Reactions of nickel(II) sulfate hexahydrate with methyl(2-pyridyl)ketone oxime: Two mononuclear sulfato complexes containing the neutral ligand

Abstract

The reactions of methyl(2-pyridyl)ketone oxime, (py)C(Me)NOH, with nickel(II) sulfate hexahydrate, in the absence of an external base, have been investigated. The reaction between equimolar quantities of NiSO4 · 6 H2O and (py)C(Me)NOH in H2O leads to the mononuclear complex [Ni(SO4){(py)C(Me)NOH}(H2O) 3] · H2O (1 · H2O), while an excess of the organic ligand affords the 1:2 compound [Ni(SO4){(py) C(Me)NOH}2(H2O)] · H2O (2 · H2O). The structures of both compounds have been determined by single crystal X-ray diffraction. In both complexes the organic ligand chelates through its nitrogen atoms and the sulfate anion acts as a monodentate ligand. The thermal decomposition of complexes 1 · H2O and 2 · H2O has been studied. The IR data are discussed in terms of the nature of bonding and the structures of the two complexes. © 2007 Verlag der Zeitschrift für Naturforschung.