Interactions of Electrons with Bare and Hydrated Biomolecules: From Nucleic Acid Bases to DNA Segments

The broadest motivation for exploring electron attachment to biological molecules comes from their important role in radiation damage. An electron trapped by a neutral molecule results in the corresponding radical anion. The energy difference between the neutral molecule and the corresponding radical anion is referred to as the electron affinity (EA). The EA is an important physical measurable quantity often used in theoretical and experimental descriptions of electron attachment to a molecule. From a theoretical viewpoint, an electron residing in a molecule leads to changes in the nuclear configuration to form an equilibrium structure for the corresponding radical anion. The VAE is the energy released from the instantaneous one electron attachment to a neutral species. No geometry relaxation takes place during this process. Therefore, both neutral and anionic molecules reflect the optimized geometry of the neutral species.