Synthesis, characterization, and electrochromic properties of conducting poly(hexanedioic acid bis-(2-thiophen-3-yl-ethyl ester) and its copolymer with thiophene

Hexanedioic acid bis-(2-thiophen-3-yl-ethyl) ester (HABTE) was synthesized via the reaction of 3-thiophene ethanol with adipoyl chloride. Resulting monomer was electrochemically homopolymerized in the presence of tetrabutylammonium tetrafluoroborate as the supporting electrolyte, in acetonitrile/borontrifloride ethylether solvent mixture (8:2, v/v). Copolymerization in the presence of thiophene was achieved in TBAFB/AN. Resulting homo and copolymers were characterized via CV, FTIR, DSC, TGA, SEM, and UV-vis Spectroscopy. Spectroelectrochemistry analysis of homopolymer, P(HABTE), reflected electronic transitions at 385, 600, and 900 nm, revealing pi-pi* transition, polaron, and bipolaron band formation, respectively. Switching ability of the homopolymer was evaluated by a kinetic study upon measuring the %T at the maximum contrast point, indicating that PHABTE is a potential material for electrochromic devices. (C) 2004 Elsevier B.V. All rights reserved.