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Vandaele E, Mališ M, Luber S. A Local Diabatisation Method for Two-State Adiabatic Conical Intersections. J Chem Theory Comput 2024; 20:856-872. [PMID: 38174710 DOI: 10.1021/acs.jctc.3c01008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
A methodology to locally characterize conical intersections (CIs) between two adiabatic electronic states for which no nonadiabatic coupling (NAC) vectors are available is presented. Based on the Hessian and gradient at the CI, the branching space coordinates are identified. The potential energy surface around the CI in the branching space is expressed in the diabatic representation, from which the NAC vectors can be calculated in a wave-function-free, energy-based approach. To demonstrate the universality of the developed methodology, the minimum-energy CI (MECI) between the first (S1) and second (S2) singlet excited states of formamide is investigated at the state-averaged complete active space self-consistent field (SA-CASSCF) and extended multistate complete active space second-order perturbation theory (XMS-CASPT2) levels of theory. In addition, the asymmetrical MECI between the ground state (S0) and S1 of cyclopropanone is evaluated using SA-CASSCF, as well as (ME)CIs between the S1 and S2 states of benzene using SA-CASSCF and time-dependent density functional theory (TDDFT). Finally, a CI between the S1 and S2 excited states of thiophene was analyzed using TDDFT.
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Affiliation(s)
- Eva Vandaele
- Department of Chemistry, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Momir Mališ
- Department of Chemistry, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Sandra Luber
- Department of Chemistry, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
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2
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Chen WK, Fang WH, Cui G. Extending multi-layer energy-based fragment method for excited-state calculations of large covalently bonded fragment systems. J Chem Phys 2023; 158:044110. [PMID: 36725521 DOI: 10.1063/5.0129458] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Recently, we developed a low-scaling Multi-Layer Energy-Based Fragment (MLEBF) method for accurate excited-state calculations and nonadiabatic dynamics simulations of nonbonded fragment systems. In this work, we extend the MLEBF method to treat covalently bonded fragment ones. The main idea is cutting a target system into many fragments according to chemical properties. Fragments with dangling bonds are first saturated by chemical groups; then, saturated fragments, together with the original fragments without dangling bonds, are grouped into different layers. The accurate total energy expression is formulated with the many-body energy expansion theory, in combination with the inclusion-exclusion principle that is used to delete the contribution of chemical groups introduced to saturate dangling bonds. Specifically, in a two-layer MLEBF model, the photochemically active and inert layers are calculated with high-level and efficient electronic structure methods, respectively. Intralayer and interlayer energies can be truncated at the two- or three-body interaction level. Subsequently, through several systems, including neutral and charged covalently bonded fragment systems, we demonstrate that MLEBF can provide accurate ground- and excited-state energies and gradients. Finally, we realize the structure, conical intersection, and path optimizations by combining our MLEBF program with commercial and free packages, e.g., ASE and SciPy. These developments make MLEBF a practical and reliable tool for studying complex photochemical and photophysical processes of large nonbonded and bonded fragment systems.
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Affiliation(s)
- Wen-Kai Chen
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Wei-Hai Fang
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Ganglong Cui
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
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3
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Abstract
Chemiluminescence (CL) utilizing chemiexcitation for energy transformation is one of the most highly sensitive and useful analytical techniques. The chemiexcitation is a chemical process of a ground-state reactant producing an excited-state product, in which a nonadiabatic event is facilitated by conical intersections (CIs), the specific molecular geometries where electronic states are degenerated. Cyclic peroxides, especially 1,2-dioxetane/dioxetanone derivatives, are the iconic chemiluminescent substances. In this Perspective, we concentrated on the CIs in the CL of cyclic peroxides. We first present a computational overview on the role of CIs between the ground (S0) state and the lowest singlet excited (S1) state in the thermolysis of cyclic peroxides. Subsequently, we discuss the role of the S0/S1 CI in the CL efficiency and point out misunderstandings in some theoretical studies on the singlet chemiexcitations of cyclic peroxides. Finally, we address the challenges and future prospects in theoretically calculating S0/S1 CIs and simulating the dynamics and chemiexcitation efficiency in the CL of cyclic peroxides.
