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 C_3v 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.