C-60 - A HOST LATTICE FOR THE INTERCALATION OF OXYGEN

The investigation of struct ural and electronic properties of the nove l family of fullerenes depends on the existence of pure reference mate rials. Sublimation of the van-der Waals solids is a suitable purificat ion method. Little attention has been paid to the question about the a ir stability of such sublimed samples in form of crystals or thin film s. A combination of thermal desorption spectroscopy, thermal analysis and diffuse reflectance FT-IR spectroscopy is used to show the extent to which oxygen from dry air is intercalated into fullerenes and which detrimental reactivity occurs from attempts to thermally remove (''an neal'') air-exposed samples. The conclusion is that any fullerene samp le exposed to air will be transformed in part into a polymeric non-ful lerene carbon upon thermal treatment to above 400 K irrespective of it s initial purity.