1
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Kochman MA. Nonadiabatic Molecular Dynamics Simulations Provide Evidence for Coexistence of Planar and Nonplanar Intramolecular Charge Transfer Structures in Fluorazene. J Phys Chem A 2024; 128:6685-6694. [PMID: 39109856 PMCID: PMC11331525 DOI: 10.1021/acs.jpca.4c03693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2024] [Revised: 07/18/2024] [Accepted: 07/22/2024] [Indexed: 08/16/2024]
Abstract
Fluorazene is a model compound for photoinduced intramolecular charge transfer (ICT) between aromatic moieties. Despite intensive studies, both spectroscopic and theoretical, a complete model of its photophysics is still lacking. Especially controversial is the geometry of its ICT structure, or structures. In order to fill in the gaps in the state of knowledge on this important model system, in the present study I report the results of nonadiabatic molecular dynamics (NAMD) simulations of its photorelaxation process in acetonitrile solution. To afford a direct comparison to spectroscopic data, I use the simulation results as the basis for the calculation of the transient absorption (TA) spectrum. The NAMD simulations provide detailed information on the sequence of events during the excited-state relaxation of the title compound. Following initial photoexcitation into the bright S2 state, the molecule undergoes rapid internal conversion into the S1 state, leading to the locally excited (LE) structure. The LE structure, in turn, undergoes isomerization into a population of ICT structures, with geometries ranging from near-planar to markedly nonplanar. The LE → ICT isomerization reaction is accompanied by the decay of the characteristic excited-state absorption band of the LE structure near 2 eV. The anomalous fluorescence emission band of fluorazene is found to originate mainly from the near-planar ICT structures, in part because they dominate the overall population of ICT structures. Thus, the planar ICT (PICT) model appears to be the most appropriate description of the geometry of the ICT structure of fluorazene.
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Affiliation(s)
- Michał Andrzej Kochman
- Institute
of Physical Chemistry of the Polish Academy of Sciences, Ul. Marcina Kasprzaka 44/52, 01-224 Warsaw, Poland
- Theoretical
Chemistry, Ruhr University Bochum, Universitätsstraße 150, 44801 Bochum, Germany
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2
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Mehmood A, Silfies MC, Durden AS, Allison TK, Levine BG. Simulating ultrafast transient absorption spectra from first principles using a time-dependent configuration interaction probe. J Chem Phys 2024; 161:044107. [PMID: 39041880 DOI: 10.1063/5.0215890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Accepted: 06/30/2024] [Indexed: 07/24/2024] Open
Abstract
Transient absorption spectroscopy (TAS) is among the most common ultrafast photochemical experiments, but its interpretation remains challenging. In this work, we present an efficient and robust method for simulating TAS signals from first principles. Excited-state absorption and stimulated emission (SE) signals are computed using time-dependent complete active space configuration interaction (TD-CASCI) simulations, leveraging the robustness of time-domain simulation to minimize electronic structure failure. We demonstrate our approach by simulating the TAS signal of 1'-hydroxy-2'-acetonapthone (HAN) from ab initio multiple spawning nonadiabatic molecular dynamics simulations. Our results are compared to gas-phase TAS data recorded from both jet-cooled (T ∼ 40 K) and hot (∼403 K) molecules via cavity-enhanced TAS (CE-TAS). Decomposition of the computed spectrum allows us to assign a rise in the SE signal to excited-state proton transfer and the ultimate decay of the signal to relaxation through a twisted conical intersection. The total cost of computing the observable signal (∼1700 graphics processing unit hours for ∼4 ns of electron dynamics) was markedly less than that of performing the ab initio multiple spawning calculations used to compute the underlying nonadiabatic dynamics.
