Physics:Kolbe electrolysis

Short description: Organic reaction

The Kolbe electrolysis or Kolbe reaction is an organic reaction named after Hermann Kolbe. 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. 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:

Further reading

• {{cite journal

| title = Zersetzung der Valeriansäure durch den elektrischen Strom
|trans-title= Decomposition of valeric acid by an electric current
| first = Hermann |last= Kolbe
| journal = Annalen der Chemie und Pharmacie
| year = 1848
| volume = 64
| issue = 3
| pages = 339–341
| url = https://babel.hathitrust.org/cgi/pt?id=uiug.30112025847739;view=1up;seq=353
| doi =  10.1002/jlac.18480640346

• {{cite journal

| title = Untersuchungen über die Elektrolyse organischer Verbindungen
|trans-title= Investigations of the electrolysis of organic compounds
| first = Hermann |last= Kolbe
| journal = Annalen der Chemie und Pharmacie
| year = 1849
| volume = 69
| issue = 3
| pages = 257–294
| url = https://babel.hathitrust.org/cgi/pt?id=hvd.hx3bh3;view=1up;seq=271
| doi =  10.1002/jlac.18490690302

See also

• Electrosynthesis
• Wurtz reaction

External links

• "Kolbe Electrolysis". Organic Chemistry Portal. https://www.organic-chemistry.org/namedreactions/kolbe-electrolysis.shtm. Retrieved 2007-10-22.