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Zhao L, Geng X, Wang J, Liu Y, Yan W, Xu Z, Chen J. Excited-state dynamics of 3-hydroxychromone in gas phase. Phys Chem Chem Phys 2024. [PMID: 39028298 DOI: 10.1039/d4cp01190b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
In recent years, 3-hydroxychromone (3-HC) and its derivatives have attracted much interest for their applications as molecular photoswitches and fluorescent probes. A clear understanding of their excited-state dynamics is essential for their applications and further development of new functional 3-HC derivatives. However, the deactivation mechanism of the photoexcited 3-HC family is still puzzling as their spectral properties are sensitive to the surrounding medium and substituents. The excited-state relaxation channels of 3-HC have been a matter of intense debate. In the current work, we thoroughly investigated the excited-state decay process of the 3-HC system in the gas phase using high-level electronic structure calculations and on-the-fly excited-state dynamic simulations intending to provide insight into the intrinsic photochemical properties of the 3-HC system. A new deactivation mechanism is proposed in the gas phase, which is different from that in solvents. The excited-state intramolecular proton transfer (ESIPT) process that occurs in solutions is not preferred in the gas phase due to the existence of a sizable energy barrier (∼0.8 eV), and thus, no dual fluorescence is found. On the contrary, the non-radiative decay process is the dominant decay channel, which is driven by photoisomerization combined with ring-puckering and ring-opening processes. The results coincide with the observations of an experiment performed in a supersonic jet by Itoh (M. Itoh, Pure Appl. Chem., 1993, 65(8), 1629-1634). The current work indicates that the solution environment plays an important role in regulating the excited-state dynamic behaviour of the 3-HC system. This study thus provides theoretical guidance for the rational design and improvement of the photochemical properties of the 3-HC system and paves the way for further investigation into its photochemical properties in complex environments.
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Affiliation(s)
- Li Zhao
- College of Science, China University of Petroleum (East China) Qingdao 266580, Shandong, China.
| | - Xuehui Geng
- College of Science, China University of Petroleum (East China) Qingdao 266580, Shandong, China.
| | - Jiangyue Wang
- College of Science, China University of Petroleum (East China) Qingdao 266580, Shandong, China.
| | - Yuxuan Liu
- College of Science, China University of Petroleum (East China) Qingdao 266580, Shandong, China.
| | - Wenhui Yan
- College of Science, China University of Petroleum (East China) Qingdao 266580, Shandong, China.
| | - Zhijie Xu
- College of Science, China University of Petroleum (East China) Qingdao 266580, Shandong, China.
| | - Junsheng Chen
- Nano-Science Center & Department of Chemistry University of Copenhagen Universitetsparken 5, 2100 KøbenhavnØ, Denmark.
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Zhao L, Geng X, Han G, Guo Y, Liu R, Chen J. Revealing the excited-state dynamics of cytidine and the role of excited-state proton transfer process. Phys Chem Chem Phys 2023; 25:32002-32009. [PMID: 37975722 DOI: 10.1039/d3cp03683a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2023]
Abstract
The high photostability of DNAs and RNAs is inextricably related to the photochemical and photophysical properties of their building blocks, nucleobases and nucleosides, which can dissipate the absorbed UV light energy in a harmless manner. The deactivation mechanism of the nucleosides, especially the decay pathways of cytidine (Cyd), has been a matter of intense debate. In the current study, we employ high-level electronic structure calculations combined with excited state non-adiabatic dynamic simulations to provide a clear picture of the excited state deactivation of Cyd in both gas phase and aqueous solution. In both environments, a barrierless decay path driven by the ring-puckering motion and a relaxation channel with a small energy barrier driven by the elongation motion of CO bond are assigned to <200 fs and sub-picosecond decay time component, respectively. The presence of ribose group has a subtle effect on the dynamic behavior of Cyd in gas phase as the ribose-to-base hydrogen/proton transfer process is energetically inaccessible with a sizable energy barrier of about 1.4 eV. However, this energy barrier is significantly reduced in water, especially when an explicit water molecule is present. Therefore, we argue that the long-lived decay channel found in aqueous solution could be assigned to the Cyd-water intermolecular hydrogen/proton transfer process. The present study postulates a novel scenario toward deep understanding the intrinsic photostability of DNAs and RNAs and provides solid evidence to disclose the long history debate of cytidine excited-state decay mechanism, especially for the assignment of experimentally observed time components.
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Affiliation(s)
- Li Zhao
- College of Science, China University of Petroleum (East China), Qingdao 266580, Shandong, China.
| | - Xuehui Geng
- College of Science, China University of Petroleum (East China), Qingdao 266580, Shandong, China.
| | - Guoxia Han
- College of Science, China University of Petroleum (East China), Qingdao 266580, Shandong, China.
| | - Yahui Guo
- College of Science, China University of Petroleum (East China), Qingdao 266580, Shandong, China.
| | - Runze Liu
- Institute of Molecular Sciences and Engineering, Shandong University, Qingdao 266235, P. R. China
| | - Junsheng Chen
- Nano-Science Center & Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 KøbenhavnØ, Denmark.