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Affiliation(s)
- Arshad Mehmood
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, USA
- Institute for Advanced Computational Science, Stony Brook University, Stony Brook, New York 11794, USA
| | - Myles C Silfies
- Department of Physics, Stony Brook University, Stony Brook, New York 11794, USA
| | - Andrew S Durden
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, USA
- Institute for Advanced Computational Science, Stony Brook University, Stony Brook, New York 11794, USA
| | - Thomas K Allison
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, USA
- Department of Physics, Stony Brook University, Stony Brook, New York 11794, USA
| | - Benjamin G Levine
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, USA
- Institute for Advanced Computational Science, Stony Brook University, Stony Brook, New York 11794, USA
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3
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Huang H, Peng J, Zhang Y, Gu FL, Lan Z, Xu C. The development of the QM/MM interface and its application for the on-the-fly QM/MM nonadiabatic dynamics in JADE package: Theory, implementation, and applications. J Chem Phys 2024; 160:234101. [PMID: 38884395 DOI: 10.1063/5.0215036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Accepted: 05/15/2024] [Indexed: 06/18/2024] Open
Abstract
Understanding the nonadiabatic dynamics of complex systems is a challenging task in computational photochemistry. Herein, we present an efficient and user-friendly quantum mechanics/molecular mechanics (QM/MM) interface to run on-the-fly nonadiabatic dynamics. Currently, this interface consists of an independent set of codes designed for general-purpose use. Herein, we demonstrate the ability and feasibility of the QM/MM interface by integrating it with our long-term developed JADE package. Tailored to handle nonadiabatic processes in various complex systems, especially condensed phases and protein environments, we delve into the theories, implementations, and applications of on-the-fly QM/MM nonadiabatic dynamics. The QM/MM approach is established within the framework of the additive QM/MM scheme, employing electrostatic embedding, link-atom inclusion, and charge-redistribution schemes to treat the QM/MM boundary. Trajectory surface-hopping dynamics are facilitated using the fewest switches algorithm, encompassing classical and quantum treatments for nuclear and electronic motions, respectively. Finally, we report simulations of nonadiabatic dynamics for two typical systems: azomethane in water and the retinal chromophore PSB3 in a protein environment. Our results not only illustrate the power of the QM/MM program but also reveal the important roles of environmental factors in nonadiabatic processes.
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Affiliation(s)
- Haiyi Huang
- MOE Key Laboratory of Environmental Theoretical Chemistry and Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety, SCNU Environmental Research Institute, School of Environment, South China Normal University, Guangzhou 510006, China
- Center for Advanced Materials Research, Beijing Normal University, Zhuhai 519087, China
- MOE Key Laboratory of Theoretical and Computational Photochemistry, College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Jiawei Peng
- MOE Key Laboratory of Environmental Theoretical Chemistry and Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety, SCNU Environmental Research Institute, School of Environment, South China Normal University, Guangzhou 510006, China
| | - Yulin Zhang
- MOE Key Laboratory of Environmental Theoretical Chemistry and Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety, SCNU Environmental Research Institute, School of Environment, South China Normal University, Guangzhou 510006, China
| | - Feng Long Gu
- MOE Key Laboratory of Environmental Theoretical Chemistry and Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety, SCNU Environmental Research Institute, School of Environment, South China Normal University, Guangzhou 510006, China
| | - Zhenggang Lan
- MOE Key Laboratory of Environmental Theoretical Chemistry and Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety, SCNU Environmental Research Institute, School of Environment, South China Normal University, Guangzhou 510006, China
| | - Chao Xu
- MOE Key Laboratory of Environmental Theoretical Chemistry and Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety, SCNU Environmental Research Institute, School of Environment, South China Normal University, Guangzhou 510006, China
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4
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Jaiswal VK, Montorsi F, Aleotti F, Segatta F, Keefer D, Mukamel S, Nenov A, Conti I, Garavelli M. Ultrafast photochemistry and electron-diffraction spectra in n → (3s) Rydberg excited cyclobutanone resolved at the multireference perturbative level. J Chem Phys 2024; 160:164316. [PMID: 38686819 DOI: 10.1063/5.0203624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Accepted: 04/10/2024] [Indexed: 05/02/2024] Open
Abstract
We study the ultrafast time evolution of cyclobutanone excited to the singlet n → Rydberg state through non-adiabatic surface-hopping simulationsperformed at extended multi-state complete active space second-order perturbation (XMS-CASPT2) level of theory. These dynamics predict relaxation to the ground-state with a timescale of 822 ± 45 fs with minimal involvement of the triplets. The major relaxation path to the ground-state involves a three-state degeneracy region and leads to a variety of fragmented photoproducts. We simulate the resulting time-resolved electron-diffraction spectra, which track the relaxation of the excited state and the formation of various photoproducts in the ground state.
