_Chloride.jpg) α-Tungsten hexachloride | |||
 β-Tungsten hexachloride | |||
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| Names | |||
|---|---|---|---|
| IUPAC names Tungsten hexachloride Tungsten(VI) chloride | |||
| Identifiers | |||
3D model (JSmol) | |||
| ChemSpider | |||
| ECHA InfoCard | 100.032.980 | ||
| EC Number |
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| RTECS number |
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| UNII | |||
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| Properties | |||
| WCl6 | |||
| Molar mass | 396.54 g·mol−1 | ||
| Appearance | dark blue crystals, moisture sensitive | ||
| Density | 3.52 g/cm3 | ||
| Melting point | 275 °C (527 °F; 548 K) | ||
| Boiling point | 346.7 °C (656.1 °F; 619.8 K) | ||
| Hydrolyzes | |||
| Solubility in chlorocarbons | soluble | ||
| −71.0·10−6 cm3/mol | |||
| Structure | |||
| α:rhombohedral, β: hexagonal | |||
| Octahedral | |||
| 0D | |||
| Hazards | |||
| Occupational safety and health (OHS/OSH): | |||
Main hazards | oxidizer; hydrolysis releases HCl | ||
| Related compounds | |||
Otheranions | |||
Othercations | |||
Related compounds | |||
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |||
Tungsten hexachloride is aninorganic chemical compound oftungsten andchlorine with thechemical formulaWCl6. This dark violet-blue compound exists asvolatile crystals understandard conditions. It is an important starting reagent in the preparation of tungsten compounds.[1] Other examples of charge-neutral hexachlorides arerhenium(VI) chloride andmolybdenum(VI) chloride. The highly volatiletungsten hexafluoride is also known.
As ad0 atom, tungsten hexachloride isdiamagnetic.
Tungsten hexachloride can be prepared by chlorinating tungsten metal in a sealed tube at 600 °C:[2]
Tungsten hexachloride exists in both blue and redpolymorphs, referred to respectively as α and β. The wine-red β can be obtained by rapid cooling, whereas the blue α form is more stable atroom temperature. Although these polymorphs are distinctly colored, their molecular structures are very similar. Both polymorphs featureWCl6 molecules that haveoctahedral geometry, in which all six W–Cl bonds are equivalent, and their length is equal to 224–226pm. The densities are very similar: 3.68 g/cm3 for α and 3.62 g/cm3 for β. The low-temperature form is slightly more dense, as expected.[3]
Tungsten hexachloride is readilyhydrolyzed, even bymoistair, giving the orangeoxychloridesWOCl4 andWO2Cl2, and subsequently,tungsten trioxide.WCl6 is soluble incarbon disulfide,carbon tetrachloride, andphosphorus oxychloride.[2]
Methylation withtrimethylaluminium affordshexamethyl tungsten:
Treatment withbutyl lithium affords areagent that is useful fordeoxygenation ofepoxides.[4]
Thechlorideligands inWCl6 can be replaced by manyanionic ligands including:bromide,thiocyanate,alkoxide,alkyl andaryl.
Reduction ofWCl6 can be effected with a mixture oftetrachloroethylene andtetraphenylarsonium chloride:[5]
The W(V) hexachloride is a derivative oftungsten(V) chloride.
It reacts witharsenic orhydrogen arsenide to formtungsten diarsenide.[6][7]
WCl6 is an aggressivelycorrosiveoxidant, andhydrolyzes to releasehydrogen chloride.
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