Liquid crystalline properties of asymmetric molecules: II. Smectic properties of 4-alkoxyphenyl 4-(4-trifluoromethylbenzoyloxy)benzoates

The thermal properties of a homologous series of 4-alkoxy-phenyl 4-(4-trifl uoromethylbenzoyloxy)benzoates were examined. The homologues show remarkabl e smectic properties involving a smectic A and a higher order smectic phase characterized by microscopic and X-ray experiments, indicating that the mo lecules have a partially bilayer arrangement in both smectic phases. Based on these results, molecular arrangements of the two smectic phases are prop osed. The effects of the trifluoromethyl group on the thermal properties of the smectic and crystalline phases are discussed in terms of the fluorophi lic interaction around the boundary of the smectic layer.