title: First principles study of photostability within hydrogen-bonded amino acids.
abstract: The photochemistry and photophysics of a two-glycine minimal model is studied at the CASPT2//CASSCF level of theory. Different photoinduced processes are discussed, on the basis of the calculated minimum energy paths and the characterization of the electronic state crossings. Two main processes could provide UV-photostability to the hydrogen-bonded peptide system: (i) forward-backward photoinduced electron/proton transfer involving the H in the hydrogen bond, (ii) singlet-singlet energy transfer between two amino acids, providing ultrafast population of the low-energy n,π* state.
authors.affiliation: Departamento de Química Física, Universidad de Alcalá, 28871 Alcalá de Henares (Madrid), Spain. marco.marazzi@uah.es
authors.forename: Marco
authors.initials: M
authors.lastname: Marazzi
authors.forename: Unai
authors.initials: U
authors.lastname: Sancho
authors.forename: Obis
authors.initials: O
authors.lastname: Castaño
authors.forename: Luis Manuel
authors.initials: LM
authors.lastname: Frutos
mesh_terms: D004151:Dipeptides / Q000737:chemistry; D005998:Glycine / Q000737:chemistry*; D006860:Hydrogen Bonding; D008958:Models, Molecular; D010455:Peptides / Q000737:chemistry; D055668:Photochemical Processes; D017433:Protein Structure, Secondary; D011789:Quantum Theory
chemical_list: D004151:Dipeptides; D010455:Peptides; D005998:Glycine