F. Kennan]].<ref>George F. Kennan, Memoirs, 1950–1963, Volume II (Little, Brown & Co., 1972), pp. 155, 156</ref>

== Operating principles ==
The Thing consisted of a tiny capacitive membrane connected to a small [[Quarter-wave antenna|quarter-wavelength]] [[antenna (radio)|antenna]]; it had no power supply or [[active component|active electronic components]]. The device, a passive [[Microwave cavity|cavity resonator]], became active only when a [[radio]] signal of the correct frequency was sent to the device from an external transmitter. Sound waves caused the membrane to vibrate, which varied the [[capacitance]] "seen" by the antenna, which in turn [[modulation|modulated]] the radio waves that struck and were re-transmitted by the Thing. A receiver [[demodulate]]d the signal so that sound picked up by the microphone could be heard, just as an ordinary radio receiver demodulates radio signals and outputs sound.

Theremin's design made the listening device very difficult to detect, because it was very small, had no power supply or [[active component|active electronic component]]s, and did not radiate any signal unless it was actively being irradiated remotely. These same design features, along with the overall simplicity of the device, made it very reliable and gave it a potentially unlimited operational life.

===Technical details===
The device consisted of a 9-inch (23 cm) long [[monopole antenna]] (quarter-wave for 330 [[Hertz|Megahertz]](MHz) frequencies, but able to also act as half-wave or full-wave, the accounts differ)—a straight rod, led through an insulating bushing into a cavity, where it was terminated with a round disc that formed one plate of a capacitor. The [[microwave cavity|cavity]] was a [[Q-factor|high-Q]] round silver-plated copper "can", with the internal diameter of 0.775 in (19.7 mm) and about 11/16 in (17.5 mm) long, with [[inductance]] of about 10 [[nanohenry]].<ref name="Elect World">{{cite journal| last=Brown(?)| first=Robert. M.| title=Electronic Eavesdroping| journal=Electronics World| year=1967| volume= 77| issue=3-6|page=23| url=http://books.google.cz/books?id=NkVJAQAAIAAJ&q=great+seal+bug+frequency+MHz&dq=great+seal+bug+frequency+MHz&hl=en&sa=X&ei=m2ALUefZBKjd4QTfiIGQBA&sqi=2&redir_esc=y| accessdate=24 September 2013| publisher=[[Ziff-Davis Publishing Company]]}}</ref> Its front side was closed with a very thin (3 [[Thousandth of an inch|mil]], or 75 micrometers) and fragile conductive membrane. In the middle of the cavity was a mushroom-shaped flat-faced tuning post, with its top adjustable to make it possible to set the membrane-post distance; the membrane and the post formed a variable capacitor acting as a [[microphone#Condenser microphone|condenser microphone]] and providing [[amplitude modulation]] (AM), with parasitic [[frequency modulation]] (FM) for the re-radiated signal. The post had machined grooves and radial lines into its face, probably to provide channels for air flow to reduce pneumatic damping of the membrane. The antenna was capacitively coupled to the post via its disc-shaped end. The total weight of the unit, including the antenna, was 1.1 ounce (31 grams).

The length of the antenna and the dimensions of the cavity were engineered in order to make the re-broadcast signal a higher [[harmonic]] of the illuminating frequency. (Note that the transmitting frequency is higher than the illuminating one.)<ref name=EEtimes>{{cite web| url=http://eetimes.com/design/audio-design/4015284/Eavesdropping-using-microwaves--addendum | title=Design How-To: Eavesdropping using microwaves – addendum| date=12 November 2005 | journal=[[EE Times]] (eetimes.com) |publisher=[[United Business Media]]| accessdate=24 September 2013}}</ref>

The original device was located with the can under the beak of the eagle on the Great Seal presented to W. Averell Harriman (see below); accounts differ on whether holes were drilled into the beak to allow sound waves to reach the membrane. Other sources say the wood behind the beak was undrilled but thin enough to pass the sound, or that the hollowed space acted like a [[sound board (music)|soundboard]] to concentrate the sound from the room onto the microphone.

The illuminating frequency used by the Soviets is said to be 330 MHz.<ref name="Elect. Design">{{cite journal| last=Pursglove| first=S. David| title=Great Seal Bug| journal=Electronic Design| year=1966 |volume= 14 |issue= 14–17|page=35| url=http://books.google.cz/books?id=E9gEAQAAIAAJ&q=great+seal+bug+frequency&dq=great+seal+bug+frequency&hl=en&sa=X&ei=QEsLUeiaDsnm4QSqiYHgCg&redir_esc=y| accessdate=24 September 2013| publisher=Hayden Publishing Company}}</ref>

== Discovery ==
The existence of the bug was discovered accidentally by a [[UK|British]] radio operator at the British embassy who overheard American conversations on an open radio channel as the Soviets were beaming radio waves at the ambassador's office. An American State Department employee was then able to reproduce the results using an untuned wideband receiver with a simple diode detector/demodulator,<ref name="counterespionage">{{Cite web|url = http://www.counterespionage.com/the-great-seal-bug-part-1.html|title = THE GREAT SEAL BUG STORY|date = |accessdate = January 10, 2016|website = CounterEspionage|publisher = counterespionage.com|last = Murray|first = Kevin}}</ref> similar to some field strength meters.

Two additional State Department employees, John W. Ford and Joseph Bezjian, were sent to Moscow in March 1951 to investigate this and other suspected bugs in the British and Canadian embassy buildings. They conducted a [[technical surveillance counter-measures]] "sweep" of the Ambassador's office, using a [[signal generator]] and a receiver in a setup that generates [[audio feedback]] ("howl") if the sound from the room is transmitted on a given frequency. During this sweep, Bezjian found the device in the Great Seal carving.<ref name="counterespionage" />{{rp|2}}

The [[Central Intelligence Agency]] set about to analyze the device, and they hired the British company the [[Marconi Company]] to help with the analysis. Marconi technician [[Peter Wright]], a British scientist and later [[MI5]] [[counterintelligence]] officer, ran the investigation.<ref name="counterespionage"/> He was able to get The Thing working reliably with an illuminating frequency of 800 MHz. (The generator which had discovered the device was tuned to 1800 MHz.)

The membrane of the Thing was extremely thin, and was damaged during handling by the Americans; Wright had to replace it.

The simplicity of the device caused some initial confusion during its analysis; the antenna and resonator had several resonant frequencies in addition to its main one, and the modulation was partially both amplitude modulated and frequency modulated. The team also lost some time on an assumption that the distance between the membrane and the tuning post needed to be increased to increase resonance.

== Aftermath ==
Wright's examination led to development of a similar British system codenamed SATYR, used throughout the 1950s by the British, Americans, Canadians and Australians.

There were later models of the device, some with more complex internal structure (the center post under the membrane attached to a helix, probably to increase [[Q factor|Q]]), and some American models with [[dipole antenna]]s. Maximizing the Q-factor was one of the engineering priorities, as this allowed higher selectivity to the illuminating signal frequency, and therefore higher operating distance and also higher acoustic sensitivity.<ref name="counterespionage"/>

In 1960, The Thing was mentioned on the fourth day of meetings in the [[United Nations Security Council]], convened by the Soviet Union over the [[1960 U-2 incident]] where a U.S. spy plane had entered their territory and been shot down. The U.S. ambassador showed off the bugging device in the Great Seal to illustrate that spying incidents between the two nations were mutual and to allege that [[Nikita Khrushchev]] had magnified this particular incident out of all proportion as a pretext to abort the 1960 Paris Summit.<ref name="UN_SPV860_page15">{{UN document |docid=S-PV-860 |type=Verbatim Report |body=Security Council |meeting=860 |highlight=rect_155,148_530,482/rect_453,130_530,148 |page=15 |accessdate=2008-08-29|date=26 May 1960}}</ref>

== See also ==
*[[Radio-frequency identification]] (RFID transmitters)
*[[Covert listening device]]
*[[Nonlinear junction detector]]
*[[Technical surveillance counter-measures]] aka bug sweeping
*[[TEMPEST]]
*[[Surveillance]]
*[[Peter Wright]]

==Notes==
{{reflist}}

== References ==
* {{cite book
| last = Wright
| first = Peter
| authorlink = Peter Wright
| title = Spycatcher: The Candid Autobiography of a Senior Intelligence Officer
| year = 1987
| publisher = Viking
| location = New York
| isbn = 0-670-82055-5
}}
* {{cite book
| last = Kennan
| first = George
| authorlink = George F. Kennan
| title = Memoirs, 1925–1950
| year = 1967
| publisher = Little, Brown
}}
* {{cite book
| last = Kennan
| first = George
| authorlink = George F. Kennan
| title = Memoirs: 1950–1963
| year = 1983
| publisher = Pantheon
| isbn = 978-0-394-71626-8
}}

