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Updated: Jun 3, 2025

Analysis of Volatile and Oxidation Sensitive Compounds Using a Cold Inlet System and Electron Impact Mass Spectrometry
Published on: September 5, 2014
Cross-Section Calculations for Electron-Impact Ionization of Pyrimidine Molecule and Its Halogenated Derivatives:
Bożena Żywicka1, Paweł Możejko1
1Faculty of Applied Physics and Mathematics, Gdańsk University of Technology, ul. Gabriela Narutowicza 11/12, 80-233 Gdańsk, Poland.
Abstract:
The total cross-sections for the single electron-impact ionization of pyrimidine (C4H4N2), 2-chloropyrimidine (2-C4H3ClN2), 5-chloropyrimidine (5-C4H3ClN2), 2-bromopyrimidine (2-C4H3BrN2) and 5-bromopyrimidine (5-C4H3BrN2) molecules have been calculated with the binary-encounter-Bethe model from the ionization threshold up to 5 keV. The input data for the BEB calculations concerning electronic structure of the studied targets have been obtained with quantum chemical methods including the Hartree-Fock (H-F) and the outer valence Green function (OVGF) methods. The calculated cross-section for the ionization of the pyrimidine molecules due to electron impact is compared with available experimental and theoretical data. The question of the magnitude the pyrimidine ionization cross-section is also discussed, as is the efficiency of the ionization process of studied halogenated derivatives of pyrimidine.
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