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The competitive mechanism between photoisomerization and excited state intramolecular proton transfer process of 2′-Hydroxychalcone system. J Photochem Photobiol A Chem 2023. [DOI: 10.1016/j.jphotochem.2022.114255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Zhao L, Zheng H, Zhan K, Guo Y, Liu B, Xu G. Position of the Benzene Ring Substituent Regulates the Excited-State Deactivation Process of the Benzyluracil Systems. J Phys Chem A 2021; 125:165-174. [PMID: 33373221 DOI: 10.1021/acs.jpca.0c08980] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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 → S1 → S0 two-step decay pattern, and the decay coordinates of the S2 → S1 and S1 → 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 → 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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Affiliation(s)
- Li Zhao
- School of Science, China University of Petroleum (East China), Qingdao 266580, Shandong, China
| | - Haixia Zheng
- School of Science, China University of Petroleum (East China), Qingdao 266580, Shandong, China
| | - Kaiyun Zhan
- School of Science, China University of Petroleum (East China), Qingdao 266580, Shandong, China
| | - Yahui Guo
- School of Science, China University of Petroleum (East China), Qingdao 266580, Shandong, China
| | - Bing Liu
- School of Science, China University of Petroleum (East China), Qingdao 266580, Shandong, China
| | - Guiyin Xu
- Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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Winslow M, Cross WB, Robinson D. Comparison of Spin-Flip TDDFT-Based Conical Intersection Approaches with XMS-CASPT2. J Chem Theory Comput 2020; 16:3253-3263. [PMID: 32302484 PMCID: PMC8279405 DOI: 10.1021/acs.jctc.9b00917] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
![]()
Determining conical intersection
geometries is of key importance
to understanding the photochemical reactivity of molecules. While
many small- to medium-sized molecules can be treated accurately using
multireference approaches, larger molecules require a less computationally
demanding approach. In this work, minimum energy crossing point conical
intersection geometries for a series of molecules have been studied
using spin-flip TDDFT (SF-TDDFT), within the Tamm-Dancoff Approximation,
both with and without explicit calculation of nonadiabatic coupling
terms, and compared with both XMS-CASPT2 and CASSCF calculated geometries.
The less computationally demanding algorithms, which do not require
explicit calculation of the nonadiabatic coupling terms, generally
fare well with the XMS-CASPT2 reference structures, while the relative
energetics are only reasonably replicated with the MECP structure
as
calculated with the BHHLYP functional and full nonadiabatic coupling
terms. We also demonstrate that, occasionally, CASSCF structures deviate
quantitatively from the XMS-CASPT2 structures, showing the importance
of including dynamical correlation.
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Affiliation(s)
- Max Winslow
- Department of Chemistry and Forensics, School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, United Kingdom
| | - Warren B Cross
- Department of Chemistry and Forensics, School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, United Kingdom
| | - David Robinson
- Department of Chemistry and Forensics, School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, United Kingdom
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Fang B, Ning F, Hu S, Guo D, Ou W, Wang C, Wen J, Sun J, Liu Z, Koh CA. The effect of surfactants on hydrate particle agglomeration in liquid hydrocarbon continuous systems: a molecular dynamics simulation study. RSC Adv 2020; 10:31027-31038. [PMID: 35520650 PMCID: PMC9056346 DOI: 10.1039/d0ra04088f] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 07/14/2020] [Indexed: 12/02/2022] Open
Abstract
Anti-agglomerants (AAs), both natural and commercial, are currently being considered for gas hydrate risk management of petroleum pipelines in offshore operations. However, the molecular mechanisms of the interaction between the AAs and gas hydrate surfaces and the prevention of hydrate agglomeration remain critical and complex questions that need to be addressed to advance this technology. Here, we use molecular dynamics (MD) simulations to investigate the effect of model surfactant molecules (polynuclear aromatic carboxylic acids) on the agglomeration behaviour of gas hydrate particles and disruption of the capillary liquid bridge between hydrate particles. The results show that the anti-agglomeration pathway can be divided into two processes: the spontaneous adsorption effect of surfactant molecules onto the hydrate surface and the weakening effect of the intensity of the liquid bridge between attracted hydrate particles. The MD simulation results also indicate that the anti-agglomeration effectiveness of surfactants is determined by the intrinsic nature of their molecular functional groups. Additionally, we find that surfactant molecules can affect hydrate growth, which decreases hydrate particle size and correspondingly lower the risk of hydrate agglomeration. This study provides molecular-level insights into the anti-agglomeration mechanism of surfactant molecules, which can aid in the ultimate application of natural or commercial AAs with optimal anti-agglomeration properties. Schematic of anti-agglomeration effect of surfactants promoting gas hydrate particle dispersion.![]()
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