The electron transfer behavior of some new polymers with viologen structure on the reduction of azobenzene in heterophases

Several polymers with viologen structure were prepared by polymer analogous reaction with poly(vinyl alcohol) (PVA) and ethylcellulose (EC). The polymers were used as electron-transfer catalysts (ETC) for the reduction of azobenzene, either in a Zn-PV²⁺ system (reductant: Zn, in CH₃CN/H₂O) or a Na₂S₂O₄-PV²⁺ system (reductant: Na₂S₂O₄, in CH₂Cl₂/H₂O). It was found that all the polymers used in our work had the ability to mediate the reduction of azobenzene. Two factors (polymeric carrier and viologen group) are believed to affect the reduction.