- Antimony pentafluoride
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ImageFileL1 = Antimony-pentafluoride-2D.png
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ImageNameL1 = Antimony pentafluoride
ImageFileR1 = Antimony-pentafluoride-monomer-3D-balls.png
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ImageNameR1 = Antimony pentafluoride
IUPACName = antimony(V) fluoride
OtherNames = antimony pentafluoride
pentafluoroantimony
Section1 = Chembox Identifiers
CASNo = 7783-70-2
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Section2 = Chembox Properties
Formula = SbF5
MolarMass = 216.74 g mol−1
Appearance =
Density = 4.07 g cm-3
MeltingPt = 8.3 °C (281.3 K)
BoilingPt = 141 °C (414 K)
Solubility = Reacts with water
SolubleOther =
Solvent = SO2, SO2FCl
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NFPA-H = 4
NFPA-F = 0
NFPA-R = 1
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PEL =Antimony pentafluoride is the
chemical compound with the formula SbF5. This colourless, viscous liquid is a valuableLewis acid and a component of thesuperacid fluoroantimonic acid , the strongest known acid. Some features that give the compound scientific interest are itsLewis acid ity and that it also reacts with almost all known compounds. [Olah, G. A.; Prakash, G. K. S.; Wang, Q.; Li, X.-y."Antimony(V) Fluoride" in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. DOI: 10.1002/047084289.]tructure and chemical reactions
In the gas phase, SbF5 adopts a trigonal bipyramidal structure of D3h point group symmetry (see picture). The structure is more complex in the liquid and solid state. The liquid contains polymers wherein each Sb is octahedral, the structure being described with the formula [SbF4(μ-F)2] n. The crystalline material is tetrameric, i.e. it has the formula [SbF4(μ-F)] 4. The Sb-F bonds are 2.02 Å within the eight-membered Sb4F4 ring; the remaining fluoride ligands radiating from the four Sb centers are shorter at 1.82 Å. [Edwards, A. J.; Taylor, P. "Crystal structure of Antimony Pentafluoride" Journal of the Chemical Society, Chemical Communications 1971, pp. 1376-7.DOI|10.1039/C29710001376] The related species PF5 and AsF5 are
monomer ic in the solid and liquid states, probably due to the smaller sizes of the central atom, which limits their coordination number. BiF5 is a polymer. [Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.]SbF5 is a strong Lewis acid, exceptionally so toward sources of F− to give the very stable anion [SbF6] −. The latter reacts with additional SbF5 to give [Sb2F11] −.
In the same way that SbF5 enhances the Brønsted acidity of HF, it enhances the oxidizing power of F2. This effect is illustrated by the oxidation of
oxygen : [Shamir, J.; Binenboym, J. "Dioxygenyl Salts" Inorganic Syntheses, 1973, XIV, 109-122. ISSN|0073-8077] :SbF5 + ½F2 + O2 → [O2] + [SbF6] -Antimony pentafluoride has also been used in the first discovered chemical reaction that produces
fluorine gas from fluoride compounds::2 SbF5 + K2MnF6 → 2 KSbF6 + MnF3 + 0.5 F2The driving force for this reactions is the high affinity of SbF5 for F-, which is the same property which recommends the use of SbF5 to generate superacids.afety
SbF5 reacts violently with many compounds, often releasing dangerous
hydrogen fluoride .References
*IPCS, CEC 2005. [http://www.inchem.org/documents/icsc/icsc/eics0220.htm "ANTIMONY PENTAFLUORIDE (ICSC)] RetrievedMay 13 ,2006 .
*Barbalace, Kenneth. [http://environmentalchemistry.com/yogi/chemicals/cn/Antimony%A0Pentafluoride.html "Chemical Database - Antimony Pentafluoride"] . 1995 - 2006. Retrieved May 13, 2006.External links
* [http://webbook.nist.gov/cgi/cbook.cgi?ID=C7783702 WebBook page for SbF5]
* [http://www.npi.gov.au/database/substance-info/profiles/10.html National Pollutant Inventory - Antimony and compounds fact sheet]
* [http://www.npi.gov.au/database/substance-info/profiles/44.html National Pollutant Inventory - Fluoride compounds fact sheet]
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