1
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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. [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)⋆ $$ {}^{\star } $$ , 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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2
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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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3
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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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4
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Wang PY, Hsu YC, Chen PH, Chen GY, Liao YK, Cheng PY. Solvent-polarity dependence of ultrafast excited-state dynamics of trans-4-nitrostilbene. Phys Chem Chem Phys 2024; 26:788-807. [PMID: 38088777 DOI: 10.1039/d3cp05245a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2023]
Abstract
Ultrafast excited-state dynamics of the simplest nitrostilbenes, namely trans-4-nitrostilbene (t-NSB), was studied in solvents of various polarities with ultrafast broadband time-resolved fluorescence and transient absorption spectroscopies, and by quantum-chemical computations. The results revealed that the initially excited S1(ππ*) state deactivation dynamics is strongly influenced by the solvent polarity. Specifically, the t-NSB S1-state lifetime decreases by three orders of magnitude from ∼60 ps in high-polarity solvents to ∼60 fs in nonpolar solvents. The strong solvent-polarity dependence arises from the differences in dipole moments among the S1 and relevant states, including the major intersystem crossing (ISC) receiver triplet states, and therefore, the solvent polarity can modulate their relative energies and ISC rates. In nonpolar solvents, the sub-100 fs lifetime is due to a combination of efficient ISC and internal conversion. In medium-polarity solvents, the S1-state population decays via a competing ISC relaxation mechanism in a biphasic manner, and the ISC rates are found to obey the inverse energy gap law of the strong coupling case. In high-polarity solvents, the S1 state is stabilized to a much lower energy such that ISC becomes energetically infeasible, and the S1 state decays via barrier crossing along the torsion angle of the central ethylenic bond to the nonfluorescent perpendicular configuration. Regardless of the initial S1-state deactivation pathways in various solvents, the excited-state population is ultimately trapped in the metastable T1-state perpendicular configuration, at which a slower ISC occurs to bring the system to the ground state and bifurcate into either trans or cis form of NSB.
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Affiliation(s)
- Peng-Yun Wang
- Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan, 30043, Republic of China.
| | - Yu-Cheng Hsu
- Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan, 30043, Republic of China.
| | - Pin-Hsun Chen
- Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan, 30043, Republic of China.
| | - Guan-Yu Chen
- Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan, 30043, Republic of China.
| | - Yi-Kai Liao
- Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan, 30043, Republic of China.
| | - Po-Yuan Cheng
- Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan, 30043, Republic of China.
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5
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Dalton AB, Fishman DA, Nizkorodov SA. Ultrafast Excited-State Proton Transfer in 4-Nitrocatechol: Implications for the Photochemistry of Nitrophenols. J Phys Chem A 2023; 127:8307-8315. [PMID: 37773630 DOI: 10.1021/acs.jpca.3c04322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/01/2023]
Abstract
Nitrophenols are a class of environmental contaminants that exhibit strong absorption at atmospherically relevant wavelengths, prompting many studies of their photochemical degradation rates and mechanisms. Despite the importance of photochemical reactions of nitrophenols in the environment, the ultrafast processes in electronically excited nitrophenols are not well understood. Here, we present an experimental study of ultrafast electron dynamics in 4-nitrocatechol (4NC), a common product of biomass burning and fossil fuel combustion. The experiments are accompanied by time-dependent quantum mechanical calculations to help assign the observed transitions in static and transient absorption spectra and to estimate the rates of singlet-to-triplet intersystem crossing. Our results suggest that electronic triplet states are not efficiently populated upon 340 nm excitation, as efficient proton transfer occurs in the excited state on a time scale of a few picoseconds in water and tens of picoseconds in 2-propanol. This suggests that triplet states do not play a significant role in the photochemical reactions of 4NC in the environment and, by extension, in nitrophenols in general. Instead, consideration should be given to the idea that this class of molecules may serve as strong photoacids.
