Tellurium hexafluoride

Tellurium hexafluoride is the inorganic compound of tellurium and fluorine with the chemical formula TeF₆. It is a colorless, highly toxic gas with an unpleasant odor.

Preparation

Tellurium hexafluoride can be prepared by treating tellurium with fluorine gas at 150 °C. It can also be prepared by fluorination of TeO₃ with bromine trifluoride. Upon heating, TeF₄ disproportionates to give TeF₆ and Te.

Properties

Tellurium hexafluoride is a highly symmetric octahedral molecule. Its physical properties resemble those of the hexafluorides of sulfur and selenium. It is less volatile, however, due to the increase in polarizability. At temperatures below −38 °C, tellurium hexafluoride condenses to a volatile white solid.

Ball-and-stick model of the crystal structure
Space-filling model of the crystal structure

Reactivity

Tellurium hexafluoride is much more chemically reactive than SF₆. For example, TeF₆ slowly hydrolyzes to Te(OH)₆:

TeF₆ + 6 H₂O → Te(OH)₆ + 6 HF

Treatment of tellurium hexafluoride with tetramethylammonium fluoride (Me₄NF) gives, sequentially, the hepta- and octafluorides:

TeF₆ + Me₄NF → Me₄NTeF₇

Me₄NTeF₇ + Me₄NF → (Me₄N)₂TeF₈

Further sources

W.C. Cooper, Tellurium, Van Nostrand Reinhold Company, New York, USA, 1971.
K.W. Bagnall, The Chemistry of Selenium, Tellurium and Polonium, Elsevier Publishing, New York, 1966.
R.T. Sanderson, Chemical Periodicity, Reinhold, New York, USA, 1960.
F. A. Cotton, G. Wilkinson, C.A. Murillo, and M. Bochmann; Advanced Inorganic Chemistry, John Wiley & Sons, 1999.
G.J. Hathaway, N.H. Proctor, Chemical Hazards of the Workplace, 5th edition, Wiley-Interscience, New Jersey, 2004.

References

^ NIOSH Pocket Guide to Chemical Hazards. "#0588". National Institute for Occupational Safety and Health (NIOSH).
^ CRC Handbook of Chemistry and Physics, 90. Auflage, CRC Press, Boca Raton, Florida, 2009, ISBN 978-1-4200-9084-0, Section 4, Physical Constants of Inorganic Compounds, p. 4-95.
"Tellurium hexafluoride (as Te)". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
^ W. Kwasnik (1963). "Tellurium Hexafluoride". In G. Brauer (ed.). Handbook of Preparative Inorganic Chemistry, 2nd Ed. Vol. 1. NY, NY: Academic Press. p. 180.
Yost, Don M. (2007) . "Sulfur, Selenium, and Tellurium Hexafluorides". Inorganic Syntheses. Vol. 1. pp. 121–122. doi:10.1002/9780470132326.ch44. ISBN 978-0-470-13232-6.
Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.

External links

Binary hexafluorides

Known binary hexafluorides

Chalcogen binary hexafluorides	SF₆ SeF₆ TeF₆ PoF₆
Noble gas binary hexafluorides	XeF₆
Transition metal binary hexafluorides	MoF₆ TcF₆ RuF₆ RhF₆ WF₆ ReF₆ OsF₆ IrF₆ PtF₆
Actinide binary hexafluorides	UF₆ NpF₆ PuF₆

Predicted binary hexafluorides

Noble gas binary hexafluorides	KrF₆ RnF ₆
Transition metal binary hexafluorides	CrF₆ PdF₆ AuF₆
Actinide binary hexafluorides	AmF₆ CmF₆ EsF₆