Synthesis and Mesomorphic Properties of Tropon-4-yl 4-n-Alkoxybenzoates: Roles of a Tropone Ring as a Polar Terminal Group

Abstract

New troponoid liquid crystals with a tropone terminal group were prepared. Tropon-4-yl 4-n-alkoxybenzoates (1T) had a monotropic smectic A phase. However the corresponding benzenoid derivatives (1B), tropolon-5-yl 4-n-alkoxybenzoates (2T), 2-methoxytropon-5-yl 4-n-alkoxybenzoates (3T), and tropon-2-yl 4-n-alkoxybenzoates (4T) were not mesomorphic. X-ray diffraction studies revealed that 1T formed the interdigitated bilayers in the smectic A phase.