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

Abstract

The basic C₆₀ and C₇₀, and the higher fullerenes, mainly C₇₆ and C₈₄ 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.

Keywords:

• Carbon soot
• higher fullerenes
• solvent extractions
• alumina column chromatographies
• optical absorption properties

Acknowledgments

We are grateful to the Ministry of Science, Serbia, for financial support of this research (project III 45009) and to MER Corporation, Tucson, USA, for carbon soot material.