Gold complexes clusters

unlike silver, forms a wide range of cluster complexes [184] where the average oxidation state of the metal is below +1 they may be synthesized by reduction of gold(I) phosphine complexes  

Crystallographic examination shows the clusters with eight or more gold atoms have structures based on an array of gold atoms surrounding a central gold atom. (Smaller polyhedra cannot accommodate a central gold because 

High nuclearity clusters [Au(AuPR3) ]JC+ with central gold atoms adopt two types of structure those with 12n + 18 electrons have essentially spherical structures, whereas those with 12n + 16 electrons have the peripheral atoms on the surface of a toroid. 

Au13(PMe2Ph) 0Cl2+(PF6)3 has an icosahedron of golds surrounding the central gold. 

There is evidently a flat potential energy surface for these clusters as different skeletal isomers can actually be isolated in the solid state for Au9[P(C6H40Me)3]8(N03)3 a brown form has a D4d crown structure and a green form has a D2h structure. In solution, however, they share a common structure with identical31P NMR spectra either the solution cluster has a regular arrangement of phosphines, or it is fluxional [186]. 

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Fig. 1. Examples of the synthesis of heteronuclear gold cluster complexes by the reaction of Au(PPh3)Cl with transition metal anions.

For gold clusters complexed by cyanide, the coalescence is still slower and oxidation of Au ,cn" by MV-+ is observed alone. 

Barton, D.G., Bowman, R.G., Dhingra, S., Ito, L., Schroden, R.C., Trent, D., Watson, K.J., and Weiner, H. (2008) Hydro-oxidation process using a catalyst prepared from a gold cluster complex, WO Patent 2008063880 Al. 

D.M.P. Mingos and M.J. Watson, Heteronuclear gold cluster complexes, Adv. Inorg. Chem., 39,327,1992. 

Dhingra, S., Schroden, R., Watson, K., et al. (2010). Hydro-oxidation Process Using a Catalyst Prepared from a Gold Cluster Complex, US Patent US20100076208. Dow Chemical Company Assignee. 

Triangular gold cluster complexes also show emissive properties. Thus, excitation of an acetonitrile solution of [Au3Cl HC(PPh3)2 2] leads to a photoluminescence centered at approximately 537 nm with a lifetime of 11 ps. The excited state redox potential for this [Au3] V[Au3] couple is -1.6V versus SSCE. ... 

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