Ferroelectric Liquid Crystals with Chiral Groups on Each Side of the Core

The syntheses and properties of a series of ferroelectric liquid crystals with two chiral groups, one on each side of the core, are described. One of the chiral groups is an optically active alkanoyl group and the other is a group derived from one of three kinds of optically active carboxylic acids. The mesomorphic properties and spontaneous polarization of these dichiral compounds are compared with those of monochiral compounds having one of the two chiral groups. These properties and polarization values are discussed in terms of the core and the chiral structure. The dichiral compounds all exhibit very large spontaneous polarization and the maximum value (11.3 mC/m2) was obtained for a compound with a hydroxyl group in the core.