Transition metal-gold compounds

The topic of molecular transition metal-gold bond-containing compounds, especially of cluster compounds, has developed considerably in recent years (Table 4.6). 

Several reviews of the chemistry ofheteronuclear gold clusters are available and the reader is referred to these works for earlier studies in the field [23-27]. Since the number of well structurally characterized compounds is quite large, this section will be focused only on the structures of basic compounds as well as the most recent results on molecular compounds containing Au-transition metal bonds or interactions. In many cases analogous compounds are available for the metals belonging to the same group and therefore, when appropriate, the common structural patterns will be presented for 

To the best of our knowledge there are no structure reports on species with Au-Group 3 metals (Sc, Y, La, Ac) as well as Au-lanthanoids and Au-actinoids bonds, or compounds with Au-Hf, Au-Zr or Au-Ta bonds or interactions. 

---

For reactions that involve transition metal hydride compounds, the gold(I) compounds Au(PR3)Me and Au(PR3)(OR ) have been shown to act as precursors to AuPR3, with the driving force for these reactions being provided by the elimination of methane or an alcohol, as in the following examples ... 

Carbonyl Complexes of the Transition Metals Cluster Compounds Inorganometalhc Compounds Containing Transition Metal Main Group Elements Cyanide Complexes of the Transition Metals Dinuclear Organometallic Cluster Complexes Gold Inorganic Coordination Chemistry. 

Organosulfur Adsorbates on Metal and Semiconductor Surfaces. Sulfur compounds (qv) and selenium compounds (qv) have a strong affinity for transition metal surfaces (206—211). The number of reported surface-active organosulfur compounds that form monolayers on gold includes di- -alkyl sulfide (212,213), di- -alkyl disulfides (108), thiophenols (214,215), mercaptopyridines (216), mercaptoanilines (217), thiophenes (217), cysteines (218,219), xanthates (220), thiocarbaminates (220), thiocarbamates (221), thioureas (222), mercaptoimidazoles (223—225), and alkaneselenoles (226) (Fig. 11). However, the most studied, and probably most understood, SAM is that of alkanethiolates on Au(lll) surfaces. 

Organometallic chemistry (see p. 1199) is not particularly extensive even though gold alkyls were amongst the first organo-transition metal compounds to be prepared. Those of Au are the most stable in this group, while Cu and Ag (but not Au ) form complexes, of lower stability, with unsaturated hydrocarbons. 

There are considerable numbers of the organogold compounds [3(b), 9,154], principally in the +1 and +3 oxidation states. Gold is unusual in transition metals in that, even in the +1 state, it has a marked preference for forming a-rather than zr-bonds, presumably related to the tendency of gold(I) to linear 2-coordination. 

The reaction of these platinum or palladium clusters with transition metal compounds has also been studied and many cluster derivatives have been prepared for this method, which included reactions with gold,3 02-3306 silver, 302,33 3,3307-3310 copper 3302,3303,3309-3311 Qr mercury com ... 

Salter, I. D. Molecular Compounds of Gold with Main Group and Transition Metals. Metal Clusters in Chemistry, Vol. 1, Braunstein, P. Oro, L. A. Raithby, R. R. Wiley-VCH Weinheim 1999, pp 509-534. 

Compounds (L)AuC=CR can appear as ligands in the coordination sphere of transition metals. The interaction may be fluxional with metal-metal contacts M-Au and the alkyne coordinated side-on (if, dihapto) to the gold atom. Typical examples are (cp)(CO)(NO)W[Ph3PAuC=C Bu 90 and l, c3(CO)9[R3PAuC=CtBu], with R = Ph, Pr, for which several isomers have been observed in solution.91... 

---