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.[1]
Preparation
Tellurium hexafluoride can be prepared by treating tellurium with fluorine gas at 150 °C.[1][2] It can also be prepared by fluorination of TeO3 with bromine trifluoride. Upon heating, TeF4 disproportionates to give TeF6 and Te.Script error: No such module "Unsubst".
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.
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Ball-and-stick model of the crystal structure
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Space-filling model of the crystal structure
Reactivity
Tellurium hexafluoride is much more chemically reactive than SF6.[3] 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
Template:Hexafluorides Template:Tellurium compounds Template:Fluorine compounds