Nickel(II) complexes of some o-hydroxyarylcarbonyl compounds

Abstract

Nickel complexes of o-hydroxyarylcarbonyl compounds, (RCOC6H4O)2Ni (R = H, CH3, C2H5, C6H5, OCH3, OC2H5), have been studied in the solid state and in solution. Their six-coordinate adducts (RCOC6H4O)2NiB2 (B = H2O or 4- methylpyridine) are unstable in solution in hydrocarbon solvents and break down to (RCOC6H4O)2Ni. In solution these anhydrous compounds are monomeric, paramagnetic (μeff 3.0-3.5), and have absorption spectra characteristic of octahedral nickel(II). It is concluded that they are probably examples of high-spin, square-planar complexes of nickel(II), though possibly polymeric and octahedral in the solid state.