Abstract Planar-sheet graphite fluorides, C x F, are prepared at ambient temperature by the reaction of graphite with the transition fluorometallates K 2MnF 6 and K 2NiF 6 in anhydrous hydrogen fluoride (AHF). In the case of K 2MnF 6, this represents the first chemical route to graphite fluorides without use of elemental fluorine. For each reagent, the net reactions are identified by stoichiometry and X-ray diffraction of the solid products. The graphite fluorides generated at the oxidation limit have stoichiometries close to C 6F and C 2F for the Mn 4+ and Ni 4+ fluorometallates, respectively. Na 3FeF 6 will also oxidize graphite to C x F in AHF, although homogeneous products were not obtained due to rapid solvolysis of the fluorometallate. CoF 3 and KF react in AHF to release F 2. C x F is produced when graphite is reacted with this oxidizing combination. The reactions and oxidation limits are discussed in terms of a thermodynamic model for graphite intercalation. A synthetic strategy for the preparation of planar-sheet graphite fluorides in organic solvents is proposed.