Molybdenum(0) and Tungsten(0) Complexes with P, S and P, Se Monooxidized Bis( phosphanyl) amine Ligands

Reactions of monooxidized thioyl and selenoyl bis(phosphanyl)amine ligands C10H7-1-N(P(E)Ph2)(PPh2) [E = S (1), Se (2)] with Mo(CO)4(pip)2 and W(CO)4(cod) afforded the complexes [M(CO)4{1-?2P,S}] [M = Mo (3), W (4)] and [M(CO)4{2-?2P,Se}] [M = Mo (5), W (6)]. Complexes 3?6 were characterized by multinuclear NMR (1H, 13C, 31P, and 77Se NMR) and IR spectroscopy. Crystal-structure determinations were carried out on 3, 5, and 6, which represent the first examples of structurally characterized complexes of such ligands with group-6 metal carbonyls.