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Microsolvation Redirects Electron-Induced Chemistry in Nucleobases
1Department of Chemistry, KAIST, Daejeon 34141, Republic of Korea.
The Journal of Physical Chemistry Letters
|July 2, 2026
Summary
Even one water molecule prevents DNA damage from low-energy electrons. Hydration redirects electron-induced chemical reactions in nucleobases, crucial for understanding biological environments.
Area of Science:
- Physical Chemistry
- Chemical Physics
- Biophysics
Background:
- Low-energy electrons cause genetic material damage via bond rupture in DNA and RNA nucleobases.
- Understanding electron-nucleobase interactions is vital for biological systems.
Purpose of the Study:
- To investigate the effect of microsolvation on electron-induced damage to nucleobases.
- To explore how water molecules alter the fragmentation dynamics of electron-attached uracil.
Main Methods:
- Mass-selected hydrated uracil anions were studied.
- Photoexcitation was performed over a broad energy range (0.5-5.5 eV).
- Photofragment excitation spectroscopy was used to probe electronic structures.
Main Results:
- A single water molecule suppresses covalent bond rupture in electron-attached uracil.
- Excited clusters relax via internal conversion and sequential water evaporation, not bond cleavage.
- A stochastic evaporation model accurately described solvent loss, with a binding energy of ~0.4 eV.
Conclusions:
- Microsolvation fundamentally alters electron-induced damage pathways in nucleobases.
- Immediate hydration redirects relaxation mechanisms, impacting electron-driven chemistry in aqueous biological environments.
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