title: Quantum Mechanical Studies on the Photophysics and the Photochemistry of Nucleic Acids and Nucleobases.
abstract: The photophysics and photochemistry of DNA is of great importance due to the potential damage of the genetic code by UV light. Quantum mechanical studies have played a key role in interpretating the results of modern time-resolved pump-probe spectroscopy, and in elucidating the main photoactivated reactive paths. This review provides a concise, complete picture of the computational studies carried out, approximately, in the past decade. We start with an overview of the photophysics of the nucleobases in the gas phase and in solution. We discuss the proposed mechanisms for ultrafast decay to the ground state, that involve conical intersections, consider the role of triplet states, and analyze how the solvent modulates the photophysics. Then we move to larger systems, from dinucleotides to single- and double-stranded oligonucleotides. We focus on the possible role of charge transfer and delocalized or excitonic states in the photophysics of these systems and discuss the main photochemical paths. We finish with an outlook on the current challenges in the field and future directions of research.
authors.affiliation: Istituto di Biostrutture Biommagini (IBB-CNR), CNR-Consiglio Nazionale delle Ricerche , Via Mezzocannone 16, I-80134, Napoli, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Improta
authors.affiliation: Area della Ricerca di Pisa, Istituto di Chimica dei Composti Organo Metallici (ICCOM-CNR), CNR-Consiglio Nazionale delle Ricerche , Via G. Moruzzi 1, I-56124 Pisa, Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Santoro
authors.affiliation: Institut de Química Computacional i Catàlisi and Departament de Química, Universitat de Girona, Campus de Montilivi , 17071 Girona, Spain.
authors.forename: Lluís
authors.initials: L
authors.lastname: Blancafort
mesh_terms: D020029:Base Pairing; D004247:DNA / Q000737:chemistry / Q000528:radiation effects*; D006860:Hydrogen Bonding; D008956:Models, Chemical; D009838:Oligodeoxyribonucleotides / Q000737:chemistry / Q000528:radiation effects*; D055668:Photochemical Processes; D011687:Purines / Q000737:chemistry / Q000528:radiation effects*; D011743:Pyrimidines / Q000737:chemistry / Q000528:radiation effects*; D011789:Quantum Theory; D014466:Ultraviolet Rays
chemical_list: D009838:Oligodeoxyribonucleotides; D011687:Purines; D011743:Pyrimidines; D004247:DNA