Bis(diphenylphosphinoethyl)phenylphosphine explained

Bis(diphenylphosphinoethyl)phenylphosphine is the organophosphorus compound with the formula [Ph₂PCH₂CH₂]₂PPh (Ph = C₆H₅). It is an air-sensitive white solid that function as tridentate ligands in coordination and organometallic chemistry.

It is prepared by the free-radical-catalysed addition of phenylphosphine to vinyldiphenylphosphine:^[1]

2 Ph₂PCH=CH₂ + H₂PPh → [Ph₂PCH₂CH₂]₂PPhIt can bind to an octahedral metal center to give either a facial or meridional isomers. Some derivatives are square planar complexes of the type [MX(triphos)]⁺ (M = Ni, Pd, Pt; X = halide).

Related ligands

• diethylenetriamine (HN(CH₂CH₂NH₂)₂)
• bis(diphenylphosphinophenyl)phenylphosphine^[2] (PhP(C₆H₄PPh₂)₂)
• 1,1,1-Tris(diphenylphosphinomethyl)ethane, a tripodal ligand.

References

1. "Synthesis of Polytertiary Phosphines and ‘Mixed’ Phosphorus–Sulphur and ‘Mixed’ Phosphorus–Nitrogen Polydentate Ligands via Free-Radical Catalysis" Daniel L. DuBois, William H. Myers, Devon W. Meek J. Chem. Soc., Dalton Trans., 1975, 1011-1015.
2. Hartley, J. G., Venanzi, L. M., Goodall, D. C., "The Preparation and Complex-Forming Properties of One tritertiary and One Tetratertiary Phosphine", J. Chem. Soc. 1963, 3930.