Eur. Phys. J. D 35, 391-398 (2005)
https://doi.org/10.1140/epjd/e2005-00205-7

Positive and negative ion formation via slow electron collisions with 5-bromouridine

Institut für Ionenphysik, Center for Molecular Biosciences, Leopold Franzens Universität, Technikerstr. 25, 6020 Innsbruck, Austria

Corresponding author: ^a paul.scheier@uibk.ac.at

Received: 5 April 2005
Revised: 27 May 2005
Published online: 26 July 2005

Abstract

Cation and anion formation is studied experimentally upon inelastic low energy electron interactions with 5-bromouridine (BrUrd) using a crossed electron/neutral beams set-up combined with a quadrupole mass spectrometer. The BrUrd molecule belongs to the class of radiosensitizers that increase the sensitivity of DNA (or RNA) to ionizing radiation. In the case of positive ion formation the ionization efficiency curves are measured near the threshold and the corresponding appearance energies are determined using a non-linear least square fitting procedure. The anion yields are investigated in the electron energy range from about 0 to 14 eV. From the comparison of the present results for negative and positive ions information concerning the underlying mechanism of radiosensitizers is deduced.