Stabilization of dimethyliron(II) and methylcobalt(I) complexes bearing a hemilabile 2-benzoylpyridine ligand in octahedral and square-pyramidal coordination

Octahedral cis-Fe(CH3)2{2-(benzoyl)pyridyl-N,O}(PMe3)2 (1), square-pyramidal Co(CH3){2-(benzoyl)pyridyl-N,O}(PMe3)2 (2), and triangular-planar Ni{2-(benzoyl)pyridyl-η2-C,O}(PMe3)2 (3) have been synthesized by reaction of 2-benzoylpyridine with thermally labile Fe(CH3)2(PMe3)4 and Co(CH3)(PMe3)4 complexes. With Ni(CH3)2(PMe3)3, reductive elimination of ethane is observed when a η2-C,O-coordination is constituted. The complexes were investigated by NMR spectroscopic methods and the molecular structures of 1 and 2 were determined by X-ray crystallography.