Reaction of silver(I) and (II) fluorides with C-60: thermodynamic control over fluorination level

Silver(I) fluoride is shown to be a weak fluorinating agent (FA) for C-60 and gives mainly C60F18. Fluorination with silver(II) fluoride yields C60F44, a new compound, as the predominant product (> 80% in the crude). Fluorination degree of fullerenes in reaction with binary metal fluorides is found to be mainly thermodynamically controlled. The correlation between the level of C-60 fluorination and oxidising fluorinating strength of the metal fluorides used for fluorofullerene preparations is discussed, permitting development of a self-consistent quantitative scale for inorganic FAs.