Cluster chemistry ruthenium catalysts

It seems that one of the future developments in cluster chemistry lies in the production of nanosized particles (1 nm = 10 A) with well defined stoichiometries, which can be used as catalysts or as catalyst precursors. In this context, high nuclearity mixed-metal clusters are particularly useful because two or more metal atoms with different chemical properties can be combined in the same unit. The Cambridge group has spent the last few years designing rational synthetic routes to mixed-metal high nuclearity clusters of ruthenium and osmium with the coinage elements, which produce cluster cores of up to one nanometer in size. ... 

The chemistry of ruthenium carbonyl clusters is littered with instances where the simple trinuclear cluster acts as a catalyst. The list is lengthened by a study showing direct carbonylation of a C-H bond in a benzene ring of 2-phenyloxazo-lines catalysed by Ru3(CO)i2. 

Organometallic catalysis most often proceeds through a catalytic cycle that involves coordination of the substrate to the metal center of the catalyst. In all these reactions, the elementary steps of the catalytic action were beheved to occur within the first coordination sphere of the organometallic catalyst, but the most recent work of professor Georg SUss-Fink, in collaboration with Matthieu Faure and professor Thomas R. Ward, Institute of Chemistry, University of Neuchatel, Switzerland, showed that it need not always be so. They supplied evidence that the ruthenium cluster cation (Figure 15.8.1) catalyzes... 

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