FRAGMENTATION OF FULLERENES IN COLLISIONS WITH ATOMIC AND MOLECULAR TARGETS

Fragmentation cross sections of fullerene cations have been measured as a function of collision energy under single collision conditions. The ions are produced by laser desorption from a C60/C70 substrate. Collision products are analyzed with a linear time of flight mass spectrometer. The collision energy ranges from 5 eV up to more than 150 eV in the center of mass reference frame. A combination of molecular dynamics calculations and statistical RRKM theory has been applied to help understand the nature of the fragmentation dynamics. The results of collisions using different fullerenes as projectiles (C+56, C+58, C+60, C+70) as well as collisions with a range of target gases (Ne, Ar, O2, CO2, (CH2)3, C3H6, SF6) give additional insight into the fragmentation mechanisms. The energy dependence of the fragmentation cross sections can be used to identify exothermic reactions between projectile and target as is shown for the case of molecular oxygen.