C-61+ PRODUCTION AND DECOMPOSITION IN C-13+ + C-60 COLLISIONS - C-ATOM EXCHANGE AND THE FRAGMENTATION-PATTERN AS A FUNCTION OF ENERGY

The reaction of C+ with C60 has been studied under single collision conditions over the energy range from 2 to 78 eV. C61+ is observed to form with no activation energy and survives for > 1 ms at excess energies up to 10 eV. At low collision energies, the dominant C61+ decay pathway is to C60+ + C, which can also result from charge transfer. These two C60+ production mechanisms can be distinguished by the different C60+ velocity distributions which result. C-13 labeling clearly demonstrates that in the C61+ adduct, the C-13+ projectile undergoes exchange with C atoms in the C60 target. At collision energies above 20 eV, a series of C60-2n+ products are observed, and C-13 labeling shows that C-atom exchange also occurs in collisions leading to these fragmentation channels. At high collision energies a small amount of C59+ is detectable, but no other odd-sized fragments were detected.