== External links ==
* [http://servv89pn0aj.sn.sourcedns.com/~gbpprorg/mil/cavity/index.html Passive Resonant Cavity & "Spycatcher" Technical Surveillance Devices]
* [http://www.spybusters.com/Great_Seal_Bug.html The Great Seal Bug Story], Spybusters, Kevin D. Murray
* [https://sm.asisonline.org/Pages/a-trojan-seal-006971.aspx A Trojan Seal] – Security Management, Ken Stanley, April 2010
* [http://www.state.gov/documents/organization/176589.pdf History of the Bureau of Diplomatic Security of the United States Department of State], October 2011, pp. 136–137
* [http://hackaday.com/2015/12/08/theremins-bug/ How the Soviet Union spied on the US embassy for 7 years], Hackaday, Adam Fabio, December 2015

{{espionage}}

{{DEFAULTSORT:Thing (Listening Device)}}
[[Category:Covert listening devices]]
[[Category:Espionage]]
[[Category:Espionage devices]]
[[Category:Espionage techniques]]
[[Category:KGB]]
[[Category:Inventions by Léon Theremin]]
[[Category:Soviet Union–United States relations]]
[[Category:Soviet Union intelligence operations]]
[[Category:Surveillance]]

[[it:Lev Sergeevič Termen#Leon Theremin e lo spionaggio]]

Acetic acid

2016-01-25T06:02:45Z

71.109.148.145: /* Acetic anhydride */

{{redirect-distinguish|Acetic|Ascetic}}
{{pp-move-indef}}
{{Use dmy dates|date=August 2014}}
{{featured article}}
{{Chembox
| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 477238786
| ImageFile3 = Acetic acid.jpg
| ImageFile3_Ref = {{chemboximage|correct|??}}
| ImageSize3 = 244
| ImageName3 = Sample of acetic acid in a reagent bottle
| ImageFileL1 = Acetic-acid-2D-skeletal.svg
| ImageFileL1_Ref = {{chemboximage|correct|??}}
| ImageNameL1 = Skeletal formula of acetic acid
| ImageFileR1 = Acetic-acid-CRC-GED-3D-vdW-B.png
| ImageFileR1_Ref = {{chemboximage|correct|??}}
| ImageNameR1 = Spacefill model of acetic acid
| ImageFileL2 =Acetic-acid-2D-flat.png
| ImageFileL2_Ref = {{chemboximage|correct|??}}
| ImageNameL2 = Skeletal formula of acetic acid with all explicit hydrogens added
| ImageFileR2 = Acetic-acid-CRC-GED-3D-balls-B.png
| ImageFileR2_Ref = {{chemboximage|correct|??}}
| ImageNameR2 = Ball and stick model of acetic acid
| IUPACName = Acetic acid<ref>{{cite book | title=A Guide to IUPAC Nomenclature of Organic Compounds (Recommendations 1993) | publisher=Blackwell Scientific publications | author=IUPAC, Commission on Nomenclature of Organic Chemistry | year=1993 | chapter = Table 28(a) Carboxylic acids and related groups. Unsubstituted parent structures | url = http://www.acdlabs.eu/iupac/nomenclature/93/r93_705.htm |isbn=0-632-03488-2 }}</ref><ref>{{cite web|url = http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=176|title = Acetic Acid – PubChem Public Chemical Database|work = The PubChem Project|location = USA|publisher = National Center for Biotechnology Information}}</ref>
| SystematicName = Ethanoic acid<ref name="BB-prs310305"/>
| OtherNames = Vinegar (when dilute); Hydrogen acetate; Methanecarboxylic acid<ref>{{cite book|title=Scientific literature reviews on generally recognised as safe (GRAS) food ingredients|publisher=National Technical Information Service|year=1974|page=1}}</ref><ref>"Chemistry", volume 5, Encyclopedia Britannica, 1961, page 374</ref>
|Section1={{Chembox Identifiers
| Abbreviations = AcOH
| CASNo = 64-19-7
| CASNo_Ref = {{cascite|correct|CAS}}
| PubChem = 176
| ChemSpiderID = 171
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| UNII = Q40Q9N063P
| UNII_Ref = {{fdacite|correct|FDA}}
| EINECS = 200-580-7
| UNNumber = 2789
| DrugBank_Ref = {{drugbankcite|correct|drugbank}}
| DrugBank = DB03166
| KEGG = D00010
| KEGG_Ref = {{keggcite|changed|kegg}}
| MeSHName = Acetic+acid
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI = 15366
| ChEMBL = 539
| ChEMBL_Ref = {{ebicite|correct|EBI}}
| IUPHAR_ligand = 1058
| Beilstein = 506007
| Gmelin = 1380
| 3DMet = B00009
| RTECS = AF1225000
| SMILES = CC(O)=O
| StdInChI = 1S/C2H4O2/c1-2(3)4/h1H3,(H,3,4)
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = QTBSBXVTEAMEQO-UHFFFAOYSA-N
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
}}
|Section2={{Chembox Properties
| C=2 | H=4 | O=2
| Appearance = Colourless liquid
| Odor = Pungent/Vinegar-like

| Density = 1.049 g cm−3
| Solubility = [[Miscible]]
| MeltingPtK = 289 to 290
| BoilingPtK = 391 to 392
| LogP = -0.322
| pKa = 4.76<ref>{{cite web|url=https://web.archive.org/web/20150722005239/http://www2.lsdiv.harvard.edu/pdf/evans_pKa_table.pdf|date=4 November 2005|title=pKa Table|last1=Ripin|first1=D. H.|last2=Evans|first2=D. A.|accessdate=19 July 2015}}</ref>
| pKb = 9.24 (basicity of acetate ion)
| Viscosity = 1.22 mPa s
| RefractIndex = 1.371
| Dipole = 1.74 D
}}
|Section5={{Chembox Thermochemistry
| DeltaHf = -483.88—483.16 kJ mol−1
| DeltaHc = -875.50—874.82 kJ mol−1
| Entropy = 158.0 J K−1 mol−1
| HeatCapacity = 123.1 J K−1 mol−1
}}
|Section6={{Chembox Pharmacology
| ATCCode_prefix = G01
| ATCCode_suffix = AD02
| ATC_Supplemental = {{ATC|S02|AA10}}
}}
|Section7={{Chembox Hazards
| GHSPictograms = {{GHS02}} {{GHS05}}
| GHSSignalWord = Danger
| HPhrases = {{H-phrases|226|314}}
| PPhrases = {{P-phrases|280|305+351+338|310}}
| EUClass = {{Hazchem C}}
| RPhrases = {{R10}}, {{R35}}
| SPhrases = {{S1/2}}, {{S23}}, {{S26}}, {{S45}}
| NFPA-F = 2
| NFPA-H = 3
| NFPA-R = 0
| FlashPtC = 40
| AutoignitionPtC = 427
| LD50 = 3.31 g kg−1, oral (rat)
| LC50 = 5620 ppm (mouse, 1 hr) 16000 ppm (rat, 4 hr)<ref>{{IDLH|64197|Acetic acid}}</ref>
| ExploLimits = 4–16%
| PEL = TWA 10 ppm (25 mg/m3)<ref name=PGCH>{{PGCH|0002}}</ref>
| REL = TWA 10 ppm (25 mg/m3) ST 15 ppm (37 mg/m3)<ref name=PGCH/>
| IDLH = 50 ppm<ref name=PGCH/>
}}
|Section8={{Chembox Related
| OtherFunction_label = [[carboxylic acid]]s
| OtherFunction = [[Formic acid]] [[Propionic acid]]
| OtherCompounds = [[Acetaldehyde]] 
[[Acetamide]] 
[[Acetic anhydride]] 
[[Acetonitrile]] 
[[Acetyl chloride]] 
[[Ethanol]] 
[[Ethyl acetate]] 
[[Potassium acetate]] 
[[Sodium acetate]] 
[[Thioacetic acid]]
}}
}}

'''Acetic acid''' {{IPAc-en|ə|ˈ|s|iː|t|ɨ|k}}, systematically named '''ethanoic acid''' {{IPAc-en|ˌ|ɛ|θ|ə|ˈ|n|oʊ|ɨ|k}}, is an [[organic compound]] with the [[chemical formula]] CH3COOH (also written as CH3CO2H or C2H4O2). It is a colourless liquid that when undiluted is also called ''glacial acetic acid''. [[Vinegar]] is roughly 3–9% acetic acid by volume, making acetic acid the main component of vinegar apart from water. Acetic acid has a distinctive sour taste and pungent smell. Besides its production as household vinegar, it is mainly produced as a precursor to polyvinylacetate and [[cellulose acetate]]. Although it is classified as a [[acid strength|weak acid]], concentrated acetic acid is corrosive and can attack the skin.

