title: Vibrationally resolved photoelectron spectroscopy of electronic excited states of DNA bases: application to the ã state of thymine cation.
abstract: For fully understanding the light-molecule interaction dynamics at short time scales, recent theoretical and experimental studies proved the importance of accurate characterizations not only of the ground (D0) but also of the electronic excited states (e.g., D1) of molecules. While ground state investigations are currently straightforward, those of electronic excited states are not. Here, we characterized the Ã electronic state of ionic thymine (T(+)) DNA base using explicitly correlated coupled cluster ab initio methods and state-of-the-art synchrotron-based electron/ion coincidence techniques. The experimental spectrum is composed of rich and long vibrational progressions corresponding to the population of the low frequency modes of T(+)(Ã). This work challenges previous numerous works carried out on DNA bases using common synchrotron and VUV-based photoelectron spectroscopies. We provide hence a powerful theoretical and experimental framework to study the electronic structure of ionized DNA bases that could be generalized to other medium-sized biologically relevant systems.
authors.affiliation: Laboratoire Modélisation et Simulation Multi Echelle, MSME UMR 8208 CNRS, Université Paris-Est , 5 bd Descartes, 77454 Marne-la-Vallée, France.
authors.forename: Majdi
authors.initials: M
authors.lastname: Hochlaf
authors.forename: Yi
authors.initials: Y
authors.lastname: Pan
authors.forename: Kai-Chung
authors.initials: KC
authors.lastname: Lau
authors.forename: Youssef
authors.initials: Y
authors.lastname: Majdi
authors.forename: Lionel
authors.initials: L
authors.lastname: Poisson
authors.forename: Gustavo A
authors.initials: GA
authors.lastname: Garcia
authors.forename: Laurent
authors.initials: L
authors.lastname: Nahon
authors.forename: Muneerah Mogren
authors.initials: MM
authors.lastname: Al Mogren
authors.forename: Martin
authors.initials: M
authors.lastname: Schwell
mesh_terms: D002412:Cations / Q000737:chemistry; D004247:DNA / Q000737:chemistry*; D004583:Electrons; D056951:Photoelectron Spectroscopy; D013941:Thymine / Q000737:chemistry*; D014466:Ultraviolet Rays; D014732:Vibration
chemical_list: D002412:Cations; D004247:DNA; D013941:Thymine