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Proton transfer dynamics modified by CH-stretching excitation
Tim Michaelsen1, Björn Bastian1, Patrick Strübin1
1Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25/3, 6020 Innsbruck, Austria. roland.wester@uibk.ac.at.
Physical Chemistry Chemical Physics : PCCP
|April 23, 2020
Summary
Exciting specific molecular vibrations in the F- + CH3I reaction significantly alters proton transfer dynamics, favoring direct reactions and increasing efficiency over collision energy alone.
Area of Science:
- Physical Chemistry
- Chemical Dynamics
- Reaction Kinetics
Background:
- Understanding how molecular vibrations affect reaction outcomes is crucial in physical chemistry.
- Statistical models often fall short in predicting state-specific influences on reactions.
- Experimental data on state-resolved ion-molecule reactions are limited.
Purpose of the Study:
- To investigate the influence of specific rovibrational states on reaction kinetics and dynamics.
- To explore the role of symmetric CH-stretching vibration in the F- + CH3I proton transfer reaction.
Main Methods:
- Utilized accurate collision experiments and high-level dynamics calculations.
- Focused on ion-molecule reactions, specifically the F- + CH3I system.
Main Results:
- Observed a shift from indirect to direct reaction dynamics for vibrationally excited F- + CH3I.
- Excited reactions occurred at larger impact parameters compared to non-excited reactions.
- Vibrational excitation was found to be more efficient than collision energy in promoting reactivity.
Conclusions:
- Specific rovibrational states profoundly impact reaction pathways and kinetics.
- Vibrational energy can be a more effective promoter of reactivity than translational energy in ion-molecule reactions.
- The findings align with recent theoretical calculations, validating the experimental approach.
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