The polarography of some substituted azobenzenes in acetonitrile. V. The effects of weak proton donors

Abstract

The polarographic behaviour observed on addition of the weak proton donors, water and diethyl malonate, to azobenzene derivatives in acetonitrile is reported. Polarographic and direct spectroscopic kinetic studies were carried out in an attempt to establish the mechanism of the reduction process giving rise to the observed enhancement of the first reduction wave. A disproportionation- regeneration mechanism with the rate-controlling step being the protonation of the monoanion is indicated by the direct spectroscopic kinetic studies but the polarographic results do not lead to an unambiguous mechanism for the electrode reactions.