Triethylphosphine


Triethylphosphine is the organophosphorus compound with the formula P3, commonly abbreviated as PEt3. It is a colorless liquid with an unpleasant odor characteristic of alkylphosphines. The compound is a common ligand in organometallic chemistry, such as in auranofin.

Structure and simple reactions

It is a pyramidal molecule with approximate C3v symmetry.
PEt3 is usually prepared using Grignard reagents:
PEt3 reacts with strong acids to give salts X. This reaction is reversible. Similarly, it is also easily alkylated to give phosphonium derivatives. PEt3 is easily oxidised to the phosphine oxide with oxygen.

Coordination chemistry

Triethylphosphine is a highly basic ligand that forms coordination complexes with many metals. As a ligand, triethylphosphine's Tolman cone angle is 132°. Being a relatively compact phosphine, several can bind to a single transition metal, as illustrated by the existence of Pt4. As a phosphine ligand, triethylphosphine gained acceptance earlier than did the simpler trimethylphosphine, as illustrated by the preparation of the hydride complex trans-PtHCl2.

Safety

PEt3 is toxic. It converts to a low toxicity phosphine oxide upon treatment with sodium hypochlorite or hydrogen peroxide.