TuP-20


METALLO-FULLERENE CATION (M@C2n+) FORMATION STUDIES BY LASER ABLATION FOURIER TRANSFORM ICR MASS SPECTROMETRY

Rui Zhang, Keith J. Fisher, Derek R. Smith, Ian G. Dance, Gary D. Willett, Femia G. Hopwood and Gerry E. Gadd*

School of Chemistry, University of New South Wales, Sydney, NSW 2052
*Australian Nuclear Science and Technology Organisation


An abundant series of metallo-fullerene1-2 positive-ions, M@C2n+, have been produced by laser ablation of a mixture of metal salts (metal oxides or metal sulfides) and coal tar pitch pyrolysis residues, carbon thermal black and kerogen using the fundamental frequency of a Nd:YAG laser (1064 nm). The mixtures of metal salts and these carbon materials in a range of carbon/metal ratios are shown to produce metallo-fullerene cations by low power laser irradiation (100 ~1000 kW cm-2). A variety of metals in the periodic table have been investigated and only the lanthanides and group IIIB metals plus some alkaline-earth metals in group IIA appear to form metallo-fullerenes. This study also shows that only long pulse (230 ms) low peak-power laser irradiation of the carbon-based mixtures forms metallo-fullerene cations. The shorter (8 ns) and much higher energy Q-switch pulse laser irradiation forms only small carbon cations, metal-carbon cluster ions MCn+ and occasionally fullerenes. Interestingly, the appearance of the small metal-carbon cluster MCn cations appears to correlate with the formation of the metallo-fullerene cations, M@C2n+.

Figure

Long pulse (230 ms; 1064 nm) laser ablation of a mixture of La2O3 and Koppers Coal Tar Pitch pyrolysis residue.


  1. Rose, H. R.; Dance, I. G.; Fisher, K. J.; Smith, D. R.; Willett, G. D.; Wilson, M. A. J. Chem. Soc. Chem. Commun. 1993, 1361-1363.
  2. Rose, H. R.; Dance, I. G.; Fisher, K. J.; Smith, D. R.; Willett, G. D. Org. Mass Spectrom. 1994, 29, 470-474.