Polymers containing pendant oligothiophenes as a novel class of electrochromic materials

Vinyl polymers containing oligothiophenes, e.g. 2,2′ : 5′,2″-terthiophene and 2,2′ : 5′,2″ : 5″,2‴-quaterthiophene, as pendant groups have been found to constitute a novel class of potential electrochromic materials. The electrochemically doped polymers undergo reversible, clear colour changes from bluish purple to pale yellowish orange, and from green to pale yellow, respectively, and vice versa on electrochemical dedoping and doping.