Two Families of Trithiatruxene Derivatives

Abstract

Homologous series of nine mesogemc hexa-n-alkanoyloxytrithiatruxenes (C_nHATxS) and hexa-n-alkoxybenzoyloxytrithiatruxenes (C_nHBTxS) have been prepared. Optical texture observations, DSC, and X-ray measurements showed that they exhibit a rich polymorphism with a nematic discoid phase occurring in an inverted sequence—a nematic phase and three successive columnar phases. The first example of a D_rd(P2₁/a) - D_rd(C2/m) transition in the C_nHATxS series was found. In contrast to the rich columnar polymorphism of the hexa-n-alkoxybenzoyloxytruxenes, the C_nHBTxS series shows only a N_D nematic discoid phase.