Electrochemical Behaviour of Nitrobenzene, Nitrosobenzene, Azobenzene, and Azoxybenzene on Hg, Pt, Cu, and Ni Electrodes in Aprotic Medium

The electrochemical behaviour of nitrobenzene and other members of the nitrobenzene family (nitrosobenzene, azoxybenzene, azobenzene) has been investigated in DMF/TEAP by cyclic voltammetry, polarography, and controlled potential electrolysis at mercury, platinum, copper, and nickel cathodes. At the four electrodes, nitrobenzene and the other members of the family are reduced to aniline via hydrazobenzene upon exhaustive electrolysis at -2.35V vs. Ag/AgNO3 (0,05M). The electrochemical reversibility of the nitrobenzene/nitrobenzene radical anion and of the azoxybenzene/azoxybenzene radical anion couples is decreased by the presence of oxides at the surface of copper and nickel. The presence of oxides has little influence on the reversibility of the nitrosobenzene/nitrosobenzene radical anion and azobenzene/azobenzene radical anion couples.