Tellurium hexafluoride

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. File:Tellurium-hexafluoride-xtal-1992-3D-balls.png|Ball-and-stick model of the crystal structure File:Tellurium-hexafluoride-xtal-1992-3D-SF.png|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 ==