Disulfur difluoride
  Sulfur, S
  Fluorine, F
Names
IUPAC name
fluorosulfanyl thiohypofluorite
Other names
Difluorodisulfane[1]
Identifiers
3D model (JSmol)
ChemSpider
  • InChI=1S/F2S2/c1-3-4-2
  • FSSF
Properties
S2F2
Molar mass 102.127 g/mol
Melting point −133 °C (−207 °F; 140 K)
Boiling point 15 °C (59 °F; 288 K)
Related compounds
Related compounds
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Disulfur difluoride is an inorganic compound with the chemical formula S2F2. It is a halide of sulfur.

Structure

Disulfur difluoride has a chain structure F−S−S−F. The angle between the Fa−S−S and S−S−Fb planes is 87.9°, while the angles of Fa−S−S and S−S−Fb are equivalent, and are equal to 108.3°. Both S−F bonds are equivalent and their length is 163.5 pm, while the length of the S−S bond is 189 pm. This structure is referred to as gauche, and is similar to H2O2.

There is a branched isomer of disulfur difluoride, thiothionyl fluoride, with the structure S=SF2.

Synthesis

Silver(II) fluoride can fluorinate sulfur in a strictly dry container at 125 °C (257 °F; 398 K), and the reaction produces FS−SF:[2]

S8 + 8 AgF2 → 4 S2F2 + 8 AgF

Reactions

Disulfur difluoride undergoes intramolecular rearrangement in the presence of fluorides of alkali metals, yielding the isomer S=SF2:[3]

FS−SF → S=SF2
2 S2F2 → SF4 + 3 S
2 S2F2 + 2 H2O → SO2 + 3 S + 4 HF
S2F2 + 3 H2SO4 → 5 SO2 + 2 HF + 2 H2O
2 S2F2 + 6 NaOH → Na2SO3 + 3 S + 4 NaF + 3 H2O
2 S2F2 + 5 O2 → SOF4 + 3 SO3[4][5][6]

References

  1. ^ "Difluorodisulfane".
  2. ^ Davis, R.Wellington; Firth, Steven (1991). "The microwave spectrum of the chain isomer of disulfur difluoride: FS-SF". Journal of Molecular Spectroscopy. 145 (2): 225. doi:10.1016/0022-2852(91)90109-N.
  3. ^ Davis, R.Wellington (1986). "The microwave spectrum of the pyramidal isomer of disulfur difluoride: S=SF2". Journal of Molecular Spectroscopy. 116 (2): 371–383. doi:10.1016/0022-2852(86)90134-7.
  4. ^ Справочник химика / Редкол.: Никольский Б.П. и др.. — 3-е изд., испр. — Л.: Химия, 1971. — Т. 2. — 1168 с. (in Russian)
  5. ^ Химическая энциклопедия / Редкол.: Кнунянц И.Л. и др.. — М.: Советская энциклопедия, 1995. — Т. 4. — 639 с. — ISBN 978-5-85270-092-6 (in Russian)
  6. ^ Лидин Р.А. и др. Химические свойства неорганических веществ: Учеб. пособие для вузов. — 3-е изд., испр. — М.: Химия, 2000. — 480 с. — ISBN 978-5-7245-1163-6 (in Russian)
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