Synthesis and Liquid Crystalline Properties of a New Homologous Series of 4,5-Disubstituted 2H-[1,2,3]-Triazoles via Azide-Chalcone Oxidative Cycloaddition Reaction

A new homologous series of 4,5-disubstituted 2H-[1,2,3]-triazole derivatives were synthesized from chalcones and sodium azide via oxidative cycloaddition reaction; CuI was used as catalyst. Flexibility in the synthesized molecules was provided by attaching straight alkoxy chains. The synthesized compounds were characterized by elemental analysis, and 1H NMR and 13C NMR and LC-MS spectroscopies . The stability and range of the mesophases increased with the length of the chain on the triazoles. The melting point, transition temperatures, and enantiotropic liquid crystal morphologies were determined by differential scanning calorimetry (DSC) and polarizing optical microscopy (POM) equipped with a hot stage.