1
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Wang Y, Ye Z, Han T, Du Y, Xue J. Transient spectroscopic insights into nitroindole's T 1 state: Elucidating its intermediates and unique photochemical properties. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2024; 319:124555. [PMID: 38823242 DOI: 10.1016/j.saa.2024.124555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Revised: 05/25/2024] [Accepted: 05/28/2024] [Indexed: 06/03/2024]
Abstract
Indoles are notable for their distinct photophysical and photochemical properties, making them useful indicators in biological systems and promising candidates for a variety of pharmaceutical applications. While some indoles exhibit room temperature phosphorescence, such a phenomenon has not been observed in nitroindoles. Typically, adding of a nitro group into aromatic compounds promotes ultrafast intersystem crossing and increases the formation quantum yield of the lowest excited triplet (T1). Therefore, understanding the reactivity of nitroindoles' T1 states is imperative. This study investigated the physical properties and chemical reactivities of the T1 state of 6-nitroindole (3HN-6NO2) in both polar aprotic and protic solvents, using transient absorption spectroscopy. Our results demonstrate the basicity and acidity of 3HN-6NO2, emphasizing its potential for protonation and dissociation in mildly acidic and basic conditions, respectively. Furthermore, 3HN-6NO2 has a high oxidizing capacity, participating in electron transfer reactions and proton-coupled electron transfer to produce radicals. Interestingly, in protic solvents like alcohols, 3HN-6NO2 dissociates at the -NH group and forms N-H…O hydrogen-bonded complexes with the nitro group. By identifying transient absorption spectra of intermediates and quantifying kinetic reaction rate constants, we illuminate the unique properties of the T1 state nitroindoles, enriching our understanding of their photophysical and photochemical behaviors. The results of this study have significant implications for their potential application in both biological systems and materials science.
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Affiliation(s)
- Yangxin Wang
- School of Chemistry and Chemical Engineering, Key Laboratory of Surface & Interface Science of Polymer Materials, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Zhao Ye
- School of Chemistry and Chemical Engineering, Key Laboratory of Surface & Interface Science of Polymer Materials, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Ting Han
- School of Chemistry and Chemical Engineering, Key Laboratory of Surface & Interface Science of Polymer Materials, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Yong Du
- Centre for THz Research, China Jiliang University, Hangzhou, 310018, China
| | - Jiadan Xue
- School of Chemistry and Chemical Engineering, Key Laboratory of Surface & Interface Science of Polymer Materials, Zhejiang Sci-Tech University, Hangzhou 310018, China.
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2
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Guzmán-Méndez Ó, Reza MM, Meza B, Jara-Cortés J, Peón J. Solvent Effects on the Singlet-Triplet Couplings in Nitroaromatic Compounds. J Phys Chem B 2023. [PMID: 37327487 DOI: 10.1021/acs.jpcb.3c01143] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Nitrated polycyclic molecules can present the largest singlet-triplet crossing rates among organic molecules. This implies that most of these compounds have no detectable steady-state fluorescence. In addition, some nitroaromatics undergo a complex series of photoinduced atom rearrangements that result in nitric oxide dissociation. The overall photochemistry of these systems depends critically on the competition between the rapid intersystem crossing channel and other excited-state pathways. In this contribution, we sought to characterize the degree of stabilization of the S1 state due to solute-solvent interactions, and to quantify the effect of such stabilization on their photophysical pathways. We studied 2- and 4-nitropyrene (2-NP and 4-NP), which are atypically emissive nitroaromatics in a series of solvents. From steady-state and time-resolved measurements, the S1 state of these molecules shows significant stabilization as the solvent polarity is increased. On the other hand, specific triplet states that are iso-energetic with the emissive singlet (T3 for 2-NP and T2 for 4-NP) in nonpolar solvents become slightly de-stabilized upon increasing the solvent polarity. These combined effects result in rapid singlet-triplet population transfer in nonpolar solvents for both molecules. In contrast, for solvents with even slightly higher polarities, the first excited singlet is stabilized in relation to the specific triplet states, leading to much longer S1 lifetimes. These effects can be summarized as a highly solvent-dependent coupling/decoupling of the manifolds. Similar effects are also likely to be present in other nitroaromatics where there is a dynamic competition between nitric oxide dissociation and intersystem crossing. The drastic effects of the solvent polarity in the manifold crossing pathway should be taken into consideration in both theoretical and experimental studies of nitroaromatics.
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Affiliation(s)
- Óscar Guzmán-Méndez
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, México, 04510 Ciudad de México, México
| | - Mariana M Reza
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, México, 04510 Ciudad de México, México
| | - Brandon Meza
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, México, 04510 Ciudad de México, México
| | - Jesús Jara-Cortés
- Unidad Académica de Ciencias Básicas e Ingenierías, Universidad Autónoma de Nayarit, Tepic 63155, México
| | - Jorge Peón
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, México, 04510 Ciudad de México, México
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3
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Toldo JM, do Casal MT, Ventura E, do Monte SA, Barbatti M. Surface hopping modeling of charge and energy transfer in active environments. Phys Chem Chem Phys 2023; 25:8293-8316. [PMID: 36916738 PMCID: PMC10034598 DOI: 10.1039/d3cp00247k] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/05/2023]
Abstract
An active environment is any atomic or molecular system changing a chromophore's nonadiabatic dynamics compared to the isolated molecule. The action of the environment on the chromophore occurs by changing the potential energy landscape and triggering new energy and charge flows unavailable in the vacuum. Surface hopping is a mixed quantum-classical approach whose extreme flexibility has made it the primary platform for implementing novel methodologies to investigate the nonadiabatic dynamics of a chromophore in active environments. This Perspective paper surveys the latest developments in the field, focusing on charge and energy transfer processes.
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Affiliation(s)
| | | | - Elizete Ventura
- Departamento de Química, CCEN, Universidade Federal da Paraíba, 58059-900, João Pessoa, Brazil.
| | - Silmar A do Monte
- Departamento de Química, CCEN, Universidade Federal da Paraíba, 58059-900, João Pessoa, Brazil.
| | - Mario Barbatti
- Aix-Marseille University, CNRS, ICR, Marseille, France.
- Institut Universitaire de France, 75231, Paris, France
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Wu Y, Wang Y, Guan H, Du Y, Zheng X, Xue J. Effect of electron-donating substitution on the triplet state reactivities of 1-nitronaphthalene. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2023; 286:121997. [PMID: 36308824 DOI: 10.1016/j.saa.2022.121997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 09/23/2022] [Accepted: 10/13/2022] [Indexed: 06/16/2023]
Abstract
Nitro-polycyclic aromatic hydrocarbons (nitro-PAHs), often found in polluted air, are carcinogenic and mutagenic. The nitro group increases the spin-orbit coupling and results in the lowest excited triplet (T1) on the picosecond time scale with a high yield. The electron-donating substituents have a significant influence on the photophysics and photochemistry of nitro-PAHs. We used transient absorption spectroscopy and kinetic analysis to investigate the reactivities of the T1 state 1-methoxy-4-nitronaphthalene (3MeO-NN) and 1-methyl-4-nitronaphthalene (3Me-NN). The results show that the methoxy and methyl substitutions have a minor effect on their hydrogen abstraction and electron accepting abilities. The main distinction is their reaction rates towards protons. The second order rate constant of 3MeO-NN towards protons is three orders of magnitude greater than that of 3Me-NN, indicating that 3MeO-NN has a stronger hydrogen bond accepting ability. The kinetic analysis reveals that the dimer of 2,2,2-trifluoroethanol participates in the reaction with 3MeO-NN. These results suggest that the formation of the hydrogen-bonded complex is responsible for the unusually short lifetime of 3MeO-NN in methanol solution and the lack of hydrogen abstraction radicals during the decay of 3MeO-NN in methanol.
