Tungsten oxyhalides

When niobium(IV) fluoride is heated to approximately 400°C., it begins to lose niobium(V) fluoride. At 400°C. cubic Nb6FiS is formed according to the reaction described by the equation  

When the decomposition reaction is performed in silica or glass containers, Nb(0,F)3 results. These materials are gray-black to black, refractory materials having the rhenium trioxide type of cubic structure, with a cell constant varying from 3.889 to 3.917 A.2 These materials contain variable amounts of oxygen and have often been erroneously identified as NbF3. 

Gortsema and R. Didchenko, assigned to Union Carbide Corporation, U.S. patent 3,272,592, 

Schafer, H. G. Schnering, K. J. Niehues, and H. G. Nieder-Vahrenholz, J. Less-Common Metals, 9,95 (1965). 

The thin yellow flakes of tungsten(VI) dichloride dioxide, and the compounds to be mentioned later as well, are sensitive to atmospheric moisture. Therefore the reaction tubes must be opened in a dry nitrogen atmosphere and stored either under vacuum or in a dry inert gas. The detailed physical and chemical properties of tungsten(VI) dichloride dioxide are described in the literature.1 

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Molybdenumfvi) and Tungsten(vi).—Halide, Oxyhalide, and Related Complexes. The MF6-XeF2 (M = Mo or AV) binary systems have been studied by... 

Tungsten halides and oxyhalides such as WCl, WBr or WOCI4 were the first unicomponent ROMP cata-... 

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