Liquid-crystalline property of polymers and twin model compounds having terphenyl analogues of 1, 3, 4-thia-and oxadiazoles as mesogenic units

Abstract

Polymers and model compounds composed of terphenyl analogues of 1, 3, 4-thia- and oxadiazole compounds were synthesized and their thermotropic liquid crystalline(LC) properties were evaluated. The model compounds of 1, 3, 4-thiadiazoles showed stable smectic or nematic phases and had high phase transition temperatures. The 1, 3, 4-oxadiazoles exhibited lower transition temperatures and less stable nematic phases than the corresponding 1, 3, 4-thiadiazoles. Most of the polymers showed no LC melts. Only the thiadiazole-containing polymers from the dicarbozylic acid with ester linkage formed nematic phase.