Pentafluorosulfur hypofluorite

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Pentafluorosulfur hypofluorite
Pentafluorosulfur hypofluorite.png
Names
IUPAC name
Pentafluorosulfur hypofluorite
Other names
  • Sulfur fluoride hypofluorite
  • Thionyl fluoride hypofluorite
Identifiers
3D model (JSmol)
PubChem CID
  • InChI=1S/F6OS/c1-7-8(2,3,4,5)6
    Key: DGQBNDRZRZYTER-UHFFFAOYSA-N
  • S(F)(F)(F)(F)(F)OF
Properties
SOF6
Molar mass 162.05 g·mol−1
AppearanceColorless gas
Density 1.947 at -47.2 °C [1]
Melting point −86 °C (−123 °F; 187 K) [1]
Boiling point −35.1 °C (−31.2 °F; 238.1 K) [1]
Reacts with water
log P 6.03633-420.35/T-78360/T2 [1]
Related compounds
Related oxohalides
Related compounds
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Pentafluorosulfur hypofluorite is an inorganic compound with the chemical formula S O F 6. In standard conditions it is a colorless gas. It is an oxyfluoride of sulfur, where sulfur is in the +6 oxidation state, with a fluorine atom attached to oxygen. [1]

Contents

Synthesis

SOF6 can be made by reacting thionyl fluoride with fluorine at 200 °C with a silver difluoride catalyst. [2]

SOF2 + 2 F2 → SOF6 (+ some SOF4)

The synthesis can also be performed from fluorine and thionyl fluoride [3] or thionyl tetrafluoride [4] using caesium fluoride as catalyst at room temperature. [5]

Properties

The molecular shape has five fluorine and one oxygen atom arranged around a sulfur atom in an octahedral arrangement. Another fluorine atom is attached to the oxygen in almost a straight line with the S-O connection. So the molecular formula can also be written as SF5−OF. The average S-F distance is 1.53 Å. The angles ∠FSF and ∠FSO are 90°. [2]

The neat 19F nuclear magnetic resonance spectrum of SOF6 was reported using SF6 as internal standard. With this reference, a -131.5 ppm shift for the hypofluorite fluorine, a +1.75 ppm shift for Fax and a +3.64 ppm shift for the four Feq was observed. A 17.4 Hz 19F-19Feq spin coupling (O-F to SF4) and a 155 Hz coupling constant was measured for 19Fax-19Feq in OSF5. No coupling was observed between the hypofluorite and the Fax. [6]

A neat (uncorrected) refined 19F nuclear magnetic resonance spectrum of SOF6 was recorded at -80°C. [5] A first order quintet was observed for F-OSF5 at 183.9 ppm with a 3J(F,Feq) coupling of 17.5 Hz. A high order AB4 system was observed for both the Feq and Fax of the OSF5 moiety. The S–Fax shift is 52.2 ppm and the S–Feq is 50.3 ppm with a measured 2J(Feq,Fax) of 153.5 Hz.

Reactions

Iodide is oxidised to iodine

SOF6 + 2 I− + H2O → SO2F2 + I2 + 2 HF + 2 F−

Alkalis such as potassium hydroxide react

2 SOF6 + 12 OH− → O2 + 10 F− + 5 H2O + 2 SO3F−

Alkenes react to add to a double bond, with −OSF5 on one carbon, and −F on the other.

C2H4 + SOF6 → FH2C−CH2−O−SF5. [7]
C2F4 + SOF6 → CF3−CF2−O−SF5. [7]

CF3−CF2−O−SF5 boils at 15°C.

SOF6 + ClCH=CH2 → FClCH−CH2−O−SF5 [8]
SOF6 + FCH=CH2 → F2CH−CH2−O−SF5 [8]
SOF6 + F2C=CH2 → F3C−CH2−O−SF5 [8]
SOF6 + SOF4 → mixture of SF6, SOF4, bis-(pentafluorosulfur) peroxide F5S−O−O−SF5 and bis-(pentafluorosulfur) oxide F5S−O−SF5. [7]

Thermal decomposition produces sulfur hexafluoride and oxygen.

2 SOF6 + heat over 210° → 2 SF6 + O2. [7]

Some reactions of SOF6 result in fluorination of other molecules

SOF6 + CO → F2CO + SOF4. [7]
SOF6 + F2CO → SF5−O−O−CF3 [9]
SOF6 + SO3 → F5S−O−O−SO2F [9]
SOF6 + N2F4 → F5S−O−NF2 [9]
3 SOF6 + Br2 → 2 BrF3 + 3 SOF4 [9]
5 SOF6 + I2 → 2 IF5 + 5 SOF4 [9]
PF3 + SOF6 → PF5 + SOF4 [9]
NO2 + SOF6 → 2 NO2F [9]

References

  1. 1 2 3 4 5 Dudley, F. B.; Cady, G. H.; Eggers, D. F. (April 1956). "Pentafluorosulfur Hypofluorite and Thionyl Tetrafluoride". Journal of the American Chemical Society. 78 (8): 1553–1557. Bibcode:1956JAChS..78.1553D. doi:10.1021/ja01589a013.
  2. 1 2 Crawford, Roger A.; Dudley, Frank B.; Hedberg, Kenneth (October 1959). "A Verification of the Molecular Structure of Pentafluorosulfur Hypofluorite (SF5OF) by Electron Diffraction". Journal of the American Chemical Society. 81 (20): 5287–5288. Bibcode:1959JAChS..81.5287C. doi:10.1021/ja01529a009.
  3. ↑ John K. Ruff (1968), William L. Jolly (ed.), "Thionyl tetrafluoride and pentafluorosulfur hypofluorite", Inorganic Syntheses, vol. 11, McGraw-Hill Book Company, Inc., pp. 131–137
  4. ↑ Ruff, J. K.; Lustig, M. (1964). "Sulfur Oxyfluoride Derivatives". Inorganic Chemistry. 3: 1422–1425. doi:10.1021/ic50020a017.
  5. 1 2 Millanvois, Alexandre; Bahri, Carlota; Drews, Thomas; Steinhauer, Simon; Riedel, Sebastian (July 2025). "Assessing Fluorosulfonyl Pentafluorooxosulfate (FSO2–OSF5) Reservoir Capacity: Selective SOF4, SO2F2 and [OSF5]– Anion Release". Angewandte Chemie International Edition: e202510796. doi:10.1002/anie.202510796. PMID   40600432.
  6. ↑ Emsley, J. W.; Feeney, J.; Sutcliffe, L. H. (22 October 2013). High Resolution Nuclear Magnetic Resonance Spectroscopy. Elsevier. p. 949. ISBN   9781483184081.
  7. 1 2 3 4 5 Williamson, Stanley M.; Cady, George H. (August 1962). "Reactions of Pentafluorosulfur Hypofluorite". Inorganic Chemistry. 1 (3): 673–677. doi:10.1021/ic50003a044.
  8. 1 2 3 Williamson, Stanley M. (1963). "On the Reaction of Pentafluorosulfur Hypofluorite with Unsymmetrical Two-Carbon Alkenes". Inorganic Chemistry. 2 (2): 421–422. doi:10.1021/ic50006a050.
  9. 1 2 3 4 5 6 7 Tattershall, B.W.; Cady, George H. (December 1967). "Reactions of pentafluorosulphur hypofluorite (SF5OF) with Cl2, Br2, I2, NO2, and PF3". Journal of Inorganic and Nuclear Chemistry. 29 (12): 3003–3005. doi:10.1016/0022-1902(67)80134-9.
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