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Isomerization dynamics of dicationic CS2 and OCS driven by electron-impact
Wenguang Wu1, Enliang Wang1, Tuo Liu1
1Hefei National Research Center for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei 230026, China.
The Journal of Chemical Physics
|July 1, 2026
Summary
Investigating carbon disulfide (CS2) and carbon oxysulfide (OCS) dications reveals distinct isomerization pathways. Molecular symmetry influences these isomerization mechanisms during dissociative ionization.
Area of Science:
- Physical Chemistry
- Chemical Physics
- Quantum Chemistry
Background:
- Dications are highly reactive species formed via high-energy processes.
- Understanding dication isomerization is crucial for interpreting dissociative ionization events.
- Molecular symmetry plays a role in chemical reaction pathways.
Purpose of the Study:
- To investigate and compare the isomerization mechanisms of CS2 and OCS dications.
- To elucidate the influence of molecular symmetry on dication isomerization.
- To validate theoretical calculations with experimental observations.
Main Methods:
- Generation of dications using high-energy electron pulse.
- Momentum imaging time-of-flight spectrometry for fragment ion detection.
- High-level quantum chemistry calculations for potential energy surfaces.
Main Results:
- Identified bond rearrangement reactions forming C+ + S2+ and C+ + OS+ fragments.
- CS2+ isomerization initiated by ionization excitation and decay.
- OCS2+ isomerization can occur on the ground dicationic state via vibrational excitation.
- Predicted kinetic energy releases align with experimental data.
Conclusions:
- Isomerization mechanisms differ between CS2+ and OCS2+ dications.
- Molecular symmetry is a key factor influencing dication isomerization pathways.
- Combined experimental and theoretical approaches provide comprehensive insights into dication dynamics.
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