Electrochemical, optical and electrochromic properties of imine polymers containing thiophene and carbazole units

New imine polymers containing thiophene and carbazole moiety were synthesized by using both chemically oxidative in the presence of FeCl3 and electrochemically oxidative process. While UV–vis, FT-IR, 1H- and 13C NMR techniques were used for the structural characterization, the number-average molecular weight (Mn), weight-average molecular weight (Mw) and polydispersity index (PDI) values were determined by size exclusion chromatography (SEC). The highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO) energy levels, electrochemical (E′g)(E′g) and optical band gap (Eg) values were calculated by using the results of cyclic voltammetry and UV–vis absorption spectroscopy measurements, respectively. Spectroelectrochemical measurements were carried out against the changes in the optical properties of conducting polymers upon voltage changed. Also the yellow color of film changed to green color with applied potential. Conductivities of these polymers were determined by using four-point probe technique. It was seen that the conductivities were increased by iodine doping.