Self-decarboxylation of trichloroacetic acid redox catalyzed by trichloroacetate ions in acetonitrile solutions.

In mixtures of trichloroacetate ion and trichloroacetic acid in acetonitrile, trichloromethyl radicals are produced as a result of the redox reaction between the acid and its conjugate base. The reaction follows a loop mechanism in which the trichloroacetic acid is slowly consumed by proton reduction while the trichloroacetate ion is oxidized like in an electrochemical Kolbe reaction. The hydroquinone-trichloroacetate complex was a good sensor of this unexpected self-decarboxylation redox reaction.