2005 58th Gaseous Electronics Conference
Sunday–Thursday, October 16–20, 2005;
San Jose, California
Session RW2: Biological Applications of Plasmas
1:30 PM–3:00 PM,
Wednesday, October 19, 2005
Doubletree Hotel
Room: Cedar
Chair: Uwe Kortshagen, University of Minnesota
Abstract ID: BAPS.2005.GEC.RW2.2
Abstract: RW2.00002 : Electron attachment to molecules of biological relevance
2:00 PM–2:30 PM
Preview Abstract
Abstract
Author:
Verena Grill
(Institut f\"{u}r Ionenphysik, Technikerstr. 25, A-6020 Innsbruck)
Free electron attachment to biomolecules in the electron energy
range from
about 0 -- 15 eV has been studied. The experiments have been
carried out
using a homebuilt crossed electron/neutral beams apparatus in
combination
with a quadrupole mass spectrometer described in detail in [1]. The
electrons are monochromatized in a high resolution hemispherical
electron
monochromator with an energy resolution of about 110 meV in the
present
experiments. The biomolecules under study include thymine, alanine,
glycolaldehydes, thymidine, uridine and uracil.
In this presentation we want to focus on one particular
experiment, where
bond-selective H- ion abstraction by electron attachment to
thymine has been
studied [2]. This study has been performed using partially
deuterated
thymine to enable the measurement of electron attachment to
certain bonds in
the molecule. The results are particularly interesting as certain
sites of
the isolated molecules are not available (or even not present)
when they are
incorporated in the DNA structure. Therefore the present results
can be used
to evaluate the previously reported DEA to isolated undeuterated
bases
concerning their importance for real DNA environments. In
particular the
radiation damage due to (dissociative) anionic resonance states
are assumed
to be critical intermediates leading to DNA strand breaks. To
support the
experimental results we have also performed quantum chemical
studies using
the G2(MP2) method. In collaboration with Stephan Denifl, Sylwia
Plasinska, Michael Probst, Paul Scheier, and Tilmann Maerk,
Institut f\"{u}r Ionenphysik, Leopold-Franzens-Universit\"{a}t
Innsbruck.
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Financial support from the FWF, \"{O}AW, and \"{O}NB (Vienna) and
the EU
Commission (Brussels) through the EPIC Network is gratefully
acknowledged.
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[1] D.Muigg, G. Denifl, A. Stamatovic, T.D.M\"{a}rk, Chem. Phys.
239 (1998)
409 \newline
[2] S. Ptasinska, S. Denifl, V. Grill, T.D. M\"{a}rk, P. Scheier,
S. Gohlke,
M.A. Huels and E. Illenberger, Bond-Selective H$^{-}$ Ion
Abstraction from
Thymine. \textit{Angew. Chem. Int. Ed.} \textbf{44} (2005) 1647--1650
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2005.GEC.RW2.2