Formation of Long-Lived Dark States during Electronic Relaxation of Pyrimidine Nucleobases Studied Using Extreme Ultraviolet Time-Resolved Photoelectron Spectroscopy
Autor: | Yuta Miura, Yo-ichi Yamamoto, Shutaro Karashima, Natsumi Orimo, Ayano Hara, Kanae Fukuoka, Tatsuya Ishiyama, Toshinori Suzuki |
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Rok vydání: | 2023 |
Předmět: | |
Zdroj: | Journal of the American Chemical Society. 145:3369-3381 |
ISSN: | 1520-5126 0002-7863 |
Popis: | Ultrafast electronic relaxation of nucleobases from ¹ππ* states to the ground state (S0) is considered essential for the photostability of DNA. However, transient absorption spectroscopy (TAS) has indicated that some nucleobases in aqueous solutions create long-lived ¹nπ*/³ππ* dark states from the ¹ππ* states with a high quantum yield of 0.4–0.5. We investigated electronic relaxation in pyrimidine nucleobases in both aqueous solutions and the gas phase using extreme ultraviolet (EUV) time-resolved photoelectron spectroscopy. Femtosecond EUV probe pulses cause ionization from all electronic states involved in the relaxation process, providing a clear overview of the electronic dynamics. The ¹nπ* quantum yields for aqueous cytidine and uracil (Ura) derivatives were found to be considerably lower ( |
Databáze: | OpenAIRE |
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