Chiral Tolans: A New Family of Ferroelectric Liquid Crystals. Synthesis and Mesomorphic Properties

Abstract
Diphenylacetylene homologues having a chiral alkyl group, synthesized by a palladium-catalyzed coupling reaction, provide a new series of liquid crystalline materials which form chiral smectic C (SmC*) phases exhibiting ferroelectric properties. Mesomorphic properties of the compounds composed of three aromatic rings is strongly affected by the position of an acetylenic linkage and the direction of an ester linking unit. The effect of variations in terminal chain length on the thermal stabilities of the smectic A (SmA) and SmC* the two and three aromatic ring systems has been systematically studied.