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Affiliation(s)
- V K Jaiswal
- Dipartimento di Chimica industriale "Toso Montanari," Università di Bologna, Viale del Risorgimento 4, 40136 Bologna, Italy
| | - F Montorsi
- Dipartimento di Chimica industriale "Toso Montanari," Università di Bologna, Viale del Risorgimento 4, 40136 Bologna, Italy
| | - F Aleotti
- Dipartimento di Chimica industriale "Toso Montanari," Università di Bologna, Viale del Risorgimento 4, 40136 Bologna, Italy
| | - F Segatta
- Dipartimento di Chimica industriale "Toso Montanari," Università di Bologna, Viale del Risorgimento 4, 40136 Bologna, Italy
| | - Daniel Keefer
- Molecular Spectroscopy Department, Max Planck Institute for Polymer Research, Mainz 55128, Germany
| | - Shaul Mukamel
- Department of Chemistry and Department of Physics and Astronomy, University of California Irvine, Irvine, California 92697, USA
| | - A Nenov
- Dipartimento di Chimica industriale "Toso Montanari," Università di Bologna, Viale del Risorgimento 4, 40136 Bologna, Italy
| | - I Conti
- Dipartimento di Chimica industriale "Toso Montanari," Università di Bologna, Viale del Risorgimento 4, 40136 Bologna, Italy
| | - M Garavelli
- Dipartimento di Chimica industriale "Toso Montanari," Università di Bologna, Viale del Risorgimento 4, 40136 Bologna, Italy
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5
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Suchan J, Liang F, Durden AS, Levine BG. Prediction challenge: First principles simulation of the ultrafast electron diffraction spectrum of cyclobutanone. J Chem Phys 2024; 160:134310. [PMID: 38573851 DOI: 10.1063/5.0198333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Accepted: 03/18/2024] [Indexed: 04/06/2024] Open
Abstract
Computer simulation has long been an essential partner of ultrafast experiments, allowing the assignment of microscopic mechanistic detail to low-dimensional spectroscopic data. However, the ability of theory to make a priori predictions of ultrafast experimental results is relatively untested. Herein, as a part of a community challenge, we attempt to predict the signal of an upcoming ultrafast photochemical experiment using state-of-the-art theory in the context of preexisting experimental data. Specifically, we employ ab initio Ehrenfest with collapse to a block mixed quantum-classical simulations to describe the real-time evolution of the electrons and nuclei of cyclobutanone following excitation to the 3s Rydberg state. The gas-phase ultrafast electron diffraction (GUED) signal is simulated for direct comparison to an upcoming experiment at the Stanford Linear Accelerator Laboratory. Following initial ring-opening, dissociation via two distinct channels is observed: the C3 dissociation channel, producing cyclopropane and CO, and the C2 channel, producing CH2CO and C2H4. Direct calculations of the GUED signal indicate how the ring-opened intermediate, the C2 products, and the C3 products can be discriminated in the GUED signal. We also report an a priori analysis of anticipated errors in our predictions: without knowledge of the experimental result, which features of the spectrum do we feel confident we have predicted correctly, and which might we have wrong?
