A promising combination of benzotriazole and quinoxaline units: A new acceptor moiety toward synthesis of multipurpose donor–acceptor type polymers

By combining benzotriazole and quinoxaline units in an acceptor unit, three novel monomers, 2-dodecyl-6,7-diphenyl-4,9-di(thiophen-2-yl)-2H-[1,2,3]triazolo[4,5-g]quinoxaline (M1), 2-dodecyl-4,6,7,9-tetra(thiophen-2-yl)-2H-[1,2,3]triazolo[4,5-g]quinoxaline (M2) and 6,7-bis(4-tert-butylphenyl)-2-dodecyl-4,9-di(thiophen-2-yl)-2H-[1,2,3]triazolo[4,5-g]quinoxaline (M3), were synthesized and polymerized electrochemically. All polymers revealed both p- and n-type doping properties under ambient conditions. As found by spectroelectrochemical studies they have small band gaps, ca. 1.00 eV. The polymers revealed two distinct absorption bands as all green coloured neutral state donor–acceptor–donor type polymers should have. Besides this, all have broad absorptions covering the region between 700 nm and 1000 nm which is rarely seen in electrochromic polymers. Due to these promising features, they are considered to be potential materials for optoelectronics.