Three-body deprotonation fragmentation dynamics of C₆H₆³⁺ induced by electron-impact ionization

The three-body fragmentation dynamics of benzene trications C 6 H 6 3 + induced by 200 eV electron-impact produced by a photoemission cathode is investigated. All three fragment ions are detected in coincidence, and their momentum vectors are determined by employing a COLTRIMS reaction microscope. The detailed kinematical information of three deprotonation fragmentation channels of H⁺ + C 3 H 2 + + C 3 H 3 + , H⁺ + C 2 H 3 + + C 4 H 2 + , and H⁺ + C 2 H 2 + + C 4 H 3 + are obtained. By analyzing the momentum and energy correlation spectra among all the three fragment ions, we find that all the three channels are primarily generated by sequential fragmentation processes. Each channel has two deprotonation pathways, corresponding to proton emission in the first or second step of sequential fragmentation, respectively. These results provide insight into the mechanisms and dynamics of deprotonation and ring-breaking reactions in the three-body fragmentation processes of aromatic ring molecules.