Synthesis and characterization of halogen-containing ferroelectric liquid crystals and side chain liquid crystalline polymers

A new series of ferroelectric liquid crystals and side chain liquid crystalline polymers based on halogen-containing chiral centres has been synthesized. Chemical structures were analysed by NMR. Liquid crystal phases were characterized by diŒerential scanning calorimetry, optical polarizing microscopy, and X-ray diŒractometry. The behaviour ofthe liquid crystalline phases was investigated as a function of spacer units and diŒering terminal asymmetric moieties. It was found that phase transition temperatures decreased with increasing length of the oligooxyethylene spacer unit. DiŒering terminal asymmetric moieties led to diŒering mesophase phenomena. Furthermore, a wide temperature range (including room temperature) of a chiral smectic C phase was achieved.