High-yield synthesis, separation, and mass-spectrometric characterization of fullerenes C60 to C266

Article abstract of DOI:10.1021/ja00020a008

The preparation of fullerenes C₆₀ to C₂₆₆ in very high yield (up to 44% extractable) by a plasms discharge is reported. Almost one-third of the extractable material is composed of giant fullerenes C₈₄ to C₂₀₀. An extraction for isolating selected molecular weight fractions of fullerenes is described. The extractions were characterized by time-of-flight mass spectrometry and Fourier transform spectrometry. We find that a Soxhlet extraction with benzene extracts 50% more soluble fullerenes than benzene reflux, Soxhlet extractions with 1,2,3,5-tetramethylbenzene preferentially extract higher molecular weight fullerenes. Hexane to limit the amount of higher fullerenes extracted, giving solutions containing C₆₀ and C₇₀ with only of the higher molecular weight fullerenes. Heptane extraction following the hexane extraction appears to preferentially extract C₆₀, C₇₀, and C₈₀. This solvent scheme is useful in preparing molecular weight fractions for subsequent separation by column chromatography.