Kolbe electrolysis
The Kolbe electrolysis or Kolbe reaction is an organic reaction named after Hermann Kolbe.[1] The Kolbe reaction is formally a decarboxylative dimerisation of two carboxylic acids (or carboxylate ions). The overall reaction is:
If a mixture of two different carboxylates are used, all combinations of them are generally seen as the organic product structures:
- 3 R1COO− + 3 R2COO− → R1−R1 + R1−R2 + R2−R2 + 6 CO2 + 6 e−
The reaction mechanism involves a two-stage radical process: electrochemical decarboxylation gives a radical intermediate, which combine to form a covalent bond.[2] As an example, electrolysis of acetic acid yields ethane and carbon dioxide:
- CH3COOH → CH3COO− → CH3COO· → CH3· + CO2
- 2CH3· → CH3CH3
Another example is the synthesis of 2,7-dimethyl-2,7-dinitrooctane from 4-methyl-4-nitrovaleric acid:[3]
Further reading
- Kolbe, Hermann (1848). "Zersetzung der Valeriansäure durch den elektrischen Strom" [Decomposition of valeric acid by an electric current]. Annalen der Chemie und Pharmacie. 64 (3): 339–341. doi:10.1002/jlac.18480640346.
- Kolbe, Hermann (1849). "Untersuchungen über die Elektrolyse organischer Verbindungen" [Investigations of the electrolysis of organic compounds]. Annalen der Chemie und Pharmacie. 69 (3): 257–294. doi:10.1002/jlac.18490690302.
gollark: Do you mean you actually focused on those things in some way and you think school usefully taught them, or they just did classes which claimed to be helpful for those?
gollark: As if it can't mess those up too.
gollark: Also "point them at walls and do not let people go in front of them".
gollark: Very basic laser safety is under physics here, since you use lasers in some practicals.
gollark: There are many things people should know. But some of them school is effectively unable to teach, and others really should be easy to learn independently for competent sane people.
See also
References
- Utley, James (1997). "Trends in Organic Electrosynthesis". Chemical Society Reviews. 26 (3): 157. doi:10.1039/cs9972600157.
- Vijh, A. K.; Conway, B. E. (1967). "Electrode Kinetic Aspects of the Kolbe Reaction". Chem Rev. 67 (6): 623–664. doi:10.1021/cr60250a003.
- Sharkey, W. H.; Langkammerer, C. M. (1973). "2,7-Dimethyl-2,7-dinitrooctane". Organic Syntheses.; Collective Volume, 5, p. 445
External links
- "Kolbe Electrolysis". Organic Chemistry Portal. Retrieved 22 October 2007.
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