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Affiliation(s)
- Jiří Suchan
- Institute of Advanced Computational Science, Stony Brook University, Stony Brook, New York 11794, USA
| | - Fangchun Liang
- Institute of Advanced Computational Science, Stony Brook University, Stony Brook, New York 11794, USA
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, USA
| | - Andrew S Durden
- Institute of Advanced Computational Science, Stony Brook University, Stony Brook, New York 11794, USA
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, USA
| | - Benjamin G Levine
- Institute of Advanced Computational Science, Stony Brook University, Stony Brook, New York 11794, USA
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, USA
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6
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Xu C, Lin C, Peng J, Zhang J, Lin S, Gu FL, Gelin MF, Lan Z. On-the-fly simulation of time-resolved fluorescence spectra and anisotropy. J Chem Phys 2024; 160:104109. [PMID: 38477337 DOI: 10.1063/5.0201204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Accepted: 02/23/2024] [Indexed: 03/14/2024] Open
Abstract
We combine on-the-fly trajectory surface hopping simulations and the doorway-window representation of nonlinear optical response functions to create an efficient protocol for the evaluation of time- and frequency-resolved fluorescence (TFRF) spectra and anisotropies of the realistic polyatomic systems. This approach gives the effective description of the proper (e.g., experimental) pulse envelopes, laser field polarizations, and the proper orientational averaging of TFRF signals directly from the well-established on-the-fly nonadiabatic dynamic simulations without extra computational cost. To discuss the implementation details of the developed protocol, we chose cis-azobenzene as a prototype to simulate the time evolution of the TFRF spectra governed by its nonadiabatic dynamics. The results show that the TFRF is determined by the interplay of several key factors, i.e., decays of excited-state populations, evolution of the transition dipole moments along with the dynamic propagation, and scaling factor of the TFRF signals associated with the cube of emission frequency. This work not only provides an efficient and effective approach to simulate the TFRF and anisotropies of realistic polyatomic systems but also discusses the important relationship between the TFRF signals and the underlining nonadiabatic dynamics.
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Affiliation(s)
- Chao Xu
- Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education and Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety; School of Environment, South China Normal University, Guangzhou 510006, People's Republic of China
| | - Congru Lin
- Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education and Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety; School of Environment, South China Normal University, Guangzhou 510006, People's Republic of China
| | - Jiawei Peng
- Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education and Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety; School of Environment, South China Normal University, Guangzhou 510006, People's Republic of China
| | - Juanjuan Zhang
- Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education and Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety; School of Environment, South China Normal University, Guangzhou 510006, People's Republic of China
| | - Shichen Lin
- Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 6-1 Kasuga-Park, Fukuoka 816-8580, Japan
| | - Feng Long Gu
- Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education and Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety; School of Environment, South China Normal University, Guangzhou 510006, People's Republic of China
| | - Maxim F Gelin
- School of Science, Hangzhou Dianzi University, Hangzhou 310018, People's Republic of China
| | - Zhenggang Lan
- Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education and Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety; School of Environment, South China Normal University, Guangzhou 510006, People's Republic of China
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7
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Kitsaras MP, Grazioli L, Stopkowicz S. The approximate coupled-cluster methods CC2 and CC3 in a finite magnetic field. J Chem Phys 2024; 160:094112. [PMID: 38441261 DOI: 10.1063/5.0189350] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 01/18/2024] [Indexed: 08/16/2024] Open
Abstract
In this paper, we report on the implementation of CC2 and CC3 in the context of molecules in finite magnetic fields. The methods are applied to the investigation of atoms and molecules through spectroscopic predictions and geometry optimizations for the study of the atmosphere of highly magnetized White Dwarf stars. We show that ground-state finite-field (ff) CC2 is a reasonable alternative to CCSD for energies and, in particular, for geometrical properties. For excited states, ff-CC2 is shown to perform well for states with predominant single-excitation character. Yet, for cases in which the excited state wavefunction has double-excitation character with respect to the reference, ff-CC2 can easily lead to completely unphysical results. Ff-CC3, however, is shown to reproduce the CCSDT behavior very well and enables the treatment of larger systems at a high accuracy.
