Thiothionyl fluoride

Thiothionyl fluoride is a chemical compound of fluorine and sulfur and an isomer of disulfur difluoride.

Thiothionyl fluoride

Names
IUPAC name difluoro(sulfanylidene)-λ^4-sulfane
Identifiers
CAS Number	16860-99-4
3D model (JSmol)	Interactive image
ChemSpider	128238
PubChem CID	145375
CompTox Dashboard (EPA)	DTXSID00144397
InChI InChI=1S/F2S2/c1-4(2)3 Key: KBYVSSUWTLBZTB-UHFFFAOYSA-N
SMILES FS(=S)F
Properties
Chemical formula	F2S2
Molar mass	102.12 g·mol^−1
Appearance	colorless gas
Melting point	−164.6 °C (−264.3 °F; 108.5 K)
Boiling point	−10.6 °C (12.9 °F; 262.5 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Preparation

Thiothionyl fluoride can be obtained from the reaction between disulfur dichloride with potassium fluoride at about 150 °C or with mercury(II) fluoride at 20 °C.[1][2]

S₂Cl₂ + 2 KF → SSF₂ + 2 KCl

Another possible preparation is by the reaction of nitrogen trifluoride with sulfur.[1]

NF₃ + 3 S → SSF₂ + NSF

It also forms from disulfur difluoride when in contact with alkali metal fluorides.[3]

Properties

Thiothionyl fluoride is a colorless gas.[2] At high temperatures and pressures, it decomposes into sulfur tetrafluoride and sulfur.[2]

2 SSF₂ → SF₄ + 3 S

With hydrogen fluoride, it forms sulfur tetrafluoride and hydrogen sulfide.[4]

SSF₂ + 2 HF → SF_4, + H₂S

References

1. Brauer, Georg; Baudler, Marianne (1975). Handbuch der Präparativen Anorganischen Chemie. Band I. (3rd ed.). Stuttgart: Ferdinand Enke. p. 182. ISBN 3-432-02328-6.
2. Holleman, A. F.; Wiberg, E.; Wiberg, N. (1995). Lehrbuch der Anorganischen Chemie (101st ed.). Berlin: Walter de Gruyter. p. 379. ISBN 3-11-012641-9.
3. Steudel, Ralf (2008). Chemie der Nichtmetalle: Von Struktur und Bindung zur Anwendung. Walter de Gruyter. p. 475. ISBN 311021128-9.
4. Kolditz, Lothar (1983). Anorganische Chemie. Berlin: Deutscher Verlag der Wissenchaften. p. 468.