Triphenylene hexa-n-alkylcyclohexanoates: a new series of disc-like liquid crystals

Abstract

A series of hexa-n-alkylcyclohexanoates of triphenylene were prepared by the esterification of hexahydroxytri-phenylene with a variety of 4-n-alkylcyclohexylcarbonyl chlorides in the presence of pyridine. The liquid-crystalline phase behaviour of the materials synthesized was investigated by a combination of thermal polarized light microscopy, differential scanning calorimetry and X-ray diffraction. All of the compounds were found to exhibit a single discotic mesophase that had hexagonal symmetry. The hexagonal columnar phase was found to occur over much wider temperature ranges in this series than was observed for the aromatic analogues.