Columnar bent-core liquid crystals with two oxadiazole units and two or four alkyl chains and their phase-dependent fluorescence

Abstract

Bent-core mesogens containing two 1,3,4-oxadiazole rings, two or four terminal alkoxy chains and a polar nitro, amino or hydroxyl substituent on the central rigid core exhibit enantiotropic hexagonal columnar mesophases and show blue fluorescence emission in solution and the solid state. Photoluminescence was measured as a function of temperature, evidencing a pronounced quenching of fluorescence by π-stacking in the columnar structure.