Characterization of Dynamical Resonances using cryo-SEVI Transition State Spectroscopy

Dynamical resonances are quasi-bound quantum states that exist in the vicinity of a transition state for a bimolecular reaction.  These resonances are predicted to be ubiquitous among chemical reactions and can mediate reactivity at low temperatures. However, only a handful of resonances have been definitively observed or characterized.  Slow photoelectron velocity-map imaging of cryogenically cooled anions (cryo-SEVI) is a promising tool to examine dynamical resonances on neutral reactive surfaces.  The high resolution of cryo-SEVI spectroscopy resolves fine resonance features previously undetected by lower resolution methods. In this presentation recent cryo-SEVI experiments on the F + H₂ and F + CH₃OH hydrogen-abstraction reactions will be discussed along with complementary multi-dimensional quantum dynamical simulations performed on high level ab initio potential energy surfaces.