Fluoroantimonic acid and Lithium monoxide anion: Difference between pages

| ImageFileL1 = Fluoroantimonic acid.png

| ImageFileL1_Ref = {{chemboximage|correct|??}}

| ImageSizeL1 = 121

| ImageNameL1 = Canonical, stereo, skeletal formula of fluoroantimonic acid

| ImageFileR1 = Fluoroantimonic-acid-3D-vdW.png

| ImageFileR1_Ref = {{chemboximage|correct|??}}

| ImageSizeR1 = 121

| ImageNameR1 = Canonical, spacefill model of fluoroantimonic acid

| IUPACName = Fluoroantimonic acid{{Citation needed|date = July 2011}}

| Section1 = {{Chembox Identifiers

| CASNo = <!-- blanked - oldvalue: 16950-06-4 -->

| PubChem = 21953576

| PubChem_Ref = {{Pubchemcite|correct|pubchem}}

| ChemSpiderID = 20137913

| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| EINECS = 241-023-8

| SMILES = F[Sb-](F)(F)(F)(F)[FH+]

| StdInChI = 1S/FH.2H2O.O.Sb/h1H;2*1H2;;/q;;;;+3/p-3

| StdInChIKey = DAIOAWAJEVEBIG-UHFFFAOYSA-K

| Section2 = {{Chembox Properties

| Formula = {{Chem|SbHF|6}}

| MolarMass = 236.76 g mol^-1

| ExactMass = 235.902062306 g mol^-1

| Appearance = Colourless liquid

| pKa = −25

| pKb = 39

| Section3 = {{Chembox Hazards

| MainHazards = Corrosive

| RPhrases = {{R26}}, {{R29}}, {{R35}}

| NFPA-H = 4

| NFPA-F = 0

| NFPA-R = 3

| NFPA-O = W

| Section4 = {{Chembox Related

| Function = [[acid]]s

| OtherFunctn = [[Antimony pentafluoride]]<br />

[[Hydrogen fluoride]]<br />

[[Magic acid]]

'''Fluoroantimonic acid''' (HSbF₆) is a mixture of [[hydrogen fluoride]] and [[antimony pentafluoride]] in various ratios.<ref name=Olah>[[George Olah|Olah]], G. A.; Prakash, G. K. S.; Wang, Q.; Li, X. “Hydrogen Fluoride–Antimony(V) Fluoride” in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. DOI: 10.1002/047084289.</ref> The 1:1 combination forms the strongest known [[superacid]], which has been demonstrated to [[protonate]] even [[hydrocarbon]]s to afford [[carbocation]]s and H₂.<ref>{{cite book

| title = A life of magic chemistry: autobiographical reflections of a nobel prize winner

| author = George Andrew Olah

| publisher = John Wiley and Sons

| year = 2001

| isbn = 0471157430

| pages = 100–101

}}</ref>

The reaction of hydrogen fluoride (HF) and SbF₅ is exothermic. HF, being a [[Lewis base]], attacks the molecules of SbF₅ to give an adduct. In the fluoroantimonic molecule, the anion is coordinated to the hydrogen, although the anion is formally classified as [[noncoordinating anion|noncoordinating]], because it is both a very weak [[nucleophile]] and a very weak [[base (chemistry)|base]].

Despite the [[proton]] being called effectively "naked," it is in fact always attached to a fluorine through a very weak [[dative bond]], similar to the [[hydronium]] cation.<ref> [http://www.psc.edu/science/klein2000.html] The quantum chemistry of proton "hopping" or transfer in his acid. Accessed 2-27-2011.</ref> However, the weakness of this bond accounts for the system's extreme acidity. Fluoroantimonic acid is 2×10¹⁹ (20 quintillion) times stronger than 100% [[sulfuric acid]].<ref name=Olah2>{{cite journal | author = Olah, George A. | year = 2005 | title = Crossing Conventional Boundaries in Half a Century of Research | journal = [[J. Org. Chem.]] | volume = 70 | issue = 7 | pages = 2413–2429 | doi = 10.1021/jo040285o | pmid = 15787527}}</ref>

:[[Image:Reaction of HF with SbF5.png|400px]]

