Trifluoromethylated pyranose derivatives as the chiral dopant for ferroelectric liquid crystals

Abstract

The novel pyranose derivatives with a trifluoromethyl group were found to be excellent chiral dopants for ferroelectric liquid crystals, inducing large spontaneous polarization by their addition even in a small quantity. These materials showed some characteristic physical properties depending on their stereochemical relationship : thus, the corresponding cis isomers exhibited high ability in inducing large spontaneous polarization and quick response but lowered the upper limit of the temperature of the S_c phase. However, the same trend in the spontaneous polarization was observed for the compounds with trans stereochemistry, without lowering the transition temperature of S_A to S_C, of the host liquid crystal. MoFover, it was also proved that the adjustment of the helical pitch of the N* phase was readily carried out. Based on these results, we have succeeded in the development of the practical ferroelectric liquid crystalline compositions with good alignment and quick response.