Synthesis of eta(6)-arene complexes of molybdenum containing beta-ketophosphine and related P,O mixed donor ligands

The reactions of the ligands Ph2PCH2C(O)R (R = Ph, NPh2) with the eta(6)-arene molybdenum complexes [Mo(eta(3)-C3H5)(mu-Cl)(eta(6)-C6H5R)](2) (R = H, Me) have been investigated. A series of complexes in which the keto- or amidophosphine acts as a monodentate P ligand or as a neutral or anionic P,O chelating ligand have been synthesised and characterised. The crystal structures of the compounds [Mo(eta(3)-C3H5)Cl(eta(6)-C6H5Me){Ph2PCH2C(O)Ph}], [Mo(eta(3)-C3H5){Ph2PCH2C(O)NPh2-kappa(2) P,O}(eta(6)-C6H5Me)][PF6] and [Mo{Ph2PCH...C(...O) Ph-kappa(2)P,O}(2)(eta(6)-C6H5R)] (R = H, Me) have been determined. Interesting differences in the reactivity of the ketophosphine ligand versus the amidophosphine ligand were discovered and an unprecedented hydrogen-deuterium exchange of methylene and olefinic protons has been observed for the coordinated neutral or anionic ketophosphine ligands.