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Affiliation(s)
- Avery B Dalton
- Department of Chemistry, University of California, Irvine, Irvine, California 92697, United States
| | - Dmitry A Fishman
- Department of Chemistry, University of California, Irvine, Irvine, California 92697, United States
| | - Sergey A Nizkorodov
- Department of Chemistry, University of California, Irvine, Irvine, California 92697, United States
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6
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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: 0] [Impact Index Per Article: 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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7
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A combined theoretical and experimental study of photo-induced intramolecular hydrogen transfer of 2,4,6-trinitrotoluene. FIREPHYSCHEM 2022. [DOI: 10.1016/j.fpc.2022.12.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
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8
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Liu R, Shang F, Xiong Y, Zhang C, Yang S, Zhou P, Liu J. A combined experimental and theoretical investigation of the excited-state dynamics of 2,4,6-trinitrotoluene (TNT) in DMSO solvent. Phys Chem Chem Phys 2021; 23:20718-20723. [PMID: 34516599 DOI: 10.1039/d1cp01782a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In the present contribution we carried out a TDDFT and femtosecond transient absorption study of the excited state dynamics of TNT in DMSO solvent. Vertical excitation and excited state relaxation were calculated at the SMD/M06-2X/TZVP level of theory. The electron absorption spectrum for the DMSO solvated TNT was calculated and compared with the experimental results. The results of the electronic excitation energies and the spin-orbital constants imply an intersystem crossing for the S1-T2 transition. The femtosecond time-resolved transient absorption measurements of the TNT in DMSO show the presence of two absorption signals around 650 nm and 540 nm, which are assigned to the population in the lowest singlet and triplet excited states, S1 and T1, respectively. The fast decay of the S1 state population is assigned to an efficient S1-T2 intersystem crossing, which soon internally converts to the T1 state. The slow decay of the T1 population is attributed to the nonradiative transition to the S0 state. The combined theoretical and experimental results present a mechanistic view of the photophysical dynamics of TNT in DMSO solution.
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Affiliation(s)
- Runze Liu
- Institute of Molecular Sciences and Engineering, Shandong University, Qingdao 266235, P. R. China.
| | - Fangjian Shang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, P. R. China. .,University of the Chinese Academy of Sciences, Beijing 10049, P. R. China
| | - Ying Xiong
- Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang 621900, P. R. China
| | - Chaoyang Zhang
- Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang 621900, P. R. China
| | - Songqiu Yang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, P. R. China.
| | - Panwang Zhou
- Institute of Molecular Sciences and Engineering, Shandong University, Qingdao 266235, P. R. China.
| | - Jianyong Liu
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, P. R. China.
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9
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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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10
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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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11
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Sviatenko LK, Gorb L, Leszczynski J, Leszczynska D, Okovytyy SI, Shukla MK. A density functional theory investigation of degradation of Nitroguanidine in the photoactivated triplet state. J Mol Model 2019; 25:372. [PMID: 31792603 DOI: 10.1007/s00894-019-4252-8] [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: 07/28/2019] [Accepted: 11/12/2019] [Indexed: 11/28/2022]
Abstract
It is well known that nitroguanidine (NQ) undergoes photodegradation when exposed to UV-radiation. However, the mechanism of NQ photolysis is not fully understood. Earlier investigations have shown that nitrocompounds undergo to their triplet state population through crossing of electronic singlet and triplet excited state potential energy surfaces due to the nitrogroup rotation and nonplanarity under electronic excitation. Therefore, it is expected that under electronic excitation, the presence of nitrogroup in NQ would also lead to the population of electronic lowest energy triplet state. To shed a light on the degradation of NQ in alkaline solution under electronic excitation, we performed a detailed investigation of a possible degradation mechanism at the IEFPCM/B3LYP/6-311++G(d,p) level in the electronic lowest energy triplet state. We found that degradation ability of NQ in the electronic triplet state would be significantly larger than in the electronic ground singlet state. It was revealed that the photodecomposition of nitroguanidine might occur through several pathways involving N-N and C-N bond ruptures, nitrite elimination, and hydroxide ion attachment. Nitrogen of nitrogroup would be released in the form of nitrite and nitrogen (I) oxide. Computationally predicted intermediates and products of nitroguanidine photolysis such as nitrite, hydroxyguanidine, cyanamide, and urea correspond to experimentally observed species.
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Affiliation(s)
- Liudmyla K Sviatenko
- Department of General and Biological Chemistry N2, Donetsk National Medical University, 1 Velyka Perspectyvna Str., Kropyvnytskyi, 25015, Ukraine
| | - Leonid Gorb
- Institute of Molecular Biology and Genetics, NAS of Ukraine, 150 Zabolotny Str, Kyiv, 03143, Ukraine
| | - Jerzy Leszczynski
- Interdisciplinary Nanotoxicity Center, Department of Chemistry, Physics and Atmospheric Sciences, Jackson State University, 1400 J.R. Lynch Street, Jackson, MS, 39217, USA.
| | - Danuta Leszczynska
- Department of Civil and Environmental Engineering, Interdisciplinary Center for Nanotoxicity, Jackson State University, Jackson, MS, 39217, USA
| | - Sergiy I Okovytyy
- Department of Organic Chemistry, Oles Honchar Dnipro National University, Dnipro, 49010, Ukraine
| | - Manoj K Shukla
- US Army Engineer Research and Development Center, Vicksburg, MS, 39180, USA.
