CYCLIC VOLTAMMETRY, ESR AND SPECTRAL INVESTIGATION OF THE ELECTROCHEMICAL REDUCTION OF SOME ACETYL DIPHENYLSULPHIDES AND SULFONES

The electrochemical reduction in dimethylsulphoxide of five mono- and diacetyl derivatives of diphenylsulphide and diphenylsulphone was inve stigated by means of cyclic voltammetry, ESR spectroscopy and optical spectroscopy. In all cases the first reduction step corresponds to a r eversible monoelectronic transfer and leads to the formation of an ani on radical which is stable enough to be detected by in-situ ESR and op tical spectroscopy. The electronic structure of the anion radical and the follow-up reactions are determined by the acetyl substituent and o nly influenced slightly by the degree of oxidation of the sulphur atom . Semi-empirical MO calculations in the frame of the AM1 method provid e a good description of the main trends observed experimentally.