Clusters molybdenum chalcogenides

Chevrel R, Gougeon P, Potel M, Sergent M (1985) Ternary molybdenum chalcogenides A route to new extended clusters. J Solid State Chem 57 25-33... 

Hughbanks T, Hoffmann R (1983) Molybdenum chalcogenides Clusters, chains, and extended solids. The approach to bonding in three dimensions. J Am Chem Soc 105 1150-1162... 

The situation is very similar in the Chevrel phases. These are ternary molybdenum chalcogenides A,.[Mo6Xg] (A = metal, X = S, Se) that have attracted much attention because of their physical properties, especially as superconductors. The parent compound is PbMo6Sg it contains Mo6Sg clusters that are linked with each other in such a way that the free coordination sites of one cluster are occupied by sulfur atoms of adjacent clusters (Fig. 13.9). The electric properties of Chevrel phases depend on the number of valence electrons. With 24 electrons per cluster (one electron pair for each edge of the... 

Mo4 clusters have been identified in many solid phases of molybdenum chalcogenides including PbMo6S8,278 MoSX (X - Cl, Br,I)2 and GaMo4(YY ) (Y, Y - S, Se, Te)-290 the physical properties of these systems are of particular significance. Tetrahedral arrays of... 

Chevrel Phases Ternary molybdenum chalcogenides, M Mo X, are polynuclear clusters of special... 

H.-L.Luo Thin-Film Ternary Superconductors. - H.Nohl, W.Klose, O.K Andersen Band Structures of MxMogXg- and M2Mo6X6-Cluster Compounds. - S.D. Bader, S.K.Sinha, B.P.Schweiss, B.Renker Phonons in Ternary Molybdenum Chalcogenide Superconductors. -F.Pobell, D. Rainer, H. Wiihl Electron-Phonon Interaction in Chevrel-Phase Compounds. - Subject Index. 

A class of metal cluster superconductors of particular Interest consists of ternary molybdenum chalcogenides, conmonly known as the Chevrel phases (13). These phases were the first type of superconducting ternary system found to have relatively high critical temperatures and exhibited the highest known critical magnetic fields (Hc2 before discovery of the copper oxide... 

Just as, in Group VB, niobium, so, in this Group, molybdenum provides most of the examples of the chalcogenide halides. The occurrence and preparation of such compounds are described in numerous publications. In most cases, they have been obtained as powders, with the composition based on chemical analyses only. The presence of defined, homogeneous phases is, therefore, in many cases doubtful. In addition, some published results are contradictory. A decision is possible where a complete structure analysis has been made. As will be shown later, the formation of metal-metal bonds (so-called clusters), as in the case of niobium, is the most characteristic building-principle. Such clusters... 

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... 

Trinuclear Molybdenum and Tungsten Cluster Chalcogenides From Solid State to Molecular Materials... 

Fig. 6.1 The fundamental structural unit found in the Chevrel phases (cluster MoeXg full circles Mo atoms) displayed in three ways to emphasize different views of the connectivity. In (a) an octahedron of molybdenums (Mo-Mo = 2.7 A) is encased in a cube of chalcogens (Mo-S 2.45 or Mo-Se 2.6 A). Scheme (b) exhibits the same cluster as consisting of an octahedron with its triangular faces capped by chalcogenides. In (c), the cluster has been reoriented so that a threefold axis is vertical. (Reproduced from [10])...

Boulanger C, Lequir JM (1988) Molybdenum cluster chalcogenide electrochemistry-111. 

A-heterocyclic germylenes and related compounds 04CCR(248)411. Supramolecular compounds of cucurbituril and chalcogenide cluster aquocom-plexes of molybdenum and tungsten 03IZV987. 

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