The polarography of some substituted azobenzenes in acetonitrile. IV. The effect of 'intermediate' strength proton donors

Abstract

The addition of proton donors to azobenzene derivatives in the aprotic solvent acetonitrile gives rise to polarographic waves at more positive potentials than the normal azo reduction waves. These waves have been ascribed to the reduction of azonium species formed by protonation of the azo compound. For the ?intermediate? strength proton donors (e.g. acetic acid) the azonium wave exhibits definite splitting which can be explained in terms of mixed general and specific protonation steps prior to the reduction of the azonium species. Evidence to support the mixed general and specific protonation effects is presented.