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Mikheev YA. Mechanism of trans-Azobenzene Izomerization: Role of the Rydberg 3s-Orbital of the Azo-Group and Phenylaminyl-Type Cations. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2021. [DOI: 10.1134/s0036024421110157] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Mikheev YA, Ershov YA. Fragmentation of Protonated Dimethylaminoazobenzene during Laser Pulsed Photolysis in a Cryogenic Atmosphere of Rarefied Helium. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2020. [DOI: 10.1134/s0036024420110254] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Krawczyk KM, Field RL, Liu LC, Dong M, Woolley GA, Miller RD. Illuminating the photoisomerization of a modified azobenzene single crystal by femtosecond absorption spectroscopy. CAN J CHEM 2019. [DOI: 10.1139/cjc-2018-0461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The mechanism of isomerization for azobenzene is a topic still to be completely elucidated. Here, we describe the ultrafast dynamics of a brominated dioxane-methoxy-azobenzene under single crystal conditions by means of femtosecond transient absorption (TA) spectroscopy. Upon excitation with 400 nm light, spectral components with decays of 0.72, 2.9, and >10 ps are observed. The fast components of the system correspond to vibrational cooling of the population on the S1 excited state, with a decay to a local minimum in the reaction coordinate, followed by a longer evolution to a dark intermediate state prior to relaxing to the ground state, S0. The long time constant can be used to describe the isomerization process, returning excited population to the ground state. Spectral frequencies observed at 33 and 82 cm−1 suggest that both rotation and inversion occur in the system, with a stronger contribution coming from the latter due to a weakened N–N double bond in the excited state. This information provides insight into the structural nature of modified azobenzene systems and sets the stage for future structural studies of the molecule’s isomerization dynamics.
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Affiliation(s)
- Kamil M. Krawczyk
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON M5S 3H6, Canada
- Department of Physics, University of Toronto, 60 St. George Street, Toronto, ON M5S 1A7, Canada
| | - Ryan L. Field
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON M5S 3H6, Canada
- Department of Physics, University of Toronto, 60 St. George Street, Toronto, ON M5S 1A7, Canada
| | - Lai Chung Liu
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON M5S 3H6, Canada
- Department of Physics, University of Toronto, 60 St. George Street, Toronto, ON M5S 1A7, Canada
| | - Mingxin Dong
- Institute of Neuroregeneration & Neurorehabilitation, Qingdao University, 308 Ningxia Street, Qingdao 266021, China
| | - G. Andrew Woolley
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON M5S 3H6, Canada
| | - R.J. Dwayne Miller
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON M5S 3H6, Canada
- Department of Physics, University of Toronto, 60 St. George Street, Toronto, ON M5S 1A7, Canada
- Max Planck Institute for the Structure and Dynamics of Matter, Building 99 (CFEL), Luruper Chaussee 149, 22761 Hamburg, Germany
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Mikheev YA, Ershov YA. Acid–Base Forms of Dimethylaminoazobenzene Derivatives, According to UV–Vis Spectroscopic Data. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2018. [DOI: 10.1134/s0036024418100205] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Mikheev YA, Ershov YA. Assignment of the π → π* and n → π* Transitions to the Spectral Bands of Azobenzene and Dimethylaminoazobenzene. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2018. [DOI: 10.1134/s0036024418080174] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Excited-state vibrational dynamics toward the polaron in methylammonium lead iodide perovskite. Nat Commun 2018; 9:2525. [PMID: 29955070 PMCID: PMC6023914 DOI: 10.1038/s41467-018-04946-7] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 06/01/2018] [Indexed: 11/08/2022] Open
Abstract
Hybrid organic–inorganic perovskites have attractive optoelectronic properties including exceptional solar cell performance. The improved properties of perovskites have been attributed to polaronic effects involving stabilization of localized charge character by structural deformations and polarizations. Here we examine the Pb–I structural dynamics leading to polaron formation in methylammonium lead iodide perovskite by transient absorption, time-domain Raman spectroscopy, and density functional theory. Methylammonium lead iodide perovskite exhibits excited-state coherent nuclear wave packets oscillating at ~20, ~43, and ~75 cm−1 which involve skeletal bending, in-plane bending, and c-axis stretching of the I–Pb–I bonds, respectively. The amplitudes of these wave packet motions report on the magnitude of the excited-state structural changes, in particular, the formation of a bent and elongated octahedral PbI64− geometry. We have predicted the excited-state geometry and structural changes between the neutral and polaron states using a normal-mode projection method, which supports and rationalizes the experimental results. This study reveals the polaron formation via nuclear dynamics that may be important for efficient charge separation. Elucidating electron-phonon coupling in hybrid organic-inorganic perovskites may help us to understand the high photovoltaic efficiency. Here, the authors observe low-frequency Raman modes and related nuclear displacements of the Pb–I framework, indicating how these vibrational motions lead to polaron formation in perovskites.
