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Electron interaction with nitromethane embedded in helium droplets: attachment and ionization measurements
F Ferreira da Silva1, S Ptasińska, S Denifl
1Institut für Ionenphysik und Angewandte Physik and Centre of Molecular Biosciences Innsbruck, Universität Innsbruck, Innsbruck, Austria.
The Journal of Chemical Physics
|November 11, 2011
Summary
Electron interactions with nitromethane in helium nanodroplets were studied. Researchers observed the formation of various anion and cation clusters, providing insights into molecular behavior in a unique environment.
Area of Science:
- Physical Chemistry
- Atomic and Molecular Physics
- Materials Science
Background:
- Nitromethane is a key molecule in energetic materials and organic synthesis.
- Understanding electron interactions is crucial for controlling chemical reactions and material properties.
- Helium nanodroplets offer a unique, weakly interacting environment for studying molecular properties.
Purpose of the Study:
- To investigate the electron-induced formation of anionic and cationic clusters of nitromethane (CH(3)NO(2)) embedded in helium nanodroplets.
- To analyze the product distribution and identify different cluster series formed.
- To compare the observed chemistry with previous studies on bare and surface-condensed nitromethane.
Main Methods:
- Irradiation of helium nanodroplets doped with nitromethane using low-energy electrons (2 eV and 8.5 eV).
- Analysis of anionic and cationic products using mass spectrometry.
- Electron ionization of the helium matrix at 70 eV to study cation formation via charge transfer.
Main Results:
- At 2 eV, only parent cluster anions (CH(3)NO(2))(n)(-) were formed.
- At 8.5 eV, three anion cluster series were observed: (CH(3)NO(2))(n)(-), [(CH(3)NO(2))(n)-H](-), and (CH(3)NO(2))(n)NO(2)(-), with the latter being most abundant.
- Cation formation was dominated by methylated and protonated clusters: (CH(3)NO(2))(n)CH(3)(+) and (CH(3)NO(2))(n)H(+).
Conclusions:
- Helium nanodroplets provide a controlled environment to study electron-molecule interactions and cluster formation.
- The observed anion and cation products reveal distinct reaction pathways dependent on electron energy.
- Results offer valuable data for understanding nitromethane's behavior in condensed phases and potential applications.
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