Preparation of Molybdenum and Tungsten Diazoalkane-Aminocarbene Complexes cis, trans-[MX2(NN=CMePh){=C(Me)NHBut}(PMe2Ph)2] (M = Mo, W; X = Cl, Br) from Dinitrogen Complexes cis-[M(N2)2(PMe2Ph)4]

Molybdenum and tungsten diazoalkane-isocyanide complexes cis, trans-[MX2(NN=CMePh)(CNBut)(PMe2Ph)2] (M = Mo: X = Cl; M = W: X = Cl, Br), derived from cis-[M(N2)2(PMe2Ph)4], reacted with AlMe3 to give diazoalkane-aminocarbene complexes cis,trans-[MX2(NN=CMePh){=C(Me)NHBut}(PMe2Ph)2] (3) after hydrolysis, whose structure has been determined by an X-ray analysis for 3a (M = W, X = Cl).