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Direct Imaging of Laser-driven Ultrafast Molecular Rotation
Published on: February 4, 2017
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Ultrafast Laser-Induced Isomerization Dynamics in Acetonitrile
Matteo McDonnell1, Aaron C LaForge1, Juan Reino-González2
1Department of Physics, University of Connecticut, Storrs, Connecticut 06269, United States.
The Journal of Physical Chemistry Letters
|July 3, 2020
Summary
Laser ionization of acetonitrile (CH3CN) surprisingly shows dominant hydrogen migration over fragmentation. Isomerization occurs rapidly, forming stable structures within hundreds of femtoseconds.
Area of Science:
- Physical Chemistry
- Chemical Physics
- Molecular Dynamics
Background:
- Investigating molecular fragmentation and isomerization pathways following ionization is crucial for understanding chemical dynamics.
- Acetonitrile (CH3CN) serves as a model system for studying laser-induced molecular transformations.
Purpose of the Study:
- To investigate laser-induced isomerization in acetonitrile cations.
- To elucidate the primary fragmentation and isomerization channels and their dynamics.
Main Methods:
- Utilizing pump-probe spectroscopy combined with ion-ion coincident Coulomb explosion imaging.
- Performing quantum chemistry calculations to support experimental observations.
Main Results:
- Identified five primary channels: C-C breakup, single/double hydrogen migration, and H/H2 dissociation.
- Observed that hydrogen migration channels dominate over direct fragmentation.
- Determined isomerization occurs within a few hundred femtoseconds.
Conclusions:
- Laser ionization of acetonitrile leads to significant isomerization via hydrogen migration, forming stable structures.
- The observed isomerization dynamics are comparable to dissociation and fragmentation timescales.
- This behavior differs from previously studied molecules under similar ionization conditions.
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