Poly (benzonitrile-2,5-diyl) (PBN) was prepared conveniently starting with 2,5-dichlorobenzonitrile (DCB). Polymerization was carried out in the presence of nickel (0) catalyst. PBN was found to be soluble in DMF and DMSO at 140°C. A cast film of PBN exhibited both reduction and oxidation peaks clearly at −2.18 and −1.95 V vs. Ag/Ag + , respectively, in acetonitrile with Bu 4 NBF 4 as electrolyte. The amount of charge, Q, exchanged during the redox cycle was found to be 0.34 electron per monomeric unit, which suggests that PBN might be used as a charge storage material.