Tellurium hexafluoride

Tellurium hexafluoride is the inorganic compound of tellurium and fluorine with the chemical formula TeF₆. It is a colorless and 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.

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

External links

• Web Elements
• OSHA
• CDC – NIOSH Pocket Guide to Chemical Hazards