Mesomorphic properties for polar liquid crystals having a 3H-benzofuran-2-one skeleton

Abstract

The homologous series of 3H-benzofuran-2-one-5-yl 4-alkoxybenzoates (1), 4-alkoxybiphenyl-4'-carboxylates (2), and 4-alkylbenzoates (3) are synthesized and their physico-chemical properties are examined. Compounds 1 and 2 show a nematic (N), smectic A (SmA) and/or smectic C (SmC) phases, while 3 are non-mesogenic even in a rapid cooling process. The layer spacing of SmA phase was examined by a small angle X-ray diffraction study, and the results are compared with molecular structures calculated by a semi-empirical molecular orbital calculation.