Syntheses and Reactions of Mo and W N-Substituted Imido Complexes with Linear Tetraphosphine Ligand

摘要

Transition-metal nitrido and imido complexes remain an important class of compounds in relevance to nitrogen fixation and as a source of nitrogen in organic synthesis. We have recently revealed that the divalent Mo and W complexes [MX_2(kappa~4-P4)] (MX = MoCl (1), MoBr (1'), WBr (1"); P4 =meso-o-C_6H_4(PPhCH_2CH_2PPh_2)_2) readily cleave the N-N bond of mono- and 1,1-disubstituted hydrazines to afford the nitride complexes [MOX(N)(kappa~4-P4)] (X = Cl (2), Br (2')) or the imido complexes [MX(NH)(kappa~4-P4)]~+ (MX = MoCl (3~+), MoBr (3'~+). WBr (3"~+)). Since the known complexes trans-[MX_2(Ph_2PCH_2CH_2PPh_2)_2] do not cause such reactions, activity of 1 is attributable to its unusual trigonal prismatic geometry forced by the linear tetraphosphine ancillary ligand P4. We wish to report here the application of the above reactions for syntheses of N-substituted imido complexes.