THEORETICAL-STUDY OF THE ELECTROREDUCTION OF HALOGENATED AROMATIC-COMPOUNDS .2. BROMINE AND CHLORINE DERIVATIVES IN DIFFERENT ORGANIC-SOLVENTS

The electrochemical dehalogenation of a variety of halogenated aromatic compounds is studied by means of semiempirical (AM1) and ab initio (ROHF 3-21G*) calculations. Comparison of the electrochemical half-wave potential values (E1/2) and calculated theoretical indices indicates the formation of a pi radical following the electron uptake. Moreover, the relationship observed between the half-wave potential, in dimethylformamide (DMF) and dimethyl sulfoxide (DMSO), and the electron affinity suggests that the reduction potential is determined by the first electron uptake and that kinetic factors play a minor role, their influence being constant or negligible.