Search for a One-Electron Reduction of the Cation Radical of an “Extended Viologen,” p-Phenylene-bis-4, 4 ′ -(1-Aryl-2,6-Diphenylpyridinium)

Abstract

Electrochemical one-electron reduction of the “extended viologen” dication proceeds reversibly at (vs electrode) to yield the red cation radical , which readily produces a dark-blue dimer hindering the observation of the one-electron reduction of . The second reduction step at seen by conventional electrochemical methods then corresponds to the reduction of a dimer . Fast cyclic voltammetry at scan rates up to kV/s and voltammetry at micromolar concentrations eliminate the coupled bimolecular chemical reactions and permit the determination of the reduction potential of the cation radical .