AN UNUSUAL ENDOTHERMIC TRANSITION TO AN OPTICALLY ISOTROPIC-PHASE ORGANIZED BY CHIRAL MOLECULAR RECOGNITION

A novel chiral liquid crystal was found to exhibit an endothermic tran sition upon cooling from a chiral smectic C phase to an optically isot ropic phase. C-13 NMR and X-ray diffraction indicate that the isotropi c phase has a layered structure in which fast isotropic reorientation of molecules or molecular assemblies occurs. We suggest that molecular aggregation via chiral recognition breaks anisotropic molecular order ing, which leads to a novel phase structure.