Selenolate Gold Complexes with Aurophilic Au(I)−Au(I) and Au(I)−Au(III) Interactions

The gold(I) selenolate compound [Au2(SePh)2(μ-dppf)] (dppf = 1,1‘-bis(diphenylphosphino)ferrocene) has been
prepared by reaction of [Au2Cl2(μ-dppf)] with PhSeSiMe3 in a molar ratio 1:2. This complex reacts with gold(I) or
gold(III) derivatives to give polynuclear gold(I)−gold(I) or gold(I)−gold(III) complexes of the type [Au4(μ-SePh)2(PPh3)2(μ-dppf)](OTf)2, [Au3(C6F5)3(μ-SePh)2(μ-dppf)], or [Au4(C6F5)6(μ-SePh)2(μ-dppf)], with bridging selenolate
ligands. The reaction of [Au2(SePh)2(μ-dppf)] with 1 equiv of AgOTf leads to the formation of the insoluble
Ag(SePh) and the compound [Au2(μ-SePh)(μ-dppf)]OTf. The complexes [Au4(C6F5)6(μ-SePh)2(μ-dppf)] and
[Au2(μ-SePh)(μ-dppf)]OTf (two different solvates) have been characterized by X-ray diffraction studies and show
the presence of weak gold(I)−gold(III) interactions in the former and intra- and intermolecular gold(I)−gold(I) inter-actions in the later.