Carbon Monofluoride

Carbon monofluoride (CF, CF_x, or (CF)_x), also called polycarbon monofluoride (PMF), polycarbon fluoride, poly(carbon monofluoride), and graphite fluoride, is a material formed by high-temperature reaction of fluorine gas with graphite, charcoal, or pyrolytic carbon powder. It is a highly hydrophobic microcrystalline powder. Its CAS number is . In contrast to graphite intercalation compounds it is a covalent graphite compound.

Carbon is stable in fluorine atmosphere up to about 400 °C, but between 420-600 °C reaction takes place to give substoichiometric carbon monofluoride, CF_0.68 appearing dark grey. With increasing temperature and fluorine pressure stoichiometries up to CF_1.12 are formed. With increasing fluorine content the colour changes from dark grey to cream white indicating the loss of the aromatic character. The fluorine atoms are located in an alternating fashion above and under the former graphene plane, which is now buckled due to formation of covalent carbon-fluorine bonds. Reaction of carbon with fluorine at even higher temperature successively destroys the graphite compound to yield a mixture of gaseous fluorocarbons such as tetrafluorocarbon, CF₄, and tetrafluoroethylene, C₂F₄.

In a similar fashion the recently found carbon allotrope fullerene, C₆₀ reacts with fluorine gas to give fullerene fluorides with stoichiometries up to C₆₀F₄₈.

A precursor of carbon monofluoride is the fluorine-graphite intercalation compound, also called fluorine-GIC.

Other intercalation fluorides of carbon are

• poly(dicarbon fluoride) ((C₂F)_n);
• tetracarbon monofluoride (TCMF, C₄F).

Graphite fluoride is a procursor for preparation of graphene fluoride by a liquid phase exfoliation.