Sulfur difluoride
IUPAC name
sulfoxylic difluoride
3D model (JSmol)
  • InChI=1S/F2S/c1-3-2
  • FSF
Molar mass 70.062 g/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Sulfur difluoride is an inorganic compound with the chemical formula SF2. It can be generated by the reaction of sulfur dichloride and potassium fluoride or mercury(II) fluoride at low pressures:

SCl2 + 2 KF → SF2 + 2 KCl
SCl2 + HgF2 → SF2 + HgCl2

The F−S−F bond angle is 98°, and the length of S−F bond is 159 pm.[1] The compound is highly unstable, dimerising to FSSF3. This unsymmetrical isomer of S2F4 is proposed to arise via insertion of SF2 into the S−F bond of a second molecule SF2:[2]

It can also be formed from oxygen difluoride and hydrogen sulfide:[citation needed]

OF2 + H2S → SF2 + H2O


  1. ^ Johnson, D. R.; Powell, F. X. (1969). "Microwave Spectrum and Structure of Sulfur Difluoride". Science. 164 (3882): 950–1. Bibcode:1969Sci...164..950J. doi:10.1126/science.164.3882.950. PMID 17775599. S2CID 46046291.
  2. ^ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.