Electroreduction of Substituted Naphthylhydrazones in DMSO

Abstract

Studies on the electroreduction of 4‐chloro‐1‐naphthylhydrazonodimedone (4‐Cl‐1‐NHD), 4‐sulpho‐1‐naphthylhydrazonodimedone (1‐NHD‐4‐SO3H) and 2‐hydroxy‐4‐sulpho‐1‐naphthylhydrazonodimedone (2‐OH‐1‐NHD‐4‐SO3H) have been carried out in 0.1 M TEAI‐DMSO using various electrochemical techniques. Each depolariser exhibits three polarographic dc waves, ac peaks or CV peaks, respectively, the nature of which have been discussed. Further, from the results of microcoulometry and macroscale cpe. a complex mechanism has been suggested for the electroreduction of these hydrazones. The mechanism has been supported by in‐situ EPR measurements, evaluations of the charge‐transfer rate constants and chromatographic analysis (by TLC and HPLC) on the products of macroscale cpe.