Synthesis and characterization of poly(3-substituted thiophene)s having liquid crystalline moiety

3-Substituted thiophene derivatives having a biphenyl or a cyclohexylphenyl moiety as the mesogenic core were synthesized and polymerized. Thiophene monomers with a cyanobiphenyl or a biphenylketone moiety showed a monotropic mesophase, but these phases are unstable by comparing with those of corresponding models. Cyclic voltammetry of these monomers showed that oxidation potentials of the thiophene moiety were more anodic than those of mesogenic cores. Oxidative polymerization by FeCl3 or electrochemical manners gave soluble and fusible polythiophenes, but these polymers had no mesophases.