Synthesis and electrochromic properties of a methacrylate polymer containing pendant terthiophene

A new methacrylate polymer containing terthiophene as a pendant group, poly[(2,2′:5′,2″-terthiophen-5-y) methyl methacrylate], has been prepared by radical polymerization of the corresponding monomer and its electrochromic properties have been examined. Electrochemical oxidation of the polymer in the presence of tetra-n-butylammonium perchlorate produced a purple-colored electrochemically doped polymer, which was identified as a radical-cation salt of pendant terthiophene with ClO4− as a dopant. The polymer undergoes a reversible clear color change from pale yellow to purple and vice versa on electrochemical doping and dedoping and is expected to be a potential electrochromic material.