Luminescent columnar liquid crystals based on 1,3,4-oxadiazole

In this study five new compounds, derivatives of 1,3,4-oxadiazole, were synthesized in order to achieve mesomorphic behavior and luminescence. Different types of aliphatic chains were used in order to investigate the influence of alkoxide groups in mesomorphic behavior. All of the compounds showed high thermal stability and strong blue photoluminescence in solution and in solid films. Furthermore, compounds 10a-d presented hexagonal columnar mesomorphism, which was characterized by polarizing optical microscopy and X-ray diffraction, and strong π-stacking was observed. Notably, for two compounds (10c,d), the liquid crystal properties were preserved on cooling from the isotropic state to room temperature. These characteristics make these materials good candidates for application in organic electronics.