Acetic acid is the second simplest [[carboxylic acid]] (after [[formic acid]]) and is an important [[reagent|chemical reagent]] and industrial chemical, mainly used in the production of [[cellulose acetate]] for [[photographic film]] and [[polyvinyl acetate]] for wood [[Adhesive|glue]], as well as synthetic fibres and fabrics. In households, diluted acetic acid is often used in [[descaling agent]]s. In the [[food industry]], acetic acid is used under the [[E number|food additive code]] E260 as an [[acidity regulator]] and as a condiment. As a [[food additive]] it is approved for usage in many countries, including Canada,<ref name=CDJ2013>{{cite web|title=Food and Drug Regulations (C.R.C., c. 870)|url=http://laws-lois.justice.gc.ca/eng/regulations/C.R.C.,_c._870/FullText.html|work=Consolidated Regulations|publisher=Canadian Department of Justice|accessdate=21 July 2013|date=31 May 2013}}</ref> the European Union,<ref>UK Food Standards Agency: {{cite web |url=http://www.food.gov.uk/safereating/chemsafe/additivesbranch/enumberlist |title=Current EU approved additives and their E Numbers |accessdate=27 October 2011}}</ref> the United States,<ref>US Food and Drug Administration: {{cite web |url=https://web.archive.org/web/20120117060614/http://www.fda.gov/Food/FoodIngredientsPackaging/FoodAdditives/FoodAdditiveListings/ucm091048.htm |title=Listing of Food Additives Status Part I |accessdate=27 October 2011}}</ref> Australia and New Zealand.<ref>Australia New Zealand Food Standards Code{{cite web |url=http://www.comlaw.gov.au/Details/F2011C00827 |title=Standard 1.2.4 – Labeling of ingredients |accessdate=27 October 2011}}</ref>

The global demand for acetic acid is around 6.5 million [[tonne]]s per year (Mt/a), of which approximately 1.5 Mt/a is met by recycling; the remainder is manufactured from [[petrochemical]] feedstock.<ref name=Ullmann/> As a chemical reagent, biological sources of acetic acid are of interest, but generally uncompetitive. Vinegar is dilute acetic acid, often produced by [[ethanol fermentation|fermentation]] and subsequent oxidation of [[ethanol]].

==Nomenclature==
The [[trivial name]] ''acetic acid'' is the most commonly used and [[preferred IUPAC name]]. The systematic name ''ethanoic acid'', a valid [[IUPAC]] name, is constructed according to the substitutive nomenclature.<ref name="BB-prs310305">IUPAC Provisional Recommendations 2004 [http://old.iupac.org/reports/provisional/abstract04/BB-prs310305/Chapter1.pdf Chapter P-12.1; page 4]</ref> The name ''acetic acid'' derives from ''acetum'', the [[Latin]] word for [[vinegar]], and is related to the word [[acid]] itself.

'''Glacial acetic acid''' is a name for water-free ([[anhydrous]]) acetic acid. Similar to the [[German language|German]] name ''Eisessig'' (''ice-vinegar''), the name comes from the ice-like crystals that form slightly below room temperature at {{convert|16.6|C|F}} (the presence of 0.1% water lowers its melting point by 0.2 °C).<ref name="Purification of Laboratory Chemicals">{{cite book|author= Armarego,W.L.F. and Chai,Christina |title=Purification of Laboratory Chemicals, 6th edition|publisher=Butterworth-Heinemann|location=|year=2009|pages=|isbn=1-85617-567-7}}</ref>

A common abbreviation for acetic acid is ''AcOH'', where ''Ac'' stands for the [[acetyl]] [[functional group|group]] CH3−C(=O)−. [[Acetate]] (CH3COO−) is abbreviated ''AcO−''. The ''Ac'' is not to be confused with the abbreviation for the [[chemical element]] [[actinium]].<ref name="Cooper">{{cite book|last=Cooper|first=Caroline |title=Organic Chemist's Desk Reference|edition=2|date=9 August 2010|publisher=CRC Press|isbn=1-4398-1166-0|pages=102–104}}</ref> To better reflect its structure, acetic acid is often written as CH3–C(O)OH, CH3–C(=O)OH, CH3COOH, and CH3CO2H. In the context of [[acid-base reaction]]s, the abbreviation ''HAc'' is sometimes used,<ref>{{cite book|last=DeSousa|first=Luís R.|title=Common Medical Abbreviations|year=1995|publisher=Cengage Learning|isbn=0-8273-6643-4|page=97}}</ref> where ''Ac'' instead stands for acetate. Acetate is the [[ion]] resulting from loss of [[proton|H+]] from acetic acid. The name ''acetate'' can also refer to a [[salt]] containing this anion, or an [[ester]] of acetic acid.<ref>{{cite book|last1=Hendrickson|first1=James B.|last2=Cram|first2=Donald J.|last3=Hammond|first3=George S.|title=Organic Chemistry|edition=3|year=1970|publisher=McGraw Hill Kogakusha|location=Tokyo|page=135}}</ref>

==Properties==
[[File:AceticAcid010.png|thumb|upright|Acetic acid crystals]]

===Acidity===
The hydrogen centre in the [[carboxyl group]] (−COOH) in carboxylic acids such as acetic acid can separate from the molecule by ionization:
:CH3CO2H → CH3CO2− + H+
Because of this release of the [[proton]] (H+), acetic acid has acidic character. Acetic acid is a weak [[monoprotic acid]]. In aqueous solution, it has a [[Acid dissociation constant|pKa]] value of 4.76.<ref name="Goldmine">
{{cite journal |title=Thermodynamic Quantities for the Ionization Reactions of Buffers |last=Goldberg |first=R.|author2=Kishore, N.|author3= Lennen, R. |journal=Journal of Physical and Chemical Reference Data |volume=31 |issue=2|pages=231–370 |year=2002 |url=http://www.nist.gov/data/PDFfiles/jpcrd615.pdf |doi=10.1063/1.1416902|bibcode = 1999JPCRD..31..231G }}</ref> Its [[conjugate acid|conjugate base]] is [[acetate]] (CH3COO−). A 1.0 [[Molarity|M]] solution (about the concentration of domestic vinegar) has a [[pH]] of 2.4, indicating that merely 0.4% of the acetic acid molecules are dissociated.<ref>[H3O+] = 10−2.4 = 0.4 %</ref>

[[File:Acetic acid deprotonation.png|375px|Deprotonation equilibrium of acetic acid in water]]
[[File:Acetic Acid Hydrogenbridge V.1.svg|thumb|Cyclic dimer of acetic acid; dashed '''green''' lines represent hydrogen bonds]]

===Structure===
In solid acetic acid, the molecules form pairs ([[Dimer (chemistry)|dimers]]), being connected by [[hydrogen bond]]s.<ref name='jones'>{{cite journal|last = Jones|first = R.E.|author2 = Templeton, D.H.|year = 1958|title = The crystal structure of acetic acid|journal = Acta Crystallographica|volume = 11|issue = 7|pages=484–487|doi = 10.1107/S0365110X58001341}}</ref> The dimers can also be detected in the vapour at {{convert|120|C|F}}. Dimers also occur in the liquid phase in dilute solutions in non-hydrogen-bonding solvents, and a certain extent in pure acetic acid,<ref name='briggs'>{{cite journal|first = James M.|last = Briggs|author2 = Toan B. Nguyen|author3= William L. Jorgensen|title = Monte Carlo simulations of liquid acetic acid and methyl acetate with the OPLS potential functions|journal = Journal of Physical Chemistry|year = 1991|volume = 95|pages=3315–3322|doi = 10.1021/j100161a065|issue = 8}}</ref> but are disrupted by hydrogen-bonding solvents. The dissociation [[enthalpy]] of the dimer is estimated at 65.0–66.0 kJ/mol, and the dissociation entropy at 154–157 J mol−1 K−1.<ref name='togeas'>{{cite journal|first = James B.|last = Togeas|title = Acetic Acid Vapor: 2. A Statistical Mechanical Critique of Vapor Density Experiments|journal = Journal of Physical Chemistry A|year = 2005|volume = 109|pages = 5438–5444|doi = 10.1021/jp058004j|pmid = 16839071|issue = 24}}</ref> Other lower carboxylic acids dimerize in a similar fashion.<ref>{{cite book|last=McMurry|first=John|title=Organic Chemistry|edition=5|year=2000|publisher=Brooks/Cole|isbn=0-534-37366-6|page=818}}</ref>

