Triphenylarsine is the chemical compound with the formula As(C6H5)3. This organoarsenic compound, often abbreviated AsPh3, is a colorless crystalline solid that is used as a ligand and a reagent in coordination chemistry and organic synthesis. The molecule is pyramidal with As-C distances of 1.942–1.956 Å and C-As-C angles of 99.6–100.5°.
This compound is prepared by the Wurtz reaction of arsenic trichloride with chlorobenzene using sodium as the reducing agent:
- AsCl3 3 PhCl 6 Na → AsPh3 6 NaCl
Reactions
Reaction of triphenylarsine with lithium gives lithium diphenylarsenide and phenyllithium:
- AsPh3 2 Li → LiAsPh2 LiPh
Triphenylarsine is the precursor to tetraphenylarsonium chloride, [AsPh4]Cl, a popular precipitating agent.
AsPh3 forms metal complexes with metals. Most are analogues of the corresponding triphenylphosphine derivatives. Examples include [IrCl(CO)(AsPh3)]2, [RhCl(AsPh3)3], and [Fe(CO)4(AsPh3)].
Tetraphenylarsonium chloride is prepared from triphenylarsine:
- (C6H5)3As Br2 → (C6H5)3AsBr2
- (C6H5)3AsBr2 H2O → (C6H5)3AsO 2 HBr
- (C6H5)3AsO C6H5MgBr → (C6H5)4AsOMgBr
- (C6H5)4AsOMgBr 3 HCl → (C6H5)4AsCl.HCl MgBrCl
- (C6H5)4AsCl.HCl NaOH → (C6H5)4AsCl NaCl H2O
References
