New Series of Ferroelectric Liquid Crystals Incorporating Stilbene Unit in the Core

Abstract

New liquid crystalline materials of the general formula have been synthesized (R1, R2 are alkyl chains). Mesomorphic properties were determined using polarizing microscopy. All compounds showed very broad smectic C* phase (about 70–90 K) and the cholesteric phase. No smectic A phase was observed. In the smectic C* phase the spontaneous polarization is very high, reaching values higher than 300 nC/cm2 at the low temperature limit of this phase for compounds with two chiral centres. The permitivity was measured showing a contribution of the Goldstone mode in the smectic C* phase.