ELECTROCHEMICAL BEHAVIOUR OF 2,2 prime -DINITROBENZIDINE IN AQUEOUS METHANOL.

The electrochemical reduction of 2,2 prime -dinitrobenzidine at a mercury cathode in buffered methanolic solutions at various compositions of methanol and pH gave a single wave which was found to be diffusion-controlled and irreversible on the basis of the usual criteria. Controlled-potential electrolysis experiments carried out at the limiting region of the wave gave a total of ten electrons in acidic and neutral media while eight electrons were obtained in alkaline medium. The presence of 3,8-diaminobenzo(c)-cinnoline-5-oxide is evidenced from cyclic voltammetric studies. A mechanism is suggested for the reduction of 2,2 prime -dinitrobenzidine in different buffered aqueous methanol media.