Anodic Oxidation of Aniline in Aqueous Alkaline Solution

Abstract

Abstract The anodic oxidation of aniline in an aqueous alkaline solution was studied. The anode materials were Ni, C, Pt, and Pb. An organic deposit (film) was formed on the anodes. The reaction mechanism was estimated through electrochemical measurements, chemical analysis, thin-layer chromatography, and UV, NMR, and IR spectrometries. The de-electronation of lone-pair electrons of the N atom in an aniline molecule caused the radical cation to be produced, (Remark: Graphics omitted.), and this process was the rate-determining step. Some of the radical cations were found to couple together to produce azo-benzene via hydrazobenzene. The other radical cations led to p-amino diphenylamine by head-to-tail coupling; this product was de-electronated again to give the polymer with a quinoid structure.