nitryl fluoride
{{chembox
|Verifiedfields = changed
|Watchedfields = changed
|verifiedrevid = 428847234
|Name = Nitryl fluoride
|ImageFileL1 = Nitryl-fluoride-2D-dimensions.svg
|ImageNameL1 = Nitryl fluoride
|ImageFileR1 = Nitryl-fluoride-3D-vdW.png
|ImageNameR1 = Nitryl fluoride
|Section1={{Chembox Identifiers
|CASNo_Ref = {{cascite|correct|??}}
|CASNo = 10022-50-1
|UNII_Ref = {{fdacite|changed|FDA}}
|UNII = DAT2I9R64A
|EINECS = 233-021-0
|PubChem = 66203
|ChemSpiderID_Ref = {{chemspidercite|changed|chemspider}}
|ChemSpiderID = 59588
|SMILES = [N+](=O)([O-])F
|InChI = 1/FNO2/c1-2(3)4
|InChIKey = JVJQPDTXIALXOG-UHFFFAOYAU
|StdInChI_Ref = {{stdinchicite|changed|chemspider}}
|StdInChI = 1S/FNO2/c1-2(3)4
|StdInChIKey_Ref = {{stdinchicite|changed|chemspider}}
|StdInChIKey = JVJQPDTXIALXOG-UHFFFAOYSA-N
}}
|Section2={{Chembox Properties
| N=1 | O=2 | F=1
|Solvent = other solvents
|MeltingPtC = -166
|BoilingPtC = -72
}}
|Section8={{Chembox Related
| OtherAnions = nitryl chloride, nitryl bromide
| OtherCations = nitrosyl fluoride, sulfuryl fluoride
}}
}}
Nitryl fluoride, NO2F, is a colourless gas and strong oxidizing agent, which is used as a fluorinating agentMerck Index, 13th edition (2001), p.1193 and has been proposed as an oxidiser in rocket propellants (though never flown).
It is a molecular species, not ionic, consistent with its low boiling point. The structure features planar nitrogen with a short N-F bond length of 135 pm.F. A. Cotton and G.Wilkinson, Advanced Inorganic Chemistry, 5th edition (1988), Wiley, p.333.
Preparation
Henri Moissan and Paul Lebeau recorded the preparation of nitryl fluoride in 1905 by the fluorination of nitrogen dioxide. This reaction is highly exothermic, which leads to contaminated products. The simplest method avoids fluorine gas but uses cobalt(III) fluoride:{{cite journal|last=Davis|first=Ralph A.|author2=Rausch, Douglas A. |title=Preparation of Nitryl Fluoride|journal=Inorganic Chemistry|volume=2|issue=6|pages=1300–1301|doi=10.1021/ic50010a048|year=1963}}
:NO2 + CoF3 → NO2F + CoF2
The CoF2 can be regenerated to CoF3. Other methods have been described.{{cite journal|last1=Faloon|first1=Albert V.|last2=Kenna|first2=William B.|title=The Preparation of Nitrosyl Fluoride and Nitryl Fluoride1|journal=Journal of the American Chemical Society|volume=73|issue=6|year=1951|pages=2937–2938|issn=0002-7863|doi=10.1021/ja01150a505|hdl=2027/mdp.39015095101013|hdl-access=free}}
Thermodynamic properties
The thermodynamic properties of this gas were determined by IR and Raman spectroscopy. The standard heat of formation of FNO2 is -19 ± 2 kcal/mol, but the compound becomes increasingly unstable at higher temperature.{{cite journal|last=Tschuikow-Roux|first=E.|title=Thermodynamic Properties of Nitryl Fluoride|journal=Journal of Physical Chemistry|volume=66|issue=9|pages=1636–1639|doi=10.1021/j100815a017|year=1962}} The homogeneous thermal decomposition cannot be studied at temperatures below 1200 kelvin, because the notional unimolecular decomposition equilibrium lies on the adduct side by at least six orders of magnitude at 500 kelvin, and two orders of magnitude at 1000 kelvin.
The dissociation energy of 46.0 kcal of the N-F bond in nitryl fluoride is about 18 kcal less than the normal N-F single bond energy. This can be attributed to the “reorganization energy” of the NO2 radical; that is, the NO2 radical in FNO2 is less stable than the free NO2 molecule. Qualitatively speaking, the odd electron “used up” in the N-F bond forms a resonating three-electron bond in free NO2, thus stabilizing the molecule with a gain of 18 kcal.
Reactions
Nitryl fluoride can be used to prepare organic nitro compounds and nitrate esters.
See also
References
{{reflist}}
External links
- [http://webbook.nist.gov/cgi/cbook.cgi?ID=C10022501 WebBook page for NO2F]
- [https://web.archive.org/web/20031222093109/http://www.npi.gov.au/database/substance-info/profiles/44.html National Pollutant Inventory - Ionic Fluoride and related compounds fact sheet]
{{fluorine compounds}}