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Affiliation(s)
- Yu Wu
- Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Yangxin Wang
- Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Huaiyu Guan
- Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Yong Du
- Centre for THz Research, Jiliang University, Hangzhou 310018, China
| | - Xuming Zheng
- Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Jiadan Xue
- Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou 310018, China; Key Laboratory of Surface & Interface Science of Polymer Materials of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China.
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5
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Rodríguez-Córdoba W, Gutiérrez-Arzaluz L, Cortés-Guzmán F, Peon J. Excited state dynamics and photochemistry of nitroaromatic compounds. Chem Commun (Camb) 2021; 57:12218-12235. [PMID: 34735557 DOI: 10.1039/d1cc04999b] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Nitrated aromatic molecules have unique photoinduced channels. Due to the presence of oxygen-centered non-bonding orbitals, they can undergo sub-picosecond intersystem crossing showing one of the strongest couplings between the singlet and triplet manifolds among organic molecules. Several nitroaromatic compounds also have a distinctive nitric oxide photodissociation channel which occurs through a complex sequence of atom rearrangements and state changes. These remarkable processes have stimulated the attention of several research groups over the last few years who have applied modern femtosecond spectroscopies and new computational methods to these topics. Nitroaromatic molecules also have demonstrated their value as case-studies, where they can serve to understand the influence of torsional motions between the nitro substituent and the aromatic system in the conversions between states. In this contribution we highlight several of the recent results in this area. Due to the importance of the atmospheric photochemistry of nitrated compounds and their accumulating applications as nitric oxide release agents, continued research about the effects of the different state orderings, substitution patterns, and solvent effects is central to the development of future applications and for a better understanding of their environmental pathways. From this analysis, several pending issues are highlighted, which include the nature of the dominant singlet state involved in intersystem crossing, the role of the formation of charge-transfer states, the yield of the internal conversion channel to the electronic ground state, and a more generalized understanding of the sequence of steps which lead to nitric oxide dissociation.
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Affiliation(s)
- William Rodríguez-Córdoba
- Facultad de ciencias, Escuela de Física, Laboratorio de Fotónica y Optoelectrónica, Universidad Nacional de Colombia - Sede Medellín, Calle 59 A No. 63-20, A.A. 3840, Medellín, Colombia.
| | - Luis Gutiérrez-Arzaluz
- Division of Physical Sciences and Engineering (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia.
| | - Fernando Cortés-Guzmán
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, México, 04510 D.F., Mexico.
| | - Jorge Peon
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, México, 04510 D.F., Mexico.
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7
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Ye Z, Du Y, Pan X, Zheng X, Xue J. Electron transfer from guanosine to the lowest triplet excited state of 4-nitroindole through hydrogen-bonded complex. J Photochem Photobiol A Chem 2021. [DOI: 10.1016/j.jphotochem.2020.113106] [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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8
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Wilson J, Octaviani M, Bandowe BAM, Wietzoreck M, Zetzsch C, Pöschl U, Berkemeier T, Lammel G. Modeling the Formation, Degradation, and Spatiotemporal Distribution of 2-Nitrofluoranthene and 2-Nitropyrene in the Global Atmosphere. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:14224-14234. [PMID: 33112146 PMCID: PMC7676291 DOI: 10.1021/acs.est.0c04319] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 10/07/2020] [Accepted: 10/16/2020] [Indexed: 05/19/2023]
Abstract
Polycyclic aromatic hydrocarbons (PAHs) are common atmospheric pollutants and known to cause adverse health effects. Nitrated PAHs (NPAHs) are formed in combustion activities and by nitration of PAHs in the atmosphere and may be equally or more toxic, but their spatial and temporal distribution in the atmosphere is not well characterized. Using the global EMAC model with atmospheric chemistry and surface compartments coupled, we investigate the formation, abundance, and fate of two secondarily formed NPAHs, 2-nitrofluoranthene (2-NFLT) and 2-nitropyrene (2-NPYR). The default reactivity scenario, the model with the simplest interpretation of parameters from the literature, tends to overestimate both absolute concentrations and NPAH/PAH ratios at observational sites. Sensitivity scenarios indicate that NO2-dependent NPAH formation leads to better agreement between measured and predicted NPAH concentrations and that photodegradation is the most important loss process of 2-NFLT and 2-NPYR. The highest concentrations of 2-NFLT and 2-NPYR are found in regions with strong PAH emissions, but because of continued secondary formation from the PAH precursors, these two NPAHs are predicted to be spread across the globe.
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Affiliation(s)
- Jake Wilson
- Multiphase
Chemistry Department, Max Planck Institute
for Chemistry, 55128 Mainz, Germany
| | - Mega Octaviani
- Multiphase
Chemistry Department, Max Planck Institute
for Chemistry, 55128 Mainz, Germany
| | | | - Marco Wietzoreck
- Multiphase
Chemistry Department, Max Planck Institute
for Chemistry, 55128 Mainz, Germany
| | - Cornelius Zetzsch
- Multiphase
Chemistry Department, Max Planck Institute
for Chemistry, 55128 Mainz, Germany
- Bayreuth
Centre for Ecology and Environmental Research, University of Bayreuth, 95448 Bayreuth, Germany
| | - Ulrich Pöschl
- Multiphase
Chemistry Department, Max Planck Institute
for Chemistry, 55128 Mainz, Germany
| | - Thomas Berkemeier
- Multiphase
Chemistry Department, Max Planck Institute
for Chemistry, 55128 Mainz, Germany
| | - Gerhard Lammel
- Multiphase
Chemistry Department, Max Planck Institute
for Chemistry, 55128 Mainz, Germany
- Research
Centre for Toxic Compounds in the Environment, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic
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9
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Long J, Ye Z, Du Y, Zheng XM, Xue JD. Direct observation of transient species generated from protonation and deprotonation of the lowest triplet of p-nitrophenylphenol. CHINESE J CHEM PHYS 2020. [DOI: 10.1063/1674-0068/cjcp2006107] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Jing Long
- Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Zhao Ye
- Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Yong Du
- Centre for THz Research, China Jiliang University, Hangzhou 310018, China
| | - Xu-ming Zheng
- Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Jia-dan Xue
- Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou 310018, China
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10
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Tahara A, Kitahara I, Sakata D, Kuninobu Y, Nagashima H. Donor–Acceptor π-Conjugated Enamines: Functional Group-Compatible Synthesis from Amides and Their Photoabsorption and Photoluminescence Properties. J Org Chem 2019; 84:15236-15254. [DOI: 10.1021/acs.joc.9b02267] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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11
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Sun H, Wang M, Nan Y, Han M, Lu H. The Kinetics and Mechanisms for Photodegradation of Nitrated Polycyclic Aromatic Hydrocarbons on Lettuce Leaf Surfaces: An In Vivo Study. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:8452-8458. [PMID: 31294967 DOI: 10.1021/acs.jafc.9b02326] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Insights into the environmental fates of nitrated polycyclic aromatic hydrocarbons (NPAHs) in edible vegetables are of great significance for better evaluating human exposure to NPAHs through the dietary pathway. In this work, a fluorescence quenching method using graphene quantum dots as a fluorescent probe was first applied for the in vivo determination of 9-nitroanthracene (9-NAnt) and 1-nitropyrene (1-NPyr) adsorbed on the leaf surfaces of living lettuce (Lactuca sativa L.) seedlings. Moreover, the photolysis kinetics and mechanisms of the two adsorbed NPAHs were discussed. The photodegradation kinetics followed the pseudo-first-order equation, and the photodegradation half-life of 1-NPyr (7.4 ± 0.2 h) was greater than that of 9-NAnt (2.3 ± 0.1 h). Anthraquinone and pyrenediones were identified to be the main photolytic products of 9-NAnt and 1-NPyr, respectively. Intramolecular rearrangement was the most reasonable mechanism for the NPAH photolysis. The photolysis-driven degradation exhibited a key role in scavenging NPAHs from the vegetable leaf, indicating the reduction of NPAH transportation in the food chain.
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Affiliation(s)
- Haifeng Sun
- College of Environment and Resource , Shanxi University , Taiyuan 030006 , P. R. China
- Key Laboratory of Soil Environment and Nutrient Resources of Shanxi Province , Taiyuan 030031 , P. R. China
| | - Meng Wang
- College of Environment and Resource , Shanxi University , Taiyuan 030006 , P. R. China
| | - Yanli Nan
- College of Environment and Resource , Shanxi University , Taiyuan 030006 , P. R. China
| | - Ming Han
- College of Environment and Resource , Shanxi University , Taiyuan 030006 , P. R. China
| | - Haoliang Lu
- Key Laboratory of Ministry of Coastal and Wetland Ecosystem , Xiamen University , Xiamen 361102 , P. R. China
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12
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Jin P, Long J, Du Y, Zheng X, Xue J. Hydrogen bond configuration and protonation of ground and lowest excited triplet states of 4‑amino‑4'‑nitrobiphenyl based on nanosecond transient absorption spectroscopy. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2019; 217:44-50. [PMID: 30927570 DOI: 10.1016/j.saa.2019.03.054] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 01/19/2019] [Accepted: 03/17/2019] [Indexed: 06/09/2023]
Abstract
Intramolecular charge transfer (ICT) is an important photochemical process. In contrast to those in singlet manifold, triplet ICT states were less studied. In this paper, the lowest excited triplet state (T1) of 4‑amino‑4'‑nitrobiphenyl (NH2-Bp-NO2) was recorded with nanosecond transient absorption spectroscopy in acidic acetonitrile and alcoholic solutions. By employing the Kamlet-Taft model to analyze the correlation between absorption maxima and alcohol solvent properties including polarity/polarizability, abilities of hydrogen bond donating and hydrogen bond accepting, hydrogen bond configuration in the ground state (S0) and T1 was resolved. The results suggest that the hydrogen bond between amino H and alcohol is dominant in S0, while in T1, hydrogen bonds between amino H and alcohol, between nitro O and alcohol have comparable contribution. By examination of the 1‑naphthol quench effect on T1, the hydrogen bond between nitro O and alcohol was confirmed present. Theoretical calculation results on the model of NH2-Bp-NO2-(MeOH)3 also indicate that hydrogen bonds between amino H and alcohol, between nitro O and alcohol are both much stronger in T1 than in S0. In acidic acetonitrile solution, in S0 of NH2-Bp-NO2 the amino group is protonated with pKa of 4.5, meanwhile in T1 the nitro group is much easier to be protonated than in S0. Its conjugated acid was measured to have a pKa of 3.1.
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Affiliation(s)
- Peipei Jin
- Department of Chemsitry, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Jing Long
- Department of Chemsitry, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Yong Du
- Center for THz Research, China Jiliang University, Hangzhou 310018, China
| | - Xuming Zheng
- Department of Chemsitry, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Jiadan Xue
- Department of Chemsitry, Zhejiang Sci-Tech University, Hangzhou 310018, China.
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13
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Zhang F, Zhang D, Du Y, Jin P, Zhao Y, Zheng X, Xue J. Direct observation of stepwise intermolecular proton and hydrogen transfer between alcohols and the triplet state of 4-nitro-1-naphthol. Phys Chem Chem Phys 2018; 20:11876-11881. [PMID: 29662995 DOI: 10.1039/c8cp00484f] [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
Solvent assisted excited state intramolecular proton or hydrogen transfer has received much attention in bi-functional molecules with hydrogen donating and hydrogen accepting groups. As a typical photoacid, 1-naphthol exhibits photo-stable behavior in methanol; whether this would be disrupted by a bonded hydrogen accepting group contained in the molecule is still not assured. We present nanosecond transient absorption measurements relating to kinetics and the characteristic absorption of key intermediates upon the excitation of 4-nitro-1-naphthol in alcoholic solutions, and also transient resonance Raman spectroscopy studies combined with theoretical calculations to identify the structures of these intermediates, and we reveal the reaction mechanism to be stepwise deprotonation, hydrogen abstraction and protonation. These results demonstrate that alcohol assisted intramolecular proton or hydrogen transfer cannot occur in this system, but that the solvent cluster plays an important role during such stepwise reactions.
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Affiliation(s)
- Fengjin Zhang
- Department of Chemsitry, Zhejiang Sci-Tech University, Hangzhou, 310018, China
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14
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Yang M, Zhang T, Xue J, Zheng X. Ab Initio Study of Decay Dynamics of 1-Nitronaphthalene Initiated from the S 2(ππ* + n NOπ*) State. J Phys Chem A 2018; 122:2732-2738. [PMID: 29488758 DOI: 10.1021/acs.jpca.7b11003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Irradiation of nitro-PAHs in solution at ambient conditions leads to formation of its lowest excited triplet, dissociation intermediates nitrogen oxide (NO•) and aryloxy radical (Ar-O•). Experimental and theoretical studies demonstrated that Franck-Condon excited singlet state SFC(ππ*) to a receiver, higher-energy triplet state Tn(nπ*) controlled the ultrafast population of the triplet state and, hence, the slight fluorescence yield of nitronaphthalenes. However, the detailed information about the curve-crossings of potential energy surfaces and the major channels for forming T1 species and Ar-O• radical were unclear. Here, by using the CASSCF//CASPT2 method, an efficient decay channel is revealed: S2-FC-1NN → S2-MIN-1NN or S2T3-MIN-1NN → T3-MIN-1NN or T3T2-MIN-1NN→ T2-MIN-1NN or T2T1-MIN-1NN → T1-MIN-1NN. This explains the high yield of T1-1NN species and minor yield of Ar-O• and NO• radicals. The calculation results suggest the bifurcation processes take place predominantly after the internal conversion to the T1-1NN state via T2T1-MIN-1NN, one leads to T1-MIN-1NN, while the other to T1-MIN-ISO to produce Ar-O• and NO• radicals.
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Affiliation(s)
- Meng Yang
- Department of Chemistry , Zhejiang Sci-Tech University , Hangzhou 310018 , P. R. China
| | - Tengshuo Zhang
- Department of Chemistry , Zhejiang Sci-Tech University , Hangzhou 310018 , P. R. China
| | - Jiadan Xue
- Department of Chemistry , Zhejiang Sci-Tech University , Hangzhou 310018 , P. R. China
| | - Xuming Zheng
- Department of Chemistry , Zhejiang Sci-Tech University , Hangzhou 310018 , P. R. China
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15
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Zhang D, Jin P, Yang M, Du Y, Zheng X, Xue J. Intermolecular Hydrogen Abstraction from Hydroxy Group and Alkyl by T 1(ππ*) of 1-Chloro-4-nitronaphthalene. J Phys Chem A 2018; 122:1831-1837. [PMID: 29432008 DOI: 10.1021/acs.jpca.7b11146] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Nanosecond transient absorption and theoretical calculations have been used to investigate the intermolecular hydrogen abstractions from alcohols and 1-naphthol by the lowest excited triplet (T1) of 1-chloro-4-nitronaphthalene upon excitation of the compound in organic solvents. The hydrogen abstraction of T1 from hydroxy group of 1-naphthol takes place through an electron transfer followed by a proton transfer through hydrogen bonding interaction with rate constants of ∼109 M-1 s-1. Hydrogen-bonding is crucial in this process, indicated by the observation of a half reduction for T1 yield when increasing the concentration of 1-naphthol. The hydrogen abstraction in this way can be decelerated by increasing solvent polarity and hydrogen-bonding donor ability. The T1 of 1-chloro-4-nitronaphthalene can undergo one-step H atom abstraction from alkyl hydrogen in alcoholic solvents, with rate constants of ∼104 M-1 s-1, and produce radical intermediates with the absorption maximum at 368 nm. DFT calculation results indicate both oxygens of the nitro group are active sites for hydrogen abstraction, and the difference of activation barriers for formation of two radical isomers is only 1.0 kcal/mol.
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Affiliation(s)
- Di Zhang
- Department of Chemsitry, Zhejiang Sci-Tech University , Hangzhou 310018, China
| | - Peipei Jin
- Department of Chemsitry, Zhejiang Sci-Tech University , Hangzhou 310018, China
| | - Meng Yang
- Department of Chemsitry, Zhejiang Sci-Tech University , Hangzhou 310018, China
| | - Yong Du
- Center for THz Research, China Jiliang University , Hangzhou 310018, China
| | - Xuming Zheng
- Department of Chemsitry, Zhejiang Sci-Tech University , Hangzhou 310018, China
| | - Jiadan Xue
- Department of Chemsitry, Zhejiang Sci-Tech University , Hangzhou 310018, China
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16
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Larsen MAB, Stephansen AB, Alarousu E, Pittelkow M, Mohammed OF, Sølling TI. Solvent-dependent dual fluorescence of the push-pull system 2-diethylamino-7-nitrofluorene. Phys Chem Chem Phys 2018; 20:5942-5951. [PMID: 29423491 DOI: 10.1039/c8cp00235e] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The solvent-dependent excited state behavior of the molecular push-pull system 2-diethylamino-7-nitrofluorene has been explored using femtosecond transient absorption spectroscopy in combination with density functional theory calculations. Several excited state minima have been identified computationally, all possessing significant intramolecular charge transfer character. The experimentally observed dual fluorescence is suggested to arise from a planar excited state minimum and another minimum reached by twisting of the aryl-nitrogen bond of the amino group. The majority of the excited state population, however, undergo non-radiative transitions and potential excited state deactivation pathways are assessed in the computational investigation. A third excited state conformer, characterized by twisting around the aryl-nitrogen bond of the nitro group, is reasoned to be responsible for the majority of the non-radiative decays and a crossing between the excited state and ground state is localized. Additionally, ultrafast intersystem crossing is observed in the apolar solvent cyclohexane and rationalized to occur via an El-Sayed assisted transition from one of the identified excited state minima. The solvent thus determines more than just the fluorescence lifetime and shapes the potential energy landscape, thereby dictating the available excited state pathways.
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Affiliation(s)
- M A B Larsen
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen Ø, Denmark.
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17
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Li A, Imasaka T, Imasaka T. Optimal Laser Wavelength for Femtosecond Ionization of Polycyclic Aromatic Hydrocarbons and Their Nitrated Compounds in Mass Spectrometry. Anal Chem 2018; 90:2963-2969. [DOI: 10.1021/acs.analchem.8b00125] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Adan Li
- College
of Environmental and Chemical Engineering, Yanshan University, 438 Hebei Street, Qinhuangdao 066004, China
- Division
of International Strategy, Center of Future Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Tomoko Imasaka
- Department
of Environmental Design, Graduate School of Design, Kyushu University, 4-9-1
Shiobaru, Minami-ku, Fukuoka 815-8540, Japan
| | - Totaro Imasaka
- Division
of International Strategy, Center of Future Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
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18
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Brister MM, Piñero-Santiago LE, Morel M, Arce R, Crespo-Hernández CE. Photochemical Relaxation Pathways in Dinitropyrene Isomer Pollutants. J Phys Chem A 2017; 121:8197-8206. [PMID: 28984454 DOI: 10.1021/acs.jpca.7b04769] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Dinitropyrenes are polycyclic aromatic pollutants prevalent in the environment. While their transformations by sunlight in the environment have been documented, the effect that the nitro-group substitution pattern has on the relaxation pathways has not been extensively studied. In this contribution, the steady-state and femtosecond-to-microsecond excited-state dynamics of 1,3-dinitropyrene and 1,8-dinitropyrene isomers are investigated upon visible light excitation at 425 nm and compared with those recently reported for the 1,6-dinitropyrene isomer. The experimental results are complemented with ground- and excited-state density functional calculations. It is shown that excitation at 425 nm results in the ultrafast branching of the excited-state population in the S1 state to populate the triplet state in ca. 90% yield and to form a nitropyrenoxy radical in less than 10% yield. In addition, the position of the NO2 group does not affect significantly the excited-state relaxation mechanism, while it does influence the absorption and fluorescence spectra, the fluorescence, triplet, singlet oxygen, and photodegradation yields, as well as the relative yield of radical formation. Radical formation is implicated in the photodegradation of these pollutants, while in the presence of hydrogen donors, direct reactions from the triplet state are also observed.
