Fig. 1

A schematic diagram of energy level showing different states of electrons during trapping and relaxation. These processes take place in a polar medium following ionizing radiation in the presence of ribothymidine (rT). An excess electron in the conduction band (CB), representing a quasi-free electron (e_qf^-), eventually becomes trapped (e_sol^-) in the solvent cage. The excited state of e_sol^- is considered as a "presolvated" electron, e_pre^-. Electrons captured by solute molecules produce transient negative ions (TNI or rT^•‒). The TNI in its excited state (TNI^*) can either liberate the excess energy to the solvent (relaxation) or undergo bond breaking (dissociation)