1
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Jeong J, Shin HH, Kim ZH. Unveiling the Mechanism of Plasmon Photocatalysis via Multiquantum Vibrational Excitation. ACS NANO 2024; 18:25290-25301. [PMID: 39185823 DOI: 10.1021/acsnano.4c08521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/27/2024]
Abstract
Plasmon photocatalysis reactions are thought to occur through vibrationally activated reactants, driven by nonthermal energy transfer from plasmon-induced hot carriers. However, a detailed quantum-state-level understanding and quantification of the activation have been lacking. Using anti-Stokes surface-enhanced Raman scattering (SERS) spectroscopy, we mapped the vibrational population distributions of reactants on plasmon-excited nanostructures. Our results reveal a highly nonthermal distribution with an anomalously enhanced population of multiquantum excited states (v ≥ 2). The shape of the distribution and its dependence on local field intensity and excitation wavelength cannot be explained by photothermal heating or vibronic optical transitions of the metal-molecule complex. Instead, it can be modeled by hot electron-molecule energy transfer mediated by the transient negative ions, establishing direct links among nonthermal reactant activation, plasmon-induced hot electrons, and negative ion resonances. Moreover, the presence of multiquantum excited reactants, which are far more reactive than those in the ground state or first excited state, presents opportunities for vibrationally controlling chemical selectivities.
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Affiliation(s)
- Jaeyoung Jeong
- Department of Chemistry, Seoul National University, Seoul 08826, Republic of Korea
| | - Hyun-Hang Shin
- Department of Chemistry, Seoul National University, Seoul 08826, Republic of Korea
| | - Zee Hwan Kim
- Department of Chemistry, Seoul National University, Seoul 08826, Republic of Korea
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2
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Máximo-Canadas M, Modesto-Costa L, Borges I. Ab initio electronic absorption spectra of para-nitroaniline in different solvents: Intramolecular charge transfer effects. J Comput Chem 2024. [PMID: 39212073 DOI: 10.1002/jcc.27493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Revised: 07/19/2024] [Accepted: 08/01/2024] [Indexed: 09/04/2024]
Abstract
Intramolecular charge transfer (ICT) effects of para-nitroaniline (pNA) in eight solvents (cyclohexane, toluene, acetic acid, dichloroethane, acetone, acetonitrile, dimethylsulfoxide, and water) are investigated extensively. The second-order algebraic diagrammatic construction, ADC(2), ab initio wave function is employed with the COSMO implicit and discrete multiscale solvation methods. We found a decreasing amine group torsion angle with increased solvent polarity and a linear correlation between the polarity and ADC(2) transition energies. The first absorption band involves π → π* transitions with ICT from the amine and the benzene ring to the nitro group, increased by 4%-11% for different solvation models of water compared to the vacuum. A second band of pNA is characterized for the first time. This band is primarily a local excitation on the nitro group, including some ICT from the amine group to the benzene ring that decreases with the solvent polarity. For cyclohexane, the COSMO implicit solvent model shows the best agreement with the experiment, while the explicit model has the best agreement for water.
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Affiliation(s)
- Matheus Máximo-Canadas
- Departamento de Química, Instituto Militar de Engenharia (IME), Rio de Janeiro, Rio de Janeiro, Brazil
| | - Lucas Modesto-Costa
- Department of Physics, Federal Rural University of Rio de Janeiro, Seropédica, Rio de Janeiro, Brazil
| | - Itamar Borges
- Departamento de Química, Instituto Militar de Engenharia (IME), Rio de Janeiro, Rio de Janeiro, Brazil
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3
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Loos PF, Jacquemin D. A mountaineering strategy to excited states: Accurate vertical transition energies and benchmarks for substituted benzenes. J Comput Chem 2024; 45:1791-1805. [PMID: 38661240 DOI: 10.1002/jcc.27358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 02/09/2024] [Accepted: 02/15/2024] [Indexed: 04/26/2024]
Abstract
In an effort to expand the existing QUEST database of accurate vertical transition energies [Véril et al. WIREs Comput. Mol. Sci. 2021, 11, e1517], we have modeled more than 100 electronic excited states of different natures (local, charge-transfer, Rydberg, singlet, and triplet) in a dozen of mono- and di-substituted benzenes, including aniline, benzonitrile, chlorobenzene, fluorobenzene, nitrobenzene, among others. To establish theoretical best estimates for these vertical excitation energies, we have employed advanced coupled-cluster methods including iterative triples (CC3 and CCSDT) and, when technically possible, iterative quadruples (CC4). These high-level computational approaches provide a robust foundation for benchmarking a series of popular wave function methods. The evaluated methods all include contributions from double excitations (ADC(2), CC2, CCSD, CIS(D), EOM-MP2, STEOM-CCSD), along with schemes that also incorporate perturbative or iterative triples (ADC(3), CCSDR(3), CCSD(T)(a) ⋆ , and CCSDT-3). This systematic exploration not only broadens the scope of the QUEST database but also facilitates a rigorous assessment of different theoretical approaches in the framework of a homologous chemical series, offering valuable insights into the accuracy and reliability of these methods in such cases. We found that both ADC(2.5) and CCSDT-3 can provide very consistent estimates, whereas among less expensive methods SCS-CC2 is likely the most effective approach. Importantly, we show that some lower order methods may offer reasonable trends in the homologous series while providing quite large average errors, and vice versa. Consequently, benchmarking the accuracy of a model based solely on absolute transition energies may not be meaningful for applications involving a series of similar compounds.
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Affiliation(s)
- Pierre-François Loos
- Laboratoire de Chimie et Physique Quantiques (UMR 5626), Université de Toulouse, CNRS, UPS, France
| | - Denis Jacquemin
- Nantes Université, CNRS, CEISAM UMR 6230, Nantes, France
- Institut Universitaire de France (IUF), Paris, France
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4
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Whitaker W, Ghosh D, Malakar P, Karras G, Orr-Ewing AJ. Femtosecond to Microsecond Observation of Photochemical Pathways in Nitroaromatic Phototriggers Using Transient Absorption Spectroscopy. J Phys Chem A 2024; 128:5892-5905. [PMID: 38988292 DOI: 10.1021/acs.jpca.4c02482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/12/2024]
Abstract
The synthetic accessibility and tolerance to structural modification of phototriggered compounds (PTs) based on the ortho- nitrobenzene (ONB) protecting group have encouraged a myriad of applications including optimization of biological activity, and supramolecular polymerization. Here, a combination of ultrafast transient absorption spectroscopy techniques is used to study the multistep photochemistry of two nitroaromatic phototriggers based on the ONB chromophore, O-(4,5-dimethoxy-2-nitrobenzyl)-l-serine (DMNB-Ser) and O-[(2-nitrophenyl)methyl]-l-tyrosine hydrochloride (NB-Tyr), in DMSO solutions on femtosecond to microsecond time scales following the absorption of UV light. From a common nitro-S1 excited state, the PTs can either undergo excited state intramolecular hydrogen transfer (ESIHT) to an aci-S1 isomer within the singlet state manifold, leading to direct S1 → S0 internal conversion through a conical intersection, or competitive intersystem crossing (ISC) to access the triplet state manifold on time scales of (1.93 ± 0.03) ps and (13.9 ± 1.2) ps for DMNB-Ser and NB-Tyr, respectively. Deprotonation of aci-T1 species to yield triplet anions is proposed to occur in both PTs, with an illustrative time constant of (9.4 ± 0.7) ns for DMNB-Ser. More than 75% of the photoexcited molecules return to their electronic ground states within 8 μs, either by direct S1 → S0 relaxation or anion reprotonation. Hence, upper limits to the quantum yields of photoproduct formation are estimated to be in the range of 13-25%. Mixed DMSO/H2O solvents show the influence of the environment on the observed photochemistry, for example, revealing two nitro-S1 lifetimes for DMNB-Ser in a 10:1 DMSO/H2O mixture of 1.95 ps and (10.1 ± 1.2) ps, which are attributed to different microsolvation environments.
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Affiliation(s)
- William Whitaker
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K
| | - Deborin Ghosh
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K
| | - Partha Malakar
- Central Laser Facility, Research Complex at Harwell, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Didcot, Oxfordshire OX11 0QX, U.K
| | - Gabriel Karras
- Central Laser Facility, Research Complex at Harwell, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Didcot, Oxfordshire OX11 0QX, U.K
| | - Andrew J Orr-Ewing
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K
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5
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Chowdhury PR, Kawade M, Patwari GN. Mechanistic variances in NO release: ortho vs. meta isomers of nitrophenol and nitroaniline. Chem Commun (Camb) 2024; 60:5431-5434. [PMID: 38686426 DOI: 10.1039/d4cc01497a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
The NO release following 266 nm photolysis of ortho and meta isomers of nitrophenol and nitroaniline shows a bimodal translational energy distribution, wherein the slow and fast components originate from dynamics in the S0 and T1 states, respectively. The translational energy distribution profiles for any NO product state show a higher slow-to-fast (s/f) branching ratio for the ortho isomer in comparison with the meta isomer. The observed variation in the s/f branching ratio vis-à-vis the ortho and meta isomers is attributed to the presence of intramolecular hydrogen bonding between the ortho substituent and NO2 moiety, which favours the roaming mechanism.
