2,6-Di(1H-tetrazol-1-yl)pyridine and its cupric chloride complex

2,6-Di(1H-tetrazol-1-yl)pyridine (DTP) was prepared by a four-stage procedure, including step-by-step heterocyclization of both amino groups of 2,6-diaminopyridine with triethyl orthoformate and sodium azide. According to quantum-chemical calculations and single crystal X-ray diffraction data, DTP crystallizes in the form of the thermodynamically most stable conformer and has an almost flat molecular geometry. DTP was found to react with CuCl2 center dot 2H(2)O in ethanol to give the [Cu(DTP)Cl-2(H2O)](n), complex, which is a 1D coordination polymer, formed at the expense of bridging DTP ligand via the tetrazole ring nitrogen atoms N-4. Possible coordination cites in DTP molecule are discussed using the data of quantum chemical calculations. The pyridine ring nitrogen atom of DTP does not participate in the formation of either coordination or intermolecular hydrogen bonds. This is explained by the results of quantum chemical calculations showing that this atom is less basic than N3 and N4 atoms of DTP molecule.