Tellurium hexafluoride explained

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.^[1]

Preparation

Tellurium hexafluoride can be prepared by treating tellurium with fluorine gas at 150 °C.^[2] 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 HFTreatment 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.

External links

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

Notes and References

1. Book: W. Kwasnik. Tellurium Hexafluoride. Handbook of Preparative Inorganic Chemistry, 2nd Ed. . G. Brauer. Academic Press. 1963. NY, NY. 1. 180.
2. Book: 10.1002/9780470132326.ch44. Sulfur, Selenium, and Tellurium Hexafluorides. 2007. Yost. Don M.. Inorganic Syntheses. 1939. 121–122. 1. 978-0-470-13232-6.