Oxidized Poly spectral features

Model compounds for poly(acetylene) and oxidized poly(acetylene) are discussed with regard to the explanation of the spectral features observed in the conducting polymer. 

Shinkai and coworkers reported cationic polythiophene 11 obtained by the direct oxidative polymerization of the tetraalkylammonium salt of a thiophene monomer (Scheme 16.3). The molecular weight of the polymer was not determined however, its absorption and fluorescence spectral properties were consistent with the polythiophene backbone structure. Schanze and coworkers reported the use of a direct polymerization method to prepare the cationic poly(arylene ethy-nylene) 8 that features a backbone that alternates thienylene-ethynylene and phenylene-ethynylene repeat units (Scheme 16.4). Thus, polymerization of the cationic tetraalkylammonium substituted 1,4-diiodobenzene with 2,5-diethynyl-thiophene via a Sonogashira coupling protocol catalyzed by Pd(0)/Cu(I) catalyst in aqueous/DMF afforded 8. The resulting polymer was purified by aqueous dialysis using an 8 kD molecular weight cutoff membrane. As with the previous examples, the molecular weight of the cationic CPE was not determined. 

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