Tungsten hexachloride is the
chemical compound of
tungsten and
chlorine with the
formula
In science, a formula is a concise way of expressing information symbolically, as in a mathematical formula or a ''chemical formula''. The informal use of the term ''formula'' in science refers to the general construct of a relationship betwee ...
WCl
6. This dark violet blue species exists as a volatile solid under standard conditions. It is an important starting reagent in the preparation of tungsten compounds. Other examples of charge-neutral hexachlorides are
rhenium(VI) chloride
Rhenium(VI) chloride is the inorganic compound with the formula ReCl6. It is a black paramagnetic solid. The molecules adopt an octahedral structure as seen in tungsten(VI) chloride.
Preparation and reactions
Rhenium(VI) chloride was first gener ...
and
molybdenum(VI) chloride
Molybdenum(VI) chloride is the inorganic compound with the formula MoCl6. It is a black diamagnetic solid. The molecules adopt an octahedral structure as seen in β- tungsten(VI) chloride.
Preparation and reactions
Molybdenum(VI) chloride is pr ...
. The highly volatile
tungsten hexafluoride
Tungsten(VI) fluoride, also known as tungsten hexafluoride, is an inorganic compound with the formula W F6. It is a toxic, corrosive, colorless gas, with a density of about (roughly 11 times heavier than air). It is one of the densest known gase ...
is also known.
As a d
0 ion, W(VI) forms
diamagnetic derivatives. The hexachloride is
octahedral with equivalent W–Cl distances of 2.24–2.26 Å.
Preparation
Tungsten hexachloride can be prepared by chlorinating tungsten metal in a sealed tube at 600 °C:
: W + 3 Cl
2 → WCl
6
Properties and Reactions
Tungsten (VI) chloride is a blue-black solid at room temperature. At lower temperatures, it becomes wine-red in color. A red form of the compound can be made by rapidly condensing its vapor, which reverts to the blue-black form on gentle heating. It is readily hydrolyzed, even by moist air, giving the orange
oxychloride
In chemistry, molecular oxohalides (oxyhalides) are a group of chemical compounds in which both oxygen and halogen atoms are attached to another chemical element A in a single molecule. They have the general formula , where X = fluorine (F), ...
s
WOCl4 and WO
2Cl
2, and subsequently,
tungsten trioxide
Tungsten(VI) oxide, also known as tungsten trioxide is a chemical compound of oxygen and the transition metal tungsten, with formula WO3. The compound is also called tungstic anhydride, reflecting its relation to tungstic acid . It is a light ...
. WCl
6 is soluble in
carbon disulfide,
carbon tetrachloride
Carbon tetrachloride, also known by many other names (such as tetrachloromethane, also IUPAC nomenclature of inorganic chemistry, recognised by the IUPAC, carbon tet in the cleaning industry, Halon-104 in firefighting, and Refrigerant-10 in HVAC ...
, and
phosphorus oxychloride.
Methylation with
trimethylaluminium affords
hexamethyl tungsten:
: WCl
6 +3 Al
2(CH
3)
6 → W(CH
3)
6 + 3 Al
2(CH
3)
4Cl
2
Treatment with
butyl lithium affords a reagent that is useful for deoxygenation of
epoxides.
The chloride ligands in WCl
6 can be replaced by many anionic ligands including:
bromide,
thiocyanate and
alkoxide
In chemistry, an alkoxide is the conjugate base of an alcohol and therefore consists of an organic group bonded to a negatively charged oxygen atom. They are written as , where R is the organic substituent. Alkoxides are strong bases and, whe ...
(R = alkyl, aryl).
Reduction of WCl
6 gives, sequentially,
tungsten(V) chloride and
tungsten(IV) chloride.
Safety considerations
WCl
6 is an aggressively corrosive oxidant, and hydrolyzes to release
hydrogen chloride.
References
{{Chlorides
Tungsten halides
Chlorides
Octahedral compounds