===Solvent properties===
[[Liquid]] acetic acid is a [[hydrophile|hydrophilic]] ([[Polar molecule|polar]]) [[protic solvent]], similar to ethanol and [[water]]. With a moderate [[relative static permittivity]] (dielectric constant) of 6.2, it dissolves not only polar compounds such as inorganic salts and [[sugar]]s, but also non-polar compounds such as oils and [[chemical element|elements]] such as [[sulfur]] and [[iodine]]. It readily mixes with other polar and non-polar [[solvent]]s such as water, [[chloroform]], and [[hexane]]. With higher alkanes (starting with [[octane]]), acetic acid is not completely [[miscible]] anymore, and its miscibility continues to decline with longer n-alkanes.<ref name='Zieborak'>{{cite journal|title=none|first = K.|last = Zieborak|author2 = K. Olszewski|journal = Bulletin de L'Academie Polonaise des Sciences-Serie des Sciences Chimiques Geologiques et Geographiques |year = 1958|volume = 6|issue=2|pages=3315–3322}}</ref> This dissolving property and [[miscibility]] of acetic acid makes it a widely used industrial chemical, for example, as a solvent in the production of [[dimethyl terephthalate]].<ref name=Ullmann>{{Ullmann | author1 = Hosea Cheung | author2 = Robin S. Tanke | author3 = G. Paul Torrence | title = Acetic Acid | doi = 10.1002/14356007.a01_045.pub2}}</ref>

===Biochemistry===
At physiological pHs, acetic acid is usually fully ionised to [[acetate]].
The [[acetyl]] [[functional group|group]], derived from acetic acid, is fundamental to all forms of life. When bound to [[coenzyme A]], it is central to the [[metabolism]] of [[carbohydrate]]s and [[fat]]s. Unlike longer-chain carboxylic acids (the [[fatty acids]]), acetic acid does not occur in natural [[triglyceride]]s. However, the artificial triglyceride [[triacetin]] (glycerine triacetate) is a common food additive and is found in cosmetics and topical medicines.<ref>{{cite journal|last=Fiume|first=M. Z.|date=June 2003|title=Final report on the safety assessment of triacetin|journal=International Journal of Toxicology|volume=22|issue=Suppl 2|pages=1–10|doi=10.1177/1091581803022S203|pmid=14555416|url=http://www.ncbi.nlm.nih.gov/pubmed/14555416|author2=Cosmetic Ingredients Review Expert Panel}}</ref>


Acetic acid is produced and [[Excretion|excreted]] by [[acetic acid bacteria]], notable ones being the ''[[Acetobacter]]'' genus and ''[[Clostridium acetobutylicum]]''. These bacteria are found universally in [[food]]stuffs, [[water]], and [[soil]], and acetic acid is produced naturally as fruits and other foods spoil. Acetic acid is also a component of the [[vaginal lubrication]] of [[human]]s and other [[primate]]s, where it appears to serve as a mild [[antibacterial]] agent.<ref name='dict'>{{cite book|title = Dictionary of Organic Compounds|edition = 6th|volume = 1 |year = 1996|location = London|publisher = Chapman & Hall|isbn = 0-412-54090-8|author = executive ed.: J. Buckingham}}</ref>

==Production==
[[File:Acetic acid 1884 plant.jpg|thumb|Purification and concentration plant for acetic acid in 1884]]
Acetic acid is produced industrially both synthetically and by bacterial [[fermentation (biochemistry)|fermentation]]. About 75% of acetic acid made for use in the chemical industry is made by the [[carbonylation]] of methanol, explained below.<ref name=Ullmann/> Alternative methods account for the rest. The biological route accounts for only about 10% of world production, but it remains important for the production of vinegar, as many food purity laws stipulate that vinegar used in foods must be of biological origin. As of 2003–2005, total worldwide production of virgin acetic acid was estimated at 5 Mt/a (million tonnes per year), approximately half of which was then produced in the [[United States]]. [[Europe]]an production stood at approximately 1 Mt/a and was declining, and 0.7 Mt/a were produced in [[Japan]]. Another 1.5 Mt were recycled each year, bringing the total world market to 6.5 Mt/a.<ref>{{cite journal|title = Production report|journal = Chemical & Engineering News|publication-date = 11 July 2005|pages=67–76}}</ref><ref name='suresh'>{{cite book|last = Suresh|first = Bala|year = 2003|url = http://www.sriconsulting.com/CEH/Public/Reports/602.5000/|chapter = Acetic Acid|title = Chemicals Economic Handbook|pages = 602.5000|publisher = SRI International}}</ref> Since then the global production has increased to 10.7 Mt/a (in 2010), and further, however, slowing increase in production is predicted.<ref>Acetic Acid :: Petrochemicals :: World Petrochemicals :: SRI Consulting. http://chemical.ihs.com/WP/Public/Reports/acetic_acid/ (accessed 18 December 2011).</ref> The two biggest producers of virgin acetic acid are [[Celanese]] and [[BP|BP Chemicals]]. Other major producers include [[Millennium Chemicals]], [[Sterling Chemicals]], [[Samsung]], [[Eastman Chemical Company|Eastman]], and [[Svensk Etanolkemi]].<ref>{{cite web|url=http://marketreportfinder.com/report/industry/http://www.reuters.com/article/2009/03/12/idUS101446+12-Mar-2009+BW20090312l|title=Reportlinker Adds Global Acetic Acid Market Analysis and Forecasts|date=March 2009|work=Market Research Database|page=contents|accessdate=6 June 2013}}</ref>

===Methanol carbonylation===
Most acetic acid is produced by methanol [[carbonylation]]. In this process, methanol and [[carbon monoxide]] react to produce acetic acid according to the equation:

:[[File:Methanol formylation.png|250px]]

The process involves [[iodomethane]] as an intermediate, and occurs in three steps. A [[catalyst]], [[metal carbonyl]], is needed for the carbonylation (step 2).<ref name=Yoneda2001>{{cite journal|author = Yoneda, N.|author2 = Kusano, S.|author3= Yasui, M.|author4= Pujado, P.|author5= Wilcher, S.|year = 2001|title = Recent advances in processes and catalysts for the production of acetic acid|journal = Applied Catalysis A, General|volume = 221|issue = 1–2|pages = 253–265|doi = 10.1016/S0926-860X(01)00800-6}}</ref>
#CH3OH + HI → CH3I + H2O
#CH3I + CO → CH3COI
#CH3COI + H2O → CH3COOH + HI

Two related processes for the carbonylation of methanol: the rhodium-catalyzed [[Monsanto process]], and the iridium-catalyzed [[Cativa process]]. The latter process is [[Green chemistry|greener]] and more efficient<ref name="lancaster"/> and has largely supplanted the former process, often in the same production plants. Catalytic amounts of water are used in both processes, but the Cativa process requires less, so the [[water-gas shift reaction]] is suppressed, and fewer by-products are formed.

By altering the process conditions, [[acetic anhydride]] may also be produced on the same plant using the rhodium catalysts.<ref>{{cite journal | author = Zoeller, J. R.; Agreda, V. H.; Cook, S. L.; Lafferty, N. L.; Polichnowski, S. W.; Pond, D. M. | title = Eastman Chemical Company Acetic Anhydride Process | journal = [[Catalysis Today]] | year = 1992 | volume = 13 | issue = 1 | pages = 73–91 | doi = 10.1016/0920-5861(92)80188-S}}</ref>

===Acetaldehyde oxidation===
Prior to the commercialization of the Monsanto process, most acetic acid was produced by oxidation of [[acetaldehyde]]. This remains the second-most-important manufacturing method, although it is usually uncompetitive with the carbonylation of methanol.

