Biomedical Engineering Reference
In-Depth Information
Chapter 4
Following Resonant Compound States
after Electron Attachment
A Quantum Modelling of the Dynamical Evolution
in Molecular Anions
Ana G. Sanz, Francesco Sebastianelli, and Francesco A. Gianturco
Abstract
The evolution pathways which can follow temporary, metastable electron
attachment processes involving polyatomic molecules in the gas phase are analysed
using a quantum method for the calculation of such transient anionic states as
a function of molecular deformations. The method is specifically applied, as an
example, to the two-dimensional deformations of bond geometries for the HCN
molecule and shown to describe well the interplay between electronic and nuclear
degrees of freedom.
4.1
Introduction
It is by now an accepted result that a great deal of the consequences, at the molecular
level, of radiation exposures of biosystems and living tissues are produced by the
secondary electrons coming from medium ionization [
1
,
2
]. Such electrons are
generally found to be energetically rather slow (E
t
15 eV) and can therefore effec-
tively interact with any of the DNA components, or with the larger DNA fragments,
thereby inducing successive fragmentations and bond ruptures by depositing their
excess energy into the molecular networks of the bonds [
3
,
4
].
