Mono-, bi-, and tri-nuclear bis(diphenylphosphino)methane gold complexes. Crystal and molecular structures of [bis(diphenylphosphino)methane]bis(pentafluorophenyl)gold(III) perchlorate and 1,2; 2,3-di-µ-[bis(diphenylphosphino)methane]-1,3-dichlorotrigold(I) chlorotris(pentafluorophenyl)aurate(III)

Abstract

Reactions of gold(III) complexes of the types [AuClR₂(dppm)] and [AuR₃(dppm)](R = C₆F₅, dppm = bis(diphenylphosphino)methane] with other gold complexes, such as [Au(O₃ClO)(PPh₃)], [Au(C₆F₅)(tht)], [AuCl(tht)], or [AuCl₃(tht)](tht = tetrahydrothiophene) which contain a readily displaceable ligand (O₃ClO^– or tht), lead to the formation of cationic binuclear complexes of the types [R₂ClAu(dppm)Au(PPh₃)]ClO₄ and [R₃Au(dppm)Au(PPh₃)]ClO₄ or of neutral ones [R₂ClAu(dppm)AuX] and [R₃Au(dppm)AuX](R = C₆F₅, X = Cl or C₆F₅). Reaction of [AuClR₂(dppm)] with AgClO₄ gives [AuR₂(dppm)]ClO₄ which has been structurally identified by X-ray crystallography. The crystals are orthorhombic, space group Pnma, with a= 17.204(4), b= 20.053(4), c= 11.348(2)Å, Z= 4, and R= 0.065 for 3 401 unique observed reflections. Oxidation of [XAu(dppm)AuX](X = Cl or C₆F₅) with [TlClR₂] or TlCl₃ leads to the cationic trinuclear complex [ClAu(dppm)Au(dppm)AuCl][AuClR₃], whose crystal structure has also been determined : space group P, with a= 12.170(6), b= 14.448(8), c= 23.780(10)Å, α= 101.29(5), β= 90.01 (4), γ= 93.68(4)°, Z= 2, and R= 0.085 for 4 891 unique observed reflections. The cation shows short Au ⋯ Au contacts (ca. 3.1 Å).