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Affiliation(s)
- Marios-Petros Kitsaras
- Fachrichtung Chemie, Universität des Saarlandes, Campus B2.2, D-66123 Saarbrücken, Germany
- Department Chemie, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, D-55128 Mainz, Germany
| | - Laura Grazioli
- Department Chemie, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, D-55128 Mainz, Germany
| | - Stella Stopkowicz
- Fachrichtung Chemie, Universität des Saarlandes, Campus B2.2, D-66123 Saarbrücken, Germany
- Department Chemie, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, D-55128 Mainz, Germany
- Hylleraas Centre for Quantum Molecular Sciences, Department of Chemistry, University of Oslo, P.O. Box 1033 Blindern, N-0315 Oslo, Norway
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8
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Maroń AM, Cannelli O, Socie EC, Lodowski P, Oppermann M, Machura B, Chergui M. Early bird or night owl? Controlling the ultrafast photodynamics of triphenylamine substituted 2,2':6',2''-terpyridine. Phys Chem Chem Phys 2024; 26:6265-6276. [PMID: 38305747 DOI: 10.1039/d3cp04492k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2024]
Abstract
Controlling the ultrafast photodynamics of metal-free organic molecules has great potential for technological applications. In this work, we use solvent polarity and viscosity as "external knobs" to govern the photodynamics of an electron-donating derivative of 2,2':6',2''-terpyridine (terpy), namely 4'-(4-(di(4-tert-butylphenyl)amine)phenyl)-2,2':6',2''-terpyridine (tBuTPAterpy). We combine femtosecond fluorescence upconversion (FlUC), transient absorption (TA) and quantum mechanical calculations to provide a comprehensive description of the tBuTPAterpy's photodynamics. Our results demonstrate that, by changing the solvent, the time scale of light-induced conformational changes of the system can be tuned over two orders of magnitude, controlling the tBuTPAterpy fluorescence spectral region and yield. As a result, depending on the local environment, tBuTPAterpy can act either as an "early bird" or a "night owl", with a tunability that makes it a promising candidate for metal-free sensors.
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Affiliation(s)
- Anna Maria Maroń
- Institute of Chemistry, University of Silesia, Szkolna 9, 40-007 Katowice, Poland.
| | - Oliviero Cannelli
- Laboratory of Ultrafast Spectroscopy (LSU) and Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne, ISIC CH H1 625, Station 6, CH-1015, Lausanne, Switzerland
- Center for Free-Electron Laser Science, DESY, Notkestraße 85, 22607 Hamburg, Germany.
| | - Etienne Christophe Socie
- Laboratory of Ultrafast Spectroscopy (LSU) and Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne, ISIC CH H1 625, Station 6, CH-1015, Lausanne, Switzerland
| | - Piotr Lodowski
- Institute of Chemistry, University of Silesia, Szkolna 9, 40-007 Katowice, Poland.
| | - Malte Oppermann
- Laboratory of Ultrafast Spectroscopy (LSU) and Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne, ISIC CH H1 625, Station 6, CH-1015, Lausanne, Switzerland
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, 4056 Basel, Switzerland
| | - Barbara Machura
- Institute of Chemistry, University of Silesia, Szkolna 9, 40-007 Katowice, Poland.