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Affiliation(s)
- Matthew M Brister
- Department of Chemistry, Case Western Reserve University , 10900 Euclid Avenue, Cleveland, Ohio 44106, United States
| | - Luis E Piñero-Santiago
- Department of Chemistry, University of Puerto Rico , Río Piedras Campus, San Juan, Puerto Rico 00931, United States
| | - María Morel
- Department of Chemistry, University of Puerto Rico , Río Piedras Campus, San Juan, Puerto Rico 00931, United States
| | - Rafael Arce
- Department of Chemistry, University of Puerto Rico , Río Piedras Campus, San Juan, Puerto Rico 00931, United States
| | - Carlos E Crespo-Hernández
- Department of Chemistry, Case Western Reserve University , 10900 Euclid Avenue, Cleveland, Ohio 44106, United States
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19
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Rodríguez-Romero J, Guarin CA, Arroyo-Pieck A, Gutiérrez-Arzaluz L, López-Arteaga R, Cortés-Guzmán F, Navarro P, Peon J. Fluorophore Release from a Polymethinic Photoremovable Protecting Group Through a Nonlinear Optical Process. CHEMPHOTOCHEM 2017. [DOI: 10.1002/cptc.201700076] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Jesús Rodríguez-Romero
- Instituto de Química; Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria; Ciudad de México 04510 México
| | - Cesar A. Guarin
- Instituto de Química; Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria; Ciudad de México 04510 México
| | - Andres Arroyo-Pieck
- Instituto de Química; Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria; Ciudad de México 04510 México
| | - Luis Gutiérrez-Arzaluz
- Instituto de Química; Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria; Ciudad de México 04510 México
| | - Rafael López-Arteaga
- Instituto de Química; Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria; Ciudad de México 04510 México
| | - Fernando Cortés-Guzmán
- Instituto de Química; Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria; Ciudad de México 04510 México
| | - Pedro Navarro
- Instituto de Química; Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria; Ciudad de México 04510 México
| | - Jorge Peon
- Instituto de Química; Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria; Ciudad de México 04510 México
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20
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Bandowe BAM, Meusel H. Nitrated polycyclic aromatic hydrocarbons (nitro-PAHs) in the environment - A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 581-582:237-257. [PMID: 28069306 DOI: 10.1016/j.scitotenv.2016.12.115] [Citation(s) in RCA: 188] [Impact Index Per Article: 26.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 12/16/2016] [Accepted: 12/16/2016] [Indexed: 05/07/2023]
Abstract
Nitrated polycyclic aromatic hydrocarbons (nitro-PAHs) are derivatives of PAHs with at least one nitro-functional group (-NO2) on the aromatic ring. The toxic effects of several nitro-PAHs are more pronounced than those of PAHs. Some nitro-PAHs are classified as possible or probable human carcinogens by the International Agency for Research on Cancer. Nitro-PAHs are released into the environment from combustion of carbonaceous materials (e.g. fossil fuels, biomass, waste) and post-emission transformation of PAHs. Most studies on nitro-PAHs are about air (gas-phase and particulate matter), therefore less is known about the occurrence, concentrations, transport and fate of nitro-PAHs in soils, aquatic environment and biota. Studies on partition and exchange of nitro-PAHs between adjacent environmental compartments are also sparse. The concentrations of nitro-PAHs cannot easily be predicted from the intensity of anthropogenic activity or easily related to those of PAHs. This is because anthropogenic source strengths of nitro-PAHs are different from those of PAHs, and also nitro-PAHs have additional sources (formed by photochemical conversion of PAHs). The fate and transport of nitro-PAHs could be considerably different from their related PAHs because of their higher molecular weights and considerably different sorption mechanisms. Hence, specific knowledge on nitro-PAHs is required. Regulations on nitro-PAHs are also lacking. We present an extensive review of published literature on the sources, formation, physico-chemical properties, methods of determination, occurrence, concentration, transport, fate, (eco)toxicological and adverse health effects of nitro-PAHs. We also make suggestions and recommendations about data needs, and future research directions on nitro-PAHs. It is expected that this review will stimulate scientific discussion and provide the basis for further research and regulations on nitro-PAHs.
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Affiliation(s)
- Benjamin A Musa Bandowe
- Institute of Geography, University of Bern, Hallerstrasse 12, 3012 Bern, Switzerland; Oeschger Centre for Climate Change Research, University of Bern, Falkenplatz 16, 3012 Bern, Switzerland.
| | - Hannah Meusel
- Multiphase Chemistry Department, Max Planck Institute for Chemistry, Hahn-Meitner-Weg 1, 55128 Mainz, Germany
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21
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García-Berríos ZI, Arce R, Burgos-Martínez M, Burgos-Polanco ND. Phototransformations of environmental contaminants in models of the aerosol: 2 and 4-Nitropyrene. J Photochem Photobiol A Chem 2017. [DOI: 10.1016/j.jphotochem.2016.08.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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22
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Rajagopal SK, Mallia AR, Hariharan M. Enhanced intersystem crossing in carbonylpyrenes. Phys Chem Chem Phys 2017; 19:28225-28231. [DOI: 10.1039/c7cp04834c] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Photoexcited state relaxation of carbonylpyrenes displays ultrafast intersystem crossing to generate near-unity triplet formation.
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Affiliation(s)
- Shinaj K. Rajagopal
- School of Chemistry
- Indian Institute of Science Education and Research Thiruvananthapuram
- Thiruvananthapuram 695551
- India
| | - Ajith R. Mallia
- School of Chemistry
- Indian Institute of Science Education and Research Thiruvananthapuram
- Thiruvananthapuram 695551
- India
| | - Mahesh Hariharan
- School of Chemistry
- Indian Institute of Science Education and Research Thiruvananthapuram
- Thiruvananthapuram 695551
- India
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23
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Brister MM, Piñero-Santiago LE, Morel M, Arce R, Crespo-Hernández CE. The Photochemical Branching Ratio in 1,6-Dinitropyrene Depends on the Excitation Energy. J Phys Chem Lett 2016; 7:5086-5092. [PMID: 27973879 DOI: 10.1021/acs.jpclett.6b02549] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Nitropolycyclic aromatic hydrocarbons constitute one of the most disconcerting classes of pollutants. Photochemical degradation is thought to be a primary mode of their natural removal from the environment, but the microscopic mechanism leading to product formation as a function of excitation wavelength is poorly understood. In this Letter, it is revealed that excitation of 1,6-dinitropyrene with 425, 415, or 340 nm radiation leads to an increasing amount of radical production through photodissociation at the expense of triplet-state population-the two primary reaction pathways in this class of pollutants. Radical formation requires overcoming an energy barrier in the excited singlet manifold. This activation energy explains the large fraction of the initial singlet-state population that intersystem crosses to a doorway triplet state, instead of leading overwhelmingly to photodissociation. The unforeseen excitation wavelength dependence of this branching process is expected to regulate the photochemistry of 1,6-dinitropyrene and possibly of other nitroaromatic pollutants in the environment.
