Synthesis and characterization of a new conducting polymer based on 4‐(2,5‐di‐2‐thiophen‐2‐yl‐pyrrol‐1‐yl)‐phthalonitrile

A new conducting polymer was synthesized by electrochemical polymerization of 4‐(2,5‐di‐2‐thiophen‐2‐yl‐pyrrol‐1‐yl)‐phthalonitrile (SNS‐PN). Electrochemical polymerization of SNS‐PN was performed in acetonitrile/0.2M LiClO₄ solvent/electrolyte couple. Characterizations of the resulting polymer P(SNS‐PN) were carried out by cyclic voltammetry, UV–vis, and Fourier transform infrared (FTIR) spectroscopic techniques. Spectroelectrochemical studies revealed that P(SNS‐PN) has an electronic band gap of 2.45 eV and exhibits electrochromic behavior. The switching ability of polymer was also monitored and the percentage transmittance change (ΔT%) was found as 24%. It is also found that P(SNS‐PN) is fluorescent and its fluorescence intensity enhances in the presence of cations. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009