Oxidative addition of arsenic halides to platinum(0)

Abstract

Reaction of AsCl₃ with Pt(0) complexes [Pt(PCy₃)₂], [Pt(PCy₃)(IMes)] and [Pt(IMes)₂] (IMes = 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene) resulted in oxidative addition of As–Cl bonds at the Pt centres to form complexes of the form trans-[PtCl(AsCl₂)L₂]. Two of these compounds were characterised by X-ray diffraction, making them the first structurally characterised examples of AsX₂ ligands (X = halogen). AsBr₃ also underwent oxidative addition to [Pt(PCy₃)₂], forming trans-[PtBr(AsBr₂)(PCy₃)₂] in situ, as judged by ³¹P NMR spectroscopy. This reaction was unselective, yielding several products, of which a Pt₃As₂ cluster could be identified by single-crystal X-ray diffraction.