Metal dusters

Trager F, zu Putfitz G (1986) Metal dusters. Springer, Berlin Heidelberg New York... 

Fig. U3 Tungsten-tungsten bond lengths as a function of bond order. Each of the points represents the mean and range of several values. See Chapter 16 for discussion of multiple bonds in metal dusters.

As you become more familiar with transition metal dusters (no nonmetals in the framework) you will come to associate doso structures with numbers of electrons. A trimer will have 48 electrons, a tetrahedron will have 60 electrons, a trigonal bipyramid will have 72 electrons, and an octahedron will have 86. Some care is required, however, as can be illustrated with Os,H2(CO),0. An electron count gives us 46 electrons rather than 48. If, however, we allow for one Os—Os double bond, the electron count is as expected. In accord with this expectation, one osmium-osmium bond is found to be shorter than the other two and the complex shows the reactivity expected for an unsaturated complex. 

Structures of small metal dusters-I Low temperature behavior (with D.G. Vlachos and L.D. Schmidt). J. Chem. Phys. 96, 6880-6890... 

Otvos JD and Armitage IM (1980) Structure of the metal dusters in rabbit liver metallothionein. Proc Natl Acad Sci USA 77 7094-7098. 

In certain early transition metal complexes and in metal dusters, organic nitriles can insert into metal-hydrogen or metal-carbon bonds (equations 92 and 93). Similarly, nucleophilic attack at coordinated nitrile can yield methyleneamido complexes (equation 94). 

Table S. Calculated [87] and experimental (in parentheses [73]) appearance critical sizes for the observation of multiply charged alkali metal dusters as a iunt n charge q.

The availability of small solids such as transition metal dusters [17-19] offers a field of research that raises basic questions How small must the number of atoms be for the properties of the original metal to be lost. How does an ordered accumulation of atoms behave when it is no longer under the influence of its ambient bulk matter And, perhaps most important in the context of this subchapter What types of applications of these new materials in microelectronic devices can be expected in the future ... 

Another interesting approach to the synthesis of metal-duster core dendrimers involves the displacement of the acetonitrile ligand from the rhenium duster dication [Re6Se6(NCMe)6] with pyridyl-functionalized dendrons. The resultant structures 8.9 possess a hexanudear cluster core and exhibit electronic transitions that are very dependent on the structure of the dendrons [29]. 

Inorganic chemists understand the term tiuster differently than physical chemists or physicists do. It is no wonder then that the objects designated in these fields as dusters have very different characteristics and that their investigations give rise to quite different concepts and require many diverse methods, both experimental and theoretical. In the following, we will focus our attention on the electronic structures of those metal dusters and metal duster compounds which represent the most important systems in each area. It will become dear that despite their often very different characteristics, the same, or at least rather similar, concepts and methods in theoretical chemistry may be profitably applied to both types of metal dusters. By highlighting both their similarities and their differences, the juxtaposition of these two classes of metal dusters will provide a more ludd view on each of them. 

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