Trimethylphosphine

Trimethylphosphine is the chemical compound with the formula P(CH3)3, commonly abbreviated PMe3. This colorless liquid has a strong unpleasant odour, characteristic of alkylphosphines. It is pyramidal with C3v symmetry, similar to ammonia (NH3) and phosphine (PH3). As a ligand, its cone angle is 118°.

PMe3 is prepared using Grignard reagents:
 * 3 CH3MgBr + P(OC6H5)3  →  P(CH3)3  +  3 MgBrOC6H5

The synthesis is conducted in a dibutyl ether, from which the more volatile PMe3 can be distilled.

Coordination chemistry
Trimethylphosphine is an excellent ligand, being highly basic. It forms complexes with most metals. The synthesis of an illustrative example is shown:
 * PMe3 +  Fe(CO)5  →  Fe(CO)4PMe3  +  CO

Its complex with silver iodide, AgI(PMe3) is a weighable, air stable compound that releases PMe3 upon heating.

Safety
PMe3 is potentially pyrophoric, as well as toxic.