New, Highly Stable Electrochromic Polymers from 3,4-Ethylenedioxythiophene−Bis-Substituted Quinoxalines toward Green Polymeric Materials

Abstract

Two new highly stable electrochromic polymers, poly(5,8-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-2,3-di(thiophen-2-yl)quinoxaline) (PDETQ) and poly(5,8-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)quinoxaline) (PDEQ) were synthesized, and their potential use as neutral state green polymeric materials was investigated. Spectroelectrochemistry showed that both polymers reveal two distinct absorption bands as expected for this type of donor–acceptor polymer, at 410 and 660 nm for PDEQ and 405 and 780 nm for PDETQ. The colorimetry analysis revealed that while PDEQ has a green-blue color, PDETQ showed a saturated green color in the neutral state which is a unique property of conjugated polymers for the completion of the RGB color system. Both polymers have excellent switching properties with satisfactory optical contrasts and very fast switching times. In addition, via both electrochemical and spectral analyses PDETQ was proven to be an n-type dopable polymer. Outstanding optical contrasts in the NIR regi...