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Devi S, Saraswat M, Grewal S, Venkataramani S. Evaluation of Substituent Effect in Z-Isomer Stability of Arylazo-1H-3,5-dimethylpyrazoles: Interplay of Steric, Electronic Effects and Hydrogen Bonding. J Org Chem 2018; 83:4307-4322. [DOI: 10.1021/acs.joc.7b02604] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Sudha Devi
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, Knowledge City, S.A.S.Nagar, Manauli, 140306 Punjab, India
| | - Mayank Saraswat
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, Knowledge City, S.A.S.Nagar, Manauli, 140306 Punjab, India
| | - Surbhi Grewal
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, Knowledge City, S.A.S.Nagar, Manauli, 140306 Punjab, India
| | - Sugumar Venkataramani
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, Knowledge City, S.A.S.Nagar, Manauli, 140306 Punjab, India
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Zheng LQ, Wang X, Shao F, Hegner M, Zenobi R. Nanoscale Chemical Imaging of Reversible Photoisomerization of an Azobenzene-Thiol Self-Assembled Monolayer by Tip-Enhanced Raman Spectroscopy. Angew Chem Int Ed Engl 2017; 57:1025-1029. [DOI: 10.1002/anie.201710443] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 11/25/2017] [Indexed: 11/06/2022]
Affiliation(s)
- Li-Qing Zheng
- Department of Chemistry and Applied Biosciences; Swiss Federal Institute of Technology; ETH Zurich; 8093 Zurich Switzerland
| | - Xing Wang
- Department of Chemistry and Applied Biosciences; Swiss Federal Institute of Technology; ETH Zurich; 8093 Zurich Switzerland
| | - Feng Shao
- Department of Chemistry and Applied Biosciences; Swiss Federal Institute of Technology; ETH Zurich; 8093 Zurich Switzerland
| | - Martin Hegner
- Center for Research on Adaptive Nanostructures and Nanodevices; School of Physics; Trinity College Dublin; Dublin 2 Ireland
| | - Renato Zenobi
- Department of Chemistry and Applied Biosciences; Swiss Federal Institute of Technology; ETH Zurich; 8093 Zurich Switzerland
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Zheng LQ, Wang X, Shao F, Hegner M, Zenobi R. Nanoscale Chemical Imaging of Reversible Photoisomerization of an Azobenzene-Thiol Self-Assembled Monolayer by Tip-Enhanced Raman Spectroscopy. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201710443] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Li-Qing Zheng
- Department of Chemistry and Applied Biosciences; Swiss Federal Institute of Technology; ETH Zurich; 8093 Zurich Switzerland
| | - Xing Wang
- Department of Chemistry and Applied Biosciences; Swiss Federal Institute of Technology; ETH Zurich; 8093 Zurich Switzerland
| | - Feng Shao
- Department of Chemistry and Applied Biosciences; Swiss Federal Institute of Technology; ETH Zurich; 8093 Zurich Switzerland
| | - Martin Hegner
- Center for Research on Adaptive Nanostructures and Nanodevices; School of Physics; Trinity College Dublin; Dublin 2 Ireland
| | - Renato Zenobi
- Department of Chemistry and Applied Biosciences; Swiss Federal Institute of Technology; ETH Zurich; 8093 Zurich Switzerland
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Koch M, Saphiannikova M, Santer S, Guskova O. Photoisomers of Azobenzene Star with a Flat Core: Theoretical Insights into Multiple States from DFT and MD Perspective. J Phys Chem B 2017; 121:8854-8867. [PMID: 28832166 DOI: 10.1021/acs.jpcb.7b07350] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This study focuses on comparing physical properties of photoisomers of an azobenzene star with benzene-1,3,5-tricarboxamide core. Three azobenzene arms of the molecule undergo a reversible trans-cis isomerization upon UV-vis light illumination giving rise to multiple states from the planar all-trans one, via two mixed states to the kinked all-cis isomer. Employing density functional theory, we characterize the structural and photophysical properties of each state indicating a role the planar core plays in the coupling between azobenzene chromophores. To characterize the light-triggered switching of solvophilicity/solvophobicity of the star, the difference in solvation free energy is calculated for the transfer of an azobenzene star from its gas phase to implicit or explicit solvents. For the latter case, classical all-atom molecular dynamics simulations of aqueous solutions of azobenzene star are performed employing the polymer consistent force field to shed light on the thermodynamics of explicit hydration as a function of the isomerization state and on the structuring of water around the star. From the analysis of two contributions to the free energy of hydration, the nonpolar van der Waals and the electrostatic terms, it is concluded that isomerization specificity largely determines the polarity of the molecule and the solute-solvent electrostatic interactions. This convertible hydrophilicity/hydrophobicity together with readjustable occupied volume and the surface area accessible to water, affects the self-assembly/disassembly of the azobenzene star with a flat core triggered by light.
