Abstract
Charge transfer has proven to be an important mechanism in DNA photochemistry. In particular, guanine (dG) plays a major role as an electron donor, but the photophysical dynamics of dG-containing charge-transfer states have not been extensively investigated so far. Here, we use UV pump (266 nm) and picosecond IR probe (similar to 5-7 mu m) spectroscopy to study ultrafast dynamics in dG-containing short oligonucleotides as a function of sequence and length. For the pure purine oligomers, we observed lifetimes for the charge-transfer states of the order of several hundreds of picoseconds, regardless of the oligonucleotide length. In contrast, pyrimidine-containing dinucleotides d(GT) and d(GC) show much faster relaxation dynamics in the 10 to 30 ps range. In all studied nucleotides, the charge-transfer states are formed with an efficiency of the order of similar to 50 %. These photophysical characteristics will lead to an improved understanding of DNA damage and repair processes.
Dokumententyp: | Zeitschriftenartikel |
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Fakultät: | Physik |
Themengebiete: | 500 Naturwissenschaften und Mathematik > 530 Physik |
ISSN: | 1439-4227 |
Sprache: | Englisch |
Dokumenten ID: | 89122 |
Datum der Veröffentlichung auf Open Access LMU: | 25. Jan. 2022, 09:28 |
Letzte Änderungen: | 25. Jan. 2022, 09:28 |