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12
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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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13
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Tang L, Fang C. Nitration of Tyrosine Channels Photoenergy through a Conical Intersection in Water. J Phys Chem B 2019; 123:4915-4928. [PMID: 31094198 DOI: 10.1021/acs.jpcb.9b03464] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Nitration of tyrosine occurs under oxidative stress in vivo. The product, 3-nitrotyrosine (3NY), has a dramatically decreased quantum yield and can be used as a molecular ruler. In this study, femtosecond transient absorption spectroscopy and quantum calculations were implemented to elucidate the photoinduced relaxation processes of anionic 3NY in water. Upon 400 nm excitation into an excited electronic state with notable charge-transfer (CT) character, a barrierless nitro-twisting motion rapidly (<100 fs) guides the chromophore into an adjacent twisted intramolecular CT state, therein reaching a sloped S1/S0 conical intersection on the ∼100 fs time scale. Once in the hot ground state, excess energy is further released through vibrational cooling with biexponential time constants of ∼140 and 680 fs in water. Nitro back-twisting occurs on longer time scales (∼1.1 and 9 ps in water), returning the system to original ground state. Systematic evaluations of excited-state potential energies of anionic 3NY were performed by density functional theory (DFT) and time-dependent DFT calculations, showing that intersystem crossing (ISC) from the first singlet state (S1) to the first or second triplet state (T1 or T2) is unlikely. Inclusion of an explicit water molecule in calculations leads to improved mapping of the excited-state energy ordering of the second singlet state (S2) and T2, further diminishing ISC probability from S1 and favoring an ultrafast internal conversion to S0. These results provide deep insights into the highly efficient nonradiative decay of anionic 3NY in aqueous solution, with nitro-site-specific information that can help infer the characterization and potential optogenetic control of 3NY in protein environment.
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Affiliation(s)
- Longteng Tang
- Department of Chemistry , Oregon State University , 153 Gilbert Hall , Corvallis , Oregon 97331-4003 , United States
| | - Chong Fang
- Department of Chemistry , Oregon State University , 153 Gilbert Hall , Corvallis , Oregon 97331-4003 , United States
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14
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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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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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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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18
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Xu C, Gu FL, Zhu C. Ultrafast intersystem crossing for nitrophenols: ab initio nonadiabatic molecular dynamics simulation. Phys Chem Chem Phys 2018; 20:5606-5616. [DOI: 10.1039/c7cp08601f] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ultrafast intersystem crossing mechanisms for two p- and m-nitrophenol groups (PNP and MNP) have been investigated using ab initio nonadiabatic molecular dynamics simulations at the 6SA-CASSCF level of theory.
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Affiliation(s)
- Chao Xu
- Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education; School of Chemistry & Environment of South China Normal University
- Guangzhou 51006
- P. R. China
| | - Feng Long Gu
- Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education; School of Chemistry & Environment of South China Normal University
- Guangzhou 51006
- P. R. China
| | - Chaoyuan Zhu
- Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education; School of Chemistry & Environment of South China Normal University
- Guangzhou 51006
- P. R. China
- Department of Applied Chemistry, Institute of Molecular Science and Center for Interdisciplinary Molecular Science, National Chiao-Tung University
- Hsinchu 30010
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Giussani A, Worth GA. Insights into the Complex Photophysics and Photochemistry of the Simplest Nitroaromatic Compound: A CASPT2//CASSCF Study on Nitrobenzene. J Chem Theory Comput 2017; 13:2777-2788. [DOI: 10.1021/acs.jctc.6b01149] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Angelo Giussani
- School
of Chemistry, University of Birmingham, Edgbaston B15 2TT, U.K
- Department
of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, U.K
| | - Graham A. Worth
- School
of Chemistry, University of Birmingham, Edgbaston B15 2TT, U.K
- Department
of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, U.K
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20
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Shukla MK. Computational prediction of electronic excited-state structures and properties of 2,4-dinitroanisole (DNAN). Struct Chem 2016. [DOI: 10.1007/s11224-015-0736-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Zobel JP, Nogueira JJ, González L. Quenching of Charge Transfer in Nitrobenzene Induced by Vibrational Motion. J Phys Chem Lett 2015; 6:3006-3011. [PMID: 26267195 DOI: 10.1021/acs.jpclett.5b00990] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Although nitrobenzene is the smallest nitro-aromatic molecule, the nature of its electronic structure is still unclear. Most notably, the lowest-energy absorption band was assessed in numerous studies providing conflicting results regarding its charge-transfer character. In this study, we employ a combination of molecular dynamics and quantum chemical methods to disentangle the nature of the lowest-energy absorption band of nitrobenzene. Surprisingly, the charge-transfer transition from the benzene moiety to the nitro group is found to be quenched by a flow of charge into the opposite direction induced by vibrational motion. Beyond clarifying the charge-transfer character of nitrobenzene, we show that the widely used approach of analyzing the ground-state minimum-energy geometry provides completely wrong conclusions.
