Mixed gold(I)-gold(III) complexes with bridging selenido ligands. Theoretical studies of the gold(I)-gold(III) interactions

Abstract

The gold(I) compounds [Se(AuPPh3)2] and [Se{Au2(μ-dppf)}] (dppf = 1,1′-bis(diphenylphosphino)ferrocene) react with 1 and 2 equiv of [Au(C6F5)3OEt2] to give the mixed gold(I)-gold(III) derivatives [Se(AuPPh3)2{Au(C6 F5)3}n] and [Se{Au2(μ-dppf)}{Au(C6 F5)3}n] (n = 1, 2). The reaction of [Se(AuPPh3)2] with [Au(C6F5)2Cl]2 affords the complex [{Se(AuPPh3)}2{μ-Au-(C6 F5)2}2]. The crystal structures of [Se{Au2(μ-dppf)}{Au(C6F5)3}] and [{Se(AuPPh3)}2{μ-Au-(C6 F5)2}2] have been characterized by X-ray diffraction studies. They show dissimilar Au(I)̇̇Au(III) distances, indicating the presence of weak interactions. Quasi-relativistic pseudopotential calculations on [Se(AuPH3)2(AuR3)], [Se(AuPH3) (AuR3)2]- (R = -H, -CH3), and [{Se(AuPH3)}2 {Au(CH3)2}2] models have been performed at Hartree-Fock and second-order Møller-Plesset perturbation theory levels. There is a good agreement between experimental and theoretical geometries at the MP2 level.