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Abstract

The fragmentation dynamics of triply charged benzene [(C6H6)(3+)]
induced by 260 eV electron-impact ionization are investigated using a
multiparticle coincidence momentum spectrometer. By measuring three
fragment ions and one outgoing electron in quadruple coincidence, we
identify the complete three-body dissociation channels of CH2+ + C2H3 +
C3H+, CH3+ + C2H2+ + C3H+, and C2H2+ + C2H2+ + C2H2+. We determine the
projectile-energy-loss spectra, Dalitz plots, Newton diagrams, momentum
correlation maps, and kinetic-energy release for each fragmentation
channel. The analysis of these spectra is supported by an ab initio
molecular dynamics simulation, which provides a molecular movie of the
dissociation process. Our study reveals sequential mechanisms for all
three dissociation channels of (C6H6)(3+) trication, i.e., an ultrafast
ring-opening reaction followed by two subsequent Coulomb-explosion
processes.