Tungsten tetrachloride oxide

Submitted by Susan E. Feid, S. Y. Tyree, Jr., and F. N. Collier, Jr. Checked by Robert E. McCARLEYf and Peter B. FLEMiNof 

Tungsten oxide tetrachloride has been prepared by heating tungsten(VI) oxide in a bomb with thionyl chloride and with a solution of chlorine in carbon tetrachloride. In the following procedure it is prepared by refluxing tungsten-(VI) oxide with octachlorocyclopentene.f 

Caution, This reaction must be carried out in a well-ventilated hood, Octachlorocyclopentene should he handled with rubber gloves. 

Tungsten oxide tetrachloride can also be prepared, using the same procedure, by refluxing tungsten (IV) oxide with 

Tungsten oxide tetrachloride crystallizes in long, orange needles, which decompose instantly upon exposure to the atmosphere. The substance melts at 211° and boils at 232°. It is soluble in carbon disulfide and benzene and slightly soluble in carbon tetrachloride and dichloromethane. 

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K. lijima and S. Shibata, Chem. Lett., 1033 (1972). Molecular Structures of Molybdenum and Tungsten Oxide Tetrachlorides by Gas Phase Electron Diffraction. 

A stoichiometric mixture of 3.478 g. (15 mmoles) of tungsten-(VI) oxide and 11.897 g. (30 mmoles) of tungsten(VI) chloride is placed in the reaction tube, and an excess of 1 mg. of tungsten(VI) chloride per milliliter of tube volume is added. The tube is sealed under vacuum and heated in a temperature gradient of 200/175°C. with the reaction mixture placed in the hotter part of the furnace (Fig. 14). After about 10 hours the reaction is complete, and 15 g. of tungsten(VI) tetrachloride oxide are obtained (98% yield). The analyses of the sublimed product by the H-tube method are somewhat inaccurate, because of the extreme moisture sensitivity of this substance (loss of hydrogen chloride by hydrolysis). Anal. Calcd. for W0C14 W, 53.82 Cl, 41.50 O, 4.68. Found W, 54.20 Q, 41.40 O, 4.46. 

It has been determined by differential thermal analyses (D.T.A.) that tungsten(V) trichloride oxide decomposes above 290°C. without a sharp transition point. On cooling, a transition is observed at 210°C., the melting point of tungsten(VI) tetrachloride oxide. Therefore the decomposition of tungsten(V) trichloride oxide seems to take place by the following reaction ... 

Tungsten(VI) oxide tetrachloride is a common impurity in tungsten(VI) chloride. By anaiogy with niobium(V) oxide trichloride (Section 9.2.2), phosgene might have been expected to convert WOCi to WClj, according to ... 

In 1789 M. H. Klaproth examined pitchblende, thought at the time to be a mixed oxide ore of zinc, iron and tungsten, and showed that it contained a new element which he named uranium after the recendy discovered planet, Uranus. Then in 1828 J. J. Berzelius obtained an oxide, from a Norwegian ore now known as thorite he named this thoria after the Scandinavian god of war and, by reduction of its tetrachloride with potassium, isolated the metal thorium. The same method was subsequendy used in 1841 by B. Peligot to effect the first preparation of metallic uranium. 

The action of carbon tetrachloride or a mixture of chlorine with a hydrocarbon or carbon monoxide on the oxide.—H. N. Warren 9 obtained aluminium chloride by heating the oxide to redness with a mixture of petroleum vapour and hydrogen chloride or chlorine, naphthalene chloride or carbon tetrachloride was also used. The bromide was prepared in a similar manner. E. Demarpay used the vapour of carbon tetrachloride, the chlorides of chromium, titanium, niobium, tantalum, zirconium, cobalt, nickel, tungsten, and molybdenum H. Quantin, a mixture of carbon monoxide and chlorine and W. Heap and E. Newbery, carbonyl chloride. 

For large-scale preparations of the tetrachloride oxides, the reaction of the metal trioxide with sulfinyl chloride is most convenient. The procedure outlined below is similar to that of Col ten and co-workers,7 but gives details for obtaining the compounds, particularly tungsten tetrachloride oxide, in excess of 50-g quantities. The reactions may be scaled up or down several fold without deleterious effect. 

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