Synthesis and mesomorphic properties of four-ring liquid crystals containing cyclohexyl, phenyl and pyridyl units

Two series of chiral and achiral 4-(3- n -alkoxycarbonylpyridyl)-6-ethynyl]phenyl 4-( trans -4- n -alkylcyclohexyl)benzoate liquid crystals have been synthesized. Their mesomorphic properties were observed and measured by polarizing optical microscopy and DSC. A broad chiral smectic C phase was observed when terminal chains contained a chiral centre.