SYNTHESIS AND CHARACTERISATION OF SOME NICKEL(II) β -KETOAMINES AND THEIR ADDUCTS WITH 2,2′-BIPYRIDINE AND 1,10-PHENANTHROLINE

A series of nickel(II) β-ketoimine complexes, {Ni[CH3-C(O)CHC(CH3)NR]2, R=CH3, C4H9}, and ketoiminates, {Ni[CH3C(O)CH(CH3)C(-N(CH2)nN-)C(CH3)CHC(O)CH3], n=2, 6, 8, 9}, and their adducts with 2,2′-bipyridine (bipy) and 1,10-phenanthroline (phen) have been synthesized and characterized using elemental analyses, magnetic susceptibility, conductivity, infrared and electronic spectral measurements. The ketoimine ligands coordinate to the nickel atom in a bidentate fashion using the N2O2 chromophore. A range of stereochemistries was observed for the nickel(II) ketoiminates from four-coordinate tetrahedral and square-planar geometry to six-coordinate octahedral geometry. Conductivity measurements indicate that the compounds are non-electrolytes. The influence of bridging chain lengthening on the adopted geometry is discussed and possible structures for the compounds are suggested.