Electron-transfer processes in the reaction of K-, K+(15-crown-5)(2) with carbazole: unexpected formation of metallic potassium

Transfer of one electron from K- to the aromatic ring occurs in the reactio n of K-, K+(15-crown-5)(2) with carbazole giving K degrees and a radical an ion. The latter rapidly decomposes with the liberation of hydrogen and form ation of carbazylpotassium. It can also undergo an intramolecular proton-ex change reaction followed by a transfer of the second electron from the part of K degrees product. That leads to a dianion which then reacts with anoth er carbazole molecule. Finally, carbazylpotassium and 1,4-dihydrocarbazylpo tassium are formed. (C) 2000 Elsevier Science S.A. All rights reserved.