Clusters halide chalcogenide

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... 

Octahedral clusters of the electropositive metals, groups 3 to 7, are stabilized by 7r-donor ligands such as halides, chalcogenides, and alk-oxides, but the majority accessible to solution chemistry are the halide complexes. These highly s5Tnmetric and aesthetically pleasing MeYs " and clusters contain a robust core of six metal... 

Phosphine complexes of Cu, Ag, and Au halides have also been used in an attempt to synthesize clusters having chalcogenide ligands. [213, 214] If, for example, [AgCl(PPh3)3] is allowed to react with E(SiMc3)2 (E = S, Se) in organic... 

The [MgXg] clusters found in the iodides Nbgln, [33] CsNbglu, [34] NbgIg(NR3)g, [35] and the unusual chain compound NbgLS [36] are rather an exception for the valence electron poor metal Nb. This type of duster however, is common with the (chalcogenide) halides of the more electron rich metals Mo [7, 9, 37, 38] and W as well as the (halide) chalcogenides of Re [7, 9, 39] and Tc. [40] There is a suffident number of d electrons in the dihalides of Mo and W to fill... 

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... 

S. C. Lee and R. H. Holm, Nonmolecular metal chalcogenide/halide solids and their molecular cluster analogues. Angew. Chem. Int. Ed. 29 (1990) 840. 

Germanes hydride, 2 76 reactivity of, 2 87 Germanium anionic cluster, 24 227 azides, preparation, 9 138 properties, 9 135-136, 139, 141 binary carbide not reported, 11 211 carbides, preparation of, 11 163 chalcogenide halides, 23 390 chlorides, mass spectra of, 18 248, 249 complexes, xenon fluoride reactions, 46 85 compounds, see also Organogermanium compounds... 

X-ray crystallography, 40 20-21 synthetic models, 40 23-48 xanthane oxidase, 40 21-23 chalcogenide halides, 23 370-377, 413 Chevrel phases, 23 376-377 metal-metal bonding, 23 330, 373 structural data, 23 373-376 as superconductors, 23 376 synthesis, 23 371-372 chloride, 46 4-24, 35-44 heterocations of, 9 290, 291 cluster compounds, 44 45-46 octahedral, 44 47-49, 53-63 electronic structure, 44 55-63 molecular structure, 44 53-54 synthesis, 44 47-49 rhomboidal, 44 75-82 solid-state clusters and, 44 66-72, 74-75, 80-82, 85-87 tetrahedral, 44 72-75 triangular, 44 82-87 cofactor, 40 2, 4-12 anaerobic isolation, 40 5 molybdopterin and, 40 4-8 reduced form, 40 12 synthesis, 40 8-12 xanthine oxidase, 45 60-63 complexes... 

NMR spectra heteronuclear gold cluster compounds, 39 345-348 Phalaris canariensis esophageal cancer, 36 144-145 scanning proton microprobe, 36 149 structural motifs of silicas, 36 146 Pharmaceuticals, 18 177 Phase transitions, in chalcogenide halide compounds, 23 332, 408, 412 [PhCHjMejNAlHjlj, 41 225-226 [(PhCH2)jNLi]3 molecular structure, 37 94, 96 in solution, 37 107-108... 

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