An assessment of possible energy migration mechanisms in irradiated DNA

Abstract The conventional treatments of mechanisms of excitation energy in DNA indicate ranges of only a few tens of base pairs at most in the triplet maniford, in agreement with experimental data from photochemical systems with activation of the lowest excited states of base moieties. This is because delocalization of excited electronic states is essentially restricted to the nearest neighbouring bases. Similar restrictive conclusions apply to transfer of charge. Under the conditions of excitation which apply when ionizing radiation is used, a coherent excitation may arise and generate solitons. This possibility provides a mechanism for extensive transport of energy and charge over very long distances. This arises from the stability of such entities due to non-linear coupling of molecular vibrations of aperiodic systems.