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Affiliation(s)
- Matthew M Brister
- Department of Chemistry, Case Western Reserve University , 10900 Euclid Avenue, Cleveland, Ohio 44106, United States
| | - Luis E Piñero-Santiago
- Department of Chemistry, University of Puerto Rico at Humacao , Humacao Campus, Humacao, Puerto Rico 00792
| | - María Morel
- Department of Chemistry, University of Puerto Rico , Río Piedras Campus, San Juan, Puerto Rico 00931
| | - Rafael Arce
- Department of Chemistry, University of Puerto Rico , Río Piedras Campus, San Juan, Puerto Rico 00931
| | - Carlos E Crespo-Hernández
- Department of Chemistry, Case Western Reserve University , 10900 Euclid Avenue, Cleveland, Ohio 44106, United States
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24
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Espinoza EM, Xia B, Darabedian N, Larsen JM, Nuñez V, Bao D, Mac JT, Botero F, Wurch M, Zhou F, Vullev VI. Nitropyrene Photoprobes: Making Them, and What Are They Good for? European J Org Chem 2015. [DOI: 10.1002/ejoc.201501339] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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25
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Tang Y, Imasaka T, Yamamoto S, Imasaka T. Multiphoton ionization mass spectrometry of nitrated polycyclic aromatic hydrocarbons. Talanta 2015; 140:109-114. [DOI: 10.1016/j.talanta.2015.03.027] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Revised: 03/13/2015] [Accepted: 03/14/2015] [Indexed: 10/23/2022]
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26
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Giussani A. Toward the Understanding of the Photophysics and Photochemistry of 1-Nitronaphthalene under Solar Radiation: The First Theoretical Evidence of a Photodegradation Intramolecular Rearrangement Mechanism Involving the Triplet States. J Chem Theory Comput 2014; 10:3987-95. [DOI: 10.1021/ct500395f] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Angelo Giussani
- Instituto
de Ciencia Molecular, Universitat de València, Apartado22085, ES-46071 Valencia, Spain
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27
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López-Arteaga R, Stephansen AB, Guarin CA, Sølling TI, Peon J. The Influence of Push–Pull States on the Ultrafast Intersystem Crossing in Nitroaromatics. J Phys Chem B 2013; 117:9947-55. [DOI: 10.1021/jp403602v] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Rafael López-Arteaga
- Instituto
de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria,
México, 04510,
D.F., México
| | - Anne B. Stephansen
- Department
of Chemistry, University of Copenhagen,
Universitetsparken 5, DK-2100
Copenhagen Ø, Denmark
| | - Cesar A. Guarin
- Instituto
de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria,
México, 04510,
D.F., México
| | - Theis I. Sølling
- Department
of Chemistry, University of Copenhagen,
Universitetsparken 5, DK-2100
Copenhagen Ø, Denmark
| | - Jorge Peon
- Instituto
de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria,
México, 04510,
D.F., México
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28
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Arce R, Morel M. Phototransformations of dinitropyrene isomers on models of the atmospheric particulate matter. ATMOSPHERIC ENVIRONMENT (OXFORD, ENGLAND : 1994) 2013; 75:171-178. [PMID: 23814479 PMCID: PMC3691884 DOI: 10.1016/j.atmosenv.2013.04.035] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The 1,6 and 1,8-dinitropyrenes (DNP) isomers are strong mutagens and carcinogens encountered in diesel exhaust and airborne particles. Relative photodegradation rates were determined and some products were characterized when these isomers were irradiated adsorbed onto models of the atmospheric matter. These are compared to their photochemical behavior in a polar nonprotic solvent. The 1,8-DNP isomer is three times more reactive than the 1,6-DNP when irradiated adsorbed onto silica gel surfaces, while the reverse order is observed in solution, demonstrating the influence of structural differences and environmental effects on the photoreactivity. Oxygen is a key factor in the formation of pyrenediones from 1,8-DNP in solution and on silica gel which is not the case for 1,6-DNP. The average pore diameter (2.5 versus 6.0 nm) of the silica surfaces induces a significant change in the product distribution and relative yields of 1,8-DNP because pyrenediones or 8-hydroxy-1-nitropyrene are not produced in the smaller pore silica. A 6-hydroxy-1-nitropyrene product is observed both in acidic alumina and silica (6.0 nm) surfaces. On acidic alumina the rates of phototransformation of the isomers are equal, a significant increase in the relative yield of the hydroxynitropyrene product is observed compared to the silica and unidentified products in which the absence of NO2 and pyrene absorption bands were observed, demonstrating the surface effect on the photodegradation. Overall, the presence of some products indicates the occurrence of a nitro-nitrite rearrangement on the surface with the participation of a pyrenoxy radical as their precursor.
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Affiliation(s)
- Rafael Arce
- Corresponding author: Department of Chemistry, University of Puerto Rico, Rio Piedras Campus, P.O. Box 23346, San Juan, Puerto Rico, 00931-3346, Phone: 787-764-0000, ext 2429; Fax 787-756-8242;
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29
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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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Hachiya S, Asai K, Konishi GI. Environment-responsive multicolor fluorescent dyes based on nitrophenyl or nitrophenylethynyl oligothiophene derivatives: correlation between fluorescence and π-conjugation length. Tetrahedron Lett 2013. [DOI: 10.1016/j.tetlet.2013.03.054] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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31
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Atamas AA, Cuppen HM, Koudriachova MV, de Leeuw SW. Monte Carlo calculations of the free energy of binary sII hydrogen clathrate hydrates for identifying efficient promoter molecules. J Phys Chem B 2013; 117:1155-65. [PMID: 23289842 DOI: 10.1021/jp306585t] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The thermodynamics of binary sII hydrogen clathrates with secondary guest molecules is studied with Monte Carlo simulations. The small cages of the sII unit cell are occupied by one H(2) guest molecule. Different promoter molecules entrapped in the large cages are considered. Simulations are conducted at a pressure of 1000 atm in a temperature range of 233-293 K. To determine the stabilizing effect of different promoter molecules on the clathrate, the Gibbs free energy of fully and partially occupied sII hydrogen clathrates are calculated. Our aim is to predict what would be an efficient promoter molecule using properties such as size, dipole moment, and hydrogen bonding capability. The gas clathrate configurational and free energies are compared. The entropy makes a considerable contribution to the free energy and should be taken into account in determining stability conditions of binary sII hydrogen clathrates.
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Affiliation(s)
- Alexander A Atamas
- Theoretical Chemistry, Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.
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Fullove TP, Johnson B, Yu H. Structure-dependent lipid peroxidation by photoirradiation of pyrene and its mono-substituted derivatives. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2013; 48:233-41. [PMID: 23245298 PMCID: PMC3939684 DOI: 10.1080/10934529.2013.729998] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Pyrene, one of the most studied polycyclic aromatic hydrocarbons, can damage biological macromolecules and cause toxicity when irradiated by light. The effect of substituents, 1-amino, 1-hydroxy, 1-nitro, and 1-bromo, on light-induced lipid peroxidation is studied. Degradation kinetics and photoproduct analyses were conducted to test how these substituents affect the photoreaction. All five compounds have widely different photodegradation rates, with degradation half-lives, ranging from 8 min to 495 min. These rates parallel their light absorptivity. Four out of the five compounds induce lipid peroxidation when irradiated with UVA light, whereas 1-aminopyrene causes minimum or no lipid peroxidation. The relative amount of lipid peroxidation caused is: 1-bromopyrene > pyrene > 1-nitropyrene ≈ 1-hydroxypyrene > 1-aminopyrene. This relative lipid peroxidation is dependent on the substituent due to the following factors: light absorptivity, relative rates of the competing processes in the excited states, nature of the photoreaction, and nature of the photoproducts.
