Structure and Properties of Naked Clusters

We will discuss metal clusters of both the main group and transition metal elements, although such a distinction is not really necessary in fact, many of the features typical of metal dusters and also their size effects have been observed for both transition metal as well as simple metal dusters. However, an obvious, but important difference is that the latter are much easier to treat theoretically and, indeed, have been studied at a much higher level of accura y. Thus, a coherent understanding of size effects in main group dusters will also be very helpful in the description of transition metal dusters. 

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This paper is a report of recent experimental observations concerning the structure and properties of naked metal clusters which ease the comparison with molecular clusters. The same nuclearity range will be considered naked clusters Mjjj, with m < 60, will be compared to molecular clusters Mj Ln with m < 55. The transformations of molecular clusters into naked clusters and vice versa, with or without changes in nuclearity and/or composition, will be discussed. Recent studies... 

A discussion of the electronic structure and properties of clusters, naked or ligated, would not be complete without addressing the problem of supported metal clus-... 

Roy, S., 8c Springborg, M. (2003). A theoretical study of structural and electronic properties of naked stoichiometric and non-stoichiometric Indium Phosphide clusters. The Journal of Physical Chemistry B, 107, 2771-2779. 

The naked C60 cluster (a fullerene) was briefly mentioned at the end of Chapter 2 as an example of a three-connect bare cluster with a delocalized system containing the external cluster electrons. Here we will discuss some properties of fullerene-derived solids (there is C60, but also C70, Cg4, etc.). At room temperature, solid C60 adopts an fee structure with weak van der Waals interactions between the C60 molecules. Look more closely at the structure of C60 itself. It has the highest symmetry possible for a molecule, Ih point group, and consists of a polyhedron with 20 hexagonal... 

Generally, a metal cluster can be regarded as a tiny metal particle. However, close inspection of the internal structure and electron configuration of a metal cluster will reveal that metal clusters are distinct from metal particles. Correspondingly, their physicochemical properties are also very different from those of metal particles. A metal cluster may be naked, but, in most cases, they are enclosed by ligands, because otherwise they would not be stable. Because in a zeolite there are framework O and extraframework cations, and these O or extra-framework cations can protect the metal clusters in the channels of zeolites, the metal clusters may be stabilized.131... 

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