Synthesis and Structural Characterization of Cobalt Complexes Ligated by N-Methyl(bis(diphenylphosphino)amine)

The reaction of the short-bite bis(diphosphino)amine ligand Ph2PN(Me)PPh2 (Medppa) with an equimolar amount of [Co2(CO)8] in toluene solution yielded the diphosphane-bridged complex bis(µ2-carbonyl)(µ-bis(diphenylphosphino)methylamine)-tetracarbonyl-dicobalt(0) (Co—Co) · 0.5 toluene, [Co2(CO)6(µ-Medppa)] 1. Using a 3:1 ratio, the ion-pair complex [Co(CO)(η2-Medppa)2][Co(CO)4] 2 was formed. The ionic intermediate [Co(CO)2(η2-Medppa)(η1-Medppa)][Co(CO)4] 3 was spectroscopically observed during the stoichiometric reaction involving [Co2(CO)8] and 2 eq. Medppa. Complexes 1 and 2 were characterized using IR and NMR spectroscopy and by single-crystal X-ray analysis performed at 100 K.