Electrochemical investigations on poly(arylene-1,3,4-oxadiazole)s

Electrochemical doping processes of aromatic poly(1,3,4-oxadiazoie)s in aceto nitrile/Bu(4)NBF(4) have been studied to characterize the charge and discharge properties of these polymers. Cyclic voltammograms were measured of thin poly(arylene-1,3,4-oxadiazole) films on glassy carbon, Pt and ITO glasses. The reduction potential values E(red) as well as the reoxidation peaks E(reox) were shifted to lower potentials if the phenylene unit in the main chain was replaced by naphthylene, biphenylene and thienylene units, owing to their mesomeric effects. The mesomery of the pyridine unit in poly(pyridinediyl-1,3,4-oxadiazole)s also had a significant influence on the electrochemical reduction behaviour. All polymers showed an electrochemical inactivity or an irreversible oxidation behaviour in the anodic sweep region. In situ u.v.-vis absorption measurements of poly[(naphthylene-2,6)-1,3,4-oxadiazole] P(N-2,6 .. OD) coated on ITO-glasses showed the formation of excited electronic states such as polarons and bipolarons.