Sulfur chloride pentafluoride

Sulfur chloride pentafluoride is an inorganic compound with the formula SF5Cl. It exists as a colorless gas at room temperature and is highly toxic, like most inorganic compounds containing the pentafluorosulfide (–SF5) functional group.[1] The compound adopts an octahedral geometry with C
4v
symmetry. Sulfur chloride pentafluoride is the only commercially available reagent for adding the –SF5 group to organic compounds.[2][3]

Sulfur chloride pentafluoride
Skeletal formula of sulfur chloride pentafluoride
Ball-and-stick model of the sulfur chloride pentafluoride molecule
Names
Other names
Pentafluorochlorosulfanyl
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.034.014 Edit this at Wikidata
UNII
  • InChI=1S/ClF5S/c1-7(2,3,4,5)6 checkY
    Key: GSYNTTDHMKSMFY-UHFFFAOYSA-N checkY
  • ClS(F)(F)(F)(F)F
Properties
SF5Cl
Molar mass 162.510 g/mol
Appearance Colorless gas
Density 6.642 g/dm3
Melting point −64 °C (−83 °F; 209 K)
Boiling point −19 °C (−2 °F; 254 K)
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
Toxic
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Reactivity

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SF5Cl is highly reactive and toxic. In contrast, sulfur hexafluoride (SF6) is inert and nontoxic despite having a closely related chemical formula. This difference highlights the lability of the S–Cl bond in SF5Cl.

Under free-radical conditions, SF5Cl adds across double bonds. The following reaction occurs with propene:

CH
3
CH=CH
2
+ SF
5
Cl
→ CH3CHClCH2SF5

The addition reaction is catalyzed by (CH3CH2)3B at around −30 °C. SF5Br is used similarly.[2]

SF5Cl is also a precursor to O(SF5)2 and F2NSF5 (from tetrafluorohydrazine).

Synthesis

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Sulfur chloropentafluoride can be synthesized by several routes, starting from two lower sulfur fluorides, sulfur tetrafluoride and disulfur decafluoride:[1]

SF4 + Cl2 + CsF → SF5Cl + CsCl
ClF + SF4 → SF5Cl
S2F10 + Cl2 → 2 SF5Cl

The corresponding SF
5
Br
is prepared similarly from in-situ generated bromine monofluoride.[4]

References

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  1. ^ a b Nyman, F., Roberts, H. L., Seaton, T. "Sulfur Chloride Pentafluoride" Inorganic Syntheses, 1966, Volume 8, p. 160. doi:10.1002/9780470132395.ch42
  2. ^ a b Dolbier, William R.; et al. (2006). "A convenient and efficient method for incorporation of pentafluorosulfanyl (SF5) substituents into aliphatic compounds". Journal of Fluorine Chemistry. 127 (10): 1302–10. doi:10.1016/j.jfluchem.2006.05.003.
  3. ^ Savoie, Paul R.; Welch, John T. (2015). "Preparation and Utility of Organic Pentafluorosulfanyl-Containing Compounds". Chemical Reviews. 115 (2): 1130–1190. doi:10.1021/cr500336u. PMID 25341449.
  4. ^ Winter, Rolf; Terjeson, Robin J.; Gard, Gary L. (1998). "An Improved and Facile Preparation of SF5Br". Journal of Fluorine Chemistry. 89: 105–106. doi:10.1016/S0022-1139(98)00094-3.