title: Photosensitized Thymine Dimerization via Delocalized Triplet Excited States.
abstract: A new mechanism of photosensitized formation of thymine (Thy) dimers is proposed, which involves generation of a delocalized triplet excited state as the key step. This is supported by chemical evidence obtained by combining one benzophenone and two Thy units with different degrees of freedom, whereby the photoreactivity is switched from a clean Paternò-Büchi reaction to a fully chemo-, regio-, and stereoselective [2+2] cycloaddition.
authors.affiliation: Instituto Universitario Mixto de Tecnología Química (UPV-CSIC), Universitat Politècnica de València, Avenida de los Naranjos s/n, 46022 Valencia (Spain).
authors.forename: Paula
authors.initials: P
authors.lastname: Miro
authors.affiliation: Instituto Universitario Mixto de Tecnología Química (UPV-CSIC), Universitat Politècnica de València, Avenida de los Naranjos s/n, 46022 Valencia (Spain).
authors.forename: Virginie
authors.initials: V
authors.lastname: Lhiaubet-Vallet
authors.affiliation: Instituto Universitario Mixto de Tecnología Química (UPV-CSIC), Universitat Politècnica de València, Avenida de los Naranjos s/n, 46022 Valencia (Spain). marmarin@qim.upv.es.
authors.forename: M Luisa
authors.initials: ML
authors.lastname: Marin
authors.affiliation: Instituto Universitario Mixto de Tecnología Química (UPV-CSIC), Universitat Politècnica de València, Avenida de los Naranjos s/n, 46022 Valencia (Spain). mmiranda@qim.upv.es.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Miranda
mesh_terms: D061565:Cycloaddition Reaction; D019281:Dimerization; D004735:Energy Transfer; D010777:Photochemistry; D017319:Photosensitizing Agents / Q000737:chemistry*; D011740:Pyrimidine Dimers / Q000737:chemistry*; D013237:Stereoisomerism; D013941:Thymine / Q000737:chemistry* / Q000378:metabolism
chemical_list: D017319:Photosensitizing Agents; D011740:Pyrimidine Dimers; D013941:Thymine
keywords: DNA damage; dimerization; nucleobases; photochemistry; reaction mechanisms