In this study, bis(thiophene)-bis(ethylenedioxythiophene)-3,3'-dinonylthiazole (ThEdNBTEdTh) comonomer was obtained by using organometallic polycondensation mediated by organotransition metal complexes. The properties of electrochemically obtained poly[bis(thiophene)-bis(ethylenedioxythiophene)-3,3'-dinonylthiazole] (P[ThEdNBTEdTh]) from this comonomer were characterized by electrochemical techniques such as voltammetry and electrochemical impedance spectroscopy (EIS). Oxidative polymerization of ThEdNBTEdTh was carried out in dichlorometane onto a platinum electrode. Effect of polymerization charge on the redox behaviour of polymer films was investigated and these films were further characterized by ATR-FTIR, UV-Visible and fluorescence spectrophotometric measurements. EIS studies revealed that high capacitance values observed in the lower frequency region and proposed electrical equivalent circuit was applied to the experimental data to correlate the results, obtain the parameter of each element and explain the interface between the Pt/P[ThEdNBTEdTh/Bu4NPF6 system. Results showed that polymer has low oxidation potential, low band gap (1.67 eV) and good stability in the oxidized state and it shows p- and n-dopable properties. n-doping was verified experimentally by ex-situ FT-IR spectroelectrochemical measurements. The measured capacitance values are quite promising for supercapacitor applications. (C) 2014 Elsevier Ltd. All rights reserved.