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Affiliation(s)
- Markus Koch
- Institute Theory of Polymers, Leibniz Institute of Polymer Research Dresden , Hohe Str. 6, 01069 Dresden, Germany.,Institute of Theoretical Physics, Technische Universität Dresden , Zellescher Weg 17, 01069 Dresden, Germany
| | - Marina Saphiannikova
- Institute Theory of Polymers, Leibniz Institute of Polymer Research Dresden , Hohe Str. 6, 01069 Dresden, Germany.,Dresden Center for Computational Materials Science (DCMS), Technische Universität Dresden , 01069 Dresden, Germany
| | - Svetlana Santer
- Institute of Physics and Astronomy, University of Potsdam , Karl-Liebknecht-Str. 24/25, 14476 Potsdam, Germany
| | - Olga Guskova
- Institute Theory of Polymers, Leibniz Institute of Polymer Research Dresden , Hohe Str. 6, 01069 Dresden, Germany.,Dresden Center for Computational Materials Science (DCMS), Technische Universität Dresden , 01069 Dresden, Germany
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Consani C, Berberich M, Würthner F, Brixner T. Ultrafast isomerization in a difluoroboryl-coordinated molecular switch. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2017.03.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Mikheev YA, Guseva LN, Ershov YA. UV–Vis spectra and structure of acid-base forms of dimethylamino- and aminoazobenzene. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2017. [DOI: 10.1134/s0036024417040161] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Staniszewska M, Kupfer S, Łabuda M, Guthmuller J. Theoretical Assessment of Excited State Gradients and Resonance Raman Intensities for the Azobenzene Molecule. J Chem Theory Comput 2017; 13:1263-1274. [PMID: 28118003 DOI: 10.1021/acs.jctc.6b00966] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The ground state geometries and vibrational frequencies as well as the excitation energies and excited state gradients of the S1(nπ*) and S2(ππ*) states of trans- and cis-azobenzene are investigated by several DFT methods, namely B3LYP, PBE, M06-2X, CAM-B3LYP, and ωB97X. Excited state properties and in particular gradients are also assessed using the wave function based methods EOM-CCSD and RASPT2/RASSCF. Comparison with experimental data shows that the B3LYP functional gives the most accurate results for the ground state geometry and vibrational frequencies. The analysis of the vertical excitation energies reveals that the RASPT2 approach provides the most accurate excitation energies with deviations of the order of 0.1 eV. Among the TDDFT methods, the CAM-B3LYP functional shows the best performance on the excitation energies. By assessing the excited state gradients with respect to the reference RASPT2 data, the most accurate gradients are obtained with B3LYP, whereas other functionals as well as the EOM-CCSD and RASSCF calculations give less consistent results. Overall, despite the tendency of B3LYP to underestimate the excitation energies, this functional provides the most balanced description of both ground and excited state properties for both isomers of azobenzene in the Franck-Condon region.
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Affiliation(s)
- Magdalena Staniszewska
- Faculty of Applied Physics and Mathematics, Gdańsk University of Technology , Narutowicza 11/12, 80-233 Gdańsk, Poland
| | - Stephan Kupfer
- Institute of Physical Chemistry, Friedrich Schiller University Jena , Helmholtzweg 4, 07-743 Jena, Germany
| | - Marta Łabuda
- Faculty of Applied Physics and Mathematics, Gdańsk University of Technology , Narutowicza 11/12, 80-233 Gdańsk, Poland
| | - Julien Guthmuller
- Faculty of Applied Physics and Mathematics, Gdańsk University of Technology , Narutowicza 11/12, 80-233 Gdańsk, Poland
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Tallarida N, Rios L, Apkarian VA, Lee J. Isomerization of One Molecule Observed through Tip-Enhanced Raman Spectroscopy. NANO LETTERS 2015; 15:6386-6394. [PMID: 26348440 DOI: 10.1021/acs.nanolett.5b01543] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
While exploring photoisomerization of azobenzyl thiols (ABT) adsorbed on Au(111), through joint scanning tunneling microscopy (STM) and tip-enhanced Raman scattering (TERS) studies, the reversible photoisomerization of one molecule is captured in TERS trajectories. The unique signature of single molecule isomerization is observed in the form of anticorrelated flip-flops between two distinct spectra with two discrete, on- and off-levels. The apparently heterogeneously photocatalyzed reaction is assigned to cis-trans isomerization of an outlier, which is chemisorbed on the silver tip of the STM. Otherwise, the ensemble of ABT molecules that lie flat on Au(111) remain strongly coupled to the surface, excluding the possibility of photoisomerization or detection through TERS.
