The ion yield curves for C60-2nz+ (n = 1-5, z = 1-3) produced by photoionization of C60 are measured in the photon energy (hν) range of 25-150 eV. The appearance hν values are higher by 30-33 eV than the thermochemical thresholds for dissociative ionization of C60 leading to C60-2nz+. Evaluation is made on the upper limits of the internal energies of the primary C60z+ above which C60-2n+2z+ fragments (n ≥ 1) cannot escape from further dissociating into C60-2nz+ C2. These upper limits agree well with the theoretical internal energies of C 60z+ corresponding to the threshold for the formation of C60-2nz+. The photofragmentation of C60 z+ is considered to be governed by the mechanism of internal conversion of the electronically excited states of C60z+, statistical redistribution of the excess energy among a number of vibrational modes, and sequential ejection of the C2 units.
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry