Antimony pentafluoride#Hexafluoroantimonate
{{chembox
| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 441020860
| ImageFileL1 = Antimony-pentafluoride-2D.png
| ImageClassL1 = skin-invert
| ImageNameL1 = Antimony pentafluoride
| ImageFileR1 = Antimony-pentafluoride-monomer-3D-balls.png
| ImageClassR1 = bg-transparent
| ImageNameR1 = Antimony pentafluoride
| ImageFile1 = SbF5.png
| ImageName1 = Antimony pentafluoride.
| IUPACName = Antimony pentafluoride
| OtherNames = Antimony(V) fluoride
pentafluoridoantimony
| SystematicName = Pentafluoro-λ5-stibane
| Section1 = {{Chembox Identifiers
|SMILES = F[Sb](F)(F)(F)F
|InChI = 1/5FH.Sb/h5*1H;/q;;;;;+5/p-5/rF5Sb/c1-6(2,3,4)5
|InChIKey = VBVBHWZYQGJZLR-NMXCDXEPAW
|StdInChI = 1S/5FH.Sb/h5*1H;/q;;;;;+5/p-5
|StdInChIKey = VBVBHWZYQGJZLR-UHFFFAOYSA-I
|StdInChI_Ref = {{stdinchicite|changed|chemspider}}
|StdInChIKey_Ref = {{stdinchicite|changed|chemspider}}
|CASNo = 7783-70-2
|CASNo_Ref = {{cascite|correct|CAS}}
|UNII_Ref = {{fdacite|correct|FDA}}
|UNII = 6C93R71VRF
|PubChem = 24557
|ChemSpiderID_Ref = {{chemspidercite|changed|chemspider}}
|ChemSpiderID = 22963
|RTECS = CC5800000
|UNNumber = 1732
|EC_number = 232-021-8
|DTXSID = DTXSID00893075
}}
| Section2 = {{Chembox Properties
|Formula = SbF5
|MolarMass = 216.74 g/mol
|Appearance = colorless oily, viscous liquid
hygroscopic
|Odor = pungent, sharp
|Density = 2.99 g/cm3 {{RubberBible87th}}
|MeltingPtC = 8.3
|BoilingPtC = 149.5
|Solubility = Reacts
|SolubleOther = soluble in KF, liquid SO2
}}
| Section3 = {{Chembox Hazards
|MainHazards = Extremely toxic, corrosive, hazardous to health. Releases hydrofluoric acid upon contact with water and biological tissues. Strong oxidizing agent.
|ExternalSDS = [http://www.inchem.org/documents/icsc/icsc/eics0220.htm ICSC 0220]
|NFPA-H = 4
|NFPA-F = 0
|NFPA-R = 3
|NFPA-S = W+OX
|GHSPictograms = {{GHS06}}{{GHS05}}{{GHS07}}{{GHS09}}{{GHS03}}{{GHS08}}
|GHSSignalWord = Danger
|HPhrases = {{H-phrases|300+310+330|314|411|412}}
|PPhrases = {{P-phrases|260|261|264|270|271|273|280|301+312|301+330+331|303+361+353|304+312|304+340|305+351+338|310|312|321|330|363|391|405|501}}
|FlashPt = noncombustible
|LC50 = 270 mg/m3 or 30 ppm (mouse, inhalation)
|LCLo = 15 mg/m3 or 1.69 ppm (rat, inhalation, 2 hours)
|LD50 = 270 mg/kg (mouse, subcutaneous)
|REL = TWA 0.5 mg/m3 or 0.05 ppm (as Sb){{PGCH|0036}}
|PEL = TWA 0.5 mg/m3 or 0.05 ppm (as Sb)
|IDLH = 50 mg/m3 (5 ppm)
}}
| Section4 = {{Chembox Related
|OtherCompounds = Antimony trifluoride
|OtherAnions = Antimony pentachloride
|OtherCations = Phosphorus pentafluoride
Arsenic pentafluoride
Bismuth pentafluoride
}}
}}
Antimony pentafluoride is the inorganic compound with the formula SbF5. This colorless, viscous liquid is a strong Lewis acid and a component of the superacid fluoroantimonic acid, formed upon mixing liquid HF with liquid SbF5 in 1:1 ratio. It is notable for its strong Lewis acidity and the ability to react 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|10.1002/047084289X}}.