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Affiliation(s)
- J Patrick Zobel
- Institute of Theoretical Chemistry, University of Vienna, Währinger Straße 17, A-1090 Vienna, Austria
| | - Juan J Nogueira
- Institute of Theoretical Chemistry, University of Vienna, Währinger Straße 17, A-1090 Vienna, Austria
| | - Leticia González
- Institute of Theoretical Chemistry, University of Vienna, Währinger Straße 17, A-1090 Vienna, Austria
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23
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A theoretical investigation of the competition between hydrogen bonding and lone pair⋯π interaction in complexes of TNT with NH3. COMPUT THEOR CHEM 2015. [DOI: 10.1016/j.comptc.2015.04.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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24
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Mosca L, Khnayzer RS, Lazorski MS, Danilov EO, Castellano FN, Anzenbacher P. Sensing of 2,4,6-Trinitrotoluene (TNT) and 2,4-Dinitrotoluene (2,4-DNT) in the Solid State with Photoluminescent RuIIand IrIIIComplexes. Chemistry 2015; 21:4056-64. [DOI: 10.1002/chem.201405717] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Indexed: 11/09/2022]
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25
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Quantum mechanical and experimental analyses of TNT metabolite 2-hydroxylamino-4,6-dinitrotoluene. J Mol Struct 2015. [DOI: 10.1016/j.molstruc.2014.09.058] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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26
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27
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Synthesis of 32-nitro-chlorophyll-a derivatives and their electronic absorption/emission data. Tetrahedron 2014. [DOI: 10.1016/j.tet.2014.01.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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28
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Mewes JM, Jovanović V, Marian CM, Dreuw A. On the molecular mechanism of non-radiative decay of nitrobenzene and the unforeseen challenges this simple molecule holds for electronic structure theory. Phys Chem Chem Phys 2014; 16:12393-406. [DOI: 10.1039/c4cp01232a] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We present a complete mechanistic picture of the non-radiative relaxation of nitrobenzene via IC and ISC along three internal coordinates.
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Affiliation(s)
- Jan-M. Mewes
- Interdisciplinary Center for Scientific Computing
- Ruprecht-Karls University
- 69120 Heidelberg, Germany
| | - Vladimir Jovanović
- Institut für Theoretische Chemie und Computerchemie
- Gebäude 26.32 Raum 03.40 und 03.42
- 40225 Düsseldorf, Germany
| | - Christel M. Marian
- Institut für Theoretische Chemie und Computerchemie
- Gebäude 26.32 Raum 03.40 und 03.42
- 40225 Düsseldorf, Germany
| | - Andreas Dreuw
- Interdisciplinary Center for Scientific Computing
- Ruprecht-Karls University
- 69120 Heidelberg, Germany
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Vogt RA, Reichardt C, Crespo-Hernández CE. Excited-State Dynamics in Nitro-Naphthalene Derivatives: Intersystem Crossing to the Triplet Manifold in Hundreds of Femtoseconds. J Phys Chem A 2013; 117:6580-8. [DOI: 10.1021/jp405656n] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- R. Aaron Vogt
- Department of Chemistry, Center
for Chemical Dynamics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106, United States
| | - Christian Reichardt
- Department of Chemistry, Center
for Chemical Dynamics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106, United States
| | - Carlos E. Crespo-Hernández
- Department of Chemistry, Center
for Chemical Dynamics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106, United States
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30
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Yu Z, Bernstein ER. On the Decomposition Mechanisms of New Imidazole-Based Energetic Materials. J Phys Chem A 2013; 117:1756-64. [DOI: 10.1021/jp312527u] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Zijun Yu
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, United
States
| | - Elliot R. Bernstein
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, United
States
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Mewes JM, Dreuw A. On the role of singlet versus triplet excited states in the uncaging of ortho-nitrobenzyl caged compounds. Phys Chem Chem Phys 2013; 15:6691-8. [DOI: 10.1039/c3cp44338h] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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32
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Orozco-Gonzalez Y, Coutinho K, Peon J, Canuto S. Theoretical study of the absorption and nonradiative deactivation of 1-nitronaphthalene in the low-lying singlet and triplet excited states including methanol and ethanol solvent effects. J Chem Phys 2012; 137:054307. [DOI: 10.1063/1.4738757] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
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33
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Al-Saidi WA, Asher SA, Norman P. Resonance Raman Spectra of TNT and RDX Using Vibronic Theory, Excited-State Gradient, and Complex Polarizability Approximations. J Phys Chem A 2012; 116:7862-72. [DOI: 10.1021/jp303920c] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- W. A. Al-Saidi
- Department of Chemical and Petroleum
Engineering, University of Pittsburgh,
Pittsburgh, Pennsylvania 15261, United States
| | - Sanford A. Asher
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania
15260, United States
| | - Patrick Norman
- Department
of Physics, Chemistry
and Biology, Linköping University, SE-581 83 Linköping, Sweden
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