Niobium chalcogenides

Although not yet published in a journal, according to thesis work, the vanadium compounds VSCl (11), VSBr, and VSI (208) seem to exist. Numerous niobium chalcogenide halides have been reported, and among these are the best characterized examples of Group VB (see Table X). Only two tantalum compounds, TaSjCU (361) and TaSCls (13) have thus far been described in the literature. 

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... 

Rouxel J (1992) Low-dimensional solids An interface between molecular and solid-state chemistry The example of chainlike niobium and tantalum chalcogenides. Acc Chem Res 25 328-336... 

Li J, Badding ME, DiSalvo FJ (1992) New layered ternary niobium teUurides Synthesis, structure, and properties of NbMTe2 (M = Fe, Co). Inorg Chem 31 1050-1054 Tremel W, Kleinke H, Derstroff V, Reisner C (1995) Transition metal chalcogenides New views on an old topic. J Alloy Compd 219 73-82... 

Heterometal alkoxide precursors, for ceramics, 12, 60-61 Heterometal chalcogenides, synthesis, 12, 62 Heterometal cubanes, as metal-organic precursor, 12, 39 Heterometallic alkenes, with platinum, 8, 639 Heterometallic alkynes, with platinum, models, 8, 650 Heterometallic clusters as heterogeneous catalyst precursors, 12, 767 in homogeneous catalysis, 12, 761 with Ni—M and Ni-C cr-bonded complexes, 8, 115 Heterometallic complexes with arene chromium carbonyls, 5, 259 bridged chromium isonitriles, 5, 274 with cyclopentadienyl hydride niobium moieties, 5, 72 with ruthenium—osmium, overview, 6, 1045—1116 with tungsten carbonyls, 5, 702 Heterometallic dimers, palladium complexes, 8, 210 Heterometallic iron-containing compounds cluster compounds, 6, 331 dinuclear compounds, 6, 319 overview, 6, 319-352... 

Sokolov MN, Fedin VP. Chalcogenide clusters of vanadium, niobium and tantalum. Coord Chem Rev 2004 248 925 14. 

Fig. 20. Example of F[b]H2 het-eropolyhedral association in the halogeno-chalcogenide of niobium Nb3Se5Cl7...

The alkali metal rhenium- and technetium chalcogenide clusters described in Section 5.6 are also octahedral.These clusters have M6Es units with eight face-capping anions on the octahedral faces in contrast to the niobium halide or oxide clusters. The A4M6S14 (A = alkali metal, M — Re, Tc), Cs6Rc6Si2, and... 

Later there was a suggestion to employ sulfur and fhen chalcogenides, primarily sulfides, as active materials for the positive electrode. Sulfur is liquid at the working temperature of the battery. The sulfur elecfrode was manufactured from a mixture of sulfur and carbon or in fhe form of a niobium box wifh niobium filler packed wifh sulfur. The high volafilify of sulfur (af 507°C fhe pressure of sulfur vapor is... 

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