Metal cluster naked clusters

Valence Bond Studies of Metallic Bonding Naked Clusters and Applications to Bulk Metals. 

Cobalt, nickel and copper naked metal clusters and olefin chemisorption models. G. A. Ozin, Coord. Chem. Rev., 1979, 28, 117-146 (45). 

Cryophotochemical techniques have been developed that (i) allow a controlled synthetic approach to mini-metal clusters 112), Hi) have the potential for "tailor-making small, bimetallic clusters (mini-alloy surfaces) 114,116), Hi) permit the determination of relative extinction-coefficients for naked-metal clusters 149), and iv) allow naked-cluster, cryophotochemical experiments to be conducted in the range of just a few atoms or so 112,150,151). 

Examples of the application of the mentioned rules to a few naked metal clusters according to Mingos and Wales (1990) are reported in Table 4.4. For each species the valence electron (s and p) count is made both on the basis of the component valences by adding/subtracting one electron for each negative/positive charge, and on the basis of the geometry and the number of vertices. 

Palladium metallic clusters have been prepared at room temperature by sonochemical reduction of Pd(OAc)2 and a surfactant, myristyltrimethylammonium bromide, in THE or MeOH [160[. It is noteworthy that nanosized amorphous Pd is obtained in THE, but in a crystalline form in MeOH. In this solvent, and in higher homologous alcohols, sonolysis of tetrachloropalladate(II) leads to Pd nanoclusters in which carbon atoms, formed by complete decomposition of the solvent, can diffuse. This results in an interstitial solid having the formula PdQ (0 < x < 0.15) [161]. Noble metal nanoparticles of Au, Pd, and Ag are obtained by sonicating aqueous solutions of the corresponding salts in the presence of a surfactant, which largely stabilise the naked col-... 

Teixidor F, Leutkens ML Jr, Rudolph RW (1983) Transition-metal insertion into naked cluster polyanions. J Am Chem Soc 105 149-150... 

Rudolph RW, Wilson WL, Taylor RC (1981) Naked-metal clusters in solution. 4. Indications... 

Rudolph RWT, Young RC (1979) The nature of naked metal clusters in solution. In Tsutsui M (ed) Fundamental research in homogeneous catalysis, vol 3. Plenum, New York, pp 997-1005... 

Nine-metal arrays in conventional coordination clusters are the confacial bioctahedron and two M4 cubanes linked through a non-cluster metal atom among naked metal clusters the M9 polyhedron is the tricapped trigonal prism or the monocapped square antiprism, and in gold clusters the metal array is the centred cube, the centred crown, or a fragment of the centred icosahedron. 

The heavier elements of Group 13, in particular thallium, are able to form discrete naked clusters with alkali metals. Table 13.7.1 lists some examples of Tl - naked anion clusters, and Fig. 13.7.3 shows their structures. 

Molecular structures of some transition-metal clusters containing a naked carbon atom. 

Metal clusters in zeolites can be regarded as intermediate forms between the naked clusters and clusters which are stabilized chemically by a ligand shell. Fe and Co clusters with diameters of 4-11 A have been prepared from bis(toluol)metal complexes and NaY zeolite93 ). 

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