The acetaldehyde may be produced via [[oxidation]] of butane or light naphtha, or by hydration of ethylene. When [[butane]] or light [[naphtha]] is heated with air in the presence of various metal [[ion]]s, including those of [[manganese]], [[cobalt]], and [[chromium]], [[organic peroxide|peroxides]] form and then decompose to produce acetic acid according to the [[chemical equation]]:

: 2 C4H10 + 5 O2 → 4 CH3COOH + 2 H2O

The typical reaction is conducted at [[temperature]]s and pressures designed to be as hot as possible while still keeping the butane a liquid. Typical reaction conditions are {{convert|150|C|F}} and 55 atm.<ref>{{cite book|last=Chenier|first=Philip J.|title=Survey of Industrial Chemistry|edition=3|year=2002|publisher=Springer|isbn=0-306-47246-5|page=151}}</ref> Side-products may also form, including [[butanone]], [[ethyl acetate]], [[formic acid]], and [[propionic acid]]. These side-products are also commercially valuable, and the reaction conditions may be altered to produce more of them where needed. However, the separation of acetic acid from these by-products adds to the cost of the process.<ref name="Sano1999">{{cite journal|last=Sano|first=Ken‐ichi|author2=Hiroshi Uchida|author3= Syoichirou Wakabayashi|year=1999|title=A new process for acetic acid production by direct oxidation of ethylene|journal=Catalysis Surveys from Japan|volume=3|issue=1|pages=55–60|issn=1384-6574|doi=10.1023/A:1019003230537}}</ref>

Under similar conditions and using similar [[catalyst]]s as are used for butane oxidation, the [[oxygen]] in [[Earth's atmosphere|air]] to produce acetic acid can oxidize [[acetaldehyde]].<ref name="Sano1999"/>

: 2 CH3CHO + O2 → 2 CH3COOH

Using modern catalysts, this reaction can have an acetic acid yield greater than 95%. The major side-products are [[ethyl acetate]], [[formic acid]], and [[formaldehyde]], all of which have lower [[boiling point]]s than acetic acid and are readily separated by [[distillation]].<ref name="Sano1999"/>

===Ethylene oxidation===
Acetaldehyde may be prepared from [[ethylene]] via the [[Wacker process]], and then oxidised as above. In more recent times, chemical company [[Showa Denko]], which opened an ethylene oxidation plant in [[Ōita Prefecture|Ōita]], [[Japan]], in 1997, commercialised a cheaper single-stage conversion of ethylene to acetic acid.<ref name='sano'>{{cite book|last = Sano|first = Ken-ichi|author2 = Uchida, Hiroshi|author3= Wakabayashi, Syoichirou|year = 1999|title = A new process for acetic acid production by direct oxidation of ethylene|
journal = [[Catalyst Surveys from Japan]]|volume = 3|pages = 66–60|doi = 10.1023/A:1019003230537}}</ref> The process is catalyzed by a [[palladium]] metal catalyst supported on a [[heteropoly acid]] such as [[tungstosilicic acid]]. It is thought to be competitive with methanol carbonylation for smaller plants (100–250 kt/a), depending on the local price of ethylene.
The approach will be based on utilizing a novel selective photocatalytic oxidation technology for the selective oxidation of ethylene and ethane to acetic acid. Unlike traditional oxidation catalysts, the selective oxidation process will use UV light to produce acetic acid at ambient temperatures and pressure.

===Oxidative fermentation===
For most of human history, acetic acid bacteria of the genus ''[[Acetobacter]]'' have made acetic acid, in the form of vinegar. Given sufficient oxygen, these bacteria can produce vinegar from a variety of alcoholic foodstuffs. Commonly used feeds include [[Cider|apple cider]], [[wine]], and fermented [[cereal|grain]], [[malt]], [[rice]], or [[potato]] mashes. The overall chemical reaction facilitated by these bacteria is:

: C2H5OH + O2 → CH3COOH + H2O

A dilute alcohol solution inoculated with ''Acetobacter'' and kept in a warm, airy place will become vinegar over the course of a few months. Industrial vinegar-making methods accelerate this process by improving the supply of [[oxygen]] to the bacteria.<ref>{{cite book |last1=Chotani |first1=Gopal K. |last2=Gaertner |first2=Alfred L. |last3= Arbige |first3=Michael V. |author4=Timothy C. Dodge |title=Kent and Riegel's Handbook of Industrial Chemistry and Biotechnology|year=2007|publisher=Springer|isbn=978-0-387-27842-1|pages=32–34|chapter=Industrial Biotechnology: Discovery to Delivery}}</ref>

The first batches of vinegar produced by fermentation probably followed errors in the [[winemaking]] process. If [[must]] is fermented at too high a temperature, acetobacter will overwhelm the [[yeast (wine)|yeast]] naturally occurring on the [[grapes]]. As the demand for vinegar for culinary, medical, and sanitary purposes increased, vintners quickly learned to use other organic materials to produce vinegar in the hot summer months before the grapes were ripe and ready for processing into wine. This method was slow, however, and not always successful, as the vintners did not understand the process.<ref name='Hromatka'>{{cite journal|title = Vinegar by Submerged Oxidative Fermentation| author = Otto Hromatka and Heinrich Ebner|journal = Industrial & Engineering Chemistry|year = 1959|volume = 51|issue = 10|pages = 1279–1280| doi = 10.1021/ie50598a033}}</ref>

One of the first modern commercial processes was the "fast method" or "German method", first practised in Germany in 1823. In this process, fermentation takes place in a tower packed with wood shavings or [[charcoal]]. The alcohol-containing feed is trickled into the top of the tower, and fresh [[Earth's atmosphere|air]] supplied from the bottom by either natural or forced [[convection]]. The improved air supply in this process cut the time to prepare vinegar from months to weeks.<ref>{{cite journal|title = Acetic Acid and Cellulose Acetate in the United States A General Survey of Economic and Technical Developments|author = Everett P. Partridge|journal = Industrial & Engineering Chemistry|year = 1931|volume = 23|issue =5|pages = 482–498|doi = 10.1021/ie50257a005}}</ref>

Nowadays, most vinegar is made in submerged tank [[Microbiological culture|culture]], first described in 1949 by Otto Hromatka and Heinrich Ebner.<ref>{{cite journal|title = Investigations on vinegar fermentation: Generator for vinegar fermentation and aeration procedures|author = O Hromatka, H Ebner|journal = Enzymologia|volume=13|page=369|year = 1949}}</ref> In this method, alcohol is fermented to vinegar in a continuously stirred tank, and oxygen is supplied by bubbling air through the solution. Using modern applications of this method, vinegar of 15% acetic acid can be prepared in only 24 hours in batch process, even 20% in 60-hour fed-batch process.<ref name='Hromatka'/>

===Anaerobic fermentation===
Species of [[anaerobic bacteria]], including members of the genus ''[[Clostridium]]'' or ''[[Acetobacterium]]'' can convert sugars to acetic acid directly, without using ethanol as an intermediate. The overall chemical reaction conducted by these bacteria may be represented as:
: C6H12O6 → 3 CH3COOH

These [[Acetogen|acetogenic bacteria]] produce acetic acid from one-carbon compounds, including methanol, [[carbon monoxide]], or a mixture of [[carbon dioxide]] and [[hydrogen]]:
: 2 CO2 + 4 H2 → CH3COOH + 2 H2O

This ability of ''Clostridium'' to utilize sugars directly, or to produce acetic acid from less costly inputs, means that these bacteria could potentially produce acetic acid more efficiently than ethanol-oxidizers like ''Acetobacter''. However, ''Clostridium'' bacteria are less acid-tolerant than ''Acetobacter''. Even the most acid-tolerant ''Clostridium'' strains can produce vinegar of only a few per cent acetic acid, compared to ''Acetobacter'' strains that can produce vinegar of up to 20% acetic acid. At present, it remains more cost-effective to produce vinegar using ''Acetobacter'' than to produce it using ''Clostridium'' and then concentrate it. As a result, although acetogenic bacteria have been known since 1940, their industrial use remains confined to a few niche applications.<ref>{{cite journal|journal = Enzyme and Microbial Technology|volume = 40|issue = 5|year = 2007|pages = 1234–1243|
doi = 10.1016/j.enzmictec.2006.09.017|title = Clostridium aceticum—A potential organism in catalyzing carbon monoxide to acetic acid: Application of response surface methodology|author = Jia Huey Sim, Azlina Harun Kamaruddin, Wei Sing Long and Ghasem Najafpour}}</ref>

==Uses==
Acetic acid is a chemical [[reagent]] for the production of chemical compounds. The largest single use of acetic acid is in the production of vinyl acetate [[monomer]], closely followed by acetic anhydride and ester production. The volume of acetic acid used in vinegar is comparatively small.<ref name = Ullmann/><ref name='suresh'/>

===Vinyl acetate monomer===
The major use of acetic acid is for the production of [[vinyl acetate|vinyl acetate monomer (VAM)]]. In 2008, this application was estimated to consume one third of the world's production of acetic acid.<ref name = Ullmann/> The reaction is of [[ethylene]] and acetic acid with [[oxygen]] over a [[palladium]] [[catalyst]], conducted in the gas phase.<ref name = vinyl-esters>{{Ullmann | title = VInyl Esters | author = Günter Roscher | doi = 10.1002/14356007.a27_419}}</ref>
: 2 H3C–COOH + 2 C2H4 + O2 → 2 H3C–CO–O–CH=CH2 + 2 H2O
Vinyl acetate can be polymerised to [[polyvinyl acetate]] or to other [[polymers]], which are components in [[paint]]s and [[adhesive]]s.<ref name = vinyl-esters/>