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Affiliation(s)
- Ling Yue
- Key Laboratory for Non-equilibrium Synthesis and Modulation of Condensed Matter, Ministry of Education, School of Chemistry, Xi'an Jiaotong University, Xi'an, Shaanxi710049, China
| | - Ya-Jun Liu
- Center for Advanced Materials Research, Beijing Normal University, Zhuhai519087, China
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing100875, China
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4
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Xie BB, Jia PK, Wang KX, Chen WK, Liu XY, Cui G. Generalized Ab Initio Nonadiabatic Dynamics Simulation Methods from Molecular to Extended Systems. J Phys Chem A 2022; 126:1789-1804. [PMID: 35266391 DOI: 10.1021/acs.jpca.1c10195] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Nonadiabatic dynamics simulation has become a powerful tool to describe nonadiabatic effects involved in photophysical processes and photochemical reactions. In the past decade, our group has developed generalized trajectory-based ab initio surface-hopping (GTSH) dynamics simulation methods, which can be used to describe a series of nonadiabatic processes, such as internal conversion, intersystem crossing, excitation energy transfer and charge transfer of molecular systems, and photoinduced nonadiabatic carrier dynamics of extended systems with and without spin-orbit couplings. In this contribution, we will first give a brief introduction to our recently developed methods and related numerical implementations at different computational levels. Later, we will present some of our latest applications in realistic systems, which cover organic molecules, biological proteins, organometallic compounds, periodic organic and inorganic materials, etc. Final discussion is given to challenges and outlooks of ab initio nonadiabatic dynamics simulations.
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Affiliation(s)
- Bin-Bin Xie
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou 311231, Zhejiang, P. R. China
| | - Pei-Ke Jia
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou 311231, Zhejiang, P. R. China
| | - Ke-Xin Wang
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou 311231, Zhejiang, P. R. China
| | - Wen-Kai Chen
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Xiang-Yang Liu
- College of Chemistry and Material Science, Sichuan Normal University, Chengdu 610068, Sichuan, P. R. China
| | - Ganglong Cui
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
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5
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Xie BB, Tang XF, Liu XY, Chang XP, Cui G. Mechanistic photophysics and photochemistry of unnatural bases and sunscreen molecules: insights from electronic structure calculations. Phys Chem Chem Phys 2021; 23:27124-27149. [PMID: 34849517 DOI: 10.1039/d1cp03994f] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Photophysics and photochemistry are basic subjects in the study of light-matter interactions and are ubiquitous in diverse fields such as biology, energy, materials, and environment. A full understanding of mechanistic photophysics and photochemistry underpins many recent advances and applications. This contribution first provides a short discussion on the theoretical calculation methods we have used in relevant studies, then we introduce our latest progress on the mechanistic photophysics and photochemistry of two classes of molecular systems, namely unnatural bases and sunscreens. For unnatural bases, we disclose the intrinsic driving forces for the ultrafast population to reactive triplet states, impacts of the position and degree of chalcogen substitutions, and the effects of complex environments. For sunscreen molecules, we reveal the photoprotection mechanisms that dissipate excess photon energy to the surroundings by ultrafast internal conversion to the ground state. Finally, relevant theoretical challenges and outlooks are discussed.
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Affiliation(s)
- Bin-Bin Xie
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou 311231, Zhejiang, P. R. China.
| | - Xiu-Fang Tang
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou 311231, Zhejiang, P. R. China.
| | - Xiang-Yang Liu
- College of Chemistry and Material Science, Sichuan Normal University, Chengdu, Sichuan, 610068, China
| | - Xue-Ping Chang
- College of Chemistry and Chemical Engineering, Xinyang Normal University, Xinyang 464000, P. R. China
| | - Ganglong Cui
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China.
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6
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Matsika S. Electronic Structure Methods for the Description of Nonadiabatic Effects and Conical Intersections. Chem Rev 2021; 121:9407-9449. [PMID: 34156838 DOI: 10.1021/acs.chemrev.1c00074] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Nonadiabatic effects are ubiquitous in photophysics and photochemistry, and therefore, many theoretical developments have been made to properly describe them. Conical intersections are central in nonadiabatic processes, as they promote efficient and ultrafast nonadiabatic transitions between electronic states. A proper theoretical description requires developments in electronic structure and specifically in methods that describe conical intersections between states and nonadiabatic coupling terms. This review focuses on the electronic structure aspects of nonadiabatic processes. We discuss the requirements of electronic structure methods to describe conical intersections and nonadiabatic couplings, how the most common excited state methods perform in describing these effects, and what the recent developments are in expanding the methodology and implementing nonadiabatic couplings.
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Affiliation(s)
- Spiridoula Matsika
- Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122, United States
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7
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Baek YS, Lee S, Filatov M, Choi CH. Optimization of Three State Conical Intersections by Adaptive Penalty Function Algorithm in Connection with the Mixed-Reference Spin-Flip Time-Dependent Density Functional Theory Method (MRSF-TDDFT). J Phys Chem A 2021; 125:1994-2006. [PMID: 33651623 DOI: 10.1021/acs.jpca.0c11294] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A new adaptive algorithm for penalty function optimization for minimum-energy three-states conical intersections (ME3CI) is suggested. The new algorithm differs from the original penalty function algorithm by (a) removing the redundancy in the target function, (b) using an adaptive increment for the penalty function weighting factor, and (c) using tighter convergence criteria for the energy gap. The latter was introduced to guarantee convergence to a true conical intersection rather than to a narrowly avoided crossing geometry. The new algorithm was tested in the optimization of the ME3CI geometries in butadiene and malonaldehyde, where all of the previously found true ME3CI geometries were recovered. The previously found butadiene's CI3/2/1 turned out to be a narrowly avoided crossing. For butadiene, seven new ME3CI geometries have been located. Because of the removal of the redundancy and the use of the adaptive weighting factor, the convergence rate of the new algorithm is noticeably improved as compared to that of the previously proposed penalty function algorithm. The application to malonaldehyde and butadiene demonstrates that the three-state conical intersections may be more abundant and hence more involved in the photochemistry than previously thought. The recently developed mixed-reference spin flip (MRSF)-TDDFT method yields ME3CI geometries and relative energies quantitatively consistent with the previously reported calculations at a much reduced computational cost.
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Affiliation(s)
- Yong Su Baek
- Department of Chemistry, Kyungpook National University, Daegu 702-701, South Korea
| | - Seunghoon Lee
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Michael Filatov
- Department of Chemistry, Kyungpook National University, Daegu 702-701, South Korea
| | - Cheol Ho Choi
- Department of Chemistry, Kyungpook National University, Daegu 702-701, South Korea
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8
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Xie BB, Liu BL, Tang XF, Tang D, Shen L, Fang WH. Nonadiabatic dynamics simulation of photoinduced ring-opening reaction of 2(5 H)-thiophenone with internal conversion and intersystem crossing. Phys Chem Chem Phys 2021; 23:9867-9877. [PMID: 33908501 DOI: 10.1039/d1cp00281c] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
In the present work, the quantum trajectory mean-field approach, which is able to overcome the overcoherence problem, was generalized to simulate internal conversion and intersystem crossing processes simultaneously. The photoinduced ring-opening and subsequent rearrangement reactions of isolated 2(5H)-thiophenone were studied based on geometry optimizations on critical structures and nonadiabatic dynamics simulations using this method. Upon 267 nm irradiation, the molecule is initially populated in the 1ππ* state. After a sudden rupture of one C-S bond within 100 fs in this state, the lowest two singlet excited states and the lowest two triplet excited states become quasi-degenerated, and then the intersystem crossing processes between singlet and triplet states accompanied by rearrangement reactions can be observed several times. Compared with our previous nonadiabatic simulations in the absence of intersystem crossing (ChemPhotoChem, 2019, 3, 897-906), some new nonadiabatic relaxation pathways involving triplet states and different ring-opening products were identified. The present work provides new mechanistic insights into the photoinduced ring-opening of thio-substituted heterocyclic molecules and reveals the importance of nonadiabatic dynamics simulation that is able to deal with multiple electronic states with different spin multiplicities.
