Tungsten hexachloride is the

chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one elemen ...

of tungsten and

chlorine Chlorine is a chemical element with the symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between them. Chlorine is ...

with the formula WCl₆. 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 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 pre ...

. The highly volatile tungsten hexafluoride is also known. As a d⁰ ion, W(VI) forms diamagnetic derivatives. The hexachloride is

octahedral In geometry, an octahedron (plural: octahedra, octahedrons) is a polyhedron with eight faces. The term is most commonly used to refer to the regular octahedron, a Platonic solid composed of eight equilateral triangles, four of which meet at ea ...

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 Cl₂ → WCl₆

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), chlor ...

s WOCl₄ and WO₂Cl₂, and subsequently, tungsten trioxide. WCl₆ is soluble in

carbon disulfide Carbon disulfide (also spelled as carbon disulphide) is a neurotoxic, colorless, volatile liquid with the formula and structure . The compound is used frequently as a building block in organic chemistry as well as an industrial and chemical non ...

carbon tetrachloride Carbon tetrachloride, also known by many other names (such as tetrachloromethane, also recognised by the IUPAC, carbon tet in the cleaning industry, Halon-104 in firefighting, and Refrigerant-10 in HVACR) is an organic compound with the chemic ...

, and

phosphorus oxychloride Phosphoryl chloride (commonly called phosphorus oxychloride) is a colourless liquid with the formula . It hydrolyses in moist air releasing phosphoric acid and fumes of hydrogen chloride. It is manufactured industrially on a large scale from phos ...

. Methylation with trimethylaluminium affords

hexamethyl tungsten Hexamethyltungsten is the chemical compound W( CH3)6 also written WMe6. Classified as a transition metal alkyl complex, hexamethyltungsten is an air-sensitive, red, crystalline solid at room temperature; however, it is extremely volatile and sub ...

: : WCl₆ +3 Al₂(CH₃)₆ → W(CH₃)₆ + 3 Al₂(CH₃)₄Cl₂ Treatment with

butyl lithium Butyllithium may refer to one of 5 isomeric organolithium reagents of which 3 are commonly used in chemical synthesis: * ''n''-Butyllithium, abbreviated BuLi or nBuLi * ''sec''-Butyllithium, abbreviated ''sec''-BuLi or sBuLi, has 2 stereoisomers, ...

affords a reagent that is useful for deoxygenation of epoxides. The chloride ligands in WCl₆ can be replaced by many anionic ligands including:

bromide A bromide ion is the negatively charged form (Br−) of the element bromine, a member of the halogens group on the periodic table. Most bromides are colorless. Bromides have many practical roles, being found in anticonvulsants, flame-retardant ...

, 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, wh ...

(R = alkyl, aryl). Reduction of WCl₆ gives, sequentially,

tungsten(V) chloride Tungsten(V) chloride is an inorganic compound with the formula W2 Cl10. This compound is analogous in many ways to the more familiar molybdenum pentachloride. The material is prepared by reduction of tungsten hexachloride. One method involves t ...

and

tungsten(IV) chloride Tungsten(IV) chloride is an inorganic compound with the formula WCl4. It is a diamagnetic black solid. The compound is of interest in research as one of a handful of binary tungsten chlorides. Structure and preparation WCl4 is usually prepare ...

Safety considerations

WCl₆ is an aggressively corrosive oxidant, and hydrolyzes to release

hydrogen chloride The compound hydrogen chloride has the chemical formula and as such is a hydrogen halide. At room temperature, it is a colourless gas, which forms white fumes of hydrochloric acid upon contact with atmospheric water vapor. Hydrogen chloride g ...

References

{{Chlorides Tungsten halides Chlorides Octahedral compounds