Tellurium hexafluoride
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2008-07-05T16:53:00Z
68.127.229.2
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{{Chembox new
| Name = Tellurium hexafluoride
| ImageFile = Sulfur-hexafluoride-3D-sticks.png
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| ImageName =
| IUPACName =
| Section1 = {{Chembox Identifiers
| CASNo = 7783-80-4
| SMILES = xxxxx
}}
| Section2 = {{Chembox Properties
| Formula = TeF<sub>6</sub>
| MolarMass = 241.59 g/mol
| Density = 0.0106 g/cm³
| MeltingPt = −38 °C
| BoilingPt = −39 °C
}}
}}
'''Tellurium hexafluoride''' is the oldest known [[fluoride]] of [[tellurium]]. It is a colorless and highly toxic gas that has a horrible 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, including [[tellurium tetrafluoride]] and [[ditellurium decafluoride]]. It can also be prepared by passing fluorine gas over TeO<sub>3</sub> or indirectly by reacting TeO<sub>2</sub> with SeF<sub>4</sub> to produce TeF<sub>4</sub> and then heating TeF<sub>4</sub> in excess of 200 °C to make TeF<sub>6</sub> and Te.
==Properties==
Tellurium hexafluoride is a highly symmetric octahedral molecule. Its physical properties resemble the [[sulfur]] and [[selenium]] analogs. It is less [[Volatility (chemistry)|volatile]], however, due to the increase in [[molecular weight]]. At temperatures below −38 °C, tellurium hexafluoride condenses to a volatile white solid.
==Reactivity==
Unlike the [[sulfur]] analog, tellurium hexafluoride is not chemically [[inert]]. 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. TeF<sub>6</sub> is hydrolyzed in water to H<sub>6</sub>TeO<sub>6</sub> and reacts with Te below 200 °C.
==Health Hazards==
People exposed to [[tellurium]] compounds exhibit "tellurium [[breath]]", which has a [[garlic]]-like [[odour]]. This garlic odour is also present in [[sweat]] and [[urine]]. Other symptoms of tellurium exposure include [[headache]], [[dyspnea]], weakness, bluish-black markings on [[finger]]s, [[neck]], [[face]] and [[gums]], [[metallic]] taste in the mouth and skin rash. Death may occur from [[pulmonary 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 produces{{Fact|date=August 2007}} the garlic-like smell.
==Suppliers==
Tellurium hexafluoride is not a very common chemical and can be found at only a few select suppilers (see below). It costs approximately 2000 USD for 50 grams.
*[http://pfaltzandbauer.com Pfaltz and Bauer]
*[http://www.foxchemicals.com/company Fox Chemicals]
==See also==
*[[Tellurium]]
==References==
{{Citationstyle|date=September 2007}}
{{reflist}}
*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]
[[Category:Fluorides]]
[[Category:Tellurium compounds]]
[[ja:六フッ化テルル]]