| | - Majed Chergui
- Laboratory of Ultrafast Spectroscopy (LSU) and Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne, ISIC CH H1 625, Station 6, CH-1015, Lausanne, Switzerland
- Elettra - Sincrotrone Trieste S.C.p.A., S.S.14 Km.163, 5 in Area Science Park, I - 34149, Trieste, Italy
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9
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Youngworth R, Roux B. Simulating the Fluorescence of the Locally Excited State of DMABN in Solvents of Different Polarities. J Phys Chem B 2024; 128:172-183. [PMID: 38113445 DOI: 10.1021/acs.jpcb.3c02975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Abstract
4-(N,N-Dimethylamino)benzonitrile (DMABN) is a luminescent probe that can be used for tracking changes in the surrounding solvent due to the large change in polarity between its ground and excited states. An important characteristic of DMABN is that it exhibits dual fluorescence with two different emission energies that can be monitored, allowing for better characterization of the surrounding system. The first excited state is called the locally excited (LE) state and is characterized by the movement of charge over the conjugated ring structure. In nonpolar solvents and in the gas phase, the fluorescence of DMABN is entirely attributed to the transition from the near-planar LE state. In more polar environments, emission occurs from both the LE and a second excited state, corresponding to a twisted intramolecular charge-transfer (ICT) structure. For the sake of simplicity, this work considers transitions between only the ground and LE state. Molecular mechanical force field models of DMABN in its ground and LE states have been developed to investigate the sensitivity of the LE state to the polarity of the solvent. Both nonpolarizable and polarizable force fields were developed to simulate the molecule in a series of 10 different solvents of different polarities. The calculated Stokes shift of DMABN increases with increasing orientation polarizability of the surrounding solvent, which is the expected trend, as seen in experimental studies.
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Affiliation(s)
- Rachael Youngworth
- Department of Chemistry, The University of Chicago, 5735 S Ellis Avenue, Chicago, Illinois 60637, United States
| | - Benoît Roux
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, Illinois 60637, United States
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10
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Abdelaziz B, Chérif I, Gassoumi B, Patanè S, Ayachi S. Linear and Nonlinear Optical Responses of Nitrobenzofurazan-Sulfide Derivatives: DFT-QTAIM Investigation on Twisted Intramolecular Charge Transfer. J Phys Chem A 2023; 127:9895-9910. [PMID: 37972307 PMCID: PMC10694821 DOI: 10.1021/acs.jpca.3c04277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 10/07/2023] [Accepted: 11/01/2023] [Indexed: 11/19/2023]
Abstract
In this study, we report on the green fluorescence exhibited by nitrobenzofurazan-sulfide derivatives (NBD-Si, i = 1-4). The optical responses of these studied compounds in a polar methanol solvent were simulated by the use of time-dependent density functional theory (TD-DFT) employing the Becke-3-Parameter-Lee-Yang-Parr (B3LYP) functional along with the 6-31G(d,p) basis set. The computed energy and oscillator strength (f) results complement the experimental results. The band gap was calculated as the difference between the lowest unoccupied molecular orbital (LUMO) and the highest occupied molecular orbital (HOMO). Additionally, the density of states (DOS) was computed, providing a comprehensive understanding of the fundamental properties of these materials and further corroborating the experimental data. When the experimental data derived from ultraviolet/visible (UV/visible) and fluorescence spectroscopic techniques and those from simulated spectra are analyzed, the extracted values match up adequately. In addition, the NBD-sulfide compounds exhibit a large Stokes shift up to 85 nm in a polar methanol solvent. They are hypothesized to represent a novel paradigm of excited-state intramolecular charge transfer (ICT). To understand the intrinsic optical properties of NBD-Si materials, an ICT was identified, and its direction within the molecule was evaluated using the ratio of βvect and βtotal, values extracted from the computed nonlinear optical (NLO) properties. Moreover, the reduced density gradient (RDG)-based noncovalent interactions (NCIs) were employed to characterize the strength and type of NBD-Si interactions. Furthermore, noncovalent interactions were identified and categorized using the Quantum Theory of Atoms in Molecules (QTAIM) analysis. Ultimately, the combination of Hirshfeld surface analysis and DFT calculations was utilized to enhance the characterization and rationalization of these NCIs.
