Dynamics of Molecular Interactions with Ions

2026-07-22

Being able to clarify the atomistic dynamics of molecular collisions and chemical reactions has been a central research goal for decades. For reactions of charged particles in particular, the importance of quantum dynamics is barely understood, as quantum state-resolved experiments beyond total cross section measurement are very challenging and most theoretical descriptions still rely on quasi-classical approaches. In particular, quantum scattering resonances, known by now to be relevant in a few well-studied neutral molecule reactions, have never been observed for ion-molecule collisions up to now. In the past years we have spearheaded research on crossed-beam reactive scattering of ions with neutral molecules. Our measured differential scattering cross sections could provide detailed insight into the dynamics of polyatomic reactions and allowed us to discover several new reaction mechanisms. In this project, we propose a novel experimental approach to achieve a multifold improved resolution for the scattering images, which will allow us to answer several key questions: Which product quantum states are populated in molecular ions that are produced in three- and four-atom reactions? How do quantum scattering resonances influence the collision dynamics and the product state distribution? Which momentum vector correlations govern the three-body break-up in ion-neutral reactions and which transition states are responsible for these dynamics? How are ionic reactions contributing to the radiation damage of biological molecules in cells? Our proposed experimental approach can answer these questions and will thereby reach a new domain for the investigation of ion-molecule reactions with unprecedented quantum state control for three- and four-atom reactions and highly differential insight into polyatomic reactions.

Austria

2025-10-01