Antimony (V) fluoride

Structural formula
General
Surname	Antimony (V) fluoride
other names	Antimony pentafluoride
Molecular formula	SbF 5
Brief description	colorless, oily liquid with a pungent odor
External identifiers / databases
CAS number 7783-70-2 EC number 232-021-8 ECHA InfoCard 100.029.110 PubChem 24557 Wikidata Q411381
properties
Molar mass	216.74 g mol −1
Physical state	liquid
density	2.99 g cm −3 (20 ° C)
Melting point	7 ° C
boiling point	149.5 ° C
Vapor pressure	13 hPa (25 ° C)
solubility	violent reaction with water
safety instructions
GHS labeling of hazardous substances danger H and P phrases H: 302 + 332-314-411 EUH: 014 P: 273-280-301 + 330 + 331-305 + 351 + 338-309 + 310
MAK	repealed as carcinogenic
Thermodynamic properties
ΔH f 0	−908.8 kJ mol −1
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Antimony pentafluoride is a combination of the elements antimony and fluorine . Under normal conditions it exists as a colorless oily liquid. It has the chemical formula SbF ₅ .

Extraction and presentation

Antimony pentafluoride is produced by reacting antimony (III) fluoride with fluorine.

${\displaystyle {\ce {SbF3 + F2 -> SbF5}}}$

It was first described in 1904 by Otto Ruff and Wilhelm Plato.

properties

Physical Properties

In the gas phase , the molecules are individually in a trigonal-bipyramidal structure. In the liquid phase, however, the antimony pentafluoride is present as a polymer chain with the empirical formula (SbF ₅ ) _n (n mostly between 5 and 10).

Up to a temperature of 152 ° C, antimony pentafluoride is present as a trimer, up to 252 ° C as a dimer, above it as a monomer.

In the solid phase, antimony pentafluoride forms cyclic tetramers.

Chemical properties

Antimony pentafluoride is a very strong Lewis acid and a strong F ^- acceptor. As a result, there are various adducts (for example SbF ₅ · SO ₂ , SbF ₅ · NO ₂ ) and complexes (for example MF · SbF ₅ = M ⁺ SbF ₆ ^- ). With xenon difluoride as fluoride donor, various ionic compounds are formed in a fluoride transfer reaction depending on the mixing ratio.

${\displaystyle {\ce {2XeF2 + SbF5 -> [Xe2F3][SbF6]}}}$

${\displaystyle {\ce {XeF2 + SbF5 -> [XeF][SbF6]}}}$

${\displaystyle {\ce {XeF2 + 2SbF5 -> [XeF][Sb2F11]}}}$

Antimony pentafluoride is able to increase the oxidizing power of fluorine, so that it is able to oxidize oxygen .

${\displaystyle {\ce {2SbF5 + F2 + 2O2 -> 2[O2][SbF6]}}}$

Antimony (V) fluoride attacks glass, but is only slightly corrosive to copper and lead. Quartz, platinum and aluminum are not attacked.

use

Due to its strong Lewis acidity, antimony pentafluoride can be used in combination with strong Brønsted acids to produce so-called super acids . The " magic acid " is known, which consists of antimony pentafluoride and fluorosulfonic acid . The most acidic mixture of both substances known to date consists of fluorosulfonic acid with 25 mol% antimony pentafluoride and has an H ₀ value of −21.5. It is therefore around 10 ¹⁰ times stronger than pure sulfuric acid . It is able to decompose paraffins and protonate very weak bases, such as CH ₄ to CH ₅ ⁺ . Fluoro-antimonic acid , a mixture of antimony pentafluoride and hydrogen fluoride in a mixing ratio of 1: 1, can do this . It has an H ₀ value of −31.3 and is therefore around 2 × 10 ¹⁹ times stronger than pure sulfuric acid.

safety instructions

Due to its high reactivity, antimony pentafluoride should be handled very carefully. Unintentional contact with other substances, especially with moisture, should be avoided in any case. Hydrogen fluoride and stibane can arise as decomposition products .

The LD ₅₀ value (mouse, inhalation) is 270 mg / m ³ .

See also

Antimony (III) fluoride

literature

• AF Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 101st edition. Walter de Gruyter, Berlin 1995, ISBN 3-11-012641-9 .
• Entry on antimony fluoride. In: Römpp Online . Georg Thieme Verlag, accessed on June 13, 2014.

Individual evidence

1. ↑ ^{a b c d e f g h i} Entry on antimony (V) fluoride in the GESTIS substance database of the IFA , accessed on February 1, 2016(JavaScript required) .
2. ^ AF Holleman , N. Wiberg : Inorganische Chemie . 103rd edition. Volume 1: Basics and main group elements. Walter de Gruyter, Berlin / Boston 2016, ISBN 978-3-11-049585-0 , p. 952 (reading sample: Part A - Basics of the chemistry of hydrogen. Google book search ).
3. ↑ Otto Ruff, Wilhelm Plato: About the representation and the physical properties of some new fluorine compounds . Titanium tetrafluoride, tin tetrafluoride, antimony pentafluoride, as well as mixed antimony trifluorides and pentafluorides. (In part jointly with Mr. Hugo Graf.). In: Reports of the German Chemical Society . tape 37 , no. 1 , 1904, p. 673-683 , doi : 10.1002 / cber.190403701109 .
4. ^ Ralf Steudel : Chemistry of the non-metals . Syntheses - Structures - Binding - Use. 4th edition. Walter de Gruyter , Berlin / Boston 2014, ISBN 978-3-11-030439-8 , pp. 570 .
5. ↑ J. Shamir, J. Binenboym: Dioxygenyl Salts . In: Inorganic Syntheses . tape 14 , January 1, 1973, p. 109-122 , doi : 10.1002 / 9780470132456.ch8 .
6. ↑ Georg Brauer (Ed.): Handbook of Preparative Inorganic Chemistry . 2nd Edition. tape 1 . Academic Press, 1963, pp. 200 .