Bis(diphenylphosphinoethyl)phenylphosphine
# Bis(diphenylphosphinoethyl)phenylphosphine

Bis(diphenylphosphinoethyl)phenylphosphine is the organophosphorus compound with the formula $[Ph_2PCH_2CH_2]_2PPh$ (Ph = $C_6H_5).$ 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:

    2 $Ph_2PCH=CH_2$ + $H_2PPh$ → $[Ph_2PCH_2CH_2]_2PPh$

It can bind to an octahedral metal center 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 $(HN(CH_2CH_2NH_2)_2)$
* bis(diphenylphosphinophenyl)phenylphosphine $(PhP(C_6H_4PPh_2)_2)$
* 1,1,1-Tris(diphenylphosphinomethyl)ethane, a tripodal ligand.