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Affiliation(s)
- Nicholas Tallarida
- Department of Chemistry, University of California, Irvine , Irvine, California 92617-2025, United States
| | - Laura Rios
- Department of Chemistry, University of California, Irvine , Irvine, California 92617-2025, United States
| | - Vartkess A Apkarian
- Department of Chemistry, University of California, Irvine , Irvine, California 92617-2025, United States
| | - Joonhee Lee
- Department of Chemistry, University of California, Irvine , Irvine, California 92617-2025, United States
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Mikheev YA, Guseva LN, Ershov YA. Origin of the coloration and structure of azobenzene chromogen. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2015. [DOI: 10.1134/s0036024415110138] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Guan PJ, Cui G, Fang Q. Computational photochemistry of the azobenzene scaffold of Sudan I and Orange II dyes: excited-state proton transfer and deactivation via conical intersections. Chemphyschem 2015; 16:805-11. [PMID: 25572608 DOI: 10.1002/cphc.201402743] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Indexed: 11/10/2022]
Abstract
We employed the complete active space self-consistent field (CASSCF) and its multistate second-order perturbation (MS-CASPT2) methods to explore the photochemical mechanism of 2-hydroxyazobenzene, the molecular scaffold of Sudan I and Orange II dyes. It was found that the excited-state intramolecular proton transfer (ESIPT) along the bright diabatic (1) ππ* state is barrierless and ultrafast. Along this diabatic (1) ππ* relaxation path, the system can jump to the dark (1) nπ* state via the (1) ππ*/(1) nπ* crossing point. However, ESIPT in this dark state is largely inhibited owing to a sizeable barrier. We also found two deactivation channels that decay (1) ππ* keto and (1) nπ* enol species to the ground state via two energetically accessible S1 /S0 conical intersections. Finally, we encountered an interesting phenomenon in the excited-state hydrogen-bonding strength: it is reinforced in the (1) ππ* state, whereas it is reduced in the (1) nπ* state. The present work sets the stage for understanding the photophysics and photochemistry of Sudan I-IV, Orange II, Ponceau 2R, Ponceau 4R, and azo violet.
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Affiliation(s)
- Pei-Jie Guan
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875 (China)
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Lygo ON, Khodot EN, Ogurtsov VA, Shelaev IV, Gostev FE, Nekipelova TD. Dynamics of trans-cis photoisomerization of hetarylazo dyes. HIGH ENERGY CHEMISTRY 2014. [DOI: 10.1134/s0018143914050099] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Lygo ON, Shvydkii VO, Khodot EN, Ogurtsov VA, Kurkovskaya LN, Levina II, Nekipelova TD. Spectral and time-resolved properties of novel hetarylazo dyes containing hydrogenated quinolines and triazole moieties. HIGH ENERGY CHEMISTRY 2014. [DOI: 10.1134/s0018143914040080] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Cui G, Guan PJ, Fang WH. Photoinduced proton transfer and isomerization in a hydrogen-bonded aromatic azo compound: a CASPT2//CASSCF study. J Phys Chem A 2014; 118:4732-9. [PMID: 24940848 DOI: 10.1021/jp503865y] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Intramolecularly hydrogen-bonded aromatic azo compound 1-cyclopropyldiazo-2-naphthol (CPDNO) exhibits complicated excited-state behaviors, e.g., wavelength-dependent photoinduced proton transfer and photoproducts. Its photochemistry differs from that of common aromatic azo compounds in which cis-trans photoisomerization is dominant. To rationalize the intriguing photochemistry of CPDNO at the atomic level, we have in this work employed the complete active space self-consistent field (CASSCF) and its second-order perturbation (CASPT2) methods to explore the S0, S1, and S2 potential-energy profiles relevant to enol-keto proton transfer and isomerization reactions. It is found that the proton transfer along the bright diabatic (1)ππ* potential-energy profile is almost barrierless, quickly forming the fluorescent (1)ππ* keto minimum. In this process, the dark (1)nπ* state is populated via a (1)ππ*/(1)nπ* crossing point, but the proton transfer on this dark state is suppressed heavily as a result of a large barrier. In addition, two deactivation paths that decay the S1 enol and keto minima to the S0 state, respectively, were uncovered. For the former, it is exoenergetic and thereby thermodynamically favorable; for the latter, it is a little endothermic (ca. 5 kcal/mol). Both are energetically allowable concerning the available total energy. Finally, on the basis of the present results, the experimentally observed wavelength-dependent photoproducts were explained very well.
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Affiliation(s)
- 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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