Long-range versus short-range effects in cold molecular ion-neutral collisions

• Published in: Nature communications Vol. 10; no. 1; pp. 5429 - 10
• Main Authors: Dörfler, Alexander D., Eberle, Pascal, Koner, Debasish, Tomza, Michał, Meuwly, Markus, Willitsch, Stefan
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 28.11.2019; Nature Publishing Group; Nature Portfolio
• Subjects: 639/638/440; 639/638/563; 639/766/36; 639/766/94; Brittleness; Channels; Charge transfer; Cold; Collisions; Cooling; Experiments; Humanities and Social Sciences; Ions; Kinetics; Lasers; Molecular ions; multidisciplinary; Organic chemistry; Reaction kinetics; Rubidium; Science; Science (multidisciplinary); Theoretical analysis
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-019-13218-x

The investigation of cold interactions between ions and neutrals has recently emerged as a new scientific frontier at the interface of physics and chemistry. Here, we report a study of charge-transfer (CT) collisions of Rb atoms with N 2 + and O 2 + ions in the mK regime using a dynamic ion-neutral hybrid trapping experiment. We observe markedly different CT kinetics and dynamics for the different systems and reaction channels studied. While the kinetics in some channels are consistent with classical capture theory, others show distinct non-universal dynamics. The experimental results are interpreted with the help of classical-capture, quasiclassical-trajectory and quantum-scattering calculations using ab-initio potentials for the highly excited molecular states involved. The theoretical analysis reveals an intricate interplay between short- and long-range effects in the different reaction channels which ultimately determines the CT dynamics and rates. Our results illustrate salient mechanisms that determine the efficiency of cold molecular CT reactions. Studies on reactions between cold molecular ions and neutral atoms provide insights into intermolecular interactions. Here the authors explore the kinetics and dynamics of charge-transfer collisions between the cold N 2 + and O 2 + ions and neutral Rb atoms and discuss the role of long- and short-range effects.