Highly effective quenching of the ultrafast radiationless decay of photoexcited pyrimidine bases by covalent modification: photophysics of 5,6-trimethylenecytosine and 5,6-trimethyleneuracil

DOI	Trouver le DOI : https://doi.org/10.1039/b704001f
Auteur	Rechercher : Zgierski, Marek¹; Rechercher : Fujiwara, Takashige; Rechercher : Kofron, William; Rechercher : Lim, Edward
Affiliation	Conseil national de recherches du Canada. Institut Steacie des sciences moléculaires du CNRC
Format	Texte, Article
Résumé	5,6-Trimethylenecytosine (TMC) and 5,6-trimethyleneuracil (TMU), in which the twist of the C5-C6 bond (or the pyrimidalization of C5) is strongly hindered, do not exhibit the subpicosecond excited-state lifetime characteristic of the naturally occurring pyrimidine bases. This result demonstrates the important role the out-of-plane deformation of the six-membered ring plays in the ultrafast (subpicosecond) internal conversion of photoexcited nucleobases. The dramatically shorter fluorescence lifetime of TMU ([similar]30 ps) relative to TMC ([similar]1.2 ns), in aqueous solution at room temperature, is attributed to the presence in TMU of an efficient, secondary nonradiative decay channel of S1([small pi][small pi]) involving a low-lying 1n[small pi] state.
Date de publication	2007
Dans	Physical Chemistry Chemical Physics 9, nº 25 : 3206–3209.
Langue	anglais
Publications évaluées par des pairs	Oui
Numéro NPARC	12339091
Exporter la notice	Exporter en format RIS
Signaler une correction	Signaler une correction (s'ouvre dans un nouvel onglet)
Identificateur de l’enregistrement	63af80a7-c137-4f1b-a80b-0a0eeb00daa4
Enregistrement créé	2009-09-11
Enregistrement modifié	2020-05-10