Synthesis, Properties and Conformations of Liquid Crystalline 1,4-Dioxanes and Comparison with the Corresponding 1,4-Dithiane, Cyclohexane, and Benzene Derivatives

Abstract

Abstract The preparation and mesomorphic properties of a series of bis-(4-alkyl- or 4-alkoxy-benzoyloxy)-trans-1,4-dioxanes 1, trans-1,4-dithianes 2 and trans-1,4-cyclohexanes 3 are reported and compared to the corresponding hydroquinone bis-esters 4. The 1,4-dithianes 2 do not show liquid crystalline properties and the 1,4-dioxanes 1 in their trans diaxial conformation are less favorable for nematic phases than the corresponding cyclohexanes 3 which are predominantly in the diequatorial conformation. However, owing to the cross-dipole moments they seem to be of advantage in stabilizing smectic phases.