Collect. Czech. Chem. Commun. 1989, 54, 1496-1507

Electrochemical reduction of benzenediazonium salts in aprotic medium

Pavel Janderka and Igor Cejpek

Department of Theoretical and Physical Chemistry, J. E. Purkyně University, 611 37 Brno


DC polarography, TAST polarography, differential pulse polarography, polarography with superimposed alternating current, slow cyclic voltammetry with a hanging Hg drop electrode and a Pt electrode, rapid cyclic voltammetry with a hanging Hg drop, and coulometry were used to study the electrochemical reduction of p-methoxy- and p-nitrobenzenediazonium cations in aprotic medium. A reduction mechanism involving two separate one-electron steps is proposed, the first of which being complicated by adsorption and follow-up chemical reaction leading to evolution of nitrogen. The basicity of the aprotic solvents, expressed by donor numbers according to Gutman, influences the reduction mechanism of these cations.