The fragmentation pathways of C6H are studied using density functional theory. All of the transition states that were found, excluding the rearrangement to the C5v structure, are significantly above the six-membered ring structure. This is consistent with the soft ionization experiments that find mostly dication production instead of fragmentation. Since the C5v structure is probably of limited importance for multiple-ring polycyclic aromatic hydrocarbons, the computed barriers suggest that Coulomb explosion is not a significant channel under most astrophysical conditions, and therefore, the dications are long-lived and should be considered in modeling of the interstellar medium
