One-pot synthesis of Mo(0) dinitrogen complexes possessing monodentate and multidentate phosphine ligands

Mo(0) dinitrogen complexes bearing electron-rich mono- and bidentate phosphines can be synthesized in good yields from inexpensive and readily accessible MoCl(5) via a one-step mild reduction with Mg metal. trans-[(N(2))(2)Mo(PMePh(2))(PPh(CH(2)CH(2)PPh(2))(2))] can also be obtained via this strategy. However, in the presence of tri- and tetradentate ligands that are sterically restrictive, the analogous reduction leads to either (η(6)-arene) formation or [Mo(multidentate phosphine)(m)](n) oligomer complexes that have no dinitrogen ligands. One such η(6)-arene complex, where the Mo(0) center is ligated by 1,1,1-tris(diphenylphosphinomethyl)ethane, was isolated and characterized via X-ray crystallography.