Synthesis and properties of polythiophene derivatives with liquid crystallne substituents

Summary form only given. In order to develop novel liquid crystalline conductive polymers, we have synthesized thiophene derivatives with liquid crystal groups and polymerized them by chemical and electrochemical polymerizations. The liquid crystalline substituents introduced into the thiophene ring consist of a phenyloyclohexyl (PCH) mesogen, a methylene chain [-(CH/sub 2/)/sub 4/-] as a spacer, and n-pentyl or n-hexyl chain, and are abbreviated as PCH504 or PCH604. The brominated precursor of PCHS04, for instance, was synthesized by reacting (trans-4-n-pentylcyclohexyl)phenol (PCH500) with Br-(CH/sub 2/)/sub 4/-Br (dibromobutane) in KOH. The Grignard reagent of PCH504-Br was coupled with 3-bromothiophene to obtain the PCH504-thiophene. The chemical and electrochemical oxidative polymerizations of the monomer gave insoluble powder of polymer. As a next step, the dehatogenative polycondensation of the 2,5 dibrominated monomer as well as the chemical oxidative polymerization of another kind of thiophene monomer that has no phenoxy-oxygen atom in the liquid crystalline substituent are underway.