The synthesis of palladium-gold and platinum-gold bimetallic complexes based upon bis(diphenylarsino)methane: Crystal structure of trans-[Pd(μ-Ph 2AsCH 2AsPh 2AuCl) 2Cl 2]· xCH 2Cl 2

Abstract

The reaction of trans-[M( η 1-Ph 2AsCH 2AsPh 2) 2Cl 2] (M  Pd or Pt) with Au(tht)Cl (tht  tetrahydrothiophen) formed trans-[M(μ-Ph 2AsPh 2AsPh 2AuCl) 2Cl 2], from which the corresponding bromides were made by reaction with LiBr. Oxidative addition of the appropriate dihalogen formed trans-[M(μ-Ph 2AsCH 2AsPh 2AuX 3) 2X n ] (M  Pd, n = 2; MPt, n = 4). The structure of the complex trans-[Pd( μ-Ph 2AsCH 2AsPh 2AuCl) 2Cl 2]· xCH 2Cl 2 has been determined ans shown to contain trans square planar palladium atoms [PdCl 2.291 (av), PdAs 2.416(2), 2.400(2) Å]. Each bis(diphenylarsino)methane ligand coordinates to palladium and gold [AsAu 2.331(2), 2.340(2) Å], but there are no significant Pd·Au interactions. The ligand Me 2AsCH 2AsMe 2 formed only insoluble, probably polymeric, 1:1 complexes [{MCl 2(Me 2AsCH 2AsMe 2)} n ], whilst reaction of [PdCl 2(Ph 2SbCH 2SbPh 2) 2] with [Au(tht)Cl] produced [PdCl 2(Ph 2SbCH 2SbPh 2)] 2 and [ClAu(Ph 2SbCH 2SbPh 2)AuCl].