Octafluorocyclobutane
Octafluorocyclobutane, or perfluorocyclobutane, C4F8, is an organofluorine compound which enjoys several niche applications. Octafluorocyclobutane is a colourless gas and shipped as a liquefied gas. It is the perfluorinated analogue of cyclobutane whereby all C–H bonds are replaced with C–F bonds.
Production
Octafluorocyclobutane is produced by the dimerization of tetrafluoroethylene and the reductive coupling of 1,2-dichloro-1,1,2,2-tetrafluoroethane.
Properties
The critical point of octafluorocyclobutane is at 115.3 °C and 2.79 MPa.
Applications
In the production of semiconductor materials and devices, octafluorocyclobutane serves mainly as a passivation layer material in etching processes. Sometimes it is used as an etchant. 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. It is investigated as a possible replacement for sulfur hexafluoride as a dielectric gas.