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• 33519-69-6 CpMo(CO)2(PPh₃)H 

Relevant academic research and scientific papers

Four-electron-donor hemilabile η3-PPh3 ligand that binds through a C=C bond rather than an agostic C-H interaction, and displacement of the C=C by methyl iodide or water

Hydride transfer from Cp(CO)2(PPh3)MoH to Ph 3C+BAr′4- [Ar′ = 3,5-bis(trifluoromethyl)phenyl] produces [Cp(CO)2(η3- PPh3)Mo]+[BArVP. Spectroscopic and crystallographic data indicate that one C=C of a Ph ring is weakly bound to the Mo, so that the PPh3 ligand is a four-electron-donor ligand. Computations (DFT/B3LYP and MP2 on [Cp(CO)2(η3-PPh3)Mo]+ and [Cp(CO)2(η-PH2Ph)Mo]+, and DFT/B3LYP on [Cp(CO)2(η3-PHtBuPh)Mo]+ and [Cp(CO)2(η3-PH2Ph)Nb]) provide further information on the bonding and on the preference for bonding of the metal to the C=C bond rather than an agostic C-H interaction found in many related complexes. The hemilabile C=C bond is readily displaced by CH3I or H2O, and crystal structures are reported for [Cp(CO) 2(PPh3)Mo(ICH3)]+ and [Cp(CO) 2(PPh3)Mo(OH2)J+. The equilibrium constant for [Cp(CO)2(η3-PPh3)Mo] + + ICH3 to give [Cp(CO)2(PPh 3)Mo(ICH3)]+ is Keq = 5.2 × 102 M-1 in CD2Cl2 at 22 °C.

An uncommon bonding mode of a familiar ligand: A molybdenum complex with a four-electron donor chelating η3-PPh3 ligand, and its structural determination using synchrotron radiation

A crystallographic study using synchrotron radiation shows that a C=C bond of one phenyl group of a PPh3 ligand bonds to Mo in [Cp(CO)2(PPh3)Mo]+, resulting in an unusual bonding mode in which PPh3 functions as a chelating four-electron donor ligand.