Absorption of low energy UV radiation by DNA: excited states and reactivity

The objective of the study is to (i) understand the primary events involved in the damage of the genetic code provoked by UV radiation and (ii) determine the factors governing the optical properties of DNA-inspired materials.

The seminar will focus on the processes occurring when low energy UV photons (l>230 nm) are absorbed directly by DNA. It will present a picture arising from results obtained in this field since the beginning of the 21^st century by optical spectroscopy and theoretical chemistry and highlight important challenges lying ahead.
Representative examples related to photon absorption, excited state relaxation and chemical reactions (base dimerization and radical generation) will be given.
Finally, the contribution of in vitro spectroscopic studies, compared to biological in vivo investigations will be highlighted.