title: New Insights into the Photophysics of DNA Nucleobases.
abstract: We report the results of an extended time-resolved study of DNA nucleobases in aqueous solutions conducted in the deep UV using broad-band femtosecond transient absorption and electronic two-dimensional spectroscopies. We found that the photodeactivation in all DNA nucleobases occurs in two steps: fast relaxation (500-700 fs) from the excited state ππ* to a "dark" state and its depopulation to the ground state within 1-2 ps. Our experimental observations and performed theoretical modeling allow us to conclude that this dark state can be associated with the nπ* electronic state, which is connected to the excited and ground states via conical intersections.
authors: Max Planck Institute for the Structure and Dynamics of Matter , Luruper Chaussee 149, 22761 Hamburg, Germany.
authors: Valentyn I
authors: VI
authors: Prokhorenko
authors: Max Planck Institute for the Structure and Dynamics of Matter , Luruper Chaussee 149, 22761 Hamburg, Germany.
authors: Alessandra
authors: A
authors: Picchiotti
authors: Institute for Theoretical Physics, University of Hamburg , Jungiusstrasse 9, 20355 Hamburg, Germany.
authors: Martina
authors: M
authors: Pola
authors: Max Planck Institute for the Structure and Dynamics of Matter , Luruper Chaussee 149, 22761 Hamburg, Germany.
authors: Arend G
authors: AG
authors: Dijkstra
authors: Max Planck Institute for the Structure and Dynamics of Matter , Luruper Chaussee 149, 22761 Hamburg, Germany.|Department of Chemistry and Department of Physics, University of Toronto , 80 St. George Street, Toronto, Canada M5S 1H6.|The Hamburg Center for Ultrafast Imaging , Luruper Chaussee 149, 22761 Hamburg, Germany.
authors: R J Dwayne
authors: RJ
authors: Miller
mesh_terms: D004247:DNA; D008958:Models, Molecular; D010777:Photochemistry; D013057:Spectrum Analysis; D014867:Water
chemical_list: D014867:Water; D004247:DNA