Synthesis and Structural Characterization of a New Tetranuclear Nickel(II) Sulfato Complex Containing the Anionic Form of Di-2-Pyridyl Ketone Oxime

The preparation and crystal structure of a tetranuclear Ni(II) sulfato cluster containing the anion of di-2-pyridyl ketone oxime, (py)2CNO−, are reported. Treatment of NiSO4·6H2O with one equivalent of (py)2CNOH and one equivalent of NEt3 in MeOH leads to the compound [Ni4{(py)2CNO}4(SO4)2(MeOH)4] (1) in moderate yield. The metal ions are linked together by two 3.2111 and two 2.1110 (Harris notation) (py)2CNO− ligands, as well as two 2.1100 SO42− ions to create a rare metallacrown-type (12-MC-4) ring. Strong H-bond intermolecular interactions in 1 lead to the formation of a 1D chain along the axis. Characteristic IR bands are discussed in terms of the known structure of 1.