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Variations characteristic of metal clusters

Although the principles of cluster bonding developed for main-group clusters carry over to transition-metal clusters of the group 8/9 metals with carbonyl ligands, we fully expect transition metals to exhibit variations on this cluster bonding theme as well as novel behavior not seen in main-group systems. In this section we introduce those aspects of cluster chemistry characteristic of transition-metal clusters. [Pg.96]

A cluster with an interstitial atom requires fewer external ligands. The total number of external ligands are limited by the space available on a cluster surface. Hence, although [Fe6C(CO)i6]2 is known, 11 CelCO) 1 hI2 is not. On the other hand, the larger surface of the Ru analog permits both [Ru6C(CO)i7] and [Ru6(CO)i8]2- to be [Pg.97]

The eve count, which includes the external ligands, hides the similarity in cluster bonding counts that exists for capped and uncapped clusters. The simple octahedral cluster has 14n + 2 = 86 eve whereas the capped octahedral cluster possesses 98 eve, i.e., 14 x 6 + 2 + 12. The correction is numerically the same but in the opposite sense to that necessary when a single vertex of a closed cluster is left vacant, i.e., in the case of capping one adds the non-bonding and ligand electrons associated with the added vertex. It follows that one adds 12 electrons to the eve count of the primary cluster for each cap present. [Pg.100]

In8R6 which consists of a In6R.4 octahedron (bare In atoms trans) capped by two RIn fragments in a transoid geometry. Formally the RIn fragments contribute two electrons each and the In contribute one if a lone pair is assumed, yielding sep = 7. [Pg.101]

Exercise 3.6. A cluster is found to have the molecular formula [Os+CO ]2-. Generate a set of likely cluster geometries. [Pg.102]


See other pages where Variations characteristic of metal clusters is mentioned: [Pg.96]    [Pg.97]    [Pg.99]    [Pg.101]    [Pg.103]    [Pg.105]    [Pg.107]    [Pg.109]    [Pg.111]    [Pg.113]    [Pg.115]    [Pg.117]    [Pg.119]    [Pg.96]    [Pg.97]    [Pg.99]    [Pg.101]    [Pg.103]    [Pg.105]    [Pg.107]    [Pg.109]    [Pg.111]    [Pg.113]    [Pg.115]    [Pg.117]    [Pg.119]    [Pg.335]    [Pg.475]    [Pg.146]    [Pg.94]    [Pg.515]    [Pg.262]    [Pg.38]    [Pg.676]    [Pg.115]    [Pg.150]    [Pg.504]    [Pg.504]    [Pg.5160]    [Pg.522]    [Pg.610]    [Pg.662]    [Pg.274]    [Pg.33]    [Pg.5159]    [Pg.1350]    [Pg.2515]    [Pg.120]    [Pg.254]    [Pg.9]    [Pg.146]    [Pg.115]    [Pg.97]    [Pg.237]    [Pg.36]    [Pg.58]    [Pg.293]    [Pg.263]    [Pg.450]    [Pg.496]    [Pg.496]    [Pg.227]   


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