Employment of the sulfate ligand in 3d-metal cluster chemistry: A novel hexanuclear nickel(II) complex with a chair metal topology

摘要

The preparation and crystal structure of a hexanuclear Ni(II) sulfato cluster containing the anion of phenyl(2-pyridyl)ketone oxime, (py)C(ph)NO-, is reported. Treatment of NiSO4 center dot 6H(2)O with 1 equiv. of (py)C(ph)NCH and I equiv. of NaOMe in DMF under reflux leads to the compound [Ni-6(SO4)(2){(py)C(ph)-NO}(8)]center dot 6DMF (1.6DMF) in moderate yield. The metal ions are linked together by two 3.211 (Harris notation) (py)C(ph)NO- ligands, six 2.111 (py)C(ph)NO- ligands and two 5.2210 SO42- ions. Its skeleton consists of six Ni-II ions arranged in a chair conformation. Compound I joins a small family of structurally characterized metal complexes containing the neutral or anionic forms of phenyl(2-pyridyl)ketone oxime as ligands, and it is a rare example in which the SO42- ions are coordinated in the 5.2210 fashion. Characteristic IR bands are discussed in terms of the known structure of 1. Its magnetic properties have been studied by variable-temperature dc magnetic susceptibility techniques which indicate competitive anti-ferromagnetic interactions within its triangular subunits.