STRUCTURE OF OPTICALLY-ACTIVE COMPOUNDS AND FERROELECTRIC PROPERTIES OF LIQUID-CRYSTALS

A new series of optically active dipole dopants - diesters of 4,4-terphenyl dicarboxylic acid -have been prepared. Most of the components are high melting substances. Some of 2-chlorine substituted compounds show a chiral smectic C phase. The Ps value induced by optically active dipole dopants depends on several factors such as the magnitude of the dipole moment and the length of the alkyl tail at the C-atom, the degree to which rotations of the molecule and the chiral center are hindered. In some cases the experimental Ps value the of the FLC-mixture induced by a pair of dopants with same Ps sign and opposite helix handedness is higher than the sum of the Ps values induced by each dopant independently. © 1991 Gordon and Breach Science Publishers S.A.