Calix[2]triazole[2]arenes; A Class of Hybrid Heterocalixarenes

A series of calix[2]triazole[2]arenes, which are members of the heterocalixarene family, were generated by copper(I)-catalyzed Huisgen reaction in a one-pot synthesis. Their various conformational structures and physical properties were characterized by a computational, NMR spectroscopic, and X-ray structural investigation. Among six conformations, the 1,2-alternate conformation was found to be the most stable due to two intramolecular hydrogen bonds between the phenolic hydroxyl group and the triazole nitrogen atom.