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Tungsten dichloride dioxide

Names
IUPAC name Tungsten(VI) dichloride dioxide
Other names Tungsten(VI) dioxydichloride Tungsten dichloride dioxide Tungstyl chloride
Identifiers
CAS Number	13520-76-8
3D model (JSmol)	Interactive image
ChemSpider	10652408
ECHA InfoCard	100.033.496
EC Number	236-862-1
PubChem CID	19092009
CompTox Dashboard (EPA)	DTXSID90894995
InChI InChI=1S/2ClH.2O.W/h2*1H;;;/q;;2*-2;/p-2Key: DVBXMVWZPVBSJY-UHFFFAOYSA-L InChI=1S/2ClH.2O.W/h2*1H;;;/q;;2*-2;/p-2
SMILES ....
Properties
Chemical formula	WO2Cl2
Molar mass	286.74 g·mol
Appearance	Yellow-red crystals
Density	4.67 g/cm
Melting point	265 °C (509 °F; 538 K)
Boiling point	Sublimes at > 350 °C in vacuum
Solubility in water	decomposes
Solubility	slightly soluble in ethanol
Structure
Crystal structure	orthorhombic
Hazards
GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H315, H319, H335
Except where otherwise noted, data are given for materials in their standard state (at 25 °C , 100 kPa). N verify (what is  ?) Infobox references

Tungsten dichloride dioxide, or Tungstyl chloride is the chemical compound with the formula WO₂Cl₂. It is a yellow-colored solid. It is used as a precursor to other tungsten compounds. Like other tungsten halides, WO₂Cl₂ is sensitive to moisture, undergoing hydrolysis.

Preparation

WO₂Cl₂ is prepared by ligand redistribution reaction from tungsten trioxide and tungsten hexachloride:

2 WO₃ + WCl₆ → 3 WO₂Cl₂

Using a two-zone tube 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. An alternative route highlights the oxophilicity of tungsten:

WCl₆ + 2 ((CH₃)₃Si)₂O → 3 WO₂Cl₂ + 4 (CH₃)₃SiCl

This reaction, like the preceding one, proceeds via the intermediacy of WOCl₄.

Structure

Gaseous tungsten dichloride dioxide is a monomer. Solid tungsten dichloride dioxide is a polymer consisting of distorted octahedral W centres. The polymer is characterized by two short W-O distances, typical for a multiple W-O bond, and two long W-O distances more typical of a single or dative W-O bond.

Related oxy halides

Tungsten forms a number of oxyhalides including WOCl₄, WOCl₃, WOCl₂. The corresponding bromides (WOBr₄, WOBr₃, WOBr₂) are also known as is WO₂I₂.

Reactions

WO₂Cl₂ is a Lewis acid, forming soluble adducts of the type WO₂Cl₂L₂, where L is a donor ligand such as bipyridine and dimethoxyethane. Such complexes often cannot be prepared by depolymerization of the inorganic solid, but are generated in situ from WOCl₄.

References

1. "C&L Inventory". echa.europa.eu. Retrieved 12 December 2021.
2. Tillack, J. (1973). "Tungsten Oxyhalides". Inorganic Syntheses. Vol. 14. pp. 109–122. doi:10.1002/9780470132456.ch22. ISBN 9780470132456. {{cite book}}: |journal= ignored (help)
3. Gibson, V. C.; Kee, T. P.; Shaw, A. (1988). "New, improved synthesis of the group 6 oxyhalides, W(O)Cl₄, W(O)₂Cl₂ and Mo(O)₂Cl₂". Polyhedron. 7 (7): 579–80. doi:10.1016/S0277-5387(00)86336-6.
4. Ward, Brian G.; Stafford, Fred E. (1968). "Synthesis and Structure of Four- and Five-Coordinated Gaseous Oxohalides of Molybdenum(VI) and Tungsten(VI)". Inorganic Chemistry. 7 (12): 2569–2573. doi:10.1021/ic50070a020.
5. Jarchow, O.; Schröder, F.; Schulz, H. "Kristallstruktur und Polytypie von WO₂Cl₂" Zeitschrift für anorganische und allgemeine Chemie 1968, vol. 363, p. 345ff. doi:10.1002/zaac.19683630108
6. Holleman, A. F.; Wiberg, E. Inorganic Chemistry Academic Press: San Diego, 2001. ISBN 0-12-352651-5.
7. K. Dreisch, C. Andersson, C. Stalhandske "Synthesis and structure of dimethoxyethane-dichlorodioxo-tungsten(VI)—a highly soluble derivative of tungsten dioxodichloride" Polyhedron 1991, volume 10, p. 2417. doi:10.1016/S0277-5387(00)86203-8

• Tungsten compounds
• Oxychlorides