Dendronized electrochromic polymer based on poly(3,4-ethylenedioxythiophene)

Abstract

In order to improve electrochromic contrast, 3,4-ethylenedioxythiophene (EDOT) substituted with the first generation dendritic wedge based on gallic acid ( M2) was synthesized by connecting 3,4,5-tribenzyloxy benzyl chloride to hydroxymethyl EDOT ( M1). Electropolymerization of M1 and M2 resulted in the formation of an electroactive and well adhered film on the electrode surface. In the case of PEDOT substituted with the dendritic wedge ( P2), it was observed that the resistance of the film increases with thickness. Spectroelectrochemical studies indicated that the polymers switch from a highly opaque dark-blue reduced state to highly transmissive oxidized state with a contrast of 67% in P2 and 46% in P1. In situ conductivity studies showed a sharp transition from a dedoped insulating state to doped conducting state at around −0.4 V with maximum in situ conductance of 0.06 S for P1 and 0.04 S for P2.