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

Abstract

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 NiSO 4·6H 2O with 1 equiv. of (py)C(ph)NOH and 1 equiv. of NaOMe in DMF under reflux leads to the compound [Νi 6(SO 4) 2{(py)C(ph)NO} 8] ·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 SO 4 2 - ions. Its skeleton consists of six Ni II ions arranged in a chair conformation. Compound 1 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 SO 4 2 - 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 antiferromagnetic interactions within its triangular subunits.