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Affiliation(s)
- Prahlad Roy Chowdhury
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
| | - Monali Kawade
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
| | - G Naresh Patwari
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
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6
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Selenius E, Sigurdarson AE, Schmerwitz YLA, Levi G. Orbital-Optimized Versus Time-Dependent Density Functional Calculations of Intramolecular Charge Transfer Excited States. J Chem Theory Comput 2024; 20:3809-3822. [PMID: 38695313 DOI: 10.1021/acs.jctc.3c01319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2024]
Abstract
The performance of time-independent, orbital-optimized calculations of excited states is assessed with respect to charge transfer excitations in organic molecules in comparison to the linear-response time-dependent density functional theory (TD-DFT) approach. A direct optimization method to converge on saddle points of the electronic energy surface is used to carry out calculations with the local density approximation (LDA) and the generalized gradient approximation (GGA) functionals PBE and BLYP for a set of 27 excitations in 15 molecules. The time-independent approach is fully variational and provides a relaxed excited state electron density from which the extent of charge transfer is quantified. The TD-DFT calculations are generally found to provide larger charge transfer distances compared to the orbital-optimized calculations, even when including orbital relaxation effects with the Z-vector method. While the error on the excitation energy relative to theoretical best estimates is found to increase with the extent of charge transfer up to ca. -2 eV for TD-DFT, no correlation is observed for the orbital-optimized approach. The orbital-optimized calculations with the LDA and the GGA functionals provide a mean absolute error of ∼0.7 eV, outperforming TD-DFT with both local and global hybrid functionals for excitations with a long-range charge transfer character. Orbital-optimized calculations with the global hybrid functional B3LYP and the range-separated hybrid functional CAM-B3LYP on a selection of states with short- and long-range charge transfer indicate that inclusion of exact exchange has a small effect on the charge transfer distance, while it significantly improves the excitation energy, with the best-performing functional CAM-B3LYP providing an absolute error typically around 0.15 eV.
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Affiliation(s)
- Elli Selenius
- Science Institute of the University of Iceland, Reykjavík 107, Iceland
| | | | | | - Gianluca Levi
- Science Institute of the University of Iceland, Reykjavík 107, Iceland
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7
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Lau N, Ghosh D, Bourne-Worster S, Kumar R, Whitaker WA, Heitland J, Davies JA, Karras G, Clark IP, Greetham GM, Worth GA, Orr-Ewing AJ, Fielding HH. Unraveling the Ultrafast Photochemical Dynamics of Nitrobenzene in Aqueous Solution. J Am Chem Soc 2024; 146:10407-10417. [PMID: 38572973 PMCID: PMC11027148 DOI: 10.1021/jacs.3c13826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 03/09/2024] [Accepted: 03/11/2024] [Indexed: 04/05/2024]
Abstract
Nitroaromatic compounds are major constituents of the brown carbon aerosol particles in the troposphere that absorb near-ultraviolet (UV) and visible solar radiation and have a profound effect on the Earth's climate. The primary sources of brown carbon include biomass burning, forest fires, and residential burning of biofuels, and an important secondary source is photochemistry in aqueous cloud and fog droplets. Nitrobenzene is the smallest nitroaromatic molecule and a model for the photochemical behavior of larger nitroaromatic compounds. Despite the obvious importance of its droplet photochemistry to the atmospheric environment, there have not been any detailed studies of the ultrafast photochemical dynamics of nitrobenzene in aqueous solution. Here, we combine femtosecond transient absorption spectroscopy, time-resolved infrared spectroscopy, and quantum chemistry calculations to investigate the primary steps following the near-UV (λ ≥ 340 nm) photoexcitation of aqueous nitrobenzene. To understand the role of the surrounding water molecules in the photochemical dynamics of nitrobenzene, we compare the results of these investigations with analogous measurements in solutions of methanol, acetonitrile, and cyclohexane. We find that vibrational energy transfer to the aqueous environment quenches internal excitation, and therefore, unlike the gas phase, we do not observe any evidence for formation of photoproducts on timescales up to 500 ns. We also find that hydrogen bonding between nitrobenzene and surrounding water molecules slows the S1/S0 internal conversion process.
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Affiliation(s)
- Nicholas
A. Lau
- Department
of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, U.K.
| | - Deborin Ghosh
- School
of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K.
| | | | - Rhea Kumar
- Department
of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, U.K.
| | - William A. Whitaker
- School
of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K.
| | - Jonas Heitland
- Department
of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, U.K.
| | - Julia A. Davies
- Department
of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, U.K.
| | - Gabriel Karras
- Central
Laser Facility, Research Complex at Harwell, STFC Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0QX, U.K.
| | - Ian P. Clark
- Central
Laser Facility, Research Complex at Harwell, STFC Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0QX, U.K.
| | - Gregory M. Greetham
- Central
Laser Facility, Research Complex at Harwell, STFC Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0QX, U.K.
| | - Graham A. Worth
- Department
of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, U.K.
| | - Andrew J. Orr-Ewing
- School
of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K.
| | - Helen H. Fielding
- Department
of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, U.K.
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8
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Schraivogel T, Kats D. Two determinant distinguishable cluster. J Chem Phys 2024; 160:124109. [PMID: 38526108 DOI: 10.1063/5.0199274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Accepted: 03/06/2024] [Indexed: 03/26/2024] Open
Abstract
A two reference determinant version of the distinguishable cluster with singles and doubles (DCSD) has been developed. We have implemented the two determinant distinguishable cluster (2D-DCSD) and the corresponding traditional 2D-CCSD method in a new open-source package written in Julia called ElemCo.jl. The methods were benchmarked on singlet and triplet excited states of valence and Rydberg character, as well as for singlet-triplet gaps of diradicals. It is demonstrated that the distinguishable cluster approximation improves the accuracy of 2D-CCSD.
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Affiliation(s)
- Thomas Schraivogel
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, 70569 Stuttgart, Germany
| | - Daniel Kats
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, 70569 Stuttgart, Germany
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9
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Giussani A, Worth GA. A First Proposal on the Nitrobenzene Photorelease Mechanism of NO 2 and Its Relation to NO Formation through a Roaming Mechanism. J Phys Chem Lett 2024; 15:2216-2221. [PMID: 38373198 PMCID: PMC10910573 DOI: 10.1021/acs.jpclett.3c03457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2023] [Revised: 02/13/2024] [Accepted: 02/14/2024] [Indexed: 02/21/2024]
Abstract
Despite the fact that NO2 is considered to be the main photoproduct of nitrobenzene photochemistry, no mechanism has ever been proposed to rationalize its formation. NO photorelease is instead a more studied process, probably due to its application in the drug delivery sector and the study of roaming mechanisms. In this contribution, a photoinduced mechanism accounting for the formation of NO2 in nitrobenzene is theorized based on CASPT2, CASSCF, and DFT electronic structure calculations and CASSCF classical dynamics. A triplet nπ* state is shown to evolve toward C-NO2 dissociation, being, in fact, the only low-lying excited state favoring such a deformation. Along the triplet dissociation path, the possibility to decay to the singlet ground state results in the frustration of the dissociation and in the recombination of the fragments, either back to the nitro or the nitrite isomer. The thermal decomposition of the latter to NO constitutes globally a roaming mechanism of NO formation.
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Affiliation(s)
- Angelo Giussani
- Instituto
de Ciencia Molecular, Universitat de València, Apartado 22085, ES-46071 Valencia, Spain
| | - Graham A. Worth
- Department
of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, U.K.
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10
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Bejoy NB, Patwari GN. Photodegradation of Flutamide and Halogen Derivatives of Nitrobenzotrifluoride: The NO Release Channel. J Phys Chem A 2023; 127:7168-7174. [PMID: 37589077 DOI: 10.1021/acs.jpca.3c03024] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/18/2023]
Abstract
The photodegradation of the nonsteroidal antiandrogen drug flutamide has been long linked to the photoisomerization involving the nitro group. In this work, the dynamics of NO photoelimination upon photolysis at 266 nm of flutamide, nitrobenzotrifluoride, and its halogen derivatives were investigated. Similar to nitrobenzene and its derivatives, a bimodal translational energy distribution was observed for the NO photofragment indicating the presence of two distinct elimination channels resulting in slow and fast components. The trends in the slow/fast branching ratio show that halogen substitution at the para position increases the triplet state yield due to the internal heavy-atom effect leading to enhancement of the fast component. Furthermore, the topology of the triplet state potential energy surface showed that the minimum energy path favors the oxaziridine ring-type intermediate over the NO2 roaming mechanism in all five molecules investigated. The steric interaction between the NO2 group and the CF3 group, which are placed in the ortho position, lowers the barrier for the formation of the oxaziridine transition state compared to that of nitrobenzene.
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Affiliation(s)
- Namitha Brijit Bejoy
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - G Naresh Patwari
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
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11
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Crane S, Garrow M, Lane PD, Robertson K, Waugh A, Woolley JM, Stavros VG, Paterson MJ, Greaves SJ, Townsend D. The Value of Different Experimental Observables: A Transient Absorption Study of the Ultraviolet Excitation Dynamics Operating in Nitrobenzene. J Phys Chem A 2023; 127:6425-6436. [PMID: 37494478 PMCID: PMC10424241 DOI: 10.1021/acs.jpca.3c02654] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 06/16/2023] [Indexed: 07/28/2023]
Abstract
Excess energy redistribution dynamics operating in nitrobenzene under hexane and isopropanol solvation were investigated using ultrafast transient absorption spectroscopy (TAS) with a 267 nm pump and a 340-750 nm white light continuum probe. The use of a nonpolar hexane solvent provides a proxy to the gas-phase environment, and the findings are directly compared with a recent time-resolved photoelectron imaging (TRPEI) study on nitrobenzene using the same excitation wavelength [L. Saalbach et al., J. Phys. Chem. A 2021, 125, 7174-7184]. Of note is the observation of a 1/e lifetime of 3.5-6.7 ps in the TAS data that was absent in the TRPEI measurements. This is interpreted as a dynamical signature of the T2 state in nitrobenzene─analogous to observations in the related nitronaphthalene system, and additionally supported by previous quantum chemistry calculations. The discrepancy between the TAS and TRPEI measurements is discussed, with the overall findings providing an example of how different spectroscopic techniques can exhibit varying sensitivity to specific steps along the overall reaction coordinate connecting reactants to photoproducts.
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Affiliation(s)
- Stuart
W. Crane
- Institute
of Photonics & Quantum Sciences, Heriot-Watt
University, Edinburgh EH14 4AS, U.K.
| | - Malcolm Garrow
- Institute
of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K.
| | - Paul D. Lane
- Institute
of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K.
| | - Kate Robertson
- Institute
of Photonics & Quantum Sciences, Heriot-Watt
University, Edinburgh EH14 4AS, U.K.
| | - Alex Waugh
- Institute
of Photonics & Quantum Sciences, Heriot-Watt
University, Edinburgh EH14 4AS, U.K.
| | - Jack M. Woolley
- Department
of Physics, University of Warwick, Coventry CV4 7AL, U.K.
| | - Vasilios G. Stavros
- School
of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K.
| | - Martin J. Paterson
- Institute
of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K.
| | - Stuart J. Greaves
- Institute
of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K.
| | - Dave Townsend
- Institute
of Photonics & Quantum Sciences, Heriot-Watt
University, Edinburgh EH14 4AS, U.K.
