Metastable dissociation of doubly charged ions produced from toluene: Kinetic energy release upon charge separation and H2 elimination

Doubly charged ions produced by electron impact ionization of toluene undergo metastable decomposition. We have determined decay channels for C 7 H y 2 + ( y = 6 – 8 ) and the average kinetic energy release (KER) by applying the MIKE scan technique. We observe several reactions that have not been reported previously, including H2 elimination from C 7 H 8 2 + . The KER distribution for H2 loss shows no evidence for a reverse barrier. The average KER is <0.1 eV; it exhibits a distinct time dependence and isotope effect. On the other hand, some charge separation reactions reported previously in the literature are likely due to isotopic interference.