Electrochemical behaviour of 2-nitrobenzidine in N,N-dimethylformamide

Electrochemical reduction of 2,4,6-trinitro diphenylamine in buffered and unbuffered methanolic solutions

2,2′-dinitrobenzidine (2,3′-DNB) gives a single diffusion-limited irreversible polarographic wave in buffered aqueous methanol. Microcoulometric experiments indicate a transfer of ten electrons in the reduction and cyclic voltammetric studies show direct proof for the existence of a nitroso intermediate. Based on the results obtained, a suitable mechanism is proposed for the reduction of 2,3′-DNB in buffered methanolic solutions.

Electrochemical reduction of 2,3'-dinitrobenzidine in buffered aqueous methanol

The electroreduction of 2-nitrobenzidine (2-NB) in buffered methanol-water mixtures in the composition range 20–80% (v/v) and pH range 2.80–12.00 gave a single six-electron diffusion-controlled irreversible wave. On the basis of the results obtained, a diphenoquinone-diimine intermediate is suggested in the mechanism of 2-NB reduction in methanol-water mixtures.

Electrochemical reduction of 2-nitrobenzidine in methanol-water mixtures

Two six-electron diffusion-controlled irreversible waves are obtained for the polarographic reduction of 2,4-dinitrodiphenylamine (DPA) in buffered and unbuffered media in all compositions of methanol-water mixtures. Based on the polarographic and coulometric data, it is suggested that each of the nitro groups is reduced to the corresponding amine in a single stepvia the diimine intermediate to give 2,4-diamino DPA as the final product. The influence of various factors such as structure of the depolariser, pH and composition of methanol on the reduction of the compound is also discussed.

C. Kalidas

Papers

Polarography of 4-nitrodiphenylamine (DPA) in methanol-water mixtures⋆