The tautomer-specific excited state dynamics of 2,6-diaminopurine using resonance-enhanced multiphoton ionization and quantum chemical calculations

0583715 - BFÚ 2024 RIV US eng J - Článek v odborném periodiku
Gate, G. - Williams, A. - Boldissar, S. - Šponer, Jiří - Szabla, R. - de Vries, M. S.
The tautomer-specific excited state dynamics of 2,6-diaminopurine using resonance-enhanced multiphoton ionization and quantum chemical calculations.
Photochemistry and Photobiology. Roč. 2023, DEC 20 2023 (2023). ISSN 0031-8655. E-ISSN 1751-1097
Grant CEP: GA ČR(CZ) GA21-23718S
Institucionální podpora: RVO:68081707
Klíčová slova: ultrafast internal-conversion * nonradiative decay * ab-initio * radiationless deactivation * electronic relaxation * isolated adenine * 2-aminopurine * spectroscopy
Obor OECD: Biochemistry and molecular biology
Impakt faktor: 3.3, rok: 2022
Způsob publikování: Open access
https://onlinelibrary.wiley.com/doi/10.1111/php.13897

2,6-Diaminopurine (2,6-dAP) is an alternative nucleobase that potentially played a role in prebiotic chemistry. We studied its excited state dynamics in the gas phase by REMPI, IR-UV hole burning, and ps pump-probe spectroscopy and performed quantum chemical calculations at the SCS-ADC(2) level of theory to interpret the experimental results. We found the 9H tautomer to have a small barrier to ultrafast relaxation via puckering of its 6-membered ring. The 7H tautomer has a larger barrier to reach a conical intersection and also has a sizable triplet yield. These results are discussed relative to other purines, for which 9H tautomerization appears to be more photostable than 7H and homosubstituted purines appear to be less photostable than heterosubstituted or singly substituted purines.
Trvalý link: https://hdl.handle.net/11104/0351709