Octafluorocyclobutane

Octafluorocyclobutane, or perfluorocyclobutane, C4F8, is an organofluorine compound which enjoys several niche applications. It is related to cyclobutane by replacement of all C–H bonds with C–F bonds. Octafluorocyclobutane is produced by the dimerization of tetrafluoroethylene and the reductive coupling of 1,2-dichloro-1,1,2,2-tetrafluoroethane.[1]

Octafluorocyclobutane
Structural formula of octafluorocyclobutane
Ball-and-stick of the octafluorocyclobutane molecule
Names
IUPAC name
Octafluorocyclobutane
Other names
Freon-C-318, perfluorocyclobutane
Identifiers
CAS Number
3D model (JSmol)
Beilstein Reference
 1909266
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.003.705
EC Number
  • 204-075-2
E number E946 (glazing agents, ...)
Gmelin Reference
 131113
PubChem CID
UNII
CompTox Dashboard (EPA)
Properties
Chemical formula
 C4F8
Molar mass 200.03 g/mol
Appearance colourless gas
Density 1.637 g/cm3 at −5.8 °C (liquid)

9.97 kg/m3 at −6 °C and 1 atm (gas)
8.82 kg/m3 15 °C and 1 atm (gas)

Melting point −40.1 °C (−40.2 °F; 233.1 K)
Boiling point −5.8 °C (21.6 °F; 267.3 K)
Solubility in water
 0.016 vol/vol (1.013 bar and 20 °C)
Viscosity 109e-6 Poise (1.013 bar and 0 °C)
Hazards
GHS pictograms
GHS Signal word Warning
GHS hazard statements
 H280, H411
GHS precautionary statements
 P273, P391, P410+403, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Applications

In the production of semiconductor materials and devices, octafluorocyclobutane serves as a deposition gas and etchant.[2] It has also been investigated as a refrigerant in specialised applications, as a replacement for ozone depleting chlorofluorocarbon refrigerants. Exploiting its volatility and chemical inertness, octafluorocyclobutane may be found in some aerosolized foods. It is listed by the Codex Alimentarius under number 946 (E946 for EU). It is investigated as a possible replacement for sulfur hexafluoride as a dielectric gas.

References
  1. Siegemund, Günter; Schwertfeger, Werner; Feiring, Andrew; Smart, Bruce; Behr, Fred; Vogel, Herward; McKusick, Blaine (2002). "Fluorine Compounds, Organic". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a11_349..
  2. "Octafluorocyclobutane (RC318)". Gas Encyclopaedia. Air Liquide. Retrieved May 15, 2013.

Appendix

Its critical point is at 115.3 °C and 2.79 MPa.