- Institute
of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K.
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12
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Vörös D, Mai S. Role of Ultrafast Internal Conversion and Intersystem Crossing in the Nonadiabatic Relaxation Dynamics of ortho-Nitrobenzaldehyde. J Phys Chem A 2023. [PMID: 37405967 PMCID: PMC10364085 DOI: 10.1021/acs.jpca.3c02899] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/07/2023]
Abstract
ortho-Nitrobenzaldehyde (oNBA) is a well-known photoactivated acid and a prototypical photolabile nitro-aromatic compound. Despite extensive investigations, the ultrafast relaxation dynamics of oNBA is still not properly understood, especially concerning the role of the triplet states. In this work, we provide an in-depth picture of this dynamics by combining single- and multireference electronic structure methods with potential energy surface exploration and nonadiabatic dynamics simulations using the Surface Hopping including ARbitary Couplings (SHARC) approach. Our results reveal that the initial decay from the bright ππ* state to the S1 minimum is barrierless. It involves three changes in electronic structure from ππ* (ring) to nπ* (nitro group), to nπ* (aldehyde group), and then to another nπ* (nitro group). The decay of the ππ* takes 60-80 fs and can be tracked with time-resolved luminescence spectroscopy, where we predict for the first time a short-lived coherence of the luminescence energy with a 25 fs period. Intersystem crossing can occur already during the S4 → S1 deactivation cascade but also from S1, with a time constant of about 2.4 ps and such that first a triplet ππ* state localized on the nitro group is populated. The triplet population first evolves into an nπ* and then quickly undergoes hydrogen transfer to form a biradical intermediate, from where the ketene is eventually produced. The majority of the excited population decays from S1 through two conical intersections of equal utilization, a previously unreported one involving a scissoring motion of the nitro group that leads back to the oNBA ground state and the one involving hydrogen transfer that leads to the ketene intermediate.
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Affiliation(s)
- Dóra Vörös
- Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Straße 17, 1090 Vienna, Austria
- Vienna Doctoral School in Physics, University of Vienna, Boltzmanngasse 5, 1090 Vienna, Austria
| | - Sebastian Mai
- Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Straße 17, 1090 Vienna, Austria
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13
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Shin HH, Jeong J, Nam Y, Lee KS, Yeon GJ, Lee H, Lee SY, Park S, Park H, Lee JY, Kim ZH. Vibrationally Hot Reactants in a Plasmon-Assisted Chemical Reaction. J Am Chem Soc 2023. [PMID: 37220278 DOI: 10.1021/jacs.3c02681] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Recent studies on plasmon-assisted chemical reactions postulate that the hot electrons of plasmon-excited nanostructures may induce a non-thermal vibrational activation of metal-bound reactants. However, the postulate has not been fully validated at the level of molecular quantum states. We directly and quantitatively prove that such activation occurs on plasmon-excited nanostructures: The anti-Stokes Raman spectra of reactants undergoing a plasmon-assisted reaction reveal that a particular vibrational mode of the reactant is selectively excited, such that the reactants possess >10 times more energy in the mode than is expected from the fully thermalized molecules at the given local temperature. Furthermore, a significant portion (∼20%) of the excited reactant is in vibrational overtone states with energies exceeding 0.5 eV. Such mode-selective multi-quantum excitation could be fully modeled by the resonant electron-molecule scattering theory. Such observations suggest that the vibrationally hot reactants are created by non-thermal hot electrons, not by thermally heated electrons or phonons of metals. The result validates the mechanism of plasmon-assisted chemical reactions and further offers a new method to explore the vibrational reaction control on metal surfaces.
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Affiliation(s)
- Hyun-Hang Shin
- Department of Chemistry, Seoul National University; Gwanak-gu, Seoul 08826, Republic of Korea
| | - Jaeyoung Jeong
- Department of Chemistry, Seoul National University; Gwanak-gu, Seoul 08826, Republic of Korea
| | - Yeonsig Nam
- Department of Chemistry, Sungkyunkwan University, Gyeonggi-do, Suwon 16419, Republic of Korea
| | - Kang Sup Lee
- Department of Chemistry, Seoul National University; Gwanak-gu, Seoul 08826, Republic of Korea
| | - Gyu Jin Yeon
- Department of Chemistry, Seoul National University; Gwanak-gu, Seoul 08826, Republic of Korea
| | - Hankyul Lee
- Department of Chemistry, Seoul National University; Gwanak-gu, Seoul 08826, Republic of Korea
| | - Seung Yeon Lee
- Department of Chemistry, Seoul National University; Gwanak-gu, Seoul 08826, Republic of Korea
| | - Sangwon Park
- Department of Chemistry, Seoul National University; Gwanak-gu, Seoul 08826, Republic of Korea
| | - Hyungjun Park
- Department of Chemistry, Seoul National University; Gwanak-gu, Seoul 08826, Republic of Korea
| | - Jin Yong Lee
- Department of Chemistry, Sungkyunkwan University, Gyeonggi-do, Suwon 16419, Republic of Korea
| | - Zee Hwan Kim
- Department of Chemistry, Seoul National University; Gwanak-gu, Seoul 08826, Republic of Korea
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14
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Bejoy NB, Roy Chowdhury P, Patwari GN. Modulating the Roaming Dynamics for the NO Release in ortho-Nitrobenzenes. J Phys Chem Lett 2023; 14:2816-2822. [PMID: 36912644 DOI: 10.1021/acs.jpclett.3c00134] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
The dynamics of NO release upon photodissociation of nitroaromatic compounds is dependent on the nature of the interaction between the NO2 group and substituent in the ortho position. A bimodal (slow and fast) translational energy distribution of the NO photofragment indicates the presence of two distinct NO elimination channels. The slow-to-fast branching ratio for the NO release is regulated by the hydrogen bonding ability of the ortho substituent and follows the order [OH > NH2 > CH3 > OCH3], indicating that the intramolecular hydrogen bonding plays a pivotal role in NO release dynamics. Further, the topology of the triplet state potential energy surface acts as a doorway to the dissociation pathway switching between the roaming and nonroaming mechanisms, with hydrogen bonding substituents (OH and NH2) favoring the roaming mechanism.
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Affiliation(s)
- Namitha Brijit Bejoy
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Prahlad Roy Chowdhury
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - G Naresh Patwari
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
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15
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Raghava T, Chattopadhyay A, Bhavana P, Banerjee S. Amino-Terephthalonitrile-Based Single Benzene Fluorophores with Large Stokes Shifts and Solvatochromic Behavior. Chem Asian J 2023; 18:e202201314. [PMID: 36892161 DOI: 10.1002/asia.202201314] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Revised: 02/25/2023] [Indexed: 03/03/2023]
Abstract
We have synthesized a small library of blue-to-green emissive single benzene-based fluorophores (SBFs) in a short synthetic sequence. The molecules exhibit good Stokes shift in the range of 60-110 nm and select examples also possess very high fluorescence quantum yields of up to 87%. Theoretical investigations into the ground state and excited state geometries of many of these compounds reveal that good degree of planarization between the electron donor secondary amines and electron accepting benzodinitrile units can be achieved under certain solvatochromic conditions, giving rise to the strongly fluorescent behavior. On the other hand, the excited state geometry which lacks co-planarity of the donor amine and the single benzene moiety can open up a non-fluorescent channel. Additionally, in molecules with a dinitrobenzene acceptor, the perpendicular nitro moieties render the molecules completely non-emissive.
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Affiliation(s)
- Tanya Raghava
- Department of Chemistry, BITS Pilani K.K. Birla Goa Campus, NH 17B, Bypass Road, Zuarinagar, Goa, 403726, India
| | - Anjan Chattopadhyay
- Department of Chemistry, BITS Pilani K.K. Birla Goa Campus, NH 17B, Bypass Road, Zuarinagar, Goa, 403726, India
| | - Purushothaman Bhavana
- Department of Chemistry, BITS Pilani K.K. Birla Goa Campus, NH 17B, Bypass Road, Zuarinagar, Goa, 403726, India
| | - Subhadeep Banerjee
- Department of Chemistry, BITS Pilani K.K. Birla Goa Campus, NH 17B, Bypass Road, Zuarinagar, Goa, 403726, India
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16
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Vörös D, Mai S. Excited states of ortho-nitrobenzaldehyde as a challenging case for single- and multi-reference electronic structure theory. J Comput Chem 2023; 44:1381-1394. [PMID: 36825673 DOI: 10.1002/jcc.27093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 02/07/2023] [Accepted: 02/08/2023] [Indexed: 02/25/2023]
Abstract
We present a large set of vertical excitation calculations for the ortho-nitrobenzaldehyde (oNBA) molecule, which exhibits a very challenging excited-state electronic structure like other nitroaromatic compounds. The single-reference methods produce mostly consistent results up to about 5.5 eV. By contrast, the CAS second-order perturbation theory (CASPT2) results depend sensitively on the employed parameters. At the CAS self-consistent field level, the energies of the bright ππ * $$ {\pi \pi}^{\ast } $$ states are strongly overestimated while doubly excited states appear too low and mix with these ππ * $$ {\pi \pi}^{\ast } $$ states. This mixing hampers the CASPT2 step, leading to inconsistent results. Only by increasing the number of states in the state-averaging step to about 40-to cover all bright ππ * $$ {\pi \pi}^{\ast } $$ states embedded in the double excitations-and employing extended multistate CASPT2 could CASPT2 results consistent with experiment be obtained. We assign the four bands in the molecule's spectrum: The weakest band at 3.7 eV arises from the n NO 2 π * $$ {n}_{\mathrm{NO}2}{\pi}^{\ast } $$ states, the second one at 4.4 eV from the ππ * $$ {\pi \pi}^{\ast } $$ ( L b $$ {L}_b $$ ) state, the shoulder at 5.2 eV from the ππ * $$ {\pi \pi}^{\ast } $$ ( L a $$ {L}_a $$ ) state, and the maximum at 5.7 eV from the ππ * $$ {\pi \pi}^{\ast } $$ ( B a / B b $$ {B}_a/{B}_b $$ ) states. We also highlight the importance of modern wave function analysis techniques in elucidating the absorption spectrum of challenging molecules.