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Affiliation(s)
- Balkis Abdelaziz
- Laboratory
of Physico-Chemistry of Materials (LR01ES19), Faculty of Sciences, University of Monastir, Avenue of the Environment, 5019 Monastir, Tunisia
- Department
of Mathematical and Computer Sciences, Physical Sciences and Earth
Sciences, University of Messina, I-98166 Messina, Italy
| | - Imen Chérif
- Laboratory
of Physico-Chemistry of Materials (LR01ES19), Faculty of Sciences, University of Monastir, Avenue of the Environment, 5019 Monastir, Tunisia
| | - Bouzid Gassoumi
- Laboratoire
Interfaces et Matériaux Avancés (LIMA), Faculté
des Sciences, Université de Monastir, Avenue de l’Environnement, 5019 Monastir, Tunisia
| | - Salvatore Patanè
- Department
of Mathematical and Computer Sciences, Physical Sciences and Earth
Sciences, University of Messina, I-98166 Messina, Italy
| | - Sahbi Ayachi
- Laboratory
of Physico-Chemistry of Materials (LR01ES19), Faculty of Sciences, University of Monastir, Avenue of the Environment, 5019 Monastir, Tunisia
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11
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Charette BJ, King SR, Chen J, Holm AR, Malme JT, Cook RD, Schaller RD, Jackson NE, Olshansky L. Excited State Dynamics of a Conformationally Fluxional Copper Coordination Complex. J Phys Chem A 2023; 127:7747-7755. [PMID: 37672011 DOI: 10.1021/acs.jpca.3c04269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/07/2023]
Abstract
The conversion of solar energy into chemical fuel represents a capstone goal of the 21st century and has the potential to supply terawatts of power in a globally distributed manner. However, the disparate time scales of photodriven charge separation (∼fs) and steps in chemical reactions (∼μs) represent an inherent bottleneck in solar-to-fuels technology. To address this discrepancy, we are developing earth-abundant coordination complexes that undergo light-induced conformational rearrangements such that charge separation (CS) is hastened, while charge recombination (CR) is slowed. To these ends, we report the preparation and characterization of a new series of conformationally fluxional copper coordination complexes that contain a twisted intramolecular charge transfer (TICT) fluorophore as part of their ligand scaffold. Structural and spectroscopic characterization of the Cu(I) and Cu(II) complexes formed with these ligands in their ground states establish oxidation state-dependent conformational dynamicity, while time-resolved emission and transient absorption spectroscopies define the photophysical parameters of photo-induced excited states. Building on initial reports with a related set of molecules, the improved ligand design presented here greatly simplifies the observed photophysics, effectively shutting down unwanted ligand-centered excited states previously observed. Time-dependent density functional theory (TDDFT) analyses reveal an unusual metal-to-TICT electronic transition only reported once before, and though the formation of a CS state is not observed directly through experiments, TDDFT geometry optimizations in the excited states support the formation of transient Cu(II) CS species, lending credence to the potential success of our approach. These studies establish a clear model for the excited state dynamics at play in proof-of-concept systems and clarify key design parameters for future optimizations toward achieving long-lived CS via photoinduced conformational gating.
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Affiliation(s)
- Bronte J Charette
- University of Illinois, Urbana-Champaign, 600 S. Mathews Avenue, Urbana, Illinois 61801, United States
| | - Shelby R King
- University of Illinois, Urbana-Champaign, 600 S. Mathews Avenue, Urbana, Illinois 61801, United States
| | - Jiaqi Chen
- University of Illinois, Urbana-Champaign, 600 S. Mathews Avenue, Urbana, Illinois 61801, United States
| | - Annika R Holm
- University of Illinois, Urbana-Champaign, 600 S. Mathews Avenue, Urbana, Illinois 61801, United States
| | - Justin T Malme
- University of Illinois, Urbana-Champaign, 600 S. Mathews Avenue, Urbana, Illinois 61801, United States
| | - Robert D Cook
- University of Illinois, Urbana-Champaign, 600 S. Mathews Avenue, Urbana, Illinois 61801, United States
| | - Richard D Schaller
- Center for Nanoscale Materials, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Nicholas E Jackson
- University of Illinois, Urbana-Champaign, 600 S. Mathews Avenue, Urbana, Illinois 61801, United States
| | - Lisa Olshansky
