Cluster compounds gold phosphines

The yields of these reactions are often improved by the addition of thallium(I) or silver(I) salts to act as halide scavengers and so generate the gold phosphine fragment in situ. This modification has been most extensively utilized in the addition of Au(PR3)+ to anionic and neutral cluster compounds, and a number of examples are given below ... 

A number of examples of gold heteronuclear cluster compounds containing AuX fragments, where X is a ligand other than phosphine, have also been synthesized. An interesting example is provided by the compound [AuIr3H6(N03)(dppe)3]+ (71), prepared by the reaction... 

The addition of gold phosphine fragments to transition metal compounds is readily extended to include reactions of heteronuclear gold cluster compounds and has been used to build up clusters of increasing nuclearity, as the following examples illustrate ... 

The gold phosphine fragment has also been abstracted from heteronuclear cluster compounds as Au(PR3)X by reaction with halide ions... 

The 31P H NMR spectra of a number of heteronuclear gold cluster compounds are found to be deceptively simple and NMR studies have been used as a probe of the behavior of these species in solution. This is especially true of the higher nuclearity clusters, which often exhibit spectra that are much simpler than would be predicted on the basis of their solid-state structures. For example, [Pt(H)(PPh3)(AuPPh3)7]2+, which adopts the solid-state structure illustrated in Fig. 9 (137) in which the phosphine ligands occupy several different chemical environments within the molecule, shows only two resonances in the 31P 1H NMR spectrum. These are in a ratio of 7 1 and exhibit satellites due to coupling to the central platinum nucleus as Fig. 10 illustrates. 

We should also note the availability of cluster compounds that contain assemblies of gold atoms numbering 13, 39 or 55 7,16,19 they are stabilised by phosphine or other ligands and are quite readily prepared. Some remarks on the physical properties of the AU55 cluster will be made later (Section 3.4). 

Mixed-Metal-Gold Phosphine Cluster Compounds 279... 

MIXED-METAL-GOLD PHOSPHINE CLUSTER COMPOUNDS... 

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