PROPOSED FULLERENE PRECURSOR CORANNULENE IDENTIFIED IN FLAMES BOTH INTHE PRESENCE AND ABSENCE OF FULLERENE PRODUCTION

Corannulene, C20H10, a bowl-shaped polycyclic aromatic hydrocarbon who se curvature and carbon framework are similar to those of fullerenes, has been widely hypothesized to be a fullerene precursor but has never been identified in flames, either in the presence or absence of fulle rene production. In research on the mechanism and prevalence of fuller ene formation in flames, we have identified corannulene in fullerene-p roducing flames and also in conventional flames that do not produce fu llerenes. The identification was achieved using a combination of analy tical methods including high performance liquid chromatography with UV -vis spectrometric detection, and gas chromatography coupled with infr ared and mass spectrometric detection. The presence of corannulene in fullerene-forming flames is consistent with the hypothesis that corann ulene is a fullerene precursor. The presence of corannulene in fullere ne-deficient flames does not necessarily contradict this hypothesis an d instead may suggest that at least some stages of fullerene formation chemistry are more generally operative in flames than had previously been known.