The Reaction Mechanism of p-Toluenediamine Anodic Oxidation:An In Situ ESR-UV/Vis/NIR Spectroelectrochemical Study

摘要

In situ ESR-UV/Vis spectroelectrochemistry is applied to obtain new insights into the intermediates and reaction products of the anodic oxidation of p-toluenediamine in aqueous solution at different pH values.A strong phi dependence of the stability of the cation radical is found.While the absence of a stable radical was proved by ESR spectroscopy at pH 2 and 10,this radical is detect-ed at medium pH values and assigned to the semiquinonediimine structure.The UVA/is absorption of the radical is observed at these pH values as well.The p-toluenediimine intermediate and the trimeric reaction product were followed during the electrode reaction by UV/Vis spectroscopy at all pH values.