The Use of Simple Molecular Orbital Theory to Elucidate the Polarographic Behaviour of Some para-Substituted Benzonitriles

Abstract

The nature of the polarographic reduction of the para-substituted benzonitriles I–VI depends strongly on the para substituent. The first reduction step could involve cleavage of the C—C bond, which leads to CN⁻ formation, or reduction of the cyano group to a−CH=NH function, or reduction of the para-substituted group. The experimental results obtained with compounds I–VI are compared with the squares of the expansion coefficients of the lowest free molecular orbital and with their bond orders before and after an uptake of two electrons.