Collision energy-dependent fragmentation of the fullerene ions C60+ and C70+ using air as target gas

Abstract

The variation of relative cross-sections for the collisional dissociation of C60+ to the large fragment fullerene ions C58+, C56 + and C54+ with air as target gas revealed a possible contribution of a C2 and/or direct C2n evaporation reaction requiring no activation energy due to the ion–dipole interaction. The small carbon-cluster ions {Cy +} were found to be formed from their parent fullerene ions accompanied by almost the same kinetic energy losses prior to fragmentation regardless of their size, which is consistent with the concurrent formation mechanism of small carbon-cluster ions {Cy+ } in a narrow internal state and/or energy of C60 + and C70+. The collision energy dependence of C60+ with regard to the relative abundance of its fragment ions suggested a considerable variation in structure beyond the parent-ion average internal energy of ca 80 eV, which coincided with the internal energy of C60+ equal to the beginning of the Pretzel phase. © 1999 John Wiley & Sons, Ltd.