Andrei Sanov, University of Arizona
When
Where
Title: When chemistry isn’t real: The physics of electron interactions with unsaturated organics
Abstract: Electron-molecule interactions provide a rich and intriguing gateway to key processes in molecular physics and chemistry. Many closed-shell molecules do not form permanent valence anions, as their vacant orbitals lie above the detachment threshold. Despite their nonexistent or negligible electron affinity, these systems host short-lived temporary anion states (resonances) embedded in the free-electron continuum, and many form stable, albeit fragile, non-valence anions. Both types of anionic states play important roles in spectroscopy, dynamics, and reactivity. We will explore electron interactions with unsaturated organics featuring low-lying vacant π* orbitals that permit temporary electron capture. Examples include benzoxazole—a benzene ring fused with an N and O-containing oxazole heterocycle—and its isomer, benzisoxazole. Experiments on both reveal signatures of anionic resonances, which we analyze using non-Hermitian theory with a complex absorbing potential to characterize these transient states. Although benzoxazole and benzisoxazole may seem like similar bicyclic molecules, they differ significantly in some respects, including the magnitudes of their dipole moments. Being more polar (due to the relative placement of the O and N atoms), benzisoxazole supports a stable dipole-bound anion state, which figures prominently in the resonance decay.
3:00 PM in PAS 201 / Zoom Meeting https://arizona.zoom.us/j/86395646910
Refreshments in PAS 236, 2:30PM