FRAGMENTATION OF FULLERENES IN COLLISIONS WITH ATOMIC AND MOLECULAR TARGETS

Fragmentation cross sections of fullerene cations have been measured a s a function of collision energy under single collision conditions. Th e ions are produced by laser desorption from a C-60/C-70 substrate. Co llision products are analyzed with a linear time of flight mass spectr ometer. The collision energy ranges from 5 eV up to more than 150 eV i n the center of mass reference frame. A combination of molecular dynam ics calculations and statistical RRKM theory has been applied to help understand the nature of the fragmentation dynamics. The results of co llisions 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, O-2, CO2, (CH2)(3), C3H6, SF6) give additional insight into th e fragmentation mechanisms. The energy dependence of the fragmentation cross sections can be used to identify exothermic reactions between p rojectile and target as is shown for the case of molecular oxygen. (C) 1996 American Institute of Physics.