Dissociation of thymine due to electron attachment in solution

Abstract

DNA damage, a consequence of ionising radiation, is exploited in cancer treatment. Ionizing radiation can excite the cellular medium to produce secondary electrons that can consequently cause damage to DNA. The damage is believed to occur via dissociative electron attachment (DEA).In DEA, the electron is captured by the DNA in a resonance and, during the subsequent decay of this transient ion, bonds dissociate. The reason this happens is that the energy of the captured electron is transferred as a vibration into specific bonds, which causes them to break. We present a model for studying the effect that transferring kinetic energy into the vibrational modes of a molecule in this way has on a DNA nucleobase. We show that when the base is in an aqueous environment, dissociation is affected by interactions with the surrounding water molecules. In particular, hydrogen bonding between the nucleobase and the solvent can suppress the dissociative channel.

Date of Award	Dec 2019
Original language	English
Awarding Institution	Queen's University Belfast
Supervisor	Jorge Kohanoff (Supervisor) & Gareth Tribello (Supervisor)