Distant Symmetry Control in Electron-Induced Bond Cleavage
T P Ragesh Kumar1, P Nag1, M Ranković1
1J. Heyrovský Institute of Physical Chemistry, The Czech Academy of Sciences, Dolejškova 3, 18223Prague, Czech Republic.
The Journal of Physical Chemistry Letters
|November 28, 2022
Summary
Electron attachment to pyrrole allows N-H bond cleavage, controlled by non-dissociating C-H bonds. This discovery enables steering bond cleavage efficiency via molecular motion.
Area of Science:
- Physical Chemistry
- Quantum Chemistry
- Chemical Physics
Background:
- Electron attachment to molecules can induce bond cleavage.
- Understanding dissociation mechanisms is crucial for controlling chemical reactions.
Purpose of the Study:
- To experimentally demonstrate and theoretically interpret N-H bond cleavage in pyrrole via electron attachment.
- To investigate the role of molecular motion in controlling dissociation pathways.
- To develop a method for analyzing electron-molecule resonant and virtual states.
Main Methods:
- All-electron R-matrix scattering calculations to locate electron-molecule system states.
- Experimental measurements of electron-induced dissociation.
- Mapping resonant and virtual states as a function of molecular geometry.
Main Results:
- N-H bond cleavage in pyrrole is experimentally shown to be allowed and controllable.
- A new method accurately locates resonant and virtual states in the complex plane.
- Two dissociation mechanisms, π* resonance and σ* virtual state, are identified and separated.
- Out-of-plane C-H bond motion couples these mechanisms on an ultrafast timescale (femtoseconds).
Conclusions:
- The motion of non-dissociating atoms, specifically C-H bonds, dictates N-H bond cleavage efficiency in pyrrole.
- Ultrafast coupling between resonance and virtual state mechanisms is essential for dissociation.
- This work provides a pathway to control bond cleavage through molecular dynamics.
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