trans-Bis(perchlorato-κO)tetrakis(1H-pyrazole-κN 2)copper(II)

The title compound, [Cu(ClO4)2(C3H4N2)4], was obtained unexpectedly by the reaction of copper(II) perchlorate hexahydrate with equimolar amounts of 1-chloro-1-nitro-2,2,2-tripyrazolylethane in methanol solution. The crystal structure comprises octahedrally coordinated Cu2+ ions, located on an inversion centre, with four pyrazole ligands in the equatorial plane. The average Cu—N distance is 2.000 (1) Å. Two perchlorate ions are coordinated to copper in trans positions [Cu—O = 2.4163 (11) Å].