title: Excited-state dynamics of cytosine tautomers.
abstract: We report the relaxation dynamics of keto and enol or keto-imino cytosine, photoexcited in the wavelength range of 260-290 nm. Three transients with femtosecond to hundreds of picoseconds lifetimes are observed for the biologically relevant keto tautomer and are assigned to internal conversion and excited-state tautomerization. Only two transients with femtosecond and picosecond lifetimes are identified for the enol or keto-imino tautomer and are assigned to internal conversion processes. The results are discussed in the context of published ab initio theory.
authors.affiliation: Max Born Institute, Max-Born-Strasse 2A, D-12489, Berlin-Adlershof, Germany.
authors.forename: Kyriaki
authors.initials: K
authors.lastname: Kosma
authors.forename: Christian
authors.initials: C
authors.lastname: Schröter
authors.forename: Elena
authors.initials: E
authors.lastname: Samoylova
authors.forename: Ingolf Volker
authors.initials: IV
authors.lastname: Hertel
authors.forename: Thomas
authors.initials: T
authors.lastname: Schultz
mesh_terms: D003596:Cytosine / Q000737:chemistry*; D004247:DNA / Q000737:chemistry* / Q000528:radiation effects*; D007536:Isomerism; D055668:Photochemical Processes
chemical_list: D003596:Cytosine; D004247:DNA