Tungsten(IV) fluoride

Tungsten(IV) fluoride
Names
IUPAC name
tetrafluorotungsten
Other names
Tungsten(4+) tetrafluoride, Tungsten tetrafluoride
Identifiers
13766-47-7
ChemSpider 123101
EC number 232-029-1
PubChem 139582
Properties
WF4
Molar mass 259.8336128 g/mol
Appearance Red-Brown or Black Solid[1]
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Tungsten tetrafluoride is an inorganic compound with the formula WF4. This little studied solid has been invoked, together with tungsten pentafluoride, as an intermediate in the chemical vapor deposition of tungsten films using tungsten hexafluoride.[2]

Preparation and properties

It has been prepared by treatment of the coordination complex WCl4(MeCN)2 with AsF3.[3] It has been produced by from the reaction of WF6 and a W filament at 600-800 °C.[1]

The compound can be re-oxidized to W(VI) compounds by treatment with fluorine and chlorine:

WF4 + X2 → WF4X2

Upon heating, it disproportionates to WF6 and tungsten metal.[1]

References

  1. 1.0 1.1 1.2 Butskii, V. D.; Perov, V. S. (1977). "Synthesis and certain properties of tungsten tetrafluoride". Zhurnal Neorganicheskoi Khimii 22 (1): 14–17.
  2. Creighton, J. R. "Selectivity loss during tungsten chemical vapor deposition: the role of tungsten pentafluoride" Journal of Vacuum Science & Technology, A: Vacuum, Surfaces, and Films (1989), volume 7, 621-4. doi:10.1116/1.575854
  3. Meinert, Hasso; Dimitrov, A. "On the chemistry of tungsten tetrafluoride" Zeitschrift fuer Chemie (1976), 16(1), 29-30.