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Xenon tetrafluoride

Xenon tetrafluoride
XeF 4 crystals. 1962.
Xenon-tetrafluoride-3D-balls.png
Xenon-tetrafluoride-3D-vdW.png
Names
IUPAC name
Xenon tetrafluoride
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.033.858
Properties
XeF
4
Molar mass 207.2836 g mol−1
Appearance White solid
Density 4.040 g cm−3, solid
Melting point 117 °C (243 °F; 390 K) sublimes[1]
Reacts
Structure
D4h
square planar
0 D
Thermochemistry
146 J·mol−1·K−1[2]
−251 kJ·mol−1[2]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Xenon tetrafluoride is a chemical compound with chemical formula XeF
4
. It was the first discovered binary compound of a noble gas.[3] It is produced by the chemical reaction of xenon with fluorine, F
2
, according to the chemical equation:[4][5]

Xe + 2 F
2
XeF
4

This reaction is exothermic, releasing an energy of 251 kJ/mol.[3]

Xenon tetrafluoride is a colorless crystalline substance. Its structure was determined by both NMR spectroscopy and X-ray crystallography in 1963.[6][7] The structure is square planar, as has been confirmed by neutron diffraction studies,[8] According to VSEPR theory, in addition to four fluoride ligands, the xenon center has two lone pairs of electrons. These lone pairs are mutually trans.

Xenon tetrafluoride sublimes at a temperature of 115.7 °C (240.26 °F).

Synthesis

Xenon tetrafluoride is produced by heating a mixture of xenon and fluorine in a 1:5 ratio in a nickel container to 400 °C. Some xenon hexafluoride, XeF
6
, is also produced, and this production is increased with an increased fluorine concentration in the input mixture.[9] The nickel is not a catalyst for this reaction; nickel containers are used because they react with fluorine to form a protective, non-peeling layer of nickel fluoride NiF
2
on their interior surfaces.

Reactions

Xenon tetrafluoride is hydrolyzes at low temperatures to form elemental xenon, oxygen, hydrofluoric acid, and aqueous xenon trioxide.[10]

Reaction with tetramethylammonium fluoride gives tetramethylammonium pentafluoroxenate, which contains the pentagonal XeF
5
anion. The XeF
5
anion is also formed by reaction with caesium fluoride:[11]

CsF + XeF
4
CsXeF
5

Reaction with bismuth pentafluoride (BiF
5
) forms the XeF+
3
cation:[12]

BiF
5
+ XeF
4
→ XeF3BiF6

The XeF+
3
cation in the salt XeF3Sb2F11 has been characterized by NMR spectroscopy.[13]

At 400 °C, XeF
4
reacts with xenon to form XeF
2
:[9]

XeF4 + Xe → 2 XeF2

The reaction of xenon tetrafluoride with platinum yields platinum tetrafluoride and xenon:[9]

XeF4 + Pt → PtF4 + Xe

Applications

Xenon tetrafluoride has no applications. It has been shown to degrade silicone rubber for analysing trace metal impurities in the rubber. XeF
4
reacts with the silicone to form simple gaseous products, leaving a residue of metal impurities.[14]

References

  1. ^ Arnold F. Holleman; Egon Wiberg (2001). Nils Wiberg (ed.). Inorganic chemistry. Translated by Mary Eagleson; William Brewer. Academic Press. p. 394. ISBN 0-12-352651-5.
  2. ^ a b Zumdahl, Steven S. (2009). Chemical Principles (6th ed.). Houghton Mifflin Company. p. A23. ISBN 0-618-94690-X.
  3. ^ a b Zumdahl (2007). Chemistry. Boston: Houghton Mifflin. p. 243. ISBN 0-618-52844-X.
  4. ^ Claassen, H. H.; Selig, H.; Malm, J. G. (1962). "Xenon Tetrafluoride". J. Am. Chem. Soc. 84 (18): 3593. doi:10.1021/ja00877a042.
  5. ^ C. L. Chernick; H. H. Claassen; P. R. Fields; H. H. Hyman; J. G. Malm; W. M. Manning; M. S. Matheson; L. A. Quarterman; F. Schreiner; H. H. Selig; I. Sheft; S. Siegel; E. N. Sloth; L. Stein; M. H. Studier; J. L. Weeks & M. H. Zirin (1962). "Fluorine Compounds of Xenon and Radon". Science. 138 (3537): 136–138. Bibcode:1962Sci...138..136C. doi:10.1126/science.138.3537.136. PMID 17818399.
  6. ^ Thomas H. Brown; E. B. Whipple & Peter H. Verdier (1963). "Xenon Tetrafluoride: Fluorine-19 High-Resolution Magnetic Resonance Spectrum". Science. 140 (3563): 178. Bibcode:1963Sci...140..178B. doi:10.1126/science.140.3563.178. PMID 17819836.
  7. ^ James A. Ibers & Walter C. Hamilton (1963). "Xenon Tetrafluoride: Crystal Structure". Science. 139 (3550): 106–107. Bibcode:1963Sci...139..106I. doi:10.1126/science.139.3550.106. PMID 17798707.
  8. ^ Burns, John H.; Agron, P. A.; Levy, Henri A (1963). "Xenon Tetrafluoride Molecule and Its Thermal Motion: A Neutron Diffraction Study". Science. 139 (3560): 1208–1209. Bibcode:1963Sci...139.1208B. doi:10.1126/science.139.3560.1208. PMID 17757912.
  9. ^ a b c Allen J. Bard; Roger Parsons; Joseph Jordan; International Union of Pure and Applied Chemistry (1985). Standard Potentials in Aqueous Solution. CRC Press. pp. 767–768. ISBN 0-8247-7291-1.
  10. ^ Williamson; Koch, C. W. (Mar 1963). "Xenon Tetrafluoride: Reaction with Aqueous Solutions". Science. 139 (3559): 1046–1047. Bibcode:1963Sci...139.1046W. doi:10.1126/science.139.3559.1046. ISSN 0036-8075. PMID 17812981.
  11. ^ Charlie Harding; David Arthur Johnson; Rob Janes (2002). Elements of the p block (Volume 9 of Molecular world). Royal Society of Chemistry. p. 93. ISBN 0-85404-690-9.
  12. ^ Hitomi Suzuki; Yoshihiro Matano (2001). Organobismuth chemistry. Elsevier. p. 8. ISBN 0-444-20528-4.
  13. ^ Gillespie, R. J.; B. Landa; G. J. Schrobilgen (1971). "Trifluoroxenon(IV)µ-fluoro-bispentafluoroantimonate(V): the XeF+
    3
    cation". Journal of the Chemical Society D: Chemical Communications (23): 1543–1544. doi:10.1039/C29710001543.
  14. ^ Rigin, V.; Skvortsov, N. K.; Rigin, V. V. (March 1997). "Xenon tetrafluoride as a decomposition agent for silicone rubber for isolation and atomic emission spectrometric determination of trace metals". Analytica Chimica Acta. 340 (1–3): 1–3. doi:10.1016/S0003-2670(96)00563-6.

External links