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Affiliation(s)
- Dóra Vörös
- Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Vienna, Austria.,Vienna Doctoral School in Physics, University of Vienna, Vienna, Austria
| | - Sebastian Mai
- Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Vienna, Austria
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17
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Osterloh WR, Desbois N, Gros CP, Kadish KM. Hypercorroles Formed via the Tail that Wagged the Dog: Charge Transfer Interactions from Innocent Corroles to Meso-Nitrophenyl Substituents. Inorg Chem 2022; 61:20576-20586. [DOI: 10.1021/acs.inorgchem.2c03425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- W. Ryan Osterloh
- ICMUB, UMR CNRS 6302, Université Bourgogne Franche-Comte, BP 47870, 21078 Dijon Cedex, France
- Department of Chemistry, University of Houston, Houston, Texas 77204-5003, United States
| | - Nicolas Desbois
- ICMUB, UMR CNRS 6302, Université Bourgogne Franche-Comte, BP 47870, 21078 Dijon Cedex, France
| | - Claude P. Gros
- ICMUB, UMR CNRS 6302, Université Bourgogne Franche-Comte, BP 47870, 21078 Dijon Cedex, France
| | - Karl M. Kadish
- Department of Chemistry, University of Houston, Houston, Texas 77204-5003, United States
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18
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Giussani A, Worth GA. On the photorelease of nitric oxide by nitrobenzene derivatives: A CASPT2//CASSCF model. J Chem Phys 2022; 157:204301. [PMID: 36456224 DOI: 10.1063/5.0125460] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Nitroaromatic compounds can photorelease nitric oxide after UV absorption. The efficiency of the photoreaction depends on the molecular structure, and two features have been pointed out as particularly important for the yield of the process: the presence of methyl groups at the ortho position with respect to the nitro group and the degree of conjugation of the molecule. In this paper, we provide a theoretical characterization at the CASPT2//CASSCF (complete active space second-order perturbation theory//complete active space self-consistent field) level of theory of the photorelease of NO for four molecules derived from nitrobenzene through the addition of ortho methyl groups and/or the elongation of the conjugation. Our previously described mechanism obtained for the photorelease of NO in nitrobenzene has been adopted as a model for the process. According to this model, the process proceeds through a reactive singlet-triplet crossing (STC) region that the system can reach from the triplet 3(πOπ*) minimum. The energy barrier that must be surmounted in order to populate the reactive STC can be associated with the efficiency of the photoreaction. Here, the obtained results display clear differences in the efficiency of the photoreaction in the studied systems and can be correlated with experimental results. Thus, the model proves its ability to highlight the differences in the photoreaction efficiency for the nitroaromatic compounds studied here.
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Affiliation(s)
- Angelo Giussani
- Instituto de Ciencia Molecular, Universitat de València, Apartado22085, ES-46071 Valencia, Spain
| | - Graham A Worth
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
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19
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Soto J, Algarra M. Electronic Structure of Nitrobenzene: A Benchmark Example of the Accuracy of the Multi-State CASPT2 Theory. J Phys Chem A 2021; 125:9431-9437. [PMID: 34677962 PMCID: PMC8573753 DOI: 10.1021/acs.jpca.1c04595] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
![]()
The electronic structure
of nitrobenzene (C6H5NO2) has been
studied by means of the complete active
space self-consistent field (CASSCF) and multi-state second-order
perturbation (MS-CASPT2) methods. To this end, an active space of
20 electrons distributed in 17 orbitals has been selected to construct
the reference wave function. In this work, we have calculated the
vertical excitation energies and the energy barrier for the dissociation
of the molecule on the ground state into phenyl and nitrogen dioxide.
After applying the corresponding vibrational corrections to the electronic
energies, it is demonstrated that the MS-CASPT2//CASSCF values obtained
in this work yield an excellent agreement between calculated and experimental
data. In addition, other active spaces of lower size have been applied
to the system in order to check the active space dependence in the
results.
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Affiliation(s)
- Juan Soto
- Department of Physical Chemistry, Faculty of Science, University of Málaga, Málaga 29071, Spain
| | - Manuel Algarra
- Department of Inorganic Chemistry, Faculty of Science, University of Málaga, Málaga 29071, Spain
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20
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Sadowski B, Kaliszewska M, Poronik YM, Czichy M, Janasik P, Banasiewicz M, Mierzwa D, Gadomski W, Lohrey TD, Clark JA, Łapkowski M, Kozankiewicz B, Vullev VI, Sobolewski AL, Piatkowski P, Gryko DT. Potent strategy towards strongly emissive nitroaromatics through a weakly electron-deficient core. Chem Sci 2021; 12:14039-14049. [PMID: 34760187 PMCID: PMC8565362 DOI: 10.1039/d1sc03670j] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 09/05/2021] [Indexed: 01/16/2023] Open
Abstract
Nitroaromatics seldom fluoresce. The importance of electron-deficient (n-type) conjugates, however, has inspired a number of strategies for suppressing the emission-quenching effects of the strongly electron-withdrawing nitro group. Here, we demonstrate how such strategies yield fluorescent nitroaryl derivatives of dipyrrolonaphthyridinedione (DPND). Nitro groups near the DPND core quench its fluorescence. Conversely, nitro groups placed farther from the core allow some of the highest fluorescence quantum yields ever recorded for nitroaromatics. This strategy of preventing the known processes that compete with photoemission, however, leads to the emergence of unprecedented alternative mechanisms for fluorescence quenching, involving transitions to dark nπ* singlet states and aborted photochemistry. Forming nπ* triplet states from ππ* singlets is a classical pathway for fluorescence quenching. In nitro-DPNDs, however, these ππ* and nπ* excited states are both singlets, and they are common for nitroaryl conjugates. Understanding the excited-state dynamics of such nitroaromatics is crucial for designing strongly fluorescent electron-deficient conjugates.
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Affiliation(s)
- Bartłomiej Sadowski
- Institute of Organic Chemistry, Polish Academy of Sciences Kasprzaka 44/52 01-224 Warsaw Poland
| | - Marzena Kaliszewska
- Faculty of Chemistry, University of Warsaw Zwirki i Wigury 101 02-089 Warsaw Poland
| | - Yevgen M Poronik
- Institute of Organic Chemistry, Polish Academy of Sciences Kasprzaka 44/52 01-224 Warsaw Poland
| | - Małgorzata Czichy
- Faculty of Chemistry, Silesian University of Technology Strzody 9 44-100 Gliwice Poland
| | - Patryk Janasik
- Faculty of Chemistry, Silesian University of Technology Strzody 9 44-100 Gliwice Poland
| | - Marzena Banasiewicz
- Institute of Physics, Polish Academy of Sciences Aleja Lotnikow 32/46 02-668 Warsaw Poland
| | - Dominik Mierzwa
- Institute of Organic Chemistry, Polish Academy of Sciences Kasprzaka 44/52 01-224 Warsaw Poland
| | - Wojciech Gadomski
- Faculty of Chemistry, University of Warsaw Zwirki i Wigury 101 02-089 Warsaw Poland
| | - Trevor D Lohrey
- Department of Chemistry, University of California Berkeley, 420 Latimer Hall Berkeley CA USA
- Chemical Sciences Division, Lawrence Berkeley National Laboratory 1 Cyclotron Road Berkeley CA USA
| | - John A Clark
- Department of Bioengineering, University of California Riverside, 900 University Ave. Riverside CA 92521 USA
| | - Mieczysław Łapkowski
- Faculty of Chemistry, Silesian University of Technology Strzody 9 44-100 Gliwice Poland
| | - Bolesław Kozankiewicz
- Institute of Physics, Polish Academy of Sciences Aleja Lotnikow 32/46 02-668 Warsaw Poland
| | - Valentine I Vullev
- Department of Bioengineering, University of California Riverside, 900 University Ave. Riverside CA 92521 USA
- Department of Chemistry, University of California Riverside, 900 University Ave. Riverside CA 92521 USA
- Department of Biochemistry, University of California Riverside, 900 University Ave. Riverside CA 92521 USA
- Materials Science and Engineering Program, University of California Riverside, 900 University Ave. Riverside CA 92521 USA
| | - Andrzej L Sobolewski
- Institute of Physics, Polish Academy of Sciences Aleja Lotnikow 32/46 02-668 Warsaw Poland
| | - Piotr Piatkowski
- Faculty of Chemistry, University of Warsaw Zwirki i Wigury 101 02-089 Warsaw Poland
| | - Daniel T Gryko
- Institute of Organic Chemistry, Polish Academy of Sciences Kasprzaka 44/52 01-224 Warsaw Poland
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21
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Rybicka-Jasińska K, Espinoza EM, Clark JA, Derr JB, Carlos G, Morales M, Billones MK, O'Mari O, Ågren H, Baryshnikov GV, Vullev VI. Making Nitronaphthalene Fluoresce. J Phys Chem Lett 2021; 12:10295-10303. [PMID: 34653339 PMCID: PMC8800371 DOI: 10.1021/acs.jpclett.1c02155] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Nitroaromatic compounds are inherently nonfluorescent, and the subpicosecond lifetimes of the singlet excited states of many small nitrated polycyclic aromatic hydrocarbons, such as nitronaphthalenes, render them unfeasible for photosensitizers and photo-oxidants, despite their immensely beneficial reduction potentials. This article reports up to a 7000-fold increase in the singlet-excited-state lifetime of 1-nitronaphthalene upon attaching an amine or an N-amide to the ring lacking the nitro group. Varying the charge-transfer (CT) character of the excited states and the medium polarity balances the decay rates along the radiative and the two nonradiative pathways and can make these nitronaphthalene derivatives fluoresce. The strong electron-donating amine suppresses intersystem crossing (ISC) but accommodates CT pathways of nonradiate deactivation. Conversely, the N-amide does not induce a pronounced CT character but slows down ISC enough to achieve relatively long lifetimes of the singlet excited state. These paradigms are key for the pursuit of electron-deficient (n-type) organic conjugates with promising optical characteristics.
