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

Abstract

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 using elemental analysis, FTIR, 1H-NMR, 13C-NMR and mass spectroscopy. The liquid crystalline properties were examined by using differential scanning calorimetry and polarized optical microscopy. Compound 4-methoxy-N'-(-5-(-4-methoxybenzylidene)-4-oxo thiazolidin-2-ylidene) benzohydrazide [V]b displays 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 nematic mesophase. While the other derivatives did not show any liquid crystalline properties. The liquid crystalline behavior was found to be dependent on the geometry of the molecule, terminal and the central linkage group.