Dynamics of hydride anion and acetyloxyl radical production by electron attachment to acetic acid

We investigate the dynamics and site-selectivity in the dissociation of transient anions formed upon attachment of low energy electrons to acetic acid by anion fragment momentum imaging experiments. The resonances at 6.7 and 7.7 eV are confirmed to dissociate exclusively by the O-H bond, while a third resonance at 9.1 eV dissociates primarily by both C-H break and O-H break. A fourth resonance near 10 eV is found to dissociate by O-H break. For each resonance, the measured kinetic energy release indicates two-body dissociation produces a neutral radical in the ground electronic state, for all four resonances. The measured angular distributions are consistent with all four resonances having A' symmetry.