Coulomb explosion of C7H72+ ions produced by electron impact ionization of toluene

Doubly charged C7H72+ ions produced by electron impact ionization of toluene (C7H8) show metastable unimolecular dissociation into two singly charged fragments. A high-resolution double focusing mass spectrometer (reversed Nier-Johnson type BE geometry) was used to monitor these decomposition reactions. We have identified four competing charge separation channels. The mass-analyzed ion kinetic energy (MIKE) technique was used to determine mean values of the kinetic energy release (KER). We obtained values of the average KER for the charge separation reactions of C7H72+ ranging from 2.5 to 3.5 eV.