SYNTHESIS AND PROPERTIES OF FERROELECTRIC LIQUID-CRYSTALS WITH TRIFLUOROMETHYL GROUP AT A CHIRAL CENTER

In order to prepare new types of ferroelectric liquid crystals (FLC) with a large spontaneous polarization and a short response time toward electric field, the optically active compounds possessing a trifluoromethyl group at the chiral center were synthesized by use of optically active 1,1, l-trifluoromethyl-2-octanol 1. It was found that the compounds in which the core moieties were connected with 1 by an ester linkage unexpectedly revealed a relatively narrower temperature range of the Sc∗ phase and a smaller spontaneous polarization, whereas, the compounds 6 (4'-alkoxy-4-biphenylyl 4-(1-trifluoromethylheptyloxy methyl) benzoate) and 7 (4-(5-alkoxy-2-pyrimidinyl)phenyl 4-(l-trifluoromethylheptyloxymethyl) benzoate) in which the core moieties were connected with 1 by an ether linkage exhibited such remarkable FLC characteristics, as a wide temperature range of the Sc∗ phase, and a large spontaneous polarization with the range of 2000~3000 μC/m2. The response times of these compounds showed a different temperature dependence with a different core structure. It was also found that 6 had favorable properties as a chiral dopant blended it with some achiral host liquid crystals. © 1990, The Chemical Society of Japan. All rights reserved.