Octafluorocyclobutane (C4F8) is an important fluorocarbon with niche industrial applications. It does not occur naturally, so how is this highly fluorinated cyclic compound synthesized and mass produced?

There are two primary industrial-scale production routes for C4F8:

Direct Fluorination

Fluorination of cyclobutane or butane feedstocks with elemental fluorine.

Multiple steps are needed to achieve full fluorination of the cyclobutane ring.

Produces yields up to 40% but handling fluorine gas is challenging.

Pyrolysis of Hexafluoropropene

Thermal cracking of hexafluoropropene (C3F6) at 700-750°C.

C3F6 decomposes to form C4F8 and C2F4. The mixture is distilled to purify C4F8.

Typical yields of 65-70%. C3F6 can be produced from other fluorocarbons.

In the laboratory, C4F8 can also be synthesized on a small scale by fluorinating cyclobutane directly with fluorine gas or from photochemical chlorine-fluorine exchange reactions.

Octafluorocyclobutane production ultimately relies on the direct fluorination of hydrocarbons. The pyrolysis of hexafluoropropene, itself also a fluorinated compound, is the most efficient and scalable process yielding high purity C4F8 for commercial use. Strict safety measures are essential when handling the fluorine chemistry involved.