Near-Infrared Electrochromism in Electroactive Pentacenediquinone-Containing Poly(aryl ether)s

The synthesis and near-infrared electrochromic properties of pentacenediquinone-containing monomers and polymers are reported. The electroactive pentacenediquinone units were incorporated into poly(aryl ether)s in varying degrees by copolymerization. The polymers possessed good thermal stabilities and high glass transition temperatures, and could undergo two reversible steps of electrochemical reduction. Near-infrared electrochromic properties of pentacenediquinone-containing poly(aryl ether)s were studied by spectroelectrochemical analysis, which showed that the radical anions possess intense near-infrared absorption with λ max values between 1331 and 1430 nm, while the dianions also exhibit absorption between 880 and 965 nm. The reduced polymer film displayed intense and broad near-infrared absorption, which was surprisingly stable in air over a long period. The neutral and reduced polymers had electrical conductivity of 1 × 10 - 6 and 3 × 10 - 3 S/cm, respectively.