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Affiliation(s)
- Bin-Bin Xie
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou 311231, Zhejiang, P. R. China.
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9
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Shen L, Xie B, Li Z, Liu L, Cui G, Fang WH. Role of Multistate Intersections in Photochemistry. J Phys Chem Lett 2020; 11:8490-8501. [PMID: 32787313 DOI: 10.1021/acs.jpclett.0c01637] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
It has been generally accepted that the intersection of potential energy surfaces can facilitate nonadiabatic transitions and plays a crucial role in photochemistry. Although most previous studies have focused on the conical intersection of two electronic states, multistate intersections are common in polyatomic molecules, and their key roles in photochemistry have been uncovered by electronic structure calculations and nonadiabatic dynamics simulations. In this Perspective, the algorithms for searching two- or three-state intersections are first examined with an emphasis on the latest development in a general algorithm for location of multistate intersections. Then, we focus on intersystem crossing (ISC) that occurs in the region of multistate intersection, paying more attention to how the state-specific spin-orbit coupling interaction influences nonadiabatic ISC processes. Finally, the interweaving of nonadiabatic dynamics simulation and electronic structure calculation has been recognized as a correct way to ascertain the vital roles of multistate intersections in photochemical reactions.
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Affiliation(s)
- Lin Shen
- Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P.R. China
| | - Binbin Xie
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou 311231, Zhejiang, P.R. China
| | - Ziwen Li
- Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P.R. China
| | - Lihong Liu
- Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P.R. China
| | - Ganglong Cui
- Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P.R. China
| | - Wei-Hai Fang
- Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P.R. China
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10
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Zhao L, Watanabe KJ, Nakatani N, Nakayama A, Xu X, Hasegawa JY. Extending nudged elastic band method to reaction pathways involving multiple spin states. J Chem Phys 2020; 153:134114. [PMID: 33032404 DOI: 10.1063/5.0021923] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
There are diverse reactions including spin-state crossing, especially the reactions catalyzed by transition metal compounds. To figure out the mechanisms of such reactions, the discussion of minimum energy intersystem crossing (MEISC) points cannot be avoided. These points may be the bottleneck of the reaction or inversely accelerate the reactions by providing a better pathway. It is of great importance to reveal their role in the reactions by computationally locating the position of the MEISC points together with the reaction pathway. However, providing a proper initial guess for the structure of the MEISC point is not as easy as that of the transition state. In this work, we extended the nudged elastic band (NEB) method for multiple spin systems, which is named the multiple spin-state NEB method, and it is successfully applied to find the MEISC points while optimizing the reaction pathway. For more precisely locating the MEISC point, a revised approach was adopted. Meanwhile, our examples also suggest that special attention should be paid to the criterion to define an image optimized as the MEISC point.