===Ester production===
The major [[ester]]s of acetic acid are commonly used solvents for [[ink]]s, [[paint]]s and [[coating]]s. The esters include [[ethyl acetate]], n-[[butyl acetate]], [[isobutyl acetate]], and [[propyl acetate]]. They are typically produced by [[catalyst|catalyzed]] reaction from acetic acid and the corresponding [[alcohol]]:
: H3C-COOH + HO-R → H3C-CO-O-R + H2O, (R = a general [[alkyl group]])

Most acetate esters, however, are produced from [[acetaldehyde]] using the [[Tishchenko reaction]]. In addition, ether acetates are used as solvents for [[nitrocellulose]], [[Acrylic paint|acrylic lacquers]], [[varnish]] removers, and wood stains. First, glycol monoethers are produced from [[ethylene oxide]] or [[propylene oxide]] with alcohol, which are then esterified with acetic acid. The three major products are ethylene glycol monoethyl ether acetate (EEA), ethylene glycol monobutyl ether acetate (EBA), and propylene glycol monomethyl ether acetate (PMA, more commonly known as PGMEA in semiconductor manufacturing processes, where it is used as a resist solvent). This application consumes about 15% to 20% of worldwide acetic acid. Ether acetates, for example EEA, have been shown to be harmful to human reproduction.<ref name='suresh'/>

===Acetic anhydride===
The product of the [[condensation reaction|condensation]] of two molecules of acetic acid is [[acetic anhydride]]. The worldwide production of acetic anhydride is a major application, and uses approximately 25% to 30% of the global production of acetic acid. The main process involves dehydration of acetone to give [[ketene]] at 700–750 °C. Ketene is thereafter reacted with acetic acid to obtain the anhydride:<ref name = acetic-anh>{{Ullmann | title = Acetic Anhydride and Mixed Fatty Acid Anhydrides | author1 = Heimo Held | author2 = Alfred Rengstl | author3 = Dieter Mayer | doi = 10.1002/14356007.a01_065}}</ref>

:CH3CO2H → CH2=C=O + H2O
:CH3CO2H + CH2=C=O → (CH3CO)2O

Acetic anhydride is an [[acetylation]] agent. As such, its major application is for [[cellulose acetate]], a synthetic [[textile]] also used for [[photographic film]]. Acetic anhydride is also a reagent for the production of [[heroin]] and other compounds.<ref name = acetic-anh/>

===Use as solvent===
Glacial acetic acid is an excellent polar [[protic solvent]], as noted [[Acetic acid#Chemical properties|above]]. It is frequently used as a solvent for [[recrystallization (chemistry)|recrystallization]] to purify organic compounds. Acetic acid is used as a [[solvent]] in the production of [[terephthalic acid]] (TPA), the raw material for [[polyethylene terephthalate]] (PET). In 2006, about 20% of acetic acid was used for TPA production.<ref name='suresh'/>

Acetic acid is often used as a solvent for reactions involving [[carbocation]]s, such as [[Friedel-Crafts#Friedel–Crafts alkylation|Friedel-Crafts alkylation]]. For example, one stage in the commercial manufacture of synthetic [[camphor]] involves a [[Wagner-Meerwein rearrangement]] of [[camphene]] to [[isobornyl acetate]]; here acetic acid acts both as a solvent and as a [[nucleophile]] to trap the [[rearrangement reaction|rearranged]] carbocation.<ref name="sell">{{cite book|last=Sell|first=Charles S.|title=The Chemistry of Fragrances: From Perfumer to Consumer|url=https://books.google.com/books?id=G90hcKHwrqEC&pg=PA80|edition=2|series=RSC Paperbacks Series|volume=38|year=2006|publisher=Royal Society of Chemistry|location=Great Britain|isbn=0-85404-824-3|page=80|chapter=4.2.15 Bicyclic Monoterpenoids}}</ref>

Glacial acetic acid is used in analytical chemistry for the estimation of weakly alkaline substances such as organic amides. Glacial acetic acid is a much weaker [[base (chemistry)|base]] than water, so the amide behaves as a strong base in this medium. It then can be titrated using a solution in glacial acetic acid of a very strong acid, such as [[perchloric acid]].<ref name="Felgner">{{cite web|url=http://www.sigmaaldrich.com/technical-documents/articles/analytix/titration-in-non-aqueous.html|title=Titration in Non-Aqueous Media|last=Felgner|first=Andrea|publisher=Sigma-Aldrich|accessdate=5 June 2013}}</ref>

===Medical use===
Diluted acetic acid is used in [[physical therapy]] using [[iontophoresis]].<ref name="KoltSnyder-Mackler2007">{{cite book|last1=Kolt|first1=Gregory S.|last2=Snyder-Mackler|first2=Lynn|title=Physical Therapies in Sport and Exercise|url=https://books.google.com/books?id=2utRky2VO0UC&pg=PA223|accessdate=7 June 2013|year=2007|publisher=Elsevier Health Sciences|isbn=978-0-443-10351-3|page=223}}</ref>

===Vinegar===
{{main|Vinegar}}
Vinegar is typically 4–18% acetic acid by mass. Vinegar is used directly as a [[condiment]], and in the [[pickling]] of vegetables and other foods. Table vinegar tends to be more diluted (4% to 8% acetic acid), while commercial food pickling employs solutions that are more concentrated. The amount of acetic acid used as vinegar on a worldwide scale is not large, but is by far the oldest and best-known application.<ref>{{cite book|last1=Bernthsen|first1=A.|last2=Sudborough|first2=J. J.|title=Organic Chemistry|year=1922|publisher=Blackie and Son|location=London|page=155}}</ref>

==Reactions==

===Organic chemistry===

[[File:Acetic acid organic reactions.png|400px|Two typical organic reactions of acetic acid]]

Acetic acid undergoes the typical [[chemical reaction]]s of a carboxylic acid. Upon treatment with a standard base, it converts to metal [[acetate]] and [[water]]. With strong bases (e.g., organolithium reagents), it can be doubly deprotonated to give LiCH2CO2Li. Reduction of acetic acid gives ethanol. The OH group is the main site of reaction, as illustrated by the conversion of acetic acid to [[acetyl chloride]]. Other substitution derivatives include [[acetic anhydride]]; this [[anhydride]] is produced by [[Condensation reaction|loss of water]] from two molecules of acetic acid. [[Ester]]s of acetic acid can likewise be formed via [[Fischer esterification]], and [[amide]]s can be formed. When heated above {{convert|440|C|F}}, acetic acid decomposes to produce [[carbon dioxide]] and [[methane]], or to produce [[ketene]] and water:<ref>{{cite journal |title=The thermal decomposition of acetic acid |journal=Journal of the Chemical Society B Physical Organic |year=1968 |pages=1153–1155 |author1=P. G. Blake |author2=G. E. Jackson |doi=10.1039/J29680001153}}</ref><ref>{{cite journal |journal=Journal of the Chemical Society |year=1949 |title=608. The thermal decomposition of acetic acid |author1 = C. H. Bamford |author2=M. J. S. Dewar |doi=10.1039/JR9490002877 |pages=2877}}</ref><ref name="Duan1995">{{cite journal |last=Duan |first=Xiaofeng |author2=Michael Page |year=1995 |title=Theoretical Investigation of Competing Mechanisms in the Thermal Unimolecular Decomposition of Acetic Acid and the Hydration Reaction of Ketene |journal=Journal of the American Chemical Society |volume=117 |issue=18 |pages=5114–5119 |issn=0002-7863 |doi=10.1021/ja00123a013}}</ref>

:CH3COOH → CH4 + CO2
:CH3COOH → CH2CO + H2O

===Reactions with inorganic compounds===
Acetic acid is mildly [[corrosion|corrosive]] to [[metal]]s including [[iron]], [[magnesium]], and [[zinc]], forming [[hydrogen]] gas and salts called [[acetate]]s:
: Mg + 2 CH3COOH → (CH3COO)2Mg + H2
Because [[aluminium]] forms a [[Passivation (chemistry)|passivating]] acid-resistant film of [[aluminium oxide]], aluminium tanks are used to transport acetic acid. Metal acetates can also be prepared from acetic acid and an appropriate [[Base (chemistry)|base]], as in the popular "[[Sodium bicarbonate|baking soda]] + vinegar" reaction:
: NaHCO3 + CH3COOH → CH3COONa + CO2 + H2O

