Triisopropylphosphine is the tertiary phosphine with the formula P(CH(CH3)2)3.

Commonly used as a ligand in organometallic chemistry, it is often abbreviated to Pi-Pr3 or PiPr3.

This ligand is one of the most basic alkyl phosphines with a large ligand cone angle of 160.

[1] Pi-Pr3 is similar to the more frequently used tricyclohexylphosphine.

The triisopropyl derivative however, is a liquid at room temperature and more soluble in hydrocarbons.