- University of Illinois, Urbana-Champaign, 600 S. Mathews Avenue, Urbana, Illinois 61801, United States
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12
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Avagliano D, Bonfanti M, Nenov A, Garavelli M. Automatized protocol and interface to simulate QM/MM time-resolved transient absorption at TD-DFT level with COBRAMM. J Comput Chem 2022; 43:1641-1655. [PMID: 35815854 PMCID: PMC9544370 DOI: 10.1002/jcc.26966] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 06/07/2022] [Accepted: 06/10/2022] [Indexed: 12/24/2022]
Abstract
We present a series of new implementations that we recently introduced in COBRAMM, the open-source academic software developed in our group. The goal of these implementations is to offer an automatized workflow and interface to simulate time-resolved transient absorption (TA) spectra of medium-to-big chromophore embedded in a complex environment. Therefore, the excited states absorption and the stimulated emission are simulated along nonadiabatic dynamics performed with trajectory surface hopping. The possibility of treating systems from medium to big size is given by the use of time-dependent density functional theory (TD-DFT) and the presence of the environment is taken into account employing a hybrid quantum mechanics/molecular mechanics (QM/MM) scheme. The full implementation includes a series of auxiliary scripts to properly setup the QM/MM system, the calculation of the wavefunction overlap along the dynamics for the propagation, the evaluation of the transition dipole moment at linear response TD-DFT level, and scripts to setup, run and analyze the TA from an ensemble of trajectories. Altogether, we believe that our implementation will open the door to the easily simulate the time-resolved TA of systems so far computationally inaccessible.
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Affiliation(s)
- Davide Avagliano
- Dipartimento di Chimica Industriale "Toso Montanari", Università degli Studi di Bologna, Bologna, Italy
| | - Matteo Bonfanti
- Dipartimento di Chimica Industriale "Toso Montanari", Università degli Studi di Bologna, Bologna, Italy.,Fondazione Human Technopole - Viale Rita Levi-Montalcini, 1 - Area MIND - Cargo 6 - 20157, Milano, Italy
| | - Artur Nenov
- Dipartimento di Chimica Industriale "Toso Montanari", Università degli Studi di Bologna, Bologna, Italy
| | - Marco Garavelli
- Dipartimento di Chimica Industriale "Toso Montanari", Università degli Studi di Bologna, Bologna, Italy
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Gómez S, Soysal EN, Worth GA. Micro-Solvated DMABN: Excited State Quantum Dynamics and Dual Fluorescence Spectra. Molecules 2021; 26:7247. [PMID: 34885829 PMCID: PMC8658867 DOI: 10.3390/molecules26237247] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 11/23/2021] [Accepted: 11/24/2021] [Indexed: 12/04/2022] Open
Abstract
In this work, we report a complete analysis by theoretical and spectroscopic methods of the short-time behaviour of 4-(dimethylamino)benzonitrile (DMABN) in the gas phase as well as in cyclohexane, tetrahydrofuran, acetonitrile, and water solution, after excitation to the La state. The spectroscopic properties of DMABN were investigated experimentally using UV absorption and fluorescence emission spectroscopy. The computational study was developed at different electronic structure levels and using the Polarisable Continuum Model (PCM) and explicit solvent molecules to reproduce the solvent environment. Additionally, excited state quantum dynamics simulations in the diabatic picture using the direct dynamics variational multiconfigurational Gaussian (DD-vMCG) method were performed, the largest quantum dynamics "on-the-fly" simulations performed with this method until now. The comparison with fully converged multilayer multiconfigurational time-dependent Hartree (ML-MCTDH) dynamics on parametrised linear vibronic coupling (LVC) potentials show very similar population decays and evolution of the nuclear wavepacket. The ring C=C stretching and three methyl tilting modes are identified as the responsible motions for the internal conversion from the La to the Lb states. No major differences are observed in the ultrafast initial decay in different solvents, but we show that this effect depends strongly on the level of electronic structure used.
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Affiliation(s)
- Sandra Gómez
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK;
| | | | - Graham A. Worth
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK;
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