Thionyl fluoride is the inorganic compound with the formula SOF2. This colourless gas is mainly of theoretical interest, but it is a product of the degradation of sulfur hexafluoride, an insulator in electrical equipment. The molecule adopts a distorted pyramidal structure, with Cs symmetry. The S-O and S-F distances are 1.42 and 1.58 Å, respectively. The O-S-F and F-S-F angles are 106.2 and 92.2°, respectively.[3][page needed]
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| Names | |||
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| IUPAC name
Thionyl fluoride
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| Identifiers | |||
3D model (JSmol)
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| ChemSpider | |||
| ECHA InfoCard | 100.029.088 | ||
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PubChem CID
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| UNII | |||
CompTox Dashboard (EPA)
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| Properties | |||
| F2OS | |||
| Molar mass | 86.06 g·mol−1 | ||
| Appearance | colorless gas | ||
| Melting point | −110.5 °C (−166.9 °F; 162.7 K) | ||
| Boiling point | −43.8 °C (−46.8 °F; 229.3 K) | ||
| hydrolysis | |||
| Solubility | soluble in ethanol, ether, benzene | ||
| Vapor pressure | 75.7 kPa (-50 °C)[1] | ||
| Structure | |||
| trigonal pyramidal | |||
| Thermochemistry[2][better source needed] | |||
Std molar
entropy (S⦵298) |
278.6 J/mol·K | ||
Std enthalpy of
formation (ΔfH⦵298) |
-715 kJ/mol | ||
Std enthalpy of
combustion (ΔcH⦵298) |
56.8 J/mol·K | ||
| Hazards | |||
| GHS labelling: | |||
 
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| Danger | |||
| H300, H310, H314, H330 | |||
| P260, P262, P264, P270, P271, P280, P284, P301+P310, P301+P330+P331, P302+P350, P303+P361+P353, P304+P340, P305+P351+P338, P310, P320, P321, P322, P330, P361, P363, P403+P233, P405, P501 | |||
| Related compounds | |||
Related oxohalides
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Thionyl chloride Thionyl bromide | ||
Related compounds
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Nitrosyl fluoride Carbonyl fluoride | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Synthesis and reactions
editThionyl fluoride can be produced by the reaction of thionyl chloride with fluoride sources such as antimony trifluoride.[4][3]: 542
Alternatively, it arises via the fluorination of sulfur dioxide:[3]: 542
- SO2 + PF5 → SOF2 + POF3
Thionyl fluoride arises as a fleeting intermediate from the decomposition of sulfur hexafluoride as the result of electrical discharges which generate sulfur tetrafluoride. SF4 hydrolyzes to give thionyl fluoride, which in turn hydrolyzes further as described below.[5]
As expected from the behavior of the other thionyl halides, this compound hydrolyzes readily, giving hydrogen fluoride and sulfur dioxide:[3]: 542
- SOF2 + H2O → 2 HF + SO2
In contrast to thionyl chloride and bromide, thionyl fluoride is not useful for halogenation. The related derivative, sulfur tetrafluoride is however useful for that purpose.[citation needed]
References
edit- ^ Thionyl fluoride in Linstrom, Peter J.; Mallard, William G. (eds.); NIST Chemistry WebBook, NIST Standard Reference Database Number 69, National Institute of Standards and Technology, Gaithersburg (MD) (retrieved 2014-05-11)
- ^ "Thionyl Fluoride". chemister.ru database.
- ^ a b c d Holleman, A.F. (2001). Holleman, A.F.; Wiberg, Egon; Wiberg, Nils (eds.). Inorganic Chemistry (1st ed.). San Diego, CA: Academic Press. ISBN 0-12-352651-5.
- ^ Smith, W. C.; Muetterties, E. L.; Park, J. D.; Settine, Robert (January 1960). "Thionyl Fluoride". Inorganic Syntheses. Vol. 6. pp. 162–163. doi:10.1002/9780470132371.ch50. ISBN 978-0-470-13165-7.
- ^ Pepi, Federico; Andreina Ricci; Marco Di Stefano; Marzio Rosi; Giuseppe D'Arcangelo (September 18, 2002). "Thionyl Fluoride from Sulfur Hexafluoride Corona Discharge Decomposition: Gas-Phase Chemistry of (SOF2)H+ Ions". Journal of Physical Chemistry A. 106 (40): 9261–9266. Bibcode:2002JPCA..106.9261P. doi:10.1021/jp021074v.
External links
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