OXIDATION AND HOMOLYTIC COUPLING REGIOSELECTIVITY OF CARBAZOLE IN ACIDIC MEDIA

Using voltammetric technique with a rotating disk electrode, the anodi c oxidation of carbazole in aqueous H2SO4 - ethanol mixtures was shown to proceed under diffusion and electron transfer control conditions. Electro-oxidation involves one electron transfer; electrode passivatio n occurs due to the formation of a poorly soluble product. By means of the SCF MO LCAO INDO, AM1-UHF and PM3-UHF methods, oxidative coupling regioselectivity for carbazole has been elucidated. Chemical oxidatio n of carbazole by ammonium vanadate in sulphuric acid medium features the stoichiometry 1 : 2, first order in substrate and first order in o xidant, and leads to the occurrence of the diimine dication of carbazo le.