Utilizing electrochemical reduction of pendant cyanopyridinium ions to cross-link polymeric viologens is well known. In this work, we report electrosynthesis of a thiophene monomer bearing a pendant cyanopyridine moiety in its side chain (Th-CN). Its electropolymerization results in the growth of a polythiophene film which is highly cross-linked by the viologen unit (PTh-V). In order to improve adhesion and insolubility of the as-formed polymer film, we choose the ionic liquid 1-butyl-3 methylimidazolium hexafluorophosphate (BmimPF(6)), as electrolyte. The obtained polymer film was studied by cyclic voltammetry, FTIR spectroscopy, in situ UV-Vis spectroelectrochemistry and electrochemical impedance spectroscopy (EIS). The CV results showed electrochemical activity both of the viologen and polythiophene moieties. FTIR spectra of the polymer film confirm the formation of viologen by disappearance of the-CN stretching band from the polymer spectrum. EIS studies revealed that both resistive as well as capacitive element controls the charge transfer mechanism. In situ spectroelectrochemical studies of the polymer film shows enhanced electrochromic contrast of polythiophene film due to incorporation of viologen pendant group with coloring characteristics both of the viologen and the polythiophene backbone. An n-doped polymer is a dark blue colored film with coloration efficiency being ca. 97 cm(2)/C at 625 nm while the p-doped polymer is transparent violet in color with coloration efficiency of ca. 12 cm(2)/C at 775 nm. The results showed that the PTh-V film can be used as redox active conducting layer to develop dynamic optoelectronic and electrochromic devices. (C) 2014 Elsevier Ltd. All rights reserved.