Electrosynthesis of a New Indole Based Donor-Acceptor Type Polymer and Investigation of Its Electrochromic Properties

Abstract

The purpose of this research is to synthesize a novel monomer, namely, 1-mety1-2,3-di(thiophen-2-y1)-1H-indole (DTI) and to present optical and electrochemical characterization of its corresponding polymer film, P(DTI). The donor thiophene unit was matched with acceptor indole unit in consideration of donor acceptor-donor approach in order to achieve DTI monomer. This monomer was electropolymerized in the medium 0.1 M LiClO4/Ethanol:ACN solution mixture and a conductive indole based polymer, P(DTI) was obtained. The spectroelectrochemical studies show that P(DTI) has a band gap of 2.45 eV and a color change from pale green to dark green with a switching time of 0.9 s during oxidation and a high coloration efficiency (286 cm(2)/C) at 830 nm. Furthermore, P(DTI) shows good environmental and redox stability with a retention of 85% after 1500th switching. (C) 2016 Elsevier B.V. All rights reserved.