Electrosynthesis Of Poly(1H-benzo[g]indole) And Investation Of The Electrochromic Properties

The preparation of polyindoles and their electrochromic properties have been oneof the focuses on the investigation of conducting polymers. Electrochemicalpolymerization has been proved to be one of the most useful approaches forconducting polymer synthesis. In this dissertation, the electrochemical polymerizationand characterizations of poly(1H-benzo[g]indole)(PBIn) films were investigated, andthe electrochromic properties and its application in electrochromic devices of theas-formed polymers were also studied.1. High-quality free-standing poly(1H-benzo[g]indole)(PBIn) films weresynthesized electrochemically by direct anodic oxidation of1H-benzo[g]indole (BIn)in boron trifluoride diethyl etherate (BFEE). PBIn films obtained from this mediumshowed good electrochemical behavior and good thermal stability with a conductivityof0.29S cm-1. PBIn films were insoluble in water, acetone and tetrahydrofuran. Thestructure and morphology of the polymer were studied by UV–vis, FTIR, and scanningelectron microscopy, respectively. The results of quantum chemistry calculations andthe spectroscopies of dedoped PBIn indicate that the polymerization of BIn mainlyoccurs via C(2)and C(5)position. Solid fluorescent spectral studies indicate that solidPBIn film is a good yellow emitter. To the best of our knowledge, this is the first reporton the electrosyntheses of free-standing PBIn films.2. A novel electrochromic material, poly(1H-benzo[g]indole)(PBIn), weresynthesized electrochemically by direct anodic oxidation of1H-benzo[g]indole (BIn)in CH3CN. Its structure and polymerization mechanism were studied by FT-IR. Theelectrochemical, fluorescent and spectroelectrochemical characterizations of this novelpolyindole derivative were reported. Spectroelectrochemical studies show that PBIn can change from hyaline reseda to pellucid grey along with the increasing potentials.ECD based on PBIn and poly(3,4-ethylenedioxythiophene)(PEDOT) was alsofabricated and showed a good electrochromic performance. The ECD constructed byPBIn and PEDOT has good optical contrast (41%at610nm), high colorationefficiency (720cm2C-1), fast response time (0.6s at610nm), better optical memoryand long-term stability. Clear change from prasinous (neutral) to wathet color(oxidized) of ECD is demonstrated with robust cycle life.