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Affiliation(s)
| | - Eli M Espinoza
- Department of Chemistry, University of California, Riverside, California 92521, United States
| | - John A Clark
- Department of Bioengineering, University of California, Riverside, California 92521, United States
| | - James B Derr
- Department of Biochemistry, University of California, Riverside, California 92521, United States
| | - Gregory Carlos
- Department of Biology, University of California, Riverside, California 92521, United States
| | - Maryann Morales
- Department of Chemistry, University of California, Riverside, California 92521, United States
| | - Mimi Karen Billones
- Department of Biology, University of California, Riverside, California 92521, United States
| | - Omar O'Mari
- Department of Bioengineering, University of California, Riverside, California 92521, United States
| | - Hans Ågren
- Department of Physics and Astronomy, Uppsala University, SE-751 20 Uppsala, Sweden
| | - Glib V Baryshnikov
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, SE-60174 Norrköping, Sweden
| | - Valentine I Vullev
- Department of Bioengineering, University of California, Riverside, California 92521, United States
- Department of Chemistry, University of California, Riverside, California 92521, United States
- Department of Biochemistry, University of California, Riverside, California 92521, United States
- Materials Science and Engineering Program, University of California, Riverside, California 92521, United States
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22
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Saalbach L, Kotsina N, Crane SW, Paterson MJ, Townsend D. Ultraviolet Excitation Dynamics of Nitrobenzenes. J Phys Chem A 2021; 125:7174-7184. [PMID: 34379417 DOI: 10.1021/acs.jpca.1c04893] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Time-resolved photoelectron imaging was used to investigate nonadiabatic processes operating in the excited electronic states of nitrobenzene and three methyl-substituted derivatives: 3,5-, 2,6-, and 2,4-dimethylnitrobenzene. The primary goal was evaluating the dynamical impact of the torsional angle between the NO2 group and the benzene ring plane-something previously implicated in mediating the propensity for branching into different photodissociation pathways (NO vs NO2 elimination). Targeted, photoinitiated release of NO radicals is of interest for clinical medicine applications, and there is a need to establish basic structure-dynamics-function principles in systematically varied model systems following photoexcitation. Within our 200 ps experimental detection window, we observed no significant differences in the excited-state lifetimes exhibited by all species under study using a 267 nm pump and ionization with an intense 400 nm probe. In agreement with previous theoretical predictions, this suggests that the initial energy redistribution dynamics within the singlet and triplet manifolds are driven by motions localized predominantly on the NO2 group. Our findings also imply that both NO and NO2 elimination occur from a vibrationally hot ground state on extended (nanosecond) timescales, and any variations in NO vs NO2 branching upon site-selective methylation are due to steric effects influencing isomerization prior to dissociation.
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Affiliation(s)
- Lisa Saalbach
- Institute of Photonics & Quantum Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
| | - Nikoleta Kotsina
- Institute of Photonics & Quantum Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
| | - Stuart W Crane
- Institute of Photonics & Quantum Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
| | - Martin J Paterson
- Institute of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
| | - Dave Townsend
- Institute of Photonics & Quantum Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K.,Institute of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
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23
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Ivanov AV, Levi G, Jónsson EÖ, Jónsson H. Method for Calculating Excited Electronic States Using Density Functionals and Direct Orbital Optimization with Real Space Grid or Plane-Wave Basis Set. J Chem Theory Comput 2021; 17:5034-5049. [PMID: 34227810 DOI: 10.1021/acs.jctc.1c00157] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A direct orbital optimization method is presented for density functional calculations of excited electronic states using either a real space grid or a plane-wave basis set. The method is variational, provides atomic forces in the excited states, and can be applied to Kohn-Sham (KS) functionals as well as orbital-density-dependent (ODD) functionals including explicit self-interaction correction. The implementation for KS functionals involves two nested loops: (1) An inner loop for finding a stationary point in a subspace spanned by the occupied and a few virtual orbitals corresponding to the excited state; (2) an outer loop for minimizing the energy in a tangential direction in the space of the orbitals. For ODD functionals, a third loop is used to find the unitary transformation that minimizes the energy functional among occupied orbitals only. Combined with the maximum overlap method, the algorithm converges in challenging cases where conventional self-consistent field algorithms tend to fail. The benchmark tests presented include two charge-transfer excitations in nitrobenzene and an excitation of CO to degenerate π* orbitals where the importance of complex orbitals is illustrated. The application of this method to several metal-to-ligand charge-transfer and metal-centered excited states of an FeII photosensitizer complex is described, and the results are compared to reported experimental estimates. This method is also used to study the effect of the Perdew-Zunger self-interaction correction on valence and Rydberg excited states of several molecules, both singlet and triplet states, and the performance compared to semilocal and hybrid functionals.
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Affiliation(s)
- Aleksei V Ivanov
- Science Institute and Faculty of Physical Sciences, University of Iceland, VR-III, 107 Reykjavík, Iceland
| | - Gianluca Levi
- Science Institute and Faculty of Physical Sciences, University of Iceland, VR-III, 107 Reykjavík, Iceland
| | - Elvar Ö Jónsson
- Science Institute and Faculty of Physical Sciences, University of Iceland, VR-III, 107 Reykjavík, Iceland
| | - Hannes Jónsson
- Science Institute and Faculty of Physical Sciences, University of Iceland, VR-III, 107 Reykjavík, Iceland
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24
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Hait D, Head-Gordon M. Orbital Optimized Density Functional Theory for Electronic Excited States. J Phys Chem Lett 2021; 12:4517-4529. [PMID: 33961437 DOI: 10.1021/acs.jpclett.1c00744] [Citation(s) in RCA: 83] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Density functional theory (DFT) based modeling of electronic excited states is of importance for investigation of the photophysical/photochemical properties and spectroscopic characterization of large systems. The widely used linear response time-dependent DFT (TDDFT) approach is, however, not effective at modeling many types of excited states, including (but not limited to) charge-transfer states, doubly excited states, and core-level excitations. In this perspective, we discuss state-specific orbital optimized (OO) DFT approaches as an alterative to TDDFT for electronic excited states. We motivate the use of OO-DFT methods and discuss reasons behind their relatively restricted historical usage (vs TDDFT). We subsequently highlight modern developments that address these factors and allow efficient and reliable OO-DFT computations. Several successful applications of OO-DFT for challenging electronic excitations are also presented, indicating their practical efficacy. OO-DFT approaches are thus increasingly becoming a useful route for computing excited states of large chemical systems. We conclude by discussing the limitations and challenges still facing OO-DFT methods, as well as some potential avenues for addressing them.
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Affiliation(s)
- Diptarka Hait
- Kenneth S. Pitzer Center for Theoretical Chemistry, Department of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Martin Head-Gordon
- Kenneth S. Pitzer Center for Theoretical Chemistry, Department of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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25
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Loos PF, Comin M, Blase X, Jacquemin D. Reference Energies for Intramolecular Charge-Transfer Excitations. J Chem Theory Comput 2021; 17:3666-3686. [DOI: 10.1021/acs.jctc.1c00226] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Pierre-François Loos
- Laboratoire de Chimie et Physique Quantiques, Université de Toulouse, CNRS, UPS, F-31400 Toulouse, France
| | | | - Xavier Blase
- Univ. Grenoble Alpes, CNRS, Inst NEEL, F-38042 Grenoble, France
| | - Denis Jacquemin
- Université de Nantes, CNRS, CEISAM UMR 6230, F-44000 Nantes, France
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26
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Chen MC, Chen DG, Chou PT. Fluorescent Chromophores Containing the Nitro Group: Relatively Unexplored Emissive Properties. Chempluschem 2020; 86:11-27. [PMID: 33094565 DOI: 10.1002/cplu.202000592] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 10/05/2020] [Indexed: 12/13/2022]
Abstract
Apart from numerous applications, for example in azo dye precursors, explosives, and industrial processes, the nitro group (-NO2 ) appears on countless molecules in photochemical research owing to its unique characteristics such as a strong electron-withdrawing ability and facile conversion to the reduced substituent. Although it is well known as a fluorescence quencher, fluorescent chromophores that contain the nitro group have also emerged, with 3-nitrophenothiazine being recently reported to have 100 % emission quantum yield in nonpolar solvents. The diverse characters of nitro-containing chromophores motivated us to systematically review those chromophores with nitro substituents, their associated photophysical properties, and applications. In this Review, we succinctly elaborate the advance of the fluorescent nitro chromophores in fields of intramolecular charge transfer, fluorescent probes and nonlinear properties. Special attention is paid to the rationalization of the associated emission spectroscopy, so that the readers can gain insights into the structure-photophysics relationship and hence gain insights for the strategic design of nitro chromophores.
