Tungsten hexachloride
[CAS# 13283-01-7]

Identification

• Classification: Inorganic chemical industry >> Inorganic salt >> Metal halides and halides >> Metal chlorides and salts
• Name: Tungsten hexachloride
• Synonyms: Tungsten(VI) chloride
• Molecular Formula: WCl₆
• Molecular Weight: 396.56
• CAS Registry Number: 13283-01-7
• EC Number: 236-293-9
• SMILES: Cl[W](Cl)(Cl)(Cl)(Cl)Cl

Properties

• Density: 3.52
• Melting point: 275 °C
• Boiling point: 347 °C

Safety Data

• Hazard Symbols: GHS05 Danger
• Risk Statements: H314
• Safety Statements: P260-P264-P280-P301+P330+P331-P302+P361+P354-P304+P340-P305+P354+P338-P316-P321-P363-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin corrosion	Skin Corr.	1B	H314
Specific target organ toxicity - single exposure	STOT SE	3	H335
Serious eye damage	Eye Dam.	1	H318
Substances or mixtures corrosive to metals	Met. Corr.	1	H290
Acute toxicity	Acute Tox.	4	H302

• Transport Information: UN 3260

Discovery and Applications

Tungsten hexachloride, with the chemical formula WCl₆, is a well-known compound in the field of inorganic chemistry. This substance was discovered in the early 20th century and has become a key reagent and catalyst in various chemical processes due to its unique properties.

The discovery of tungsten hexachloride can be traced back to advances in the synthesis of transition metal chlorides. Tungsten is a dense metal with a high melting point that forms a variety of chlorides, with tungsten hexachloride being the most reactive one. It was originally synthesized by reacting tungsten metal with chlorine gas, a method that revealed its powerful chemical behavior.

Tungsten hexachloride is characterized by high reactivity and volatility. It is a yellow to brown solid that sublimates easily, making it useful in vapor phase processes. This property is particularly advantageous in chemical vapor deposition (CVD), where tungsten hexachloride is used to deposit tungsten films on substrates. These films are an integral part of the electronics industry, particularly in the manufacture of semiconductor devices and thin film transistors.

In addition to its role in CVD, tungsten hexachloride is used as a catalyst for various organic reactions. Its ability to coordinate with a variety of ligands makes it an effective catalyst for the synthesis of complex organic molecules. It is particularly useful in reactions involving carbonyl compounds and in the formation of organometallic compounds. The compound's high oxidation state and strong Lewis acidity contribute to its catalytic efficiency.

Tungsten hexachloride is also used in materials science for the production of tungsten-based materials with unique properties. These materials can be used in high-performance applications such as aerospace components and cutting tools, due to tungsten's outstanding hardness and high melting point.

The compound's role extends to inorganic chemistry research, where it is used to explore the reactivity and properties of transition metal chlorides. Research involving tungsten hexachloride has led to a better understanding of metal-chloride interactions and has facilitated the development of new synthetic methods.

Overall, tungsten hexachloride is a valuable chemical in both industrial and research settings. Its unique properties, including high reactivity and volatility, make it necessary for processes such as chemical vapor deposition and catalytic synthesis. As research and technology develop, the applications of tungsten hexachloride are expected to expand, further solidifying its importance in modern chemistry and materials science.

References

1965. Tungsten and Molybdenum Coated Nonmetallic Powders. JOM, 17(8).
DOI: 10.1007/bf03398942

2023. ROMP-Derived Aerogels. Springer Handbook of Aerogels.
DOI: 10.1007/978-3-030-27322-4_23

2023. Liquid crystal photo-cross-linking phenomenon: synthesis of disubstituted polyacetylenes and emission from liquid crystal. Journal of Materials Science, 58(7).
DOI: 10.1007/s10853-023-08192-1