PPV-Based n-Type Conjugated Polymer

Significance

PPV-based homopolymer 4 bearing two cyano units and two symmetrical alkoxyl groups on the phenyl ring was prepared by Stille coupling. The electrochemical cyclic voltammogram of the polymer showed distinct reversible reduction/reoxidation redox peaks with an onset reduction potential of -1.06 V vs Ag/Ag⁺. UV-vis absorption spectra of the polymer film showed the decrease of the visible absorption peak and the appearance of two NIR absorption peaks after the reduction, which confirms the reversible and stable n-doping/dedoping processes of the polymer. The polymer film also showed a reversible color change between red (at neutral state) and gray (at reduced state), further supporting that polymer 4 is a novel n-type conjugated polymer with strong electron-accepting ability and electrochromic property in the n-doping potential region.