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Affiliation(s)
- Meng-Chi Chen
- Department of Chemistry, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei, 10617, Taiwan
| | - Deng-Gao Chen
- Department of Chemistry, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei, 10617, Taiwan
| | - Pi-Tai Chou
- Department of Chemistry, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei, 10617, Taiwan
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27
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Levi G, Ivanov AV, Jónsson H. Variational Density Functional Calculations of Excited States via Direct Optimization. J Chem Theory Comput 2020; 16:6968-6982. [DOI: 10.1021/acs.jctc.0c00597] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Gianluca Levi
- Science Institute and Faculty of Physical Sciences, University of Iceland, 107 Reykjavík, Iceland
| | - Aleksei V. Ivanov
- Science Institute and Faculty of Physical Sciences, University of Iceland, 107 Reykjavík, Iceland
- Saint Petersburg State University, 199034 Saint Petersburg, Russia
| | - Hannes Jónsson
- Science Institute and Faculty of Physical Sciences, University of Iceland, 107 Reykjavík, Iceland
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28
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Hait D, Haugen EA, Yang Z, Oosterbaan KJ, Leone SR, Head-Gordon M. Accurate prediction of core-level spectra of radicals at density functional theory cost via square gradient minimization and recoupling of mixed configurations. J Chem Phys 2020; 153:134108. [DOI: 10.1063/5.0018833] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Diptarka Hait
- Department of Chemistry, University of California, Berkeley, California 94720, USA
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Eric A. Haugen
- Department of Chemistry, University of California, Berkeley, California 94720, USA
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Zheyue Yang
- Department of Chemistry, University of California, Berkeley, California 94720, USA
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Katherine J. Oosterbaan
- Department of Chemistry, University of California, Berkeley, California 94720, USA
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Stephen R. Leone
- Department of Chemistry, University of California, Berkeley, California 94720, USA
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - Martin Head-Gordon
- Department of Chemistry, University of California, Berkeley, California 94720, USA
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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29
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Ashok Phadte A, Chattopadhyay A, Banerjee S, Singh Sisodiya D, Raghava T. Synthesis of Green Emitting Multi‐substituted Dibenzodioxins and Related Heteroacenes and Computational Investigation of Substituent Effects on Emission Spectra. ChemistrySelect 2020. [DOI: 10.1002/slct.202001999] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Apeksha Ashok Phadte
- Department of Chemistry BITS Pilani KK Birla Goa Campus NH 17B, Bypass Road Zuarinagar, Goa 403726 India
| | - Anjan Chattopadhyay
- Department of Chemistry BITS Pilani KK Birla Goa Campus NH 17B, Bypass Road Zuarinagar, Goa 403726 India
| | - Subhadeep Banerjee
- Department of Chemistry BITS Pilani KK Birla Goa Campus NH 17B, Bypass Road Zuarinagar, Goa 403726 India
| | - Dilawar Singh Sisodiya
- Department of Chemistry BITS Pilani KK Birla Goa Campus NH 17B, Bypass Road Zuarinagar, Goa 403726 India
| | - Tanya Raghava
- Department of Chemistry BITS Pilani KK Birla Goa Campus NH 17B, Bypass Road Zuarinagar, Goa 403726 India
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30
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Carter-Fenk K, Herbert JM. State-Targeted Energy Projection: A Simple and Robust Approach to Orbital Relaxation of Non-Aufbau Self-Consistent Field Solutions. J Chem Theory Comput 2020; 16:5067-5082. [DOI: 10.1021/acs.jctc.0c00502] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Kevin Carter-Fenk
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - John M. Herbert
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
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31
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Thurston R, Brister MM, Belkacem A, Weber T, Shivaram N, Slaughter DS. Time-resolved ultrafast transient polarization spectroscopy to investigate nonlinear processes and dynamics in electronically excited molecules on the femtosecond time scale. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2020; 91:053101. [PMID: 32486703 DOI: 10.1063/1.5144482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 04/12/2020] [Indexed: 06/11/2023]
Abstract
We report a novel experimental technique to investigate ultrafast dynamics in photoexcited molecules by probing the 3rd-order nonlinear optical susceptibility. A non-collinear 3-pulse scheme is developed to probe the ultrafast dynamics of excited electronic states using the optical Kerr effect. Optical homodyne and optical heterodyne detections are demonstrated to measure the 3rd-order nonlinear optical response for the S1 excited state of liquid nitrobenzene, which is populated by 2-photon absorption of a 780 nm 40 fs excitation pulse.
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Affiliation(s)
- Richard Thurston
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Matthew M Brister
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Ali Belkacem
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Thorsten Weber
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Niranjan Shivaram
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Daniel S Slaughter
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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32
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Thurston R, Brister MM, Tan LZ, Champenois EG, Bakhti S, Muddukrishna P, Weber T, Belkacem A, Slaughter DS, Shivaram N. Ultrafast Dynamics of Excited Electronic States in Nitrobenzene Measured by Ultrafast Transient Polarization Spectroscopy. J Phys Chem A 2020; 124:2573-2579. [DOI: 10.1021/acs.jpca.0c01943] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Richard Thurston
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Matthew M. Brister
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Liang Z. Tan
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Elio G. Champenois
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Graduate Group in Applied Science and Technology, University of California, Berkeley, Berkeley, California 94720, United States
| | - Said Bakhti
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Pavan Muddukrishna
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Thorsten Weber
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Ali Belkacem
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Daniel S. Slaughter
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Niranjan Shivaram
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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33
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Hait D, Head-Gordon M. Excited State Orbital Optimization via Minimizing the Square of the Gradient: General Approach and Application to Singly and Doubly Excited States via Density Functional Theory. J Chem Theory Comput 2020; 16:1699-1710. [PMID: 32017554 DOI: 10.1021/acs.jctc.9b01127] [Citation(s) in RCA: 99] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We present a general approach to converge excited state solutions to any quantum chemistry orbital optimization process, without the risk of variational collapse. The resulting square gradient minimization (SGM) approach only requires analytic energy/Lagrangian orbital gradients and merely costs 3 times as much as ground state orbital optimization (per iteration), when implemented via a finite difference approach. SGM is applied to both single determinant ΔSCF and spin-purified restricted open-shell Kohn-Sham (ROKS) approaches to study the accuracy of orbital optimized DFT excited states. It is found that SGM can converge challenging states where the maximum overlap method (MOM) or analogues either collapse to the ground state or fail to converge. We also report that ΔSCF/ROKS predict highly accurate excitation energies for doubly excited states (which are inaccessible via TDDFT). Singly excited states obtained via ROKS are also found to be quite accurate, especially for Rydberg states that frustrate (semi)local TDDFT. Our results suggest that orbital optimized excited state DFT methods can be used to push past the limitations of TDDFT to doubly excited, charge-transfer, or Rydberg states, making them a useful tool for the practical quantum chemist's toolbox for studying excited states in large systems.
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Affiliation(s)
- Diptarka Hait
- Kenneth S. Pitzer Center for Theoretical Chemistry, Department of Chemistry, University of California, Berkeley, California 94720, United States.,Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Martin Head-Gordon
- Kenneth S. Pitzer Center for Theoretical Chemistry, Department of Chemistry, University of California, Berkeley, California 94720, United States.,Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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34
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Giussani A, Worth GA. How important is roaming in the photodegradation of nitrobenzene? Phys Chem Chem Phys 2020; 22:15945-15952. [DOI: 10.1039/d0cp02077j] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Three pathways have been found for the formation of NO from nitrobenzene photodegradation that lead to either low or high translational energy, with a roaming mechanism involved at high excitation energies.
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Affiliation(s)
- Angelo Giussani
- Department of Chemistry
- University College London
- London WC1H 0AJ
- UK
| | - Graham A. Worth
- Department of Chemistry
- University College London
- London WC1H 0AJ
- UK
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35
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Levi G, Ivanov AV, Jónsson H. Variational calculations of excited states via direct optimization of the orbitals in DFT. Faraday Discuss 2020; 224:448-466. [DOI: 10.1039/d0fd00064g] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
A direct optimization method for obtaining excited electronic states using density functionals is presented.
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Affiliation(s)
- Gianluca Levi
- Science Institute and Faculty of Physical Sciences
- University of Iceland
- Iceland
| | - Aleksei V. Ivanov
- Science Institute and Faculty of Physical Sciences
- University of Iceland
- Iceland
- Saint Petersburg State University
- 199034 Saint Petersburg
| | - Hannes Jónsson
- Science Institute and Faculty of Physical Sciences
- University of Iceland
- Iceland
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36
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Lee J, Small DW, Head-Gordon M. Excited states via coupled cluster theory without equation-of-motion methods: Seeking higher roots with application to doubly excited states and double core hole states. J Chem Phys 2019; 151:214103. [DOI: 10.1063/1.5128795] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Joonho Lee
- Department of Chemistry, University of California, Berkeley, California 94720, USA and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - David W. Small
- Department of Chemistry, University of California, Berkeley, California 94720, USA and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Martin Head-Gordon
- Department of Chemistry, University of California, Berkeley, California 94720, USA and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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37
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Zobel JP, González L. Nonadiabatic Dynamics Simulation Predict Intersystem Crossing in Nitroaromatic Molecules on a Picosecond Time Scale. CHEMPHOTOCHEM 2019; 3:833-845. [PMID: 31681833 PMCID: PMC6813632 DOI: 10.1002/cptc.201900108] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Revised: 05/06/2019] [Indexed: 12/19/2022]
Abstract
Previous time-resolved spectroscopic experiments and static quantum-chemical calculations attributed nitronaphthalene derivatives one of the fastest time scales for intersystem crossing within organic molecules, reaching the 100 fs mark. Nonadiabatic dynamics simulations on three nitronaphthalene derivatives challenge this view, showing that the experimentally observed ∼100 fs process corresponds to internal conversion in the singlet manifolds. Intersystem crossing, instead, takes place on a longer time scale of ∼1 ps. The dynamics simulations further reveal that the spin transitions occur via two distinct pathways with different contribution for the three systems, which are determined by electronic factors and the torsion of the nitro group. This study, therefore, indicates that the existence of sub-picosecond intersystem crossing in other nitroaromatic molecules should be questioned.
