CHARACTERIZATION OF THE SOLUBLE ALL-CARBON MOLECULES C60 AND C70

We report on the further physical and chemical characterization of the new forms of molecular carbon, C60 and C70. Our results demonstrate a high yield of production (14%) under optimized conditions and reveal only C60 and C70 in measurable quantity, in an 85:15 ratio. These two new molecular forms of carbon can be completely separated in analytical amounts by column chromatography on alumina. Comparison among mass spectra obtained by the electron impact, laser desorption, and fast atom bombardment (FAB) methods allows a clear assessment of the composition of the mixed and pure samples, and of the fragmentation and double ionization patterns of the molecules. In addition, spectroscopic analyses are reported for the crude mixture by 13C NMR and by IR spectroscopy in KBr pellet, and for pure C60 and C70 in solution by UV-vis spectroscopy. © 1990 American Chemical Society.