9816. Tungsten Hexafluoride

Nomenclature

CAS number: 7783-82-6
F6W; mol wt 297.83.
F 38.27%, W 61.73%.
WF6.

Description and references

Prepd by direct fluorination of powdered tungsten. Can be purified by distillation, preferably under pressure: Ruff, Ascher, Z. Anorg. Allg. Chem. 196, 413 (1931); Henkel, Klemm, ibid. 222, 68 (1935); Marchi, Inorg. Synth. 3, 181 (1950); from ClF and tungsten: Pitts, Jache, Inorg. Chem. 7, 1661 (1968). Review of toxicology and human exposure: Toxicological Profile for Tungsten (PB2006-100007, 2005) 203 pp.

Properties

Colorless gas or pale yellow liquid. Orthorhombic, deliquescent crystals when solid. Poisonous; corrosive. d15liq 3.441. mp 2.3°. bp 17.5°. Soly in anhydr HF: 3.14 moles/1000 g HF, Frlec, Hyman, Inorg. Chem. 6, 1596 (1967). May be stored in glass pressure ampuls.

Use

In the electronics industry as a source of tungsten metal that connects the aluminum layers within semiconductor devices.