Trapped O₂⁺Reactions with C₃H₄Isomers

Cold ion-neutral reactions within laser-cooled trapped ion ensembles are a powerful model system for studying the fundamental dynamics of chemistry present in the Interstellar Medium (ISM). Laser-cooled ions allow us to sympathetically cool molecular ions thereby translationally cooling the reactants to temperatures similar to the ISM. Time-of-flight mass spectroscopy enables us to monitor the temporal evolution of reactions and measure product branching ratios. Recently we investigated the reaction between the O₂⁺ cation and the C₃H₄ isomers, propyne (HC₃H₃) and allene (H₂C₃H₂). Measurements show significant differences in the reaction dynamics and kinetics of these two reactions. These measurements are supported through the use of isotopologue substitution and quantum chemistry calculations. This work builds on previous isomer-specific reaction studies and contributes to the knowledge of ion-molecule reactions relevant to the ISM.