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Affiliation(s)
- Liming Zhao
- Institute for Catalysis, Hokkaido University, N21 W10 Kita-ku, Sapporo 001-0021, Hokkaido, Japan
| | - K-Jiro Watanabe
- Institute for Catalysis, Hokkaido University, N21 W10 Kita-ku, Sapporo 001-0021, Hokkaido, Japan
| | - Naoki Nakatani
- Graduate School of Science and Engineering, Tokyo Metropolitan University, Minami-Osawa 1-1, Tokyo 192-0397, Japan
| | - Akira Nakayama
- Department of Chemical System Engineering, The University of Tokyo, Tokyo 113-8656, Japan
| | - Xin Xu
- Department of Chemistry, Fudan University, Shanghai 200433, China
| | - Jun-Ya Hasegawa
- Institute for Catalysis, Hokkaido University, N21 W10 Kita-ku, Sapporo 001-0021, Hokkaido, Japan
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11
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Shi HM, Guo GH, Sun ZG. Numerical convergence of the Sinc discrete variable representation for solving molecular vibrational states with a conical intersection in adiabatic representation. CHINESE J CHEM PHYS 2019. [DOI: 10.1063/1674-0068/cjcp1812275] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Hai-mei Shi
- School of Mathematics and Physics, Qingdao University of Science and Technology, Qingdao 266061, China
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Guang-hai Guo
- School of Mathematics and Physics, Qingdao University of Science and Technology, Qingdao 266061, China
| | - Zhi-gang Sun
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
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12
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Liu XY, Fang YG, Xie BB, Fang WH, Cui G. QM/MM nonadiabatic dynamics simulations on photoinduced Wolff rearrangements of 1,2,3-thiadiazole. J Chem Phys 2018; 146:224302. [PMID: 29166059 DOI: 10.1063/1.4984589] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The photoinduced rearrangement reaction mechanism of 1,2,3-thiadiazole remains experimentally elusive. Two possible mechanisms have been proposed to date. The first is a stepwise mechanism via a thiocarbene intermediate; the second is an excited-state concerted rearrangement mechanism. Herein we have adopted both the electronic structure calculations and nonadiabatic dynamics simulations to study the photoinduced rearrangement reactions of 1,2,3-thiadiazole in the S2, S1, and S0 states in solution. On the basis of QM(CASPT2)/MM [quantum mechanics(complete active space self-consistent field second-order perturbation theory)/molecular mechanics] calculations, we have found that (1) the thiocarbene intermediate is not stable; thus, the stepwise mechanism should be unfavorable; (2) the excited-state decay from the S2 via S1 to S0 state is ultrafast and completed within ca. 200 fs; therefore, both the S2 and S1 states should not have a long enough time for the excited-state rearrangements. Instead, we have computationally proposed a modified photoinduced rearrangement mechanism. Upon irradiation, the S2 state is first populated (114.0 kcal/mol), followed by an ultrafast S2 → S1 → S0 excited-state decay along the S-N bond fission, which eventually leads to a very "hot" intermediate with the S-N bond broken (18.3 kcal/mol). Then, thermal rearrangements to thioketene, thiirene, and ethynethiol occur in a concerted asynchronous way. This mechanistic scenario has been verified by full-dimensional trajectory-based nonadiabatic dynamics simulations at the QM(CASPT2)/MM level. Finally, our present computational work provides experimentally interesting mechanistic insights into the photoinduced rearrangement reactions of cyclic and acyclic diazo compounds.
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Affiliation(s)
- Xiang-Yang Liu
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Ye-Guang Fang
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Bin-Bin Xie
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Wei-Hai Fang
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Ganglong Cui
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
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Li C, Xiao P, Fang WH, Cui G. Excited-state proton transfer induced [4 + 2] and [4 + 4] photocycloaddition reactions of an oxazoline: Mechanism and selectivity. J Photochem Photobiol A Chem 2018. [DOI: 10.1016/j.jphotochem.2017.09.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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14
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Xie BB, Cui CX, Fang WH, Cui G. Photoinduced Curtius rearrangements of fluorocarbonyl azide, FC(O)N 3: a QM/MM nonadiabatic dynamics simulation. Phys Chem Chem Phys 2018; 20:19363-19372. [DOI: 10.1039/c8cp02651c] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
Abstract
Upon either photolysis or pyrolysis, carbonyl azide can eliminate molecular nitrogen along with the formation of isocyanate.