==Structure==

Two related products have been crystallised from HF-SbF₅ mixtures, and both have been analyzed by single crystal X-ray [[crystallography]]. These salts have the formulas [H₂F⁺][Sb₂F₁₁⁻] and [H₃F₂⁺][Sb₂F₁₁⁻]. In both salts the anion is Sb₂F₁₁⁻.<ref>{{cite journal | author = Mootz, D.; Bartmann, K. | title = The Fluoronium Ions H₂F⁺ and H₃F₂⁺: Characterization by Crystal Structure Analysis | journal = [[Angewandte Chemie, International Edition in English]] | year = 1988 | volume = 27 | pages = 391–392 | doi = 10.1002/anie.198803911 | issue = 3}}</ref> As mentioned above, SbF₆⁻ is classified as weakly basic; the larger monoanion Sb₂F₁₁⁻ would be expected to be still weaker.

===Comparison with other acids===

The following values{{Citation needed|date=March 2009}} are based upon the [[Hammett acidity function]]. Acidity is indicated by large negative values of H₀.

* Fluoroantimonic acid (1990) (H₀ Value = −31.3)

* [[Magic acid]] (1974) (H₀ Value = −19.2)

* [[Carborane superacid]] (1969) (H₀ Value = −18.0)

* [[Fluorosulfuric acid]] (1944) (H₀ Value = −15.1)

* [[Triflic acid]] (1940) (H₀ Value = −14.9)

==Applications==

{{Main|Superacid#Applications}}

This extraordinarily strong acid protonates nearly all [[organic compound]]s. In 1967, Bickel and Hogeveen showed that HF-SbF₅ will remove H₂ from [[isobutane]] and methane from [[neopentane]]:<ref>{{cite journal | author = Bickel, A. F.; Gaasbeek, C. J.; Hogeveen, H.; Oelderik, J. M.; Platteeuw, J. C. | title = Chemistry and spectroscopy in strongly acidic solutions: reversible reaction between aliphatic carbonium ions and hydrogen | journal = [[Chemical Communications]] | year = 1967 | volume = 1967 | pages = 634–5 | doi = 10.1039/C19670000634 | issue = 13}}</ref><ref>{{cite journal | author = Hogeveen, H.; Bickel, A. F. | title = Chemistry and spectroscopy in strongly acidic solutions: electrophilic substitution at alkane-carbon by protons | journal = [[Chemical Communications]] | year = 1967 | volume = 1967 | pages = 635–6 | doi = 10.1039/C19670000635 | issue = 13}}</ref>

:(CH₃)₃CH + H⁺ → (CH₃)₃C⁺ + H₂

:(CH₃)₄C + H⁺ → (CH₃)₃C⁺ + CH₄

==Safety==

HF-SbF₅ is rapidly and explosively decomposed by water. It reacts with virtually all known solvents.<ref name=Olah/> [[Solvent]]s that have been proven to be compatible with HF-SbF₅ are [[sulfuryl chloride fluoride|SO₂ClF]] and liquefied [[sulfur dioxide]]. [[Chlorofluorocarbon]]s have also been used as solvents. Containers for

HF-SbF₅ are made of [[Polytetrafluoroethylene|PTFE]].

==See also==

* [[Fluoroboric acid]]

* [[Fluorosulfuric acid]]

[[Category:Antimony compounds]]

[[Category:Fluorides]]

[[Category:Inorganic compounds]]

[[Category:Superacids]]

[[cs:Kyselina fluoroantimoničná]]

[[de:Fluor-Antimonsäure]]

[[es:Ácido fluoroantimónico]]

[[fr:Acide fluoroantimonique]]

[[it:Acido fluoroantimonico]]

[[he:חומצה פלואורואנטימונית]]

[[ja:フルオロアンチモン酸]]

[[pl:Kwas fluoroantymonowy]]

[[pt:Ácido fluorantimônico]]

[[ro:Acid fluoroantimonic]]

[[sr:Fluoroantimonska kiselina]]

[[sh:Fluoroantimonska kiselina]]

[[fi:Fluoriantimonihappo]]

[[tr:Floroantimonik asit]]

[[zh:氟銻酸]]