INTERCALATION CHEMISTRY OF GRAPHITE FLUORIDES

Graphite fluorides of the general composition CF(n), with n = 0.25-1.0, are found, according to X-ray diffraction and X-ray photoelectron studies, to contain graphitic zones which allow oxidative intercalation by bis(fluorosulfuryl)peroxide, S2O6F2, as well as intercalation by fluorosulfuric acid HSO3F and trifluoromethylsulfuric acid HSO3CF3. The reactions produce materials of the general composition CFn(SO3F)m or CFn(HSO3X)m, with X = F or CF3. While intercalation of S2O6F2 into the graphitic zones results in the formation of first-stage intercalation products in all instances, higher-stage materials form with HSO3F and to an increased degree with HSO3CF3, particularly when graphite fluorides with low fluorine contents are used. Interestingly, according to their X-ray photoelectron spectra, intercalation of all three reagents causes an increase in the polarity of the C-F bond; the oxidized graphitic zones appear to increase while the fluorine 1s binding energies suggest an increased ionic character.