Triethylphosphine
Triethylphosphine is the organophosphorus compound with the formula P(CHCH), commonly abbreviated as PEt. 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" symmetry. PEt is usually prepared using Grignard reagents: PEt reacts with strong acids to give salts [HPEt]X. This reaction is reversible. Similarly, it is also easily alkylated to give phosphonium derivatives. PEt 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 Pt(PEt). As a phosphine ligand, triethylphosphine gained acceptance earlier than did the simpler trimethylphosphine, as illustrated by the preparation of the hydride complex "trans"-PtHCl(PEt). Safety. PEt is toxic. It converts to a low toxicity phosphine oxide upon treatment with sodium hypochlorite or hydrogen peroxide.