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Affiliation(s)
- Tracie Perkins Fullove
- Department of Chemistry and Biochemistry, Jackson State University, Jackson, Mississippi, USA
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García-Berríos ZI, Arce R. Photodegradation mechanisms of 1-nitropyrene, an environmental pollutant: the effect of organic solvents, water, oxygen, phenols, and polycyclic aromatics on the destruction and product yields. J Phys Chem A 2012; 116:3652-64. [PMID: 22458822 PMCID: PMC3334876 DOI: 10.1021/jp2126416] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
This work describes studies of the photodegradation mechanism of 1-nitropyrene (1-NO(2)Py) in a chemical model system consisting of an organic solvent and known constituents of an aerosol particle. Photoproducts such as 1-hydroxypyrene (1-OHPy), 1-hydroxy-x-nitropyrenes (1-OH-x-NO(2)Py), 1-nitrosopyrene, and 1,6- and 1,8-pyrenediones were identified by high-performance liquid chromatography (HPLC) and HPLC/mass spectrometry (HPLC/MS) techniques, and their quantum yields show a significant dependence on the type of solvent. The photodegradation quantum yield of 1-NO(2)Py, φ((-1-NO2Py)), was larger in toluene, benzene, and polar protic solvents (10(-3)) in comparison with nonpolar and polar aprotic solvents, where the yield is on the order of 10(-4). In solvents with an abstractable hydrogen atom, the products formed in higher yields were 1-OHPy and 1-OH-x-NO(2)Py. These represent 60-80% of the photodestruction yield and result from abstraction and recombination reactions of the pyrenoxy radical, an intermediate postulated to be formed as a result of a nitro-nitrite rearrangement in nitroaromatics. The small O(2) effect in the photodegradation yield and the quenching experiments with azulene demonstrate the small contribution of the (3)(π,π*) state in the 1-NO(2)Py photoreaction. The nitrosopyrene product was not observed under these conditions, demonstrating the participation of the (3)(π,π*) state in its formation. In the presence various phenol aerosol constituents, the photodegradation yield increased by 10-fold in all solvents. This effect is partly ascribed to the reaction of the (3)(π,π*) state with the phenol. The effect of water resulted in the reduction of the 1-NO(2)Py photodegradation yield and of its photoproducts. The phototodegradation of 1-NO(2)Py was also studied in a viscous solvent, hexadecane, and it was determined that this medium does not inhibit its photodecay.
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Affiliation(s)
- Zulma I. García-Berríos
- Department of Chemistry, University of Puerto Rico, Río Piedras Campus, San Juan, Puerto Rico, 00931-3346
| | - Rafael Arce
- Department of Chemistry, University of Puerto Rico, Río Piedras Campus, San Juan, Puerto Rico, 00931-3346
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KAMEDA TAKAYUKI, AKIYAMA AYUKO, TORIBA AKIRA, TANG NING, HAYAKAWA KAZUICHI. Atmospheric Formation of Hydroxynitrofluoranthene from Photochemical Reactions of 2-Nitrofluoranthene. Polycycl Aromat Compd 2012. [DOI: 10.1080/10406638.2011.654307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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35
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Murudkar S, Mora AK, Singh PK, Nath S. Origin of ultrafast excited state dynamics of 1-nitropyrene. J Phys Chem A 2011; 115:10762-6. [PMID: 21861515 DOI: 10.1021/jp205946c] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Time-resolved emission measurements in subpicosecond time domain have been carried out for 1-nitropyrene in different solvents to understand the mechanism for the observed ultrafast decay of its first excited singlet state. Excited-state dynamics of 1-nitropyrene is found to be independent of the solvent viscosity. This result contradicts the proposition in the literature (J. Phys. Chem. A 2007, 111, 552) that the ultrafast decay in 1-nitropyrene is due to the large amplitude torsional motion of the nitro group around the pyrene moiety. Excited-state dynamics of 1-nitropyrene in solvents with different dielectric constants shows that excited-state lifetime suddenly increases after a certain value of the dielectric constant. Detailed quantum chemical calculations have been carried out to understand the process that is responsible for the observed effect of the dielectric constant on the excited-state dynamics of 1-nitropyrene. It is seen that the excited-state lifetime and the singlet-triplet energy gap follow similar variation with the dielectric constant of the medium. Such a correlation between the excited-state lifetime and the singlet-triplet energy gap supports the fact that the observed ultrafast decay for 1-nitropyrene is due to an efficient intersystem crossing rather than to the torsional motion of the nitro group as proposed in the literature.
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Affiliation(s)
- Sushant Murudkar
- Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India
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Plaza-Medina EF, Rodríguez-Córdoba W, Peon J. Role of upper triplet states on the photophysics of nitrated polyaromatic compounds: S(1) lifetimes of singly nitrated pyrenes. J Phys Chem A 2011; 115:9782-9. [PMID: 21790204 DOI: 10.1021/jp204321h] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The photophysics of most nitrated polycyclic aromatic compounds is dominated by an ultrafast intersystem crossing channel, which makes their first singlet excited states decay with rates on the order of 10(12) to 10(13) s(-1). Some questions, however, remain about the nature of the receiver triplet states, which have been in principle assigned to specific triplets of a different electronic configuration from T(1). In particular, it could be suggested that even a small degree of n-π* character of the T(1) state may be enough to allow the S(1) state to couple to upper vibronic states of the lowest energy triplet, without the requirement for specific upper triplet states. In this report, we show that there are, in fact, nitroaromatic compounds that do not show the ultrafast intersystem crossing channel but instead have S(1) states that are two to three orders of magnitude longer lived. Our studies focused on the time resolution of the emission from singly nitrated pyrenes, which show a strong photophysical dependence on the position of the NO(2) group: Whereas S(1) in 1-nitropyrene is short-lived (up to 3 ps), in 4-nitropyrene and 2-nitropyrene this state has 0.41 and 1.2 ns lifetimes, respectively, in acetonitrile solution. Computational work at the TD-DFT level of theory indicates that such remarkable increase in the first excited singlet lifetime can indeed be explained by a loss of the energy coincidence between the S(1) state with specific upper triplet states formed from transitions that involve the nonbonding orbitals at the oxygen atoms. These results are in strong support of the previous descriptions about the requirement for intermediacy of specific triplet states in the ultrafast decay of the fluorescent state present in most nitroaromatics. The implications for the photochemistry of this group of toxic atmospheric pollutants, including the channel that redounds in the dissociation of the NO· fragment, are discussed in view of the present results.
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Affiliation(s)
- Eddy F Plaza-Medina
- Instituto de Química, Universidad Nacional Autónoma de México , Circuito Exterior, Ciudad Universitaria, México, 04510 D.F., México
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Kameda T, Akiyama A, Toriba A, Tang N, Hayakawa K. Atmospheric formation of hydroxynitropyrenes from a photochemical reaction of particle-associated 1-nitropyrene. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2011; 45:3325-3332. [PMID: 21405083 DOI: 10.1021/es1042172] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The formation of hydroxynitropyrene (OHNP) via a photochemical reaction of 1-nitropyrene (1-NP) was demonstrated using a UV irradiation system. The photoreaction of 1-NP in methanol gave products that were hydroxy-substituted at position 1 and mononitro-substituted at positions 2, 3, 5, 6, and 8 [1-hydroxy-x-nitropyrenes (1-OH-x-NPs); x = 2, 3, 5, 6, and 8]. 1-OH-2-NP and 1-OH-5-NP have been identified in ambient airborne particles for the first time. On the contrary, these two OHNP isomers were not found in standard reference materials (SRM) 1650b and SRM 1975, which are typical samples of diesel exhaust particles (DEPs). The concentrations of the other OHNP isomers in the DEP samples were much lower than the concentration of 1-NP, which is a representative nitro-derivative polycyclic aromatic hydrocarbon that is emitted directly from combustion sources. On the other hand, significantly higher concentration ratios of ∑OHNP (=1-OH-3-NP + 1-OH-6-NP + 1-OH-8-NP) to 1-NP were observed in ambient airborne particles than in the DEP samples. In ambient airborne particles, the mean ∑OHNP/1-NP concentration ratio of 1.4 was 35 times higher than that in SRM 1650b and 470 times higher than that in SRM 1975. The diurnal concentration of 1-NP, which was observed at a typical residential area in Osaka, Japan, increased early in the morning and late in the evening, suggesting that automotive emissions contributed to the occurrence of 1-NP. The OHNP concentrations also rose in the morning, and variations of OHNP concentrations similar to those of 1-NP were observed during the daytime. However, the concentrations of OHNPs did not increase in the evening rush hour, and were low at night, i.e., in the absence of sunlight. These results support the idea that atmospheric OHNPs are predominantly formed via secondary formation processes; i.e., photochemical reactions of 1-NP are expected to have a significant effect on the occurrence of OHNPs in the atmosphere.
