Tetrachloride Oxide

Cl interactions through the basal plane, suggesting incipient dimer 

Imido ligands are not included in this synthesis herewith. 

Submitted by PAUL R. SHARP, JEFFREY C. BRYAN,f aud JAMES M. MAYERf 

The procedures described are conducted under an inert atmosphere using either Schlenk-vacuum-line or dry-box techniques. An argon atmosphere is recommended for the reduction reactions because of the facile formation of low valent tungsten dinitrogen complexes. Solvents must be free of oxygen and water. Toluene and tetrahydroliiran (THF) are distilled from CaH2 or sodium benzophenone. Pentane is distilled from n-butyl lithium or CaHj. Dichloromethane is distilled from CaHj or P4O10. 

The red crystalline product is sensitive to air in solution but much less so in the solid state. Solid samples show little decomposition after several days in the air but decompose to a white solid after several weeks exposure. The X-ray crystal structure shows an approximate capped octahedral geometry. The product is paramagnetic but gives a relatively sharp HNMR (CD2O2) signid at —7.9 ppm (Av,/2 4 Hz). It is soluble in dichloromethane, slightly 

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Rhenium tetrachloride oxide, 4167 Rhodium(III) chloride, 4155 Rhodium tetrafluoride, 4349 Ruthenium(III) chloride, 4156 Silver chloride, 0008... 

Rhenium tetrachloride oxide, 4167 Ruthenium(VIII) oxide, 4862... 

The crude tetrachloride mixture of zirconium and hafnium is dissolved in ammonium thiocyanate solution. The solution is extracted with methyl isobutyl ketone (MIBK). MIBK is passed countercurrent to aqueous mixture of tetrachloride in the extraction column. Halhium is preferentially extracted into MIBK leaving zirconium in the aqueous phase. Simultaneously, zirconium tetrachloride oxidizes to zirconyl chloride, ZrOCb. When sulfuric acid is added to aqueous solution of zirconyl chloride, the chloride precipitates as a basic zirconium sulfate. On treatment with ammonia solution the basic sulfate is converted into zirconium hydroxide, Zr(OH)4. Zirconium hydroxide is washed, dried, and calcined to form zirconium oxide, Zr02. 

Mg+" reacts with alkyl halides in the gas phase via a range of substrate-dependent pathways Not all halides are reactive—examples of unreactive substrates include methyl chloride, vinyl chloride, trichloro and tetrachloro ethylene. Reaction with ethyl chloride proceeds via an elimination reaction (equation 18) followed by a displacement reaction (equation 19). For larger alkyl halides, such as isopropyl chloride, chloride abstraction also occurs (equation 20). For multiply halogenated substrates such as carbon tetrachloride, oxidative reactions occur (equations 21 and 22), although organometallic... 

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 ... 

Slightly soluble in air-free water soluble in alcohol, benzene, chloroform, acetone, and carbon tetrachloride. Oxidizes in air.1... 

Dimethylacetamide is incompatible with carbon tetrachloride, oxidizing agents, halogenated compounds, and iron. It attacks plastic and rubber. Contact with strong oxidizers may cause fire. 

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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