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Affiliation(s)
- J. Patrick Zobel
- Division of Theoretical Chemistry, KemicentrumLund UniversityP.O. Box 124SE-221 00LundSweden
| | - Leticia González
- Institute of Theoretical ChemistryUniversity of ViennaWähringer Straße 17A-1090ViennaAustria
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38
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Blackshaw KJ, Ortega BI, Quartey NK, Fritzeen WE, Korb RT, Ajmani AK, Montgomery L, Marracci M, Vanegas GG, Galvan J, Sarvas Z, Petit AS, Kidwell NM. Nonstatistical Dissociation Dynamics of Nitroaromatic Chromophores. J Phys Chem A 2019; 123:4262-4273. [DOI: 10.1021/acs.jpca.9b02312] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- K. Jacob Blackshaw
- Department of Chemistry, The College of William and Mary, Williamsburg, Virginia 23187-8795, United States
| | - Belinda I. Ortega
- Department of Chemistry and Biochemistry, California State University—Fullerton, Fullerton, California 92834-6866, United States
| | - Naa-Kwarley Quartey
- Department of Chemistry, The College of William and Mary, Williamsburg, Virginia 23187-8795, United States
| | - Wade E. Fritzeen
- Department of Chemistry, The College of William and Mary, Williamsburg, Virginia 23187-8795, United States
| | - Robert T. Korb
- Department of Chemistry, The College of William and Mary, Williamsburg, Virginia 23187-8795, United States
| | - Annalise K. Ajmani
- Department of Chemistry, The College of William and Mary, Williamsburg, Virginia 23187-8795, United States
| | - Lehman Montgomery
- Department of Chemistry, The College of William and Mary, Williamsburg, Virginia 23187-8795, United States
| | - Marcus Marracci
- Department of Chemistry and Biochemistry, California State University—Fullerton, Fullerton, California 92834-6866, United States
| | - Geronimo Gudino Vanegas
- Department of Chemistry and Biochemistry, California State University—Fullerton, Fullerton, California 92834-6866, United States
| | - John Galvan
- Department of Chemistry and Biochemistry, California State University—Fullerton, Fullerton, California 92834-6866, United States
| | - Zach Sarvas
- Department of Chemistry and Biochemistry, California State University—Fullerton, Fullerton, California 92834-6866, United States
| | - Andrew S. Petit
- Department of Chemistry and Biochemistry, California State University—Fullerton, Fullerton, California 92834-6866, United States
| | - Nathanael M. Kidwell
- Department of Chemistry, The College of William and Mary, Williamsburg, Virginia 23187-8795, United States
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39
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Mewes SA, Dreuw A. Density-based descriptors and exciton analyses for visualizing and understanding the electronic structure of excited states. Phys Chem Chem Phys 2019; 21:2843-2856. [PMID: 30687866 DOI: 10.1039/c8cp07191h] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Analysis and interpretation of the electronic structure of excited electronic states are prerequisites for developing a fundamental understanding of photochemistry and optical properties of molecular systems and an everyday task for a computational photochemist. Hence, wavefunction-based and density-based analysis tools have been devised over the last decades, and most recently also a family of quantitative exciton-wavefunction based descriptors has been developed. While the latter represent the main focus of this perspective, they are also discussed in the context of other existing analysis methods. Exciton analysis bridges the gap between the physically intuitive exciton picture and complex quantum-chemical wavefunctions by yielding insightful quantitative descriptors like exciton size, hole and electron size, electron-hole distance and exciton correlation. Thereby, not only a comprehensive characterization of the electronic structure is provided, but moreover, the formalism is automatizable and thus also optimally suited for benchmarking excited-state electronic structure methods.
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Affiliation(s)
- Stefanie A Mewes
- Interdisciplinary Center for Scientific Computing, Im Neuenheimer Feld 205 A, 69120 Heidelberg, Germany.
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40
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Ciavardini A, Coreno M, Callegari C, Spezzani C, De Ninno G, Ressel B, Grazioli C, de Simone M, Kivimäki A, Miotti P, Frassetto F, Poletto L, Puglia C, Fornarini S, Pezzella M, Bodo E, Piccirillo S. Ultra-Fast-VUV Photoemission Study of UV Excited 2-Nitrophenol. J Phys Chem A 2019; 123:1295-1302. [DOI: 10.1021/acs.jpca.8b10136] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Alessandra Ciavardini
- Dipartimento di Chimica e Tecnologie del Farmaco, Università di Roma “La Sapienza”, Ple A. Moro, 5, 00185 Rome, Italy
- Dipartimento di Scienze e Tecnologie Chimiche, Università di Roma “Tor Vergata”, Via della Ricerca Scientifica, 00133 Rome, Italy
| | - Marcello Coreno
- ISM-CNR, in Basovizza Area Science Park, 34149 Trieste, Italy
- Elettra - Sincrotrone Trieste, ss. 14, Km. 163,5, 34149 Trieste, Italy
| | - Carlo Callegari
- Elettra - Sincrotrone Trieste, ss. 14, Km. 163,5, 34149 Trieste, Italy
| | - Carlo Spezzani
- Elettra - Sincrotrone Trieste, ss. 14, Km. 163,5, 34149 Trieste, Italy
| | - Giovanni De Ninno
- Elettra - Sincrotrone Trieste, ss. 14, Km. 163,5, 34149 Trieste, Italy
- Laboratory of Quantum Optics, University of Nova Gorica, Vipavska 11c, SI-5270 Ajdovščina, Slovenia
| | - Barbara Ressel
- Elettra - Sincrotrone Trieste, ss. 14, Km. 163,5, 34149 Trieste, Italy
- Laboratory of Quantum Optics, University of Nova Gorica, Vipavska 11c, SI-5270 Ajdovščina, Slovenia
| | - Cesare Grazioli
- Laboratorio TASV, IOM-CNR, Basovizza SS-14, km 163.5, 34012 Trieste, Italy
| | - Monica de Simone
- Laboratorio TASV, IOM-CNR, Basovizza SS-14, km 163.5, 34012 Trieste, Italy
| | - Antti Kivimäki
- Laboratorio TASV, IOM-CNR, Basovizza SS-14, km 163.5, 34012 Trieste, Italy
| | - Paolo Miotti
- Padova Research Unit, IFN-CNR, Via Trasea 7, I-35131 Padova, Italy
| | - Fabio Frassetto
- Padova Research Unit, IFN-CNR, Via Trasea 7, I-35131 Padova, Italy
| | - Luca Poletto
- Padova Research Unit, IFN-CNR, Via Trasea 7, I-35131 Padova, Italy
| | - Carla Puglia
- Department of Physics and Astronomy, Uppsala University, SE-75120 Uppsala, Sweden
| | - Simonetta Fornarini
- Dipartimento di Chimica e Tecnologie del Farmaco, Università di Roma “La Sapienza”, Ple A. Moro, 5, 00185 Rome, Italy
| | - Marco Pezzella
- Dipartimento di Chimica, Università di Roma “La Sapienza”, Ple A. Moro, 5, 00185 Rome, Italy
| | - Enrico Bodo
- Dipartimento di Chimica, Università di Roma “La Sapienza”, Ple A. Moro, 5, 00185 Rome, Italy
| | - Susanna Piccirillo
- Dipartimento di Scienze e Tecnologie Chimiche, Università di Roma “Tor Vergata”, Via della Ricerca Scientifica, 00133 Rome, Italy
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41
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Giussani A, Worth GA. Similar chemical structures, dissimilar triplet quantum yields: a CASPT2 model rationalizing the trend of triplet quantum yields in nitroaromatic systems. Phys Chem Chem Phys 2019; 21:10514-10522. [DOI: 10.1039/c9cp00705a] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
S1/S0 accessibility strongly influences the triplet quantum yields of nitronaphthalenes.
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Affiliation(s)
- Angelo Giussani
- Department of Chemistry
- University College London
- London WC1H 0AJ
- UK
| | - Graham A. Worth
- Department of Chemistry
- University College London
- London WC1H 0AJ
- UK
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42
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Mewes JM, Jerabek P, Bohle DS, Schwerdtfeger P. The Light-Driven Isomerization of Aqueous Nitrate: A Theoretical Perspective. CHEMPHOTOCHEM 2018. [DOI: 10.1002/cptc.201800022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Jan-Michael Mewes
- The New Zealand Institute for Advanced Study; Massey University (Albany); Private Bag 102904, North Shore, 0632 Auckland New Zealand
| | - Paul Jerabek
- The New Zealand Institute for Advanced Study; Massey University (Albany); Private Bag 102904, North Shore, 0632 Auckland New Zealand
| | - D. Scott Bohle
- The Department of Chemistry; McGill University; 801 Sherbrooke St. W Montreal H3A 8B0 Canada
| | - Peter Schwerdtfeger
- The New Zealand Institute for Advanced Study; Massey University (Albany); Private Bag 102904, North Shore, 0632 Auckland New Zealand
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43
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A Photophysical Deactivation Channel of Laser-Excited TATB Based on Semiclassical Dynamics Simulation and TD-DFT Calculation. Molecules 2018; 23:molecules23071593. [PMID: 29966325 PMCID: PMC6099943 DOI: 10.3390/molecules23071593] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 06/23/2018] [Accepted: 06/28/2018] [Indexed: 12/02/2022] Open
Abstract
A deactivation channel for laser-excited 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) was studied by semiclassical dynamics. Results indicate that the excited state resulting from an electronic transition from the highest occupied molecular orbital (HOMO) to the lowest unoccupied molecular mrbital (LUMO) is deactivated via pyramidalization of the activated N atom in a nitro group, with a lifetime of 2.4 ps. An approximately 0.5-electron transfer from the aromatic ring to the activated nitro group led to a significant increase of the C–NO2 bond length, which suggests that C–NO2 bond breaking could be a trigger for an explosive reaction. The time-dependent density functional theory (TD-DFT) method was used to calculate the energies of the ground and S1 excited states for each configuration in the simulated trajectory. The S1←S0 energy gap at the instance of non-adiabatic decay was found to be 0.096 eV, suggesting that the decay geometry is close to the conical intersection.
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44
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Gudem M, Hazra A. Intersystem Crossing Drives Photoisomerization in o-Nitrotoluene, a Model for Photolabile Caged Compounds. J Phys Chem A 2018; 122:4845-4853. [PMID: 29733607 DOI: 10.1021/acs.jpca.8b03439] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
o-Nitrobenzyl (oNB) derivatives are widely used photolabile caged compounds in chemical and biological applications. The primary step in the photoinduced deprotection is an excited state intramolecular hydrogen transfer (ESIHT) leading to tautomerization of the oNB compound and subsequent release of the protecting group. The prototype molecule for studying such ESIHT is o-nitrotoluene (oNT), where hydrogen transfers from the methyl to the nitro group. Using the complete active space self-consistent field (CASSCF) method with second-order perturbative energy corrections (CASPT2), we have comprehensively investigated the photoisomerization and photo decay mechanisms in oNT. We have obtained the minimum energy crossing points (MECPs) between relevant electronic states and identified the singlet and triplet pathways. There is a barrierless path for oNT to relax to the lowest triplet state. In this T1 state, the ESIHT products are more stable than T1 oNT. Hydrogen-transfer occurs on the T1 state followed by relaxation to the ground state to give the isomerized product. A biradical intermediate proposed by previous studies is characterized to be the hydrogen-transferred T1 product. On the singlet pathway, in contrast to the triplet, the ground state tautomer is formed from the S1 oNT through a geometrically distant and energetically higher S1/S0 conical intersection. Although nonadiabatic dynamical studies are essential for determining branching ratios, our study, which considers the accessibility of different MECPs based on geometry and energy, and the magnitude of spin-orbit coupling at singlet-triplet MECPs, suggests that a significant fraction of the isomerization yield is due to the triplet channel.
