Preparation and properties of molybdenum and tungsten dinitrogen complexes: XXXV. Synthesis of diazoalkane and hydrazido(2 − ) complexes of tungsten containing a π-acceptor ligand

Abstract

Diazoalkane complexes [MCl 2(NNCRR′)(PMe 2Ph) 3] (M = W or Mo; R, R′ = Me or Ph), derived from dinitrogen complexes cis-[M(N 2) 2(PMe 2Ph) 4], reacted with various π-acceptor molecules at 50°C to give a series of new diazoalkane complexes [MCl 2(L)(NNCRR′)(PMe 2Ph) 2] (L = olefins, CO, tBuNC, or aldehydes). Analogous substitution of ethylene or CO for one phosphine ligand occurred in the hydrazido(2 −) complex [WCl 2(NNH 2(PMe 2Ph) 3], which resulted in the formation of [WCl 2(L)(NNH(in2) (PMe 2Ph) 2]. Condensation of this new hydrazido(2 − ) complex (L = CO) with aldehyde or ketone gives the diazoalkane complexes of the type [WCl 2(CO)(NNCRR′)(PMe 2Ph) 2]. The structures of [WCl 2(C 2H 4)(NNCMe 2(PMe 2Ph) 2] 4 and [WCl 2 (η 2- p-CH 3C 6H 4CHO)(NNCMePh) (PMe 2Ph) 2] 13 were determined by single-crystal X-ray diffraction studies: 4 crystallizes in the monoclinic space group P2 1/ n with a = 12.755(7), b = 18.528(6), c = 10.791(3) Å, β = 93.25(4)°, Z = 4, and R = 0.036 for 4199 reflections, while 13 crystallizes in the monoclinic space group P2 1/ n with a = 31.519(13), b = 11.360(5), c = 9.348(3) Å, β = 92.28(3)°, Z = 4, and R = 0.053 for 3522 reflections. Both have an octahedral geometry with the diazoalkane and the π-acceptor ligands in mutual cis positions.