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Hypofluorous acid

Hypofluorous acid
IUPAC name hypofluorous acid
Other names hydrogen hypofluorite
hydrogen fluorate(I)
fluoric(I) acid
CAS number 14034-79-8
Molecular formula HFO
Molar mass 36.0057 g mol−1
Appearance pale yellow liquid above −117 °C
white solid below −117 °C
Density  ? g/cm3, ?
Melting point

−117 °C (? K)

Boiling point

< 0 °C
decomposes at 0 °C

Solubility in water  ?
Related Compounds
Other cations lithium hypofluorite, LiOF
Related compounds hypochlorous acid, HOCl
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)

Infobox disclaimer and references

Hypofluorous acid is the chemical compound with the formula HOF. It is an intermediate in the oxidation of water by fluorine, which affords HF and oxygen. It is the only hypohalic acid that can be isolated as a solid. HOF is explosive, decomposing to oxygen and HF[1].

The compound has been characterized in the solid phase by X-ray crystallography[1] as a bent molecule with an angle of 101°. The O-F and O-H bond lengths are 1.442 and 0.78 A, respectively. The solid framework consists of chains with O-H---O linkages. Note that these solid phase measurements differ somewhat from those observed in the gaseous phase, which are shown in the accompanying illustration.

Hypofluorous acid in acetonitrile (generated in situ by passing gaseous fluorine through "wet" acetonitrile) serves as a highly electrophilic oxygen-transfer agent.[2] Treating phenanthroline with this reagent yielded the previously elusive 1,10-phenanthroline dioxide,[3] more than 50 years after the first unsuccessful attempt.[4]

See also

  • Hypochlorous acid, a related species that is more technologically important but has not been obtained in pure form.


  1. ^ a b W. Poll, G. Pawelke, D. Mootz, E. H. Appelman, “The Crystal Structure of Hypofluorous Acid : Chain Formation by O-H. . . O Hydrogen Bonds” Angewandte Chemie International Edition in English 1988, volume 27, pp 392-3.
  2. ^ S. Rozen, M. Brand, Angew. Chem. Int. Ed. 1986, 25, 554-5; S. Dayan, Y. Bareket, S. Rozen, Tetrahedron 1999, 55, 3657.
  3. ^ S. Rozen, S. Dayan, Angew. Chem. Int. Ed. 1999, 38, 3471-3.
  4. ^ F. Linsker, R.L. Evans, J. Am. Chem. Soc. 1946, 68, 403.
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Hypofluorous_acid". A list of authors is available in Wikipedia.
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