Electrochemical copolymerization of 3-octyloxy-4-methylthiophene (OOT) and 1-[6-[(4-methyl-3-thienyl) oxy] hexyl]-4-cyanopyridinium bromide (HOT-CNP) was carried out using tetrabutylammonium hexafluorophosphate and acetonitrile (TBAPF(6)/ACN) as electrolyte. The cyanopyridine functionalized HOT-CNP undergoes further electrochemical reductive coupling to viologen. Both polymer (POUT) and copolymer P(OOT-co-HOT-CNP) were characterized by cyclic voltammetry (CV), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and in situ UV-vis spectroscopy. The effect of the monomer concentration ratio and the scan rate on the electrochemical properties of the copolymer was studied by the CV technique. The electrochemical redox response of the copolymer together with FIR analysis further confirms the formation of viologen. The surface morphology was studied using SEM analysis. The polymer POUT revealed color changes between violet and bright blue, whereas the copolymer showed the most vivid change of color between purple and greenish blue in its fully reduced and oxidized states respectively. The results showed that copolymerization is a valuable approach in order to achieve desired electrochromic and redox properties. (C) 2013 Elsevier Ltd. All rights reserved.