Disulfur decafluoride

Disulfur decafluoride
Preferred IUPAC name Disulfur decafluoride
Systematic name Decafluoro-1λ6,2λ6-disulfane
Identifiers
CAS number	5714-22-7
PubChem	62586 Y
ChemSpider	56348 Y
EC number	227-204-4
MeSH	Disulfur+decafluoride
Jmol-3D images	Image 1
SMILES FS(F)(F)(F)(F)S(F)(F)(F)(F)F
InChI InChI=1S/F10S2/c1-11(2,3,4,5)12(6,7,8,9)10 Key: BPFZRKQDXVZTFD-UHFFFAOYSA-N
Properties
Molecular formula	S2F10
Appearance	colorless liquid
Melting point	-53 °C
Boiling point	30.1 °C
Hazards
NFPA 704	3 4 2
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Disulfur decafluoride (S₂F₁₀) is a gas discovered in 1934 by Denbigh and Whytlaw-Gray.^[1] Each S of the S₂F₁₀ molecule is octahedral, and surrounded by 5 fluorines.^[2] S₂F₁₀ is highly toxic, with toxicity similar to phosgene. It was considered a potential chemical warfare pulmonary agent in World War II because it does not produce lacrimation or skin irritation, thus providing little warning of exposure. It is a possible by-product of electrically decomposed SF₆ gas -- an essentially inert insulator used in high voltage systems such as transmission lines, substations and switchgear. S₂F₁₀ is also made during the production of SF₆, but is distilled out.

Properties

This compound contains sulfur in the +5 oxidation state.

At temperatures above 150°C, S₂F₁₀ decomposes slowly to SF₆ and SF₄.

S₂F₁₀ reacts with N₂F₄ to give SF₅NF₂. It reacts with SO₂ to form SF₅OSO₂F in the presence of ultraviolet radiation.

In the presence of excess chlorine gas, S₂F₁₀ reacts to form sulfur chloride pentafluoride (SF₅Cl):

S₂F₁₀ + Cl₂ → 2 SF₅Cl

The analogous reaction with bromine is reversible and yields SF₅Br.^[3] The reversibility of this reaction can be used to synthesize S₂F₁₀ from SF₅Br.^[4]

Ammonia is oxidised by S₂F₁₀ into NSF₃.^[5]

Toxicity

S₂F₁₀ is a colorless, odorless liquid about 4 times as poisonous as phosgene; a single breath can kill within a day. Its toxicity is thought to be caused by its disproportionation in the lungs into SF₆, which is inert, and SF₄, which reacts with moisture to form sulfurous acid and hydrofluoric acid.^[6]

External links

• CDC page on the substance's toxicology

References

1. ^ Kenneth G. Denbigh and Robert Whytlaw-Gray (1934). "The preparation and properties of disulphur decafluoride". J. Chem. Soc.: 1346–1352. doi:10.1039/JR9340001346. 
2. ^ Harvey, R. B.; Bauer, S. H. (June 1953). "An Electron Diffraction Study of Disulfur Decafluoride". Journal of the American Chemical Society 75 (12): 2840–2846. doi:10.1021/ja01108a015.  edit
3. ^ Cohen, B.; MacDiarmid, A. G. (December 1965). "Chemical Properties of Disulfur Decafluoride". Inorganic Chemistry 4 (12): 1782–1785. doi:10.1021/ic50034a025.  edit
4. ^ Winter, R.; Nixon, P.; Gard, G. (January 1998). "A new preparation of disulfur decafluoride". Journal of Fluorine Chemistry 87 (1): 85–86. doi:10.1016/S0022-1139(97)00096-1.  edit
5. ^ Steve Mitchell (1996). Steve Mitchell. ed. Biological interactions of sulfur compounds. CRC Press. p. 14. ISBN 0748402454. 
6. ^ Harold Johnston (2003). A bridge not attacked: chemical warfare civilian research during World War II. World Scientific. pp. 33–36. ISBN 9812381538. 

• Loucas G. Christophorou; Isidor Sauers (1991). Christophorou, Loucas G., Isidor Sauers. ed. Gaseous Dielectrics VI. Plenum Press. ISBN 0-306-43894-1.