Gold(II) Trihalide Complexes from Organogold(III) Precursors.

The mononuclear gold(II) halide complexes [AuCl3 ]- and [AuBr3 ]- are formed in the gas phase by collision-induced homolytic splitting of the only Au-C bond in the monoalkylgold(III) precursors [CF3 AuX3 ]- . The geometries of the whole series of [AuX3 ]- complexes (X=F, Cl, Br, I) have been calculated by DFT methods. It has also been found that the neutral AuX2 molecules behave as unsaturated species, showing significant affinity for an additional X- ligand. Moreover, in the open-shell [AuX3 ]- anions, homolytic splitting of one of the Au-X bonds and formation of the lower-valent [AuX2 ]- anions is favored over non-reducing halide dissociation. They should therefore be prone to disproportionation.