RSC Prizewinner's Lecture : New methods for studying ion–neutral reactions at low temperatures

In spite of their real-world importance, very few experimental methods can be applied to the precise study of gas-phase reactions between ions and radicals. One of the reasons for this is the challenges associated with generating a pure beam of gas-phase radicals with tuneable properties. In this talk, I will present our approach to generating beams of velocity- and state-selected radicals [1-2]. We are in the process of combining a radical beam source with a cryogenic ion trap, for the study of ion-radical reactions under cold and controlled conditions. Reactions will take place within Coulomb crystals, enabling us to monitor processes with exceptional sensitivity (down to the single-ion level). Recent work on some 'simple' ion-neutral reactions will be discussed [3], revealing the advantages of studying reaction processes within Coulomb crystals.

References
1. J. Toscano, C. J. Rennick, T. P. Softley, and B. R. Heazlewood, “A magnetic guide to purify radical beams” J. Phys. Chem., 149, 174201 (2018).
2. C. Miossec, L. Y. Wu, P. Bertier, M. Hejduk, and B. R. Heazlewood, “A stand-alone magnetic guide for producing tuneable radical beams” J. Chem. Phys., 153, 104202 (2020).
3. A. Tsikritea, K. Park, P. Bertier, J. Loreau, T. P. Softley, and B. R. Heazlewood, “Inverse kinetic isotope effects in the charge transfer reactions of ammonia with rare gas ions” Chem. Sci., 12, 10005 (2021).