Vibrational Feshbach resonances in uracil and thymine

Authors

Paul Burrow, University of Nebraska-LincolnFollow
Gordon A. Gallup, University of Nebraska-LincolnFollow
Adam M. Scheer, University of Nebraska-LincolnFollow
G. Denifl, Leopold-Franzens Universität Innsbruck
S. Ptasinska, Leopold-Franzens Universität Innsbruck
T. Märk, Leopold-Franzens Universität Innsbruck
P. Scheier, Leopold-Franzens Universität Innsbruck

Date of this Version

March 2006

Comments

Published in THE JOURNAL OF CHEMICAL PHYSICS 124, 124310 (2006). http://jcp.aip.org/ © 2006 American Institute of Physics. Used by permission.

Abstract

Sharp peaks in the dissociative electron attachment (DEA) cross sections of uracil and thymine at energies below 3 eV are assigned to vibrational Feshbach resonances (VFRs) arising from coupling between the dipole bound state and the temporary anion state associated with occupation of the lowest σ* orbital. Three distinct vibrational modes are identified, and their presence as VFRs is consistent with the amplitudes and bonding characteristics of the σ * orbital wave function. A deconvolution method is also employed to yield higher effective energy resolution in the DEA spectra. The site dependence of DEA cross sections is evaluated using methyl substituted uracil and thymine to block H atom loss selectively. Implications for the broader issue of DNA damage are briefly discussed. © 2006 American Institute of Physics. (DOI: 10.1063/1.2181570)