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Low-energy electron driven reactions in 2-bromo-5-nitrothiazole.
Jiakuan Chen1,2, Dipayan Chakraborty3, Milan Ončák1
1Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, A-6020 Innsbruck, Austria.
The Journal of Chemical Physics
|January 22, 2025
Summary
Electron attachment to 2-bromo-5-nitrothiazole (BNT) shows it is susceptible to low-energy electrons, unlike thiazole. BNT primarily loses neutral Br and NO2 radicals, leading to thiazole ring opening.
Area of Science:
- Physical Chemistry
- Chemical Physics
- Molecular Physics
Background:
- Thiazole derivatives are vital in pharmaceuticals.
- Understanding electron interactions with such molecules is crucial for their application.
Purpose of the Study:
- Investigate electron attachment to 2-bromo-5-nitrothiazole (BNT) in the gas phase.
- Compare BNT's electron attachment characteristics with native thiazole.
- Elucidate dissociation pathways and energetics.
Main Methods:
- Utilized crossed electron-molecule beam experiments to measure anion fragment efficiency curves.
- Analyzed ion emission angles and kinetic energy distributions.
- Performed quantum chemical calculations to support experimental findings.
Main Results:
- BNT shows enhanced cross-section for dissociative electron attachment at low energies (near 0 eV), unlike thiazole (5-10 eV).
- Electron attachment to BNT predominantly results in neutral Br and NO2 radical abstraction, not anion formation.
- The thiazole ring opens due to a weak C-S bond.
Conclusions:
- BNT is more sensitive to low-energy electrons than thiazole.
- Dissociative electron attachment in BNT favors neutral radical loss and ring fragmentation.
- The electronic structure and substituent effects significantly influence electron interaction pathways.
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