Synthesis and crystal structures of novel group 6B metal carbonyl complexes with N-(4-methyl-2- pyridinyl)-P,P-diphenylphosphinous amide ligand.

The reaction of N-(4-methyl-2-pyridinyl)-P,P-diphenylphosphi- nous amide ligand 4-Me-C5H3N-2-NH(PPh2) (1) with M(CO)6 (M=Cr, Mo, W) in refluxing toluene afforded a mononuclear group VIB metal tetracarbonyls [M(CO)4{1-k2P,N}] (M=Cr(2), Mo(3), W(4)). Complexes 2?4 were characterized by multi- nuclear NMR (1H, 13C and 31P NMR) and IR spectroscopy, and their structures were also determined by single crystal X-ray diffraction. 2 and 4 represent the first examples of structurally characterized complexes of such ligands with group 6B metal carbonyl