Evidence for the formation of radical anion in the reductive cleavage of carbon-bromine bond in 4′-bromomethylbiphenyl-2-carbonitrile

Electrochemical reduction of 4′-bromomethylbiphenyl-2-carbonitrile at glassy carbon electrodes is studied wherein the cleavage of carbon-bromine bond occurs in a single step in general. With increase in the driving force of the reaction, an unusual bell-shaped variation of the transfer coefficient with logarithmic scan rate has been observed, indicating the possibility of radical anion of 4′-bromomethylbiphenyl-2-carbonitrile as the intermediate. The finer details of the reduction have been studied by the convolution analysis of the voltammetric data and the reorganization energy of the reaction obtained at higher scan rates establishes the formation of radical anion of 4′-bromomethylbiphenyl-2-carbonitrile.