Distinct ferroelectric smectic liquid crystals consisting of banana shaped achiral molecules

Abstract

The synthesis of a banana-shaped molecule is reported and it is found that the smectic phase which it forms is biaxial with the molecules packed in the best direction into a layer. Because of this characteristic packing, spontaneous polarization appears parallel to the layer and switches on reversal of an applied electric field. This is the first obvious example of ferroelectricity in an achiral smectic phase and is ascribed to the C_2v symmetry of the molecular packing.