Heteronuclear clusters moieties

Protonation and deprotonation reactions have been reported for Group IB metal heteronuclear clusters (e.g.,66,103), but cleavage of the coinage metal moiety from the cluster often occurs instead (e.g., 20). 

A great variety of heteronuclear gold cluster compounds are known. In many of these clusters the AUPR3 moiety behaves like an isolobal proton" " and bridges an edge of a transition metal cluster. While another type of heteronuclear clusters is built up by one central transition metal atom and up to twelve gold atoms, as described in several reviews. " ... 

It is possible that a heteronuclear molecular cluster can offer a suitable explanation of these latter results a greater variety of heteronuclear molecular clusters with different transition metals are known. However most of them possess three or four metal atoms and do not represent the best models for very small particles of alloys. Examples of heteronuclear clusters with more than four metal atoms are rare. An interesting example is given by the hexanuclear iridium-copper complex syn-thetized by Bruce et al [135] of formula Cu4lr2(PPh3)2 ( C = C-Ph)g. In this cluster the six metal atoms form a distorted octahedron in which two PhaP-Ir moieties are mutually trans four — C = C-Ph units are only a bonded to each Ir atom and four — C = C-Ph units (one from each Ir) form tt linkages to each of the four equatorial copper atoms (Figure 25). 

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