A [[colour reaction]] for salts of acetic acid is [[iron(III) chloride]] solution, which results in a deeply red colour that disappears after acidification.<ref name="Charlot">{{cite book|last1=Charlot|first1=G.|last2=Murray|first2=R. G.|title=Qualitative Inorganic Analysis|url=https://books.google.com/books?id=rzI9AAAAIAAJ&pg=PA110|edition=4|year=1954|publisher=CUP Archive|page=110}}</ref> A more sensitive test uses lanthanum nitrate with iodine and ammonia to give a blue solution.<ref name="Neelakantam">{{cite web|url=http://repository.ias.ac.in/33062/1/33062.pdf|title=The Lanthanum Nitrate Test for Acetatein Inorganic Qualitative Analysis|last=Neelakantam|first=K.|author2=L Ramachangra Row|year=1940|accessdate=5 June 2013}}</ref> Acetates when heated with [[arsenic trioxide]] form [[cacodyl oxide]], which can be detected by its [[odour|malodorous]] vapours.<ref name="Brantley1947">{{cite journal|last=Brantley|first=L. R.|author2=T. M. Cromwell|author3= J. F. Mead|year=1947|title=Detection of acetate ion by the reaction with arsenious oxide to form cacodyl oxide|journal=Journal of Chemical Education|volume=24|issue=7|page=353|issn=0021-9584|doi=10.1021/ed024p353|bibcode = 1947JChEd..24..353B}}</ref>

===Other derivatives===
Organic or inorganic salts are produced from acetic acid, including:
*[[Sodium acetate]], used in the [[textile]] industry and as a food [[preservative]] ([[E number|E262]]).
*[[Copper(II) acetate]], used as a [[pigment]] and a [[fungicide]].
*[[Aluminium acetate]] and [[iron(II) acetate]]—used as [[mordant]]s for [[dye]]s.
*[[Palladium(II) acetate]], used as a catalyst for organic coupling reactions such as the [[Heck reaction]].
*[[Silver acetate]], used as a [[pesticide]].

Substituted acetic acids produced include:
*[[Chloroacetic acid]] (monochloroacetic acid, MCA), dichloroacetic acid (considered a by-product), and [[trichloroacetic acid]]. MCA is used in the manufacture of [[indigo dye]].
*[[Bromoacetic acid]], which is esterified to produce the reagent [[ethyl bromoacetate]].
*[[Trifluoroacetic acid]], which is a common reagent in [[organic synthesis]].

Amounts of acetic acid used in these other applications together (apart from TPA) account for another 5–10% of acetic acid use worldwide. These applications are, however, not expected to grow as much as TPA production.<ref name='suresh'/>

==History==
[[Vinegar]] was known early in civilization as the natural result of exposure of [[beer]] and [[wine]] to air, because acetic acid-producing bacteria are present globally. The use of acetic acid in [[alchemy]] extends into the 3rd century BC, when the [[Greece|Greek]] philosopher [[Theophrastus]] described how vinegar acted on metals to produce [[pigment]]s useful in art, including ''white lead'' ([[lead carbonate]]) and ''[[verdigris]]'', a green mixture of [[copper]] salts including [[copper(II) acetate]]. Ancient [[Rome|Romans]] boiled soured wine to produce a highly sweet syrup called ''sapa''. [[Defrutum|Sapa]] that was produced in lead pots was rich in [[Lead(II) acetate|lead acetate]], a sweet substance also called ''sugar of lead'' or ''sugar of [[Saturn (mythology)|Saturn]]'', which contributed to [[lead poisoning]] among the Roman aristocracy.<ref name='martin'>{{cite book|last = Martin|first = Geoffrey|year = 1917|title = Industrial and Manufacturing Chemistry|edition = Part 1, Organic|location = London|publisher = Crosby Lockwood|pages=330–331}}</ref>

In the 16th-century [[Germany|German]] alchemist [[Andreas Libavius]] described the production of [[acetone]] from the [[dry distillation]] of lead acetate, [[ketonic decarboxylation]]. The presence of water in vinegar has such a profound effect on acetic acid's properties that for centuries chemists believed that glacial acetic acid and the acid found in vinegar were two different substances. French chemist [[Pierre Adet]] proved them identical.<ref name='martin'/><ref>{{cite journal|author=P. A. Adet|year=1798|title=Mémoire sur l'acide acétique (Memoir on acetic acid)|journal=Annales de Chemie|volume=27|pages=299–319}}</ref>
[[File:AceticAcid012.jpg|upright|thumb|left|alt=glass beaker of crystallised acetic acid|Crystallised acetic acid.]]
In 1845 German chemist [[Hermann Kolbe]] [[Chemical synthesis|synthesised]] acetic acid from [[inorganic compound]]s for the first time. This reaction sequence consisted of [[halogenation|chlorination]] of [[carbon disulfide]] to [[carbon tetrachloride]], followed by [[pyrolysis]] to [[tetrachloroethylene]] and aqueous chlorination to [[trichloroacetic acid]], and concluded with [[electrolysis|electrolytic]] [[organic redox reaction|reduction]] to acetic acid.<ref name='goldwhite'>{{cite journal|url = http://membership.acs.org/N/NewHaven/bulletins/Bulletin_2003-09.pdf|last = Goldwhite|first = Harold|journal = New Haven Section Bulletin American Chemical Society|volume = 20|issue = 3|date=September 2003|title = Short summary of the career of the German organic chemist, Hermann Kolbe|format=PDF}}</ref>

By 1910, most glacial acetic acid was obtained from the "pyroligneous liquor" from distillation of wood. The acetic acid was isolated from this by treatment with [[calcium hydroxide|milk of lime]], and the resulting [[calcium acetate]] was then acidified with [[sulfuric acid]] to recover acetic acid. At that time, Germany was producing 10,000 [[ton]]s of glacial acetic acid, around 30% of which was used for the manufacture of [[indigo dye]].<ref name='martin'/><ref name='schweppe'>{{cite journal|last = Schweppe|first = Helmut|year = 1979|url = http://aic.stanford.edu/jaic/articles/jaic19-01-003_1.html|title = Identification of dyes on old textiles|journal = Journal of the American Institute for Conservation|volume = 19|issue = 1/3|pages=14–23|doi = 10.2307/3179569|jstor = 3179569}}</ref>

Because both [[methanol]] and [[carbon monoxide]] are commodity raw materials, methanol carbonylation long appeared to be attractive precursors to acetic acid. [[Henri Dreyfus]] at [[British Celanese]] developed a methanol carbonylation pilot plant as early as 1925.<ref name='wagner'>{{cite book|last = Wagner|first = Frank S.|year = 1978|chapter = Acetic acid|editor-last = Grayson|editor-first = Martin|title = Kirk-Othmer Encyclopedia of Chemical Technology|edition = 3rd|location = New York|publisher = [[John Wiley & Sons]]}}</ref> However, a lack of practical materials that could contain the corrosive reaction mixture at the high [[pressure]]s needed (200 [[Atmosphere (unit)|atm]] or more) discouraged commercialization of these routes. The first commercial methanol carbonylation process, which used a [[cobalt]] catalyst, was developed by German chemical company [[BASF]] in 1963. In 1968, a [[rhodium]]-based catalyst (''cis''−[Rh(CO)2I2]−) was discovered that could operate efficiently at lower pressure with almost no by-products. US chemical company [[Monsanto Company]] built the first plant using this catalyst in 1970, and rhodium-catalyzed methanol carbonylation became the dominant method of acetic acid production (see [[Monsanto process]]). In the late 1990s, the chemicals company [[BP|BP Chemicals]] commercialised the [[Cativa process|Cativa]] catalyst ([Ir(CO)2I2]−), which is promoted by [[iridium]]<ref>[https://books.google.com.br/books?id=4KHzc-nYPNsC&pg=PA365&dq=Cativa+BP&hl=en&sa=X&ei=LYYZVZ5_jN2wBILkgqAK&ved=0CCsQ6AEwAA#v=onepage&q=Cativa%20BP&f=false Industrial Organic Chemicals], Harold A. Wittcoff, Bryan G. Reuben, Jeffery S. Plotkin</ref> for greater efficiency. This [[iridium]]-catalyzed [[Cativa process]] is [[Green chemistry|greener]] and more efficient<ref name='lancaster'>{{cite book|last = Lancaster|first = Mike|year = 2002|title = Green Chemistry, an Introductory Text|location = Cambridge|publisher = Royal Society of Chemistry|pages=262–266|isbn = 0-85404-620-8}}</ref> and has largely supplanted the Monsanto process, often in the same production plants.

