DESIGN OF NOVEL ELECTROACTIVE POLYBITHIOPHENE DERIVATIVES

Various derivatives of polybithiophene were synthesized and characteri zed. Poly(3,3'-dibutoxy-2,2'-bithiophene) and poly(4,4'-dibutoxy-2,2'- bithiophene) were found to be conducting upon doping but only partiall y soluble in common organic solvents. The oxidation potential of poly( 4,4'-dibutoxy-2,2'-bithiophene) was only +0.05 V vs SCE, one of the lo west values for a polythiophene derivative. This low oxidation potenti al allows then the formation of a stable conducting state in the polym er. Moreover, upon oxidation, thin films of poly(dialkoxybithiophenes) became nearly transparent. Asymmetric disubstitution gave poly(3-buto xy-3'-decyl-2,2'-bithiophene) and poly(4-butoxy-4'-decyl-2,2'-bithioph ene) which were completely soluble in chloroform. Their properties wer e intermediate between those of poly(alkylthiophenes) and poly-(dialko xybithiophenes).