EVIDENCE FOR THE ENTRAPMENT OF C-60, C-70 AND ODD-NUMBERED HIGH-MASS CARBON CLUSTERS

The carbon arc soot from a fullerene generator was exhaustively extracted with toluene, pyridine, toluene then pyridine, benzene and carbon disulphide. Complete extraction of C60 and C70 was not fully achieved with any solvent since the residue was shown to contain occluded C60 and C70. Fourier transform infrared, solid-state nuclear magnetic resonance and threshold laser desorption Fourier transform ion cyclotron resonance mass spectrometric experiments were used to show the presence of C60 and C70 in the exhaustively extracted residues. Low-power laser irradiation also indicated the presence of higher fullerenes in the extracted arc soot. Laser ablation of the extracted arc soot gave FT ion cyclotron resonance mass spectra which showed regions with odd-numbered carbon clusters. It is suggested that the smaller fullerenes and possibly the odd-numbered clusters may be trapped in hyperfullerenes such as the 'Russian egg' or in 'buckytubes'.