Position of the Benzene Ring Substituent Regulates the Excited-State Deactivation Process of the Benzyluracil Systems.
J Phys Chem A
; 125(1): 165-174, 2021 Jan 14.
Article
em En
| MEDLINE
| ID: mdl-33373221
ABSTRACT
A systematic theoretical study of the regulating effect of the substituent position on the photoinduced deactivation process of the benzyluracil systems has been performed based on the high-level static electronic structure calculations and on-the-fly full-dimensional excited-state dynamics simulations. Similarities and differences coexist for the two systems by comparative studies on the photoinduced deactivation process of the 5-benzyluracil (5-BU) and 6-benzyluracil (6-BU) systems. They both obey an S2 â S1 â S0 two-step decay pattern, and the decay coordinates of the S2 â S1 and S1 â S0 processes are mainly driven by the elongation of the bridging bond and the out-of-plane ring deformation motion, respectively. However, the puckering motion occurring at the C2 atom in the uracil fragment dominates the decay pathway of the 5-BU system. On the contrary, the puckering motion at the C5 atom in the benzene fragment mainly drives the decay coordinate of the 6-BU system. Therefore, the substituent position could play significant roles in the deactivation process of the benzyluracil systems. Moreover, the S1 â S0 decay process of the 6-BU system consists of five pathways, possessing a more complex deactivation picture than the 5-BU system. The fitted time scale of the puckering motion is compatible with the experimentally observed lifetimes. This work provides a fundamental understanding of the photophysical and photochemical properties of the benzyluracil systems and can give rational suggestions to further design or regulate the bionic molecular systems.
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01-internacional
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MEDLINE
Idioma:
En
Ano de publicação:
2021
Tipo de documento:
Article