- Tellurium hexafluoride
Chembox new
Name = Tellurium hexafluoride
ImageFile = Sulfur-hexafluoride-3D-sticks.png
IUPACName =
Section1 = Chembox Identifiers
CASNo = 7783-80-4
SMILES = xxxxx
Section2 = Chembox Properties
Formula = TeF6
MolarMass = 241.59 g/mol
Density = 0.0106 g/cm³
MeltingPt = −38 °C
BoilingPt = −39 °CTellurium hexafluoride is the oldest known
fluoride oftellurium . It is a colorless, highly toxic gas with an extremely unpleasant smell.Preparation
Tellurium hexafluoride is most commonly prepared by passing
fluorine gas over tellurium metal at 150 °C. Below this temperature a mixture of lower fluorides form, includingtellurium tetrafluoride andditellurium decafluoride . It can also be prepared by passing fluorine gas over TeO3 or indirectly by reacting TeO2 with SeF4 to produce TeF4 and then heating TeF4 in excess of 200 °C to make TeF6 and Te.Properties
Tellurium hexafluoride is a highly symmetric octahedral molecule. Its physical properties resemble the
sulfur andselenium analogs. It is less volatile, however, due to the increase inmolecular weight . At temperatures below −38 °C, tellurium hexafluoride condenses to a volatile white solid.Reactivity
Unlike the
sulfur analog, tellurium hexafluoride is not chemicallyinert . This can be attributed to the greater availability of the "d" orbitals and perhaps the availability of the "f" orbitals which neither sulfur or selenium have access to. TeF6 is hydrolyzed in water to H6TeO6 and reacts with Te below 200 °C.Health Hazards
People exposed to
tellurium compounds exhibit "telluriumbreath ", which has agarlic -likeodour . This garlic odour is also present insweat andurine . Other symptoms of tellurium exposure includeheadache ,dyspnea , weakness, bluish-black markings onfinger s,neck ,face andgums ,metallic taste in the mouth and skin rash. Death may occur frompulmonary edema . People exposed to tellurium compounds should be removed from the area and seek medical attention.Reasons for "Tellurium-Breath"
The garlic odour that is associated with human intake of tellurium compounds is caused from the tellurium being metabolized by the body. When the body metabolizes tellurium in any oxidation state, the tellurium gets converted into dimethyl telluride. Dimethyl telluride is volatile and producesFact|date=August 2007 the garlic-like smell.
uppliers
Tellurium hexafluoride is not a very common chemical and can be found at few suppliers. It costs approximately 2000 USD for 50 grams.
ee also
*
Tellurium References
*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.
*N.N. Greenwood and A. Earnshaw; "Chemistry of the Elements", 2nd edition, Butterworth, UK, 1997.
*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
* [http://www.webelements.com/webelements/compounds/text/Te/F6Te1-7783804.html Web Elements]
* [http://www.osha.gov/SLTC/healthguidelines/telluriumhexafluoride/ OSHA]
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