ELENA-RALUCA BULAI (CIOANCA), IRINA CARLESCU, DAN SCUTARU SYNTHESIS AND CHARACTERIZATION OF LIQUID CRYSTALLINE COMPOUNDS BASED ON A SYMMETRIC <1,3,4>OXADIAZOLE CORE This paper presents the synthesis and liquid crystalline properties of some new bent core liquid crystalline compounds based on a symmetric <1,3,4>oxadiazole core and containing azo and esteric linking groups. Compounds were prepared by the esterification reaction of 2,5-bis-(4-(4’-hydroxy)azobenzene)-<1,3,4>oxadiazole with aliphatic carboxylic acids containing 5¸10 and 18 carbon atoms and structurally characterized by means of NMR, FT-IR and mass spectroscopy. Their mesomorphic properties were investigated by differential scanning calorimetry (DSC) and polarized optical microscopy. Seven compounds presented liquid crystalline properties, mainly enantiotropic, the identified mesophases being of nematic, smectic and of B type, characteristic to biaxial compounds.
Keywords: liquid crystals, bent core molecules, 2,5-disubstituted-<1,3,4>oxadiazole