"Bond-selective chemistry with low-energy electrons", Friday, November 4, 12:00pm, MH 629

 

Daniel Slaughter, Lawrence Berkley National Laboratory

 
ABSTRACT: Anion momentum imaging experiments are combined with electron scattering calculations to investigate the dynamics of dissociative electron attachment in isolated molecules. Electronic Feshbach resonances typically play a central role in dissociative electron attachment. In these resonances, a valence electron is excited to an unoccupied orbital and the incident electron is captured in the same orbital. For the case of methane, one triply-degenerate Feshbach resonance undergoes Jahn-Teller splitting through molecular distortions, leading to four observed final states, each having a 2-body and a 3-body dissociation with anionic products H- and CH2- and neutrals CH3, CH2, H2 or H. In ammonia, one resonance leads to H- + NH2 and NH2- + H, the latter resulting from non-adiabatic charge transfer. A higher energy resonance leads directly to H- and electronically excited NH2 and indirectly to NH2-. The dynamics of damage of isolated DNA and RNA bases by resonant low energy electrons will also be discussed.