Preparation
Antimony pentafluoride is prepared by the reaction of antimony pentachloride with anhydrous hydrogen fluoride:Sabina C. Grund, Kunibert Hanusch, Hans J. Breunig, Hans Uwe Wolf "Antimony and Antimony Compounds" in Ullmann's Encyclopedia of Industrial Chemistry 2006, Wiley-VCH, Weinheim {{doi| 10.1002/14356007.a03_055.pub2}}
:SbCl5 + 5 HF → SbF5 + 5 HCl
It can also be prepared from antimony trifluoride and fluorine.Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. Vol. 1. p. 200.
Structure and chemical reactions
In the gas phase, SbF5 adopts a trigonal bipyramidal structure of D3h point group symmetry (see picture). The material adopts a more complicated structure in the liquid and solid states. The liquid contains polymers wherein each Sb is octahedral, the structure being described with the formula [SbF4(μ-F)2]n ((μ-F) denotes the fact that fluoride centres bridge two Sb centers). The crystalline material is a tetramer, meaning that 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 monomeric 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}}.
Antimony pentafluoride is a very strong oxidizing agent. Phosphorus burns on contact with it.
SbF5 increases the oxidizing power of Fluorine, making it able to oxidize oxygen:
:2 SbF5 + F2 + 2 O2 → 2 [O2
:
SbF5 has also been used in the first discovered chemical reaction that produces fluorine gas from fluoride compounds:
:{{chem2|4 SbF5 + 2 K2MnF6 → 4 KSbF6 + 2 MnF3 + F2}}
The driving force for this reaction is the high affinity of SbF5 for {{chem2|F-}}, which is the same property that recommends the use of SbF5 to generate superacids.
=Hexafluoroantimonate=
SbF5 is a strong Lewis acid, exceptionally so toward sources of F− to give the very stable anion [SbF6]−, called hexafluoroantimonate. It is the conjugate base of the superacid fluoroantimonic acid. [SbF6]− is a weakly coordinating anion akin to PF6−. Although it is only weakly basic, [SbF6]− does react with additional SbF5 to give a centrosymmetric adduct:
:SbF5 + [SbF6]− → [Sb2F11]−
The [Sb2F11]− anion is one of the ions found in HF/SbF5 Mixture.
Safety
SbF5 is highly corrosive to the skin and the eyes. It is extremely toxic and hazardous to health. Its lethal dose (LD50) is reported to be 270 mg/kg (mouse, subcutaneous) with lowest concentration (LCLo) of 15 mg/m3 or 1.69 ppm (rat, inhalation, 2 hours). Occupational exposure limit set by NIOSH stands at 50 mg/m3 (5 ppm). It is considered to be Immediately dangerous to life and health at this concentration. Other than that, SbF5 reacts violently with water along with many other compounds, often releasing dangerous hydrogen fluoride. It is a very strong oxidizer.{{cite web | publisher = Commission of the European Communities (CEC) | author = International Programme on Chemical Safety | title = Antimony pentafluoride | access-date = 2010-05-10 | year = 2005 | url = http://www.inchem.org/documents/icsc/icsc/eics0220.htm }}{{cite web | url = http://environmentalchemistry.com/yogi/chemicals/cn/Antimony%A0Pentafluoride.html | title = Chemical Database - Antimony Pentafluoride | access-date = 2010-05-10 | author = Barbalace, Kenneth | year = 2006 | publisher = Environmental Chemistry }}
References
{{Reflist}}
External links
- [http://webbook.nist.gov/cgi/cbook.cgi?ID=C7783702 WebBook page for SbF5]
- [http://www.npi.gov.au/resource/antimony-and-compounds National Pollutant Inventory - Antimony and compounds fact sheet]
- [http://www.npi.gov.au/resource/fluoride-compounds-sources-emissions National Pollutant Inventory - Fluoride compounds fact sheet]
{{Antimony compounds}}
{{fluorides}}