Inversion of chirality-dependent properties in optically active liquid crystals

Abstract

Three new low-molar-mass liquid crystals are reported, each of which shows remarkable phase behaviour. One of the materials exhibits a temperature-dependent unwinding of the helix in the cholesteric (chiral nematic) and chiral smectic C phases. This is the first example of a single, pure material to show both of these inversions. The inversion phenomena were studied in terms of the helical pitch and the electrooptic switching behaviour in the cholesteric phase and in terms of the temperature dependence of the apparent optical tilt angle and the spontaneous polarization in the chiral smectic C phase.