A theoretical study on the excited-state deactivation paths for the A-5FU dimer
| Autor: | Ting-he Fu, Qingzhong Li, Hong-yuan Yu, Xue-fang Yu, Bo Xiao |
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| Rok vydání: | 2021 |
| Předmět: |
Models
Molecular Double bond Proton Base pair Dimer General Physics and Astronomy 010402 general chemistry 01 natural sciences Molecular physics chemistry.chemical_compound 0103 physical sciences Atom Physical and Theoretical Chemistry Base Pairing Density Functional Theory chemistry.chemical_classification Physics 010304 chemical physics Hydrogen Bonding Time-dependent density functional theory DNA Photochemical Processes 0104 chemical sciences chemistry Excited state Nucleic Acid Conformation Thermodynamics Fluorouracil Protons Dimerization Methyl group |
| Zdroj: | Physical chemistry chemical physics : PCCP. 23(30) |
| ISSN: | 1463-9084 |
| Popis: | The photostability of DNA plays a key role in the normal function of organisms. A-5FU is a base pair derivative of the A-T dimer where the methyl group is replaced by a F atom. Here, accurate static TDDFT calculations and non-adiabatic dynamic simulations are used to systematically investigate the excited-state decay paths of the A-5FU dimer related to the proton transfer and the out-of-plane twisting deformation motion of A and 5FU in the 1ππ* and 1nπ* states. CC2 is used to check the accuracy of the current TDDFT calculations. Our results show that the deformation of the C[double bond, length as m-dash]C or C[double bond, length as m-dash]N double bond in A and 5FU provides an efficient pathway for the depopulation of the lowest excited states, which can compete with the excited-state proton transfer paths in the dimer. This finding indicates that monomer-like decay paths could be important for the photostability of weakly hydrogen-bonded DNA base pairs and provide a new insight into the excited-state decay paths in base pairs and their analogues. |
| Databáze: | OpenAIRE |
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