Advances in Chromatographic Separation on Al2O3 and Spectroscopic Characterization of the Higher Fullerenes

Abstract

The basic C-60 and C-70, and the higher fullerenes, mainly C-76 and C-84 were extracted with a series of different and previously unapplied solvents or combinations of solvents, by original advanced procedures, from the samples of carbon soot, produced in electric arc. The solubility of the basic and the higher fullerenes in the applied series of solvents was compared. Chromatographic separations of fullerenes from the obtained extracts were performed by continue elution, in one phase of each process, under atmospheric pressure, with the original, defined gradients of solvents, from pure hexane or 5% toluene in hexane to pure toluene, on active Al2O3 columns, by the new, improved methods. Identifications of fullerenes in all the chromatographically purified fractions and the extracts were performed using determined techniques of IR and UV/VIS spectroscopy that have not been presented previously for the higher fullerenes. The advances in chromatographic purification using alumina, as well as in understanding of the unique and the main optical absorption properties of these molecules are reported.