===In the interstellar medium===
Acetic acid was discovered in the [[interstellar medium]] in 1996 by a team led by David Mehringer<ref name=Meh>{{Cite journal | display-authors=1 | last1=Mehringer | first1=David M. | last2=Snyder | first2=Lewis E. | last3=Miao | first3=Yanti | last4=Lovas | first4=Frank J. | title=Detection and Confirmation of Interstellar Acetic Acid | journal=Astrophysical Journal Letters | year=1997 | volume=480 | page=L71 | bibcode=1997ApJ...480L..71M | doi=10.1086/310612}}</ref> who detected it using the former Berkeley-Illinois-Maryland Association array at the [[Hat Creek Radio Observatory]] and the former Millimeter Array located at the [[Owens Valley Radio Observatory]]. It was first detected in the [[Sagittarius B2]] North molecular cloud (also known as the Sgr B2 [[Large Molecule Heimat]] source). Acetic acid has the distinction of being the first molecule discovered in the interstellar medium using solely [[Radio telescope#Radio interferometry|radio interferometers]]; in all previous ISM molecular discoveries made in the millimetre and centimetre wavelength regimes, single dish radio telescopes were at least partly responsible for the detections.<ref name=Meh/>

==Health effects and safety==
Concentrated acetic acid is [[corrosion|corrosive]] to skin and must, therefore, be handled with appropriate care, since it can cause skin burns, permanent eye damage, and irritation to the mucous membranes.<ref name="IPCS card">{{cite web | url=http://www.inchem.org/documents/icsc/icsc/eics0363.htm | title=ICSC 0363 – ACETIC ACID | publisher=International Programme on Chemical Safety | date=5 June 2010}}</ref><ref name=CDC>{{cite web | url=http://www.cdc.gov/niosh/docs/81-123/pdfs/0002-rev.pdf | title=Occupational Safety and Health Guideline for Acetic Acid | publisher=Centers for Disease Control and Prevention |accessdate=8 May 2013}}</ref> These burns or blisters may not appear until hours after exposure. [[Latex]] gloves offer no protection, so specially resistant gloves, such as those made of [[nitrile rubber]], are worn when handling the compound. Concentrated acetic acid can be ignited with difficulty in the laboratory. It becomes a flammable risk if the ambient temperature exceeds {{convert|39|C|F}}, and can form explosive mixtures with air above this temperature ([[explosive limit]]s: 5.4–16%).

Acetic acid is a strong eye, skin, and mucous membrane irritant. Prolonged skin contact with glacial acetic acid may result in tissue destruction. Inhalation exposure (eight hours) to acetic acid vapours at 10 ppm could produce some irritation of eyes, nose, and throat; at 100 ppm marked lung irritation and possible damage to lungs, eyes, and skin might result. Vapour concentrations of 1,000 ppm cause marked irritation of eyes, nose and upper respiratory tract and cannot be tolerated. These predictions were based on animal experiments and industrial exposure. Skin sensitization to acetic acid is rare, but has occurred.

It has been reported that, in 12 workers exposed for two or more years to an estimated mean acetic acid airborne concentration of 51 ppm, there were symptoms of conjunctive irritation, upper respiratory tract irritation, and hyperkeratotic dermatitis. Exposure to 50 ppm or more is intolerable to most persons and results in intensive lacrimation and irritation of the eyes, nose, and throat, with pharyngeal oedema and chronic bronchitis. Unacclimatised humans experience extreme eye and nasal irritation at concentrations in excess of 25 ppm, and conjunctivitis from concentrations below 10 ppm has been reported. In a study of five workers exposed for seven to 12 years to concentrations of 80 to 200 ppm at peaks, the principal findings were blackening and hyperkeratosis of the skin of the hands, conjunctivitis (but no corneal damage), bronchitis and pharyngitis, and erosion of the exposed teeth (incisors and canines).<ref>{{citation |publisher=Virginia Department of Health Division of Health Hazards Control |first=Peter C. |last= Sherertz |date=1 June 1994 |title=Acetic Acid |url=http://www.vdh.virginia.gov/epidemiology/DEE/PublicHealthToxicology/documents/pdf/aceticacid.PDF}}</ref>

The hazards of solutions of acetic acid depend on the concentration. The following table lists the [[Directive 67/548/EEC|EU classification]] of acetic acid solutions:<ref name="Yee13">{{cite web |url=http://hsis.safeworkaustralia.gov.au/downloads/HSIS%20Consolidated%20List%20-%20Alphabetical%20Index.xlsx |title=HSIS Consolidated List – Alphabetical Index|last=Yee|first=Allan|date=10 May 2013|publisher=Safe Work Australia|accessdate=11 June 2013}}</ref>


{| class="wikitable"
|-
! [[Concentration]] by weight
! Molarity
! Classification
! [[List of R-phrases|R-Phrases]]
|-
| 10–25%
| 1.67–4.16 mol/L
| Irritant ('''Xi''')
| {{R36/38}}
|-
| 25–90%
| 4.16–14.99 mol/L
| Corrosive ('''C''')
| {{R34}}
|-
| >90%
| >14.99 mol/L
| Corrosive ('''C''') Flammable ('''F''')
| {{R10}}, {{R35}}
|}

Solutions at more than 25% acetic acid are handled in a fume hood because of the pungent, corrosive vapour. [[Concentration|Dilute]] acetic acid, in the form of [[vinegar]], is practically harmless. However, ingestion of stronger solutions is dangerous to human and animal life. It can cause severe damage to the [[digestive system]], and a potentially lethal change in the acidity of the [[blood]].

Due to incompatibilities, it is recommended to keep acetic acid away from [[chromic acid]], [[ethylene glycol]], [[nitric acid]], [[perchloric acid]], [[permanganate]]s, [[peroxide]]s and [[hydroxyl]]s.<ref>{{cite web|url=http://www.sciencelab.com/msds.php?msdsId=9922769|title=Acetic acid MSDS|date=21 May 2013|accessdate=7 June 2013}}</ref>

==See also==
*[[Acetic acid (data page)]]
*[[Acetyl group]], the CH3-CO– group
*[[Acids in wine]]

==References==
{{Reflist|colwidth=30em}}


==External links==
{{wiktionary|acetic}}
{{commons}}
*{{ICSC|0363|03}}
*[http://www.npi.gov.au/substances/acetic-acid/index.html National Pollutant Inventory – Acetic acid fact sheet]
*[http://www.cdc.gov/niosh/npg/npgd0002.html NIOSH Pocket Guide to Chemical Hazards]
*[http://www.cdc.gov/niosh/docs/2003-154/pdfs/1603.pdf Method for sampling and analysis]
*[https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9992 29 CFR 1910.1000, Table Z-1] (US Permissible exposure limits)
*[http://chemsub.online.fr/name/Acetic_acid.html ChemSub Online: Acetic acid]
*Calculation of [http://ddbonline.ddbst.de/AntoineCalculation/AntoineCalculationCGI.exe?component=Acetic+acid vapor pressure], [http://ddbonline.ddbst.de/DIPPR105DensityCalculation/DIPPR105CalculationCGI.exe?component=Acetic+acid liquid density], [http://ddbonline.ddbst.de/VogelCalculation/VogelCalculationCGI.exe?component=Acetic+acid dynamic liquid viscosity], [http://ddbonline.ddbst.de/DIPPR106SFTCalculation/DIPPR106SFTCalculationCGI.exe?component=Acetic+acid surface tension] of acetic acid
* [http://www.ebi.ac.uk/pdbe-srv/PDBeXplore/ligand/?ligand=ACT Acetic acid bound to proteins] in the [[Protein Data Bank|PDB]]
*[http://apps.kemi.se/flodessok/floden/kemamne_eng/attiksyra_eng.htm Swedish Chemicals Agency. Information sheet – Acetic Acid]
* Process Flow sheet of Acetic acid Production by the [http://www.inclusive-science-engineering.com/processes-for-manufacturing-acetic-acid/acetic-acid/ Carbonylation of Methanol]
{{Gynecological anti-infectives and antiseptics}}
{{Otologicals}}
{{Fatty acids}}
{{Molecules detected in outer space}}

{{Authority control}}

{{DEFAULTSORT:Acetic Acid}}
[[Category:Acetates]]
[[Category:Acetic acids| ]]
[[Category:Acids in wine]]
[[Category:Antiseptics]]
[[Category:Flavors]]
[[Category:Household chemicals]]
[[Category:Otologicals]]
[[Category:Photographic chemicals]]
[[Category:Solvents]]
[[Category:World Health Organization essential medicines]]
[[Category:Commodity chemicals]]
[[Category:Alkanoic acids]]