ELECTROCHEMICAL STUDY OF POLYTHIONITE SOLUTIONS IN HMPA

Polythionite solutions Li(SO2)(n), prepared by chemical reduction of s ulfur dioxide by lithium, have been investigated by classical electroc hemical techniques (cyclic voltammetry, electrochemical impedance spec troscopy). The study of Li(SO2)-hexamethylphosphoramide (HMPA) solutio ns shows that the dithionite ion S2O42- is not electroactive, and conf irms that the concentration of SO2-. is very low in these solutions. T he study of Li(SO2)(n)-HMPA solutions with n > 1 allows to identify tw o redox couples: SO2/SO2-., and S2O4/S2O4-., and some of the homogeneo us chemical reactions coupled to these electron transfers. (C) 1997 El sevier Science S.A.