Syntheses, characterization and structures of chromium group carbonyl complexes containing a multifunctional Ph2P(o-C6H4)CHN(CH2)2(o-C6H4N) ligand

Reactions of the phosphine–imine–pyridine-containing ligand Ph2P(o-C6H4)CHN(CH2)2(o-C6H4N) (PNN) with M(CO)3(NCMe)3 (M=Cr, Mo, W) produce the tridentate complexes fac-M(CO)3(η3-PNN). On the other hand, treating W(CO)4(NCMe)2 with PNN results in the bidentate complex W(CO)4(η2-PNN), which converts to fac-W(CO)3(η3-PNN) upon heating, but no facial→meridional isomerism is evidenced. The new compounds have been characterized by elemental analysis and mass, IR, and NMR spectroscopy. The molecular structures of W(CO)4(η2-PNN), fac-W(CO)3(η3-PNN) and fac-Mo(CO)3(η3-PNN) are determined by an X-ray diffraction study.