Tungsten dichloride dioxide
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{{Chembox new
| Name = Tungsten(VI) dioxydichloride
| ImageFile = WO2Cl2.png
<!-- | ImageSize = 150px -->
| ImageName = Tungsten(VI) dioxydichloride
| OtherNames = tungsten(VI) dioxydichloride
| Section1 = {{Chembox Identifiers
| CASNo = 13520-76-8
}}
| Section2 = {{Chembox Properties
| Formula = WO<sub>2</sub>Cl<sub>2</sub>
| MolarMass = 286.75 g/mol
| Appearance = yellow crystals
| Density = 4.67 g/cm<sup>3</sup>, solid
| MeltingPt = 265 °C
| BoilingPt = sublimes > 350 °C in vacuo
| Solubility = decomposes
}}
| Section3 = {{Chembox Structure
| CrystalStruct = orthorhombic
}}
| Section7 = {{Chembox Hazards
| EUClass = not listed
}}
}}
'''Tungsten dichloride dioxide''' is the [[chemical compound]] with the formula [[Tungsten|W]][[Oxygen|O<sub>2</sub>]][[Chlorine|Cl<sub>2</sub>]]. This yellow-colored solid is used as a precursor to other tungsten compounds. Like other tungsten halides, WO<sub>2</sub>Cl<sub>2</sub> is sensitive to moisture, ungoing hydrolysis.
==Preparation==
WO<sub>2</sub>Cl<sub>2</sub> is prepared by ligand redistribution reaction:
: 2 [[tungsten trioxide|WO<sub>3</sub>]] + [[tungsten hexachloride|WCl<sub>6</sub>]] → 3 WO<sub>2</sub>Cl<sub>2</sub>
Using a two-zone furnace, a vacuum-sealed tube containing these solids is heated to 350 C. The yellow product sublimes to the cooler end of the reaction tube. No redox occurs in this process.<ref>Tillack, J. "Tungsten Oxyhalides" Inorganic Syntheses, 1973, XIV, 109-122. ISBN 0-07-071320-0.</ref> An alternative route highlights the "oxophilicity" of tungsten:<ref>Gibson, V. C.; Kee, T. P.; Shaw, A. "New, improved synthesis of the group 6 oxyhalides, W(O)Cl<sub>4</sub>, W(O)<sub>2</sub>Cl<sub>2</sub> and Mo(O)<sub>2</sub>Cl<sub>2</sub>" Polyhedron 1988, volume 7, pages 579-80.</ref>
:WCl<sub>6</sub> + 2 O(Si(CH<sub>3</sub>)<sub>3</sub>)<sub>2</sub> → 3 WO<sub>2</sub>Cl<sub>2</sub> + 4 ClSi(CH<sub>3</sub>)<sub>3</sub>
This reaction, like the preceding one, proceeds via the intermediacy of W(O)Cl<sub>4</sub>.
==Other tungsten oxy chlorides==
Tungsten forms a number of oxyhalides including WOCl<sub>4</sub>, WOCl<sub>3</sub>, WOCl<sub>2</sub>. The corresponding bromides are also known as is WO<sub>2</sub>I<sub>2</sub>.<ref>Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.</ref>
==Reactions==
WO<sub>2</sub>Cl<sub>2</sub> is a [[Lewis acid]], forming soluble adducts of the type WO<sub>2</sub>Cl<sub>2</sub>L<sub>2</sub>, where L is a donor ligand such as [[bipy]].
==References==
{{reflist}}
[[Category:Oxides]]
[[Category:Chlorides]]
[[Category:Tungsten compounds]]
[[Category:Inorganic compound stubs]]
{{inorganic-compound-stub}}
[[ar:ثنائي كلوريد ثنائي أكسيد تنغستن سداسي]]