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Affiliation(s)
- Mahesh Gudem
- Department of Chemistry , Indian Institute of Science Education and Research Pune , Dr. Homi Bhabha Road , Pune 411008 , Maharashtra , India
| | - Anirban Hazra
- Department of Chemistry , Indian Institute of Science Education and Research Pune , Dr. Homi Bhabha Road , Pune 411008 , Maharashtra , India
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45
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Mewes JM. Modeling TADF in organic emitters requires a careful consideration of the environment and going beyond the Franck-Condon approximation. Phys Chem Chem Phys 2018; 20:12454-12469. [PMID: 29700532 DOI: 10.1039/c8cp01792a] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The origin of the thermally-activated delayed fluorescence (TADF) of three organic emitters is investigated, focusing on the nature of the lowest excited states, their transition properties, as well as the role of the environment. For this purpose, the algebraic-diagrammatic construction for the polarization propagator at second order of perturbation theory [ADC(2)], time-dependent density-functional theory in the Tamm-Dancoff approximation (TDA) and unrestricted Kohn-Sham DFT in combination with the maximum-overlap method (ΔDFT) are employed. The influence of the dielectric environment is rigorously included using different variants of the polarizable continuum model. The calculations reveal the lowest excited singlet and triplet states of all studied emitters to be dominated by charge-transfer (CT) character already in the most apolar environment corresponding to cyclo-hexane. The dielectric stabilization entails a drastic reduction of the singlet-triplet gaps, increasing the calculated TADF rates by several orders of magnitude. Another ingredient for accurate TADF rates is hidden in the excited-state potential-energy surfaces along the donor-acceptor twisting angle. A presence of large, shallow plateaus in apolar environments causes the transition properties to be governed by thermal fluctuations rather than the minimum-energy geometries. This leads to a large increase of the oscillator strengths, as well as a breakdown of the Franck-Condon approximation. The last ingredient is a small but significant spin-orbit coupling (SOC) between the singlet and triplet CT states, which is traced back to a delocalization of the excitation hole or excited electron of the triplet CT state. Taking into account all of these effects, a reasonable agreement with experimental TADF and fluorescence lifetimes is obtained. For this, it proves to be sufficient to consider only the lowest lying singlet and triplet excited states.
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Affiliation(s)
- Jan-Michael Mewes
- Jan-Michael Mewes, Centre For Theoretical Chemistry and Physics, New-Zealand Institute for Advanced Study, Massey University (Albany), Private Bag 102-904, North Shore Mail Centre, 0632 Auckland, New Zealand.
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Dobrowolski JC, Lipiński PFJ, Karpińska G. Substituent Effect in the First Excited Singlet State of Monosubstituted Benzenes. J Phys Chem A 2018; 122:4609-4621. [PMID: 29698609 DOI: 10.1021/acs.jpca.8b02209] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
sEDA, pEDA, and cSAR descriptors of the substituent effect were determined for >30 monosubstituted benzenes in the first excited singlet S1 state at the LC-ωB97XD/aug-cc-pVTZ level. It was found that in the S1 state, the σ- and π-valence electrons are a bit less and a bit more affected, respectively, than in the S0 state, but basically, the effect in both states remains the same. In the S0 and S1 states, the d(C-X) distances to the substituent's first atom and the ring perimeter correlate with the sEDA and pEDA in the appropriate states, respectively. The energies and the gap of the frontier orbitals in the two states are linearly correlated and for the HOMO(S1), LUMO(S1), and HOMO(S1)-LUMO(S1) gap correlate also with the pEDA(S1) and cSAR(S1) descriptors. In all studied correlations, three similar groups of substituents can be distinguished, for which correlations (i) are very good, (ii) deviate slightly, and (iii) deviate significantly. Comparison of the shape of the HOMO(S0) and HOMO(S1) orbitals shows that for case (i) HOMO orbitals exhibit almost perfect antisymmetry against the benzene plane, for case (ii) the antisymmetry of HOMO in one of the states is either perturbed or changed, and for case (iii) one HOMO state has σ-character.
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Affiliation(s)
- Jan Cz Dobrowolski
- Department for Medicines Biotechnology and Bioinformatics , National Medicines Institute , 30/34 Chełmska Street , 00-725 Warsaw , Poland
| | - Piotr F J Lipiński
- Department of Neuropeptides , Mossakowski Medical Research Centre PAS , 5 Pawińskiego Street , 02-106 Warsaw , Poland
| | - Grażyna Karpińska
- Department for Medicines Biotechnology and Bioinformatics , National Medicines Institute , 30/34 Chełmska Street , 00-725 Warsaw , Poland
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Michenfelder NC, Ernst HA, Schweigert C, Olzmann M, Unterreiner AN. Ultrafast stimulated emission of nitrophenolates in organic and aqueous solutions. Phys Chem Chem Phys 2018; 20:10713-10720. [PMID: 29340390 DOI: 10.1039/c7cp07774b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Early-time dynamics of nitroaromatics and its coressponding bases can give valuable insights into photo-induced reactions relevant to atmospheric and environmental processes. In this work, femtosecond broadband absorption spectroscopy between 350 and 700 nm has been applied to explore the ultrafast dynamics of o-, p- and m-nitrophenol anions (NP-) in basic organic and aqueous solution. Excitation at 400 nm promotes these compounds into the first bright electronic singlet state, which is a charge-transfer state. A surprising finding for all nitrophenolates was a characteristic, spectrally broad stimulated emission (SE) from the electronically excited state into the ground state. The corresponding lifetime was on the order of a few hundred femtoseconds for o- and p-NP- while it was roughly ten times larger for m-NP-. In line with earlier observations, the SE is governed by an out-of-plane torsional motion of the nitro group, leading to a close energetic approach of the relevant electronically excited singlet and ground states. Subsequent dynamics can be assigned to excited state absorption and ground state relaxation due to energy dissipation of the vibrational modes to the solvent that occur for up to several tens of picoseconds. No longer-lasting transient absorption (TA) was found; instead, a complete recovery of the ground state bleaching was observed indicating that triplet state relaxation is either not significantly involved in this spectral part or shifted to other regions. In the aqueous system, time constants for all processes are much smaller than in organic solution, a fact that can be explained by the larger dipole moment of the solvent and the correspondingly stronger intermolecular coupling between NP- and the aqueous solvent.
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Affiliation(s)
- N C Michenfelder
- Institut für Physikalische Chemie, Karlsruher Institut für Technologie (KIT), Kaiserstr. 12, 76131 Karlsruhe, Germany.
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Zobel JP, Nogueira JJ, González L. Mechanism of Ultrafast Intersystem Crossing in 2-Nitronaphthalene. Chemistry 2018; 24:5379-5387. [PMID: 29377370 PMCID: PMC5947663 DOI: 10.1002/chem.201705854] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2017] [Indexed: 01/10/2023]
Abstract
Nitronaphthalene derivatives efficiently populate their electronically excited triplet states upon photoexcitation through ultrafast intersystem crossing (ISC). Despite having been studied extensively by time-resolved spectroscopy, the reasons behind their ultrafast ISC remain unknown. Herein, we present the first ab initio nonadiabatic molecular dynamics study of a nitronaphthalene derivative, 2-nitronaphthalene, including singlet and triplet states. We find that there are two distinct ISC reaction pathways involving different electronic states at distinct nuclear configurations. The high ISC efficiency is explained by the very small electronic and nuclear alterations that the chromophore needs to undergo during the singlet-triplet transition in the dominating ISC pathway after initial dynamics in the singlet manifold. The insights gained in this work are expected to shed new light on the photochemistry of other nitro polycyclic aromatic hydrocarbons that exhibit ultrafast intersystem crossing.
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Affiliation(s)
- J. Patrick Zobel
- Institute of Theoretical Chemistry, Faculty of ChemistryUniversity of ViennaWähringer Straße 171090ViennaAustria
| | - Juan J. Nogueira
- Institute of Theoretical Chemistry, Faculty of ChemistryUniversity of ViennaWähringer Straße 171090ViennaAustria
| | - Leticia González
- Institute of Theoretical Chemistry, Faculty of ChemistryUniversity of ViennaWähringer Straße 171090ViennaAustria
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Penfold TJ, Gindensperger E, Daniel C, Marian CM. Spin-Vibronic Mechanism for Intersystem Crossing. Chem Rev 2018; 118:6975-7025. [DOI: 10.1021/acs.chemrev.7b00617] [Citation(s) in RCA: 401] [Impact Index Per Article: 66.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Thomas J. Penfold
- Chemistry - School of Natural and Environmental Sciences, Newcastle University, Newcastle Upon-Tyne NE1 7RU, United Kingdom
| | - Etienne Gindensperger
- Laboratoire de Chimie Quantique, Institut de Chimie UMR-7177, CNRS - Université de Strasbourg, 1 Rue Blaise Pascal 67008 Strasbourg, France
| | - Chantal Daniel
- Laboratoire de Chimie Quantique, Institut de Chimie UMR-7177, CNRS - Université de Strasbourg, 1 Rue Blaise Pascal 67008 Strasbourg, France
| | - Christel M. Marian
- Institut für Theoretische Chemie, Heinrich-Heine-Universität Düsseldorf, Universitätsstrasse 1, 40225 Düsseldorf, Germany
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Stepwise photoinduced transformation of fused aziridines via stable biradicals and azomethine ylides. J Photochem Photobiol A Chem 2018. [DOI: 10.1016/j.jphotochem.2017.11.053] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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