Title: Tungsten Hexafluoride
CAS Registry Number: 7783-82-6
Molecular Formula: F6W
Molecular Weight: 297.83
Percent Composition: F 38.27%, W 61.73%
Line Formula: WF6
Literature 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. 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.
Melting point: mp 2.3°
Boiling point: bp 17.5°
Density: d15liq 3.441
Use: In the electronics industry as a source of tungsten metal that connects the aluminum layers within semiconductor devices. |