Columnar mesophases of luminescent polycatenar liquid crystals incorporating a 1,3-substituted benzene ring interconnecting two 1,3,4-oxadiazoles

Abstract

New polycatenar liquid crystals containing two 1,3,4-oxadiazole rings interconnected by a bent 1,3-substituted benzene ring as the central linking unit and three alkoxy chains at each terminal have been synthesized and investigated by polarizing microscopy, DSC, XRD scattering, UV-vis spectroscopy and photoluminescence measurements. All compounds form enantiotropic hexagonal columnar phases and have broader mesophase ranges than the corresponding para substituted analogues and show strong blue fluorescence emission with a large Stokes shift in solution.