ELECTROCHEMICAL BEHAVIOR OF 4,4'-AZOPYRIDINE-1,1'-DIOXIDE

The electroreduction of 4,4′-azobispyridine-1,1′-dioxide (APDO) in dimethylformamide solutions was studied by polarography, cyclic voltammetry, controlled potential coulometry, and electron spin resonance, Voltammetric reduction showed two well-defined, reversible one-electron transfers. Coulometric reduction at a potential corresponding to the plateau of the first wave gave evidence of chemical reactions following the initial electron transfer producing intermediates which were also electroactive at the same potentials. Coulometry at the second wave gave an over-all value of six Faradays per mole for the complete reduction of APDO to the dianion of azopyridine (AP), identified by electrochemical and electron spin resonance techniques. A mechanism for the reduction process consistent with the experimental evidence is presented. © 1968, The Electrochemical Society, Inc. All rights reserved.