Electropolymerization of D-A type EDOT-based monomers consisting of camphor substituted quinoxaline unit for electrochromism with enhanced performance

In this study, three novel donor-acceptor type monomers based on EDOT (3,4-ethoxylene dioxy thiophene) and quinoxaline derivates were designed and synthesized through Stille coupling reaction, and further polymerized by electrochemical polymerization for electrochromic application. Specially, a quinoxaline-based acceptor with bulky and rigid camphor group was introduced into the polyEDOT backbone, which was demonstrated to be effective for the improvement of electrochromic performance. The corresponding redox active polymers PCQ-EDOT and PCQ-DEDOT performed transparent oxidation states and robust switching stability. Polymer PCQ-EDOT showed superior electrochromic performances with high optical contrast (over 50%) at 647 nm, short switching time (around 0.5 s) and high coloration efficiency (427 cm2 C−1) under a low applied potential of 0.7 V.