A theoretical study of the effect of copper(I) chloride on the azido/tetrazole isomerism

B3LYP/6-31G(d), B3LYP/6-311++G(d,p), and CBS-QB3 calculations on the effect of CuCl on the azido/tetrazole isomerism have been performed. The cases of 2-azidopyridine and 2-azido-1H-imidazole have been selected as examples of heteroaromatic six- and five-membered rings. All minima and transition states have been characterized.