Phase transitions of new antiferroelectric thiobenzoate†

Abstract

This article reports on the phase sequences in a new chiral liquid crystalline compound, a member of the thioester series, (S)-(+)-4-[(4-{[1-methyl]heptylcarboxyl}phenyl)-carbonylthio]phenyl-4′-decyloxy-1-benzencarboxylate, referred to as 10.OPOSMH, which has been recently synthesized. 10.OPOSMH exhibits ferro- and antiferroelectric behaviour. This compound contains three benzene rings connected with the ester and thioester central groups. The 10.OPOSMH molecule is terminated with the achiral n-decyloxy and chiral (S)-(+)-1-methylheptyl carboxylate terminal chains, where the chiral group is in para position with respect to the thioester group. This mesogen assumes the existence of antiferroelectric smectic C () and ferroelectric smectic C () phases and also the smectic chiral subphases: , and , both on heating and cooling. †This article is dedicated to Prof. Dr Jerzy A. Janik on his 80th birthday.