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Affiliation(s)
- Takayuki Kameda
- Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kakuma-machi , Kanazawa, Ishikawa 920-1192, Japan.
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Arce R, Pino EF, Valle C, Negrón-Encarnación I, Morel M. A comparative photophysical and photochemical study of nitropyrene isomers occurring in the environment. J Phys Chem A 2011; 115:152-60. [PMID: 21162566 PMCID: PMC3020990 DOI: 10.1021/jp108652p] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Ground state absorption, first excited-singlet state, and properties of reactive intermediates of mononitropyrene isomers encountered in the atmospheric aerosol have been studied under different conditions that could mimic the environment. The nitro group can present different orientations relative to the pyrene ring depending on its geometric location and could induce differences in the photochemistry of the isomers. The 2-NO(2)Py isomer has the largest red shift and lowest oscillator strength in the UV-visible band associated with the nitro group. The isomers show very low fluorescence yields (10(-3)-10(-4)). Only 1-NO(2)Py and 4-NO(2)Py have phosphorescence emission (Φ(p) ≈ 10(-4)), indicating that the lowest triplet state decays mainly through effective radiationless channels. Laser photolysis produces a low-lying triplet state (τ(T) = 10(-5)-10(-6) s), a long-lived pyrenoxy radical, and a PyNO(2)H radical in solvents in which the triplet can abstract a hydrogen atom. Similar triplet yields were calculated (0.1-0.6) for the isomers, while significant differences in the relative yield of the long-lived species were determined. Differences in the quenching rate constants of the triplet by water and phenols suggest a strong hydrogen-bond interaction with the nitro group in the C-2 position, which provides for radiationless deactivation routes.
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Affiliation(s)
- Rafael Arce
- Department of Chemistry, University of Puerto Rico, Rio Piedras Campus, San Juan, Puerto Rico.
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Plaza-Medina EF, Rodríguez-Córdoba W, Morales-Cueto R, Peon J. Primary photochemistry of nitrated aromatic compounds: excited-state dynamics and NO· dissociation from 9-nitroanthracene. J Phys Chem A 2011; 115:577-85. [PMID: 21214230 DOI: 10.1021/jp109041y] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We report results of femtosecond-resolved ex-periments which elucidate the time scale for the primary photoinduced events in the model nitroaromatic compound 9-nitroanthracene. Through time-resolved fluorescence measurements, we observed the ultrafast decay of the initially excited singlet state, and through transient absorption experiments, we observed the spectral evolution associated with the formation of the relaxed phosphorescent T(1) state. Additionally, we have detected for the first time the accumulation of the anthryloxy radical which results from the nitro-group rearrangement and NO(•) dissociation from photoexcited 9-nitroanthracene, a photochemical channel which occurs in parallel with the formation of the phosphorescent state. The spectral evolution in this molecule is highly complex since both channels take place in similar time ranges of up to a few picoseconds. Despite this complexity, our experiments provide the general time scales in which the primary products are formed. In addition, we include calculations at the time-dependent density functional level of theory which distinguish the molecular orbitals responsible for the n-π* character of the "receiver" vibronic triplet states that couple with the first singlet state and promote the ultrafast transfer of population between the two manifolds. Comparisons with the isoelectronic compounds anthracene-9-carboxylic acid and its conjugated base, which are highly fluorescent, show that in these two compounds the near-isoenergeticity of the S(1) with an appropriate "receiver" triplet state is disrupted, providing support to the idea that a specific energy coincidence is important for the ultrafast population of the triplet manifold, prevalent in polycyclic nitrated aromatic compounds.
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Affiliation(s)
- Eddy F Plaza-Medina
- Instituto de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, México, DF, México
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Reichardt C, Vogt RA, Crespo-Hernández CE. On the origin of ultrafast nonradiative transitions in nitro-polycyclic aromatic hydrocarbons: Excited-state dynamics in 1-nitronaphthalene. J Chem Phys 2009; 131:224518. [DOI: 10.1063/1.3272536] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
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Sonoda Y, Tsuzuki S, Goto M, Tohnai N, Yoshida M. Fluorescence Spectroscopic Properties of Nitro-Substituted Diphenylpolyenes: Effects of Intramolecular Planarization and Intermolecular Interactions in Crystals. J Phys Chem A 2009; 114:172-82. [DOI: 10.1021/jp907441p] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Yoriko Sonoda
- Nanotechnology Research Institute and Technical Center, National Institute of Advanced Industrial Science and Technology (AIST), Higashi 1-1-1, Tsukuba, Ibaraki 305-8565, Japan, Research Institute of Computational Sciences, AIST, Umezono 1-1, Tsukuba, Ibaraki 305-8568, Japan, and Department of Material and Life Science, Graduate School of Engineering, Osaka University, 2-1, Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Seiji Tsuzuki
- Nanotechnology Research Institute and Technical Center, National Institute of Advanced Industrial Science and Technology (AIST), Higashi 1-1-1, Tsukuba, Ibaraki 305-8565, Japan, Research Institute of Computational Sciences, AIST, Umezono 1-1, Tsukuba, Ibaraki 305-8568, Japan, and Department of Material and Life Science, Graduate School of Engineering, Osaka University, 2-1, Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Midori Goto
- Nanotechnology Research Institute and Technical Center, National Institute of Advanced Industrial Science and Technology (AIST), Higashi 1-1-1, Tsukuba, Ibaraki 305-8565, Japan, Research Institute of Computational Sciences, AIST, Umezono 1-1, Tsukuba, Ibaraki 305-8568, Japan, and Department of Material and Life Science, Graduate School of Engineering, Osaka University, 2-1, Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Norimitsu Tohnai
- Nanotechnology Research Institute and Technical Center, National Institute of Advanced Industrial Science and Technology (AIST), Higashi 1-1-1, Tsukuba, Ibaraki 305-8565, Japan, Research Institute of Computational Sciences, AIST, Umezono 1-1, Tsukuba, Ibaraki 305-8568, Japan, and Department of Material and Life Science, Graduate School of Engineering, Osaka University, 2-1, Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Masaru Yoshida
- Nanotechnology Research Institute and Technical Center, National Institute of Advanced Industrial Science and Technology (AIST), Higashi 1-1-1, Tsukuba, Ibaraki 305-8565, Japan, Research Institute of Computational Sciences, AIST, Umezono 1-1, Tsukuba, Ibaraki 305-8568, Japan, and Department of Material and Life Science, Graduate School of Engineering, Osaka University, 2-1, Yamadaoka, Suita, Osaka 565-0871, Japan
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Collado-Fregoso E, Zugazagoitia JS, Plaza-Medina EF, Peon J. Excited-State Dynamics of