A new thiazoldinone and triazole derivatives: Synthesis, characterization and liquid crystalline properties

The new compounds of thiazoldinone and triazole derivatives have been synthesized by many steps procedure. The 4-methoxybenzo-hydrazide [II]a and benzene-1,3,5-tricarbohydrazide [II]b were used as starting materials for the synthesis of these new derivatives. These compounds were identified by us-ing elemental analysis, FTIR, 1H-NMR, 13C-NMR and mass spectroscopy. The liquid crystalline proper-ties were examined by using differential scanning calorimetry and polarized optical microscopy. Com-pound 4-methoxy-N'-(-5-(-4-methoxybenzylidene)-4-oxo thiazolidin-2-ylidene) benzohydrazide [V]b dis-plays smectic A (SmA) mesophase, whereas compound 5-(2-(1-(4-nitrophenyl) ethylidene) hydrazinyl)-3-(3-(5-(2-(1-(4-nitro phenyl) ethylidene) hydrazinyl)-4H-1,2,4-triazol-3-yl)-5-(5-(2-(1-(4-nitro phenyl) ethylidene) hydrazinyl)-4H-1,2,4-triazol-3-yl) phenyl)-1H-1,2,4-triazole [VIII]a exhibits monotropic ne -matic mesophase. While the other derivatives did not show any liquid crystalline properties. The liq-uid crystalline behavior was found to be dependent on the geometry of the molecule, terminal and the central linkage group.(c) 2022 Elsevier B.V. All rights reserved.