Synthesis and characterization of highly fluorinated graphite containing sp2 and sp3 carbon

Highly fluorinated graphites were obtained by reaction of fluorine with graphite, at room temperature, in the presence of iodine pentafluoride and hydrogen fluoride. The refluorination between 100 and 600 degreesC yielded a series of fluorinated graphites with semiionic and covalent C-F bonds with varying amounts of Sp(2)- and Sp(3)-type carbon hybridization. Three types of materials have been generated: for re-fluorination lower than 400 degreesC, the C-F bond is still mainly semi-ionic and the carbon atoms are Sp(2) coplanar; for re-fluorination temperatures between 400 and 550 degreesC, "hybrid" graphite fluorides characterized by two types Sp(3) of C-F bonds, semi-ionic and covalent, with Sp(2) and carbon hybridization were found. For higher re-fluorination temperatures (between 550 and 600 degreesC), despite a similar fluorination amount and a covalent C-F bond, the sp(2) character never completely vanished even at a high re-fluorination temperature of 600 degreesC. At, such a temperature, a directly fluorinated graphite would be of the pure Sp(3) type.