Synthesis and Structure of Copper(II) Nitrate Complexes with 2, 6‐Bis(pyrazolyl)pyridine

Three mononuclear copper(II) complexes of copper nitrate with 2, 6-bis(pyrazol-1-yl)pyridine (bPzPy) and 2, 6-bis(3′,5′-dimethylpyrazol-1-yl)pyridine (bdmPzPy), [Cu(bPzPy)(NO3)2] (1), [Cu(bPzPy)(H2O)(NO3)2] (2) and [Cu(bdmPzPy)(NO3)2] (3) were synthesized by the reaction of copper nitrate with the ligand in ethanol solution. The complexes have been characterized through analytical, spectroscopic and EPR measurements. Single crystal X-ray structure analysis of complexes 1 and 2 revealed a five-coordinate copper atom in 1, whereas 2 contains a six-coordinate (4+2) CuII ion with molecular units acting as supramolecular nodes. These neutral nodes are connected through O–H···O(nitrate) hydrogen bonds to give couples of parallel linear strips assembled in 1D-chains in a zipper-like motif.