FULLERENES AND FULLERANES IN METEORITES REVISITED

Fullerenes C-60 and C-70 and the fullerane C60H2 were not found in the toluene extract from 200 g of the C3V carbonaceous chondrite Allende by high-performance liquid chromatography (HPLC). Two distinct substan ces in the HPLC chromatogram of the extract, called A alpha and A beta , were found to have absorption spectra in the wavelength range 300-65 0 nm similar in shape to that of C-60. The HPLC chromatograms of A alp ha and A beta show conclusively that A alpha and A beta are not C-60, C-70, C60O, or C60H2. The mass spectrometric analysis shows that Act a nd A beta do not contain any fullerene derivatives in the mass range 7 22 to 800. However, A beta may contain corannulene (C20H20), a suggest ed precursor in the formation of C-60 by condensation of carbon vapor. The discrepancy between the results of Becker et al. and Heymann rema ins essentially unresolved, but the probability of finding fullerenes or fulleranes in samples of the Allende, or other meteorites, has now become very small. The implications of the new results for theories of fullerene and fullerane formation in stellar and interstellar media a re that these substances, if they formed in such environments, apparen tly were destroyed in the interstellar cloud from which the solar syst em formed, did not survive the formation of the solar system, or did n ot survive the formation of meteorites.