Vibrationally induced charge transfer in a bimolecular model complex in vacuo
Benjamin J Knurr1, Anne B McCoy, J Mathias Weber
1JILA and Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309, USA.
The Journal of Chemical Physics
|June 21, 2013
Summary
Vibrational excitation triggers charge transfer from nitromethane anion to methyliodide. This reaction, quenched by argon solvation, reveals insights into electron transfer dynamics and reaction barriers.
Area of Science:
- Physical Chemistry
- Chemical Physics
- Molecular Dynamics
Background:
- Electron transfer reactions are fundamental in chemistry.
- Vibrational modes can influence reaction pathways and rates.
- Molecular complexes offer a controlled environment to study intermolecular interactions.
Purpose of the Study:
- To investigate vibrationally induced charge transfer in a nitromethane anion-methyliodide molecular complex.
- To understand the role of vibrational excitation in initiating electron transfer.
- To determine the reaction barrier using solvation effects.
Main Methods:
- Formation and study of molecular complexes in a cold environment.
- Infrared laser excitation of specific vibrational modes (CH stretching).
- Mass spectrometry to detect product anions (I(-)).
- Electronic structure calculations.
- Argon (Ar) atom solvation to probe reaction dynamics.
Main Results:
- CH stretching vibrations in either molecule initiate dissociative electron transfer to methyliodide.
- Iodide (I(-)) anions are observed as products of the electron transfer.
- Solvation with more than two Ar atoms completely quenches the reaction.
- The quenching provides an estimate for the reaction barrier.
Conclusions:
- Vibrational energy can overcome the activation barrier for electron transfer in this system.
- Argon solvation acts as a probe for reaction dynamics and barrier height.
- The findings contribute to understanding vibrationally mediated electron transfer mechanisms in molecular systems.
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