CLUSTERS chemistry

Gonzalez-Moraga G 993 Cluster Chemistry (BerWn Springer)... 

Berg C, Beyer M, Achatz U, Joes S, Niedner-Schatteburg G and Bondybey V 1998 Effect of charge upon metal cluster chemistry reactions of Nb and Rh anions and cations with benzene J. Chem. Rhys. 108 5398... 

Thus far the importance of carbon cluster chemistry has been in the discovery of new knowl edge Many scientists feel that the earliest industrial applications of the fullerenes will be based on their novel electrical properties Buckminsterfullerene is an insulator but has a high electron affinity and is a superconductor in its reduced form Nanotubes have aroused a great deal of interest for their electrical properties and as potential sources of carbon fibers of great strength... 

As a result of the systematic application of coordination-chemistry principles, dozens of previously unsuspected stnicture types have been synthesized in which polyhedral boranes or their anions can be considered to act as ligands which donate electron density to metal centres, thereby forming novel metallaboranc elusters, ". Some 40 metals have been found to act as acceptors in this way (see also p. 178). The ideas have been particularly helpful m emphasizing the close interconnection between several previously separated branches of chemistry, notably boron hydride clu.ster chemistry, metallaboranc and metallacarbaborane chemistry (pp. 189-95). organometallic chemistry and metal-metal cluster chemistry. All are now seen to be parts of a coherent whole. 

Structural and bonding patterns in cluster chemistry. K. Wade, Adv. Inorg. Chem. Radiochem., 1976,18,1-66 (220). 

Developments in transition metal cluster chemistry — the way to large clusters. G, Schmid, Struct. Bonding (Berlin), 1985,62, 51 (132). 

Structural and Bonding Patterns in Cluster Chemistry K. Wade... 

Schmelcher PS, Cederbaum LS (1996) Two Interacting Charged Particles in Strong Static Fields A Variety of Two-Body Phenomena. 86 27-62 Schmid G (1985) Developments in Transition Metal Cluster Chemistry. The Way to Large Clusters. 62 51-85... 

Reactivity studies of organic ligands with mixed-metal clusters have been utilized in an attempt to shed light on the fundamental steps that occur in heterogeneous catalysis (Table VIII), although the correspondence between cluster chemistry and surface-adsorbate interactions is often poor. While some of these studies have been mentioned in Section ll.D., it is useful to revisit them in the context of the catalytic process for which they are models. Shapley and co-workers have examined the solution chemistry of tungsten-iridium clusters in an effort to understand hydrogenolysis of butane. The reaction of excess diphenylacetylene with... 

In this article we will review some recent results in mixed-halide zirconium cluster chemistry, which were developed starting from John Corbetts protocols. 

John D. Corbett once said There are many wonders still to be discovered [4]. This certainly holds generally for all the different areas and niches of early transition cluster chemistry and especially for the mixed-hahde systems. The results reported above so far cover a very Hmited selection of only chloride/iodide systems and basically boron as the interstitial. Because of the very sensitive dependence of the stable stracture built in the soHd-state reaction type on parameters like optimal bonding electron counts, number of cations present, size and type of cations (bonding requirements for the cations), metal/halide ratio, and type of halide, a much larger mixed-hahde cluster chemistry can be expected. Further developments, also in mixed-hahde systems, can be expected by using solution chemistry of molecular clusters, excised from solid-state precursors. 

Solid-state cluster chemistry is dominated by octahedral (M 5L8)L6 and (MsLi2)L units which are the focus of this paper. These two cluster types are different in the way the metal octahedral core is surrounded by the ligands. In (MsLg)L6-type clusters (Fig. 6.1a), typical for molybdenum and rhenium halides, chalcogenides, and chalcohalides, eight innei hgands (L ) cap the octahedron faces and six outer ligands (L ) are located in the apical positions [9]. For metals with a smaller number of valence electrons, the (M6L i2)L -type clusters... 

Long et al. reported the synthesis of tungsten oxychloride clusters via a soft-chemistry route [60], which confirms the potential for wide applications of the ligand combination strategy in cluster chemistry. 

E. (ed.). Modern Perspectives in Inorganic Crystal Chemistry, Kluwer Academic Publishers, Netherlands, 1992 (e) Gonzalez-Moraga, G. Cluster Chemistry, Springer, New York, 1993 (f) Corbett, J.D./. Alloys Compd. 1995, 229, 10-23 (g) Cotton,... 

J.D. Corbett, Structural and Electronic Paradigms in Cluster Chemistry, 87 (1997), 157. 

Mingos, D.P. Wales D.J. Introduction to Cluster Chemistry 1990, Prentice Hall, Englewood Cliffs, New Jersey. 

These early results demonstrating the richness of unsupported cluster chemistry are very promising, and much more extensive studies are currently in progress. 

Schmid, G. Developments in Transition Metal Cluster Chemistry. The Way to Large Clusters. Vol. 62, pp. 51-85. 

D. M. P. Mingos, D. J. Wals, Introduction to Cluster Chemistry. Prentice-Hall, 1990. 

J.D. Corbett, Structural and bonding principles in metal halide cluster chemistry. In Modem Perspectives in Inorganic Crystal Chemistry (E. Parthe, ed.), p. 27. Kluwer, 1992. 

The field of alkyl and aryl Co complexes in low formal oxidation states has been extensively studied, and is frequently associated with cluster chemistry.92 Alkyl and aryl ligands, with or without additional functionality, are often co-ligands with tt acceptors such as carbonyls and/or phosphines, e.g., (MeOCOCH2)Co(CO)3(PPh3).93 A simple example of a cluster is (RC)Co3(CO)9, where the triangular Co(CO)3 3 moiety is capped by the 73-alkyl fragment, which occupies the apex of a distorted Co3C tetrahedron. 

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