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Affiliation(s)
- Bin-Bin Xie
- Hangzhou Institute of Advanced Studies
- Zhejiang Normal University
- Hangzhou 311231
- P. R. China
- Key Laboratory of Theoretical and Computational Photochemistry
| | - Cheng-Xing Cui
- School of Chemistry and Chemical Engineering
- Henan Institute of Science and Technology
- Xinxiang 453003
- P. R. China
| | - Wei-Hai Fang
- Hangzhou Institute of Advanced Studies
- Zhejiang Normal University
- Hangzhou 311231
- P. R. China
- Key Laboratory of Theoretical and Computational Photochemistry
| | - Ganglong Cui
- Key Laboratory of Theoretical and Computational Photochemistry
- Ministry of Education College of Chemistry
- Beijing Normal University
- Beijing 100875
- P. R. China
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15
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Liu XY, Xiao P, Fang WH, Cui G. Theoretical studies of spin state-specific [2 + 2] and [5 + 2] photocycloaddition reactions of n-(1-penten-5-yl)maleimide. J Comput Chem 2017; 38:2388-2395. [PMID: 28762255 DOI: 10.1002/jcc.24897] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 06/20/2017] [Accepted: 06/21/2017] [Indexed: 01/24/2023]
Abstract
N-alkenyl maleimides are found to exhibit spin state-specific chemoselectivities for [2 + 2] and [5 + 2] photocycloadditions; but, reaction mechanism is still unclear. In this work, we have used high-level electronic structure methods (DFT, CASSCF, and CASPT2) to explore [2 + 2] and [5 + 2] photocycloaddition reaction paths of an N-alkenyl maleimide in the S1 and T1 states as well as relevant photophysical processes. It is found that in the S1 state [5 + 2] photocycloaddition reaction is barrierless and thus overwhelmingly dominant; [2 + 2] photocycloaddition reaction is unimportant because of its large barrier. On the contrary, in the T1 state [2 + 2] photocycloaddition reaction is much more favorable than [5 + 2] photocyclo-addition reaction. Mechanistically, both S1 [5 + 2] and T1 [2 + 2] photocycloaddition reactions occur in a stepwise, nonadiabatic means. In the S1 [5 + 2] reaction, the secondary C atom of the ethenyl moiety first attacks the N atom of the maleimide moiety forming an S1 intermediate, which then decays to the S0 state as a result of an S1 → S0 internal conversion. In the T1 [2 + 2] reaction, the terminal C atom of the ethenyl moiety first attacks the C atom of the maleimide moiety, followed by a T1 → S0 intersystem crossing process to the S0 state. In the S0 state, the second CC bond is formed. Our present computational results not only rationalize available experiments but also provide new mechanistic insights. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Xiang-Yang Liu
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, 100875, China
| | - Pin Xiao
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, 100875, China
| | - Wei-Hai Fang
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, 100875, China
| | - Ganglong Cui
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, 100875, China
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16
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Chang XP, Xiao P, Han J, Fang WH, Cui G. A theoretical study of the light-induced cross-linking reaction of 5-fluoro-4-thiouridine with thymine. Phys Chem Chem Phys 2017; 19:13524-13533. [PMID: 28498381 DOI: 10.1039/c7cp01511a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
In contrast to photophysics of thio-substituted nucleobases, their photoinduced cross-linking reactions with canonical nucleobases remain scarcely investigated computationally. In this work, we have adopted combined CASPT2/PCM//CASSCF and B3LYP-D3/PCM electronic structure methods to study this kind of photochemical reaction of 5-fluoro-4-thiouridine (truncated 5-fluoro-1-methyl-4-thiouracil used in calculations) and 1-methylthymine (referred to as thymine for clarity hereinafter). On the basis of CASPT2/PCM computed results, we have proposed two efficient excited-state relaxation pathways to populate the lowest T1 state of the complex of 5-fluoro-1-methyl-4-thiouracil and thymine from its initially populated S2(1ππ*) state. In the first one, the S2 system first hops to the S1 state via an S2/S1 conical intersection, followed by a direct S1 → T1 intersystem crossing process enhanced by large S1/T1 spin-orbit coupling. In the second path, the resultant S1 system first jumps to the T2 state, from which an efficient T2 → T1 internal conversion occurs. The T1 cross-linking reaction is overall divided into two phases. The first phase is a stepwise and nonadiabatic photocyclization reaction, which starts from the T1 complex and ends up with an S0 thietane intermediate. The second phase is a thermal reaction. The system first rearranges its four- and six-membered rings to form three new rings; then, an S0 fluorine atom transfer occurs, followed by the formation of photoproducts. Finally, the present work paves the way for studying light-induced cross-linking reactions of thionucleobases with canonical bases in DNA and RNA.
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Affiliation(s)
- Xue-Ping Chang
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China.
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17
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Xie B, Cui G, Fang WH. Multiple-State Nonadiabatic Dynamics Simulation of Photoisomerization of Acetylacetone with the Direct ab Initio QTMF Approach. J Chem Theory Comput 2017; 13:2717-2729. [DOI: 10.1021/acs.jctc.7b00153] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Binbin Xie
- Key Laboratory of Theoretical
and Computational Photochemistry, Ministry of Education, College of
Chemistry, Beijing Normal University, Beijing 100875, China
| | - Ganglong Cui
- Key Laboratory of Theoretical
and Computational Photochemistry, Ministry of Education, College of
Chemistry, Beijing Normal University, Beijing 100875, China
| | - Wei-Hai Fang
- Key Laboratory of Theoretical
and Computational Photochemistry, Ministry of Education, College of
Chemistry, Beijing Normal University, Beijing 100875, China
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18
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Xiao P, Wu D, Fang WH, Cui G. Mechanistic insights into the light-driven hydrogen evolution reaction from formic acid mediated by an iridium photocatalyst. Catal Sci Technol 2017. [DOI: 10.1039/c7cy00785j] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Electronic structure calculations shed important mechanistic light on light-driven hydrogen evolution from formic acid mediated by an iridium photocatalyst.
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Affiliation(s)
- Pin Xiao
- Key Laboratory of Theoretical and Computational Photochemistry
- Ministry of Education
- College of Chemistry
- Beijing Normal University
- Beijing 100875
| | - Dan Wu
- Key Laboratory of Theoretical and Computational Photochemistry
- Ministry of Education
- College of Chemistry
- Beijing Normal University
- Beijing 100875
| | - Wei-Hai Fang
- Key Laboratory of Theoretical and Computational Photochemistry
- Ministry of Education
- College of Chemistry
- Beijing Normal University
- Beijing 100875
| | - Ganglong Cui
- Key Laboratory of Theoretical and Computational Photochemistry
- Ministry of Education
- College of Chemistry
- Beijing Normal University
- Beijing 100875
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19
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Xie BB, Wang Q, Guo WW, Cui G. The excited-state decay mechanism of 2,4-dithiothymine in the gas phase, microsolvated surroundings, and aqueous solution. Phys Chem Chem Phys 2017; 19:7689-7698. [DOI: 10.1039/c7cp00478h] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
Abstract
We have employed computational methods to systematically explore the excited-state decay mechanism of 2,4-dithiothymine.
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Affiliation(s)
- Bin-Bin Xie
- Key Laboratory of Theoretical and Computational Photochemistry
- Ministry of Education
- College of Chemistry
- Beijing Normal University
- Beijing 100875
| | - Qian Wang
- Key Laboratory of Theoretical and Computational Photochemistry
- Ministry of Education
- College of Chemistry
- Beijing Normal University
- Beijing 100875
| | - Wei-Wei Guo
- Key Laboratory of Theoretical and Computational Photochemistry
- Ministry of Education
- College of Chemistry
- Beijing Normal University
- Beijing 100875
| | - Ganglong Cui
- Key Laboratory of Theoretical and Computational Photochemistry
- Ministry of Education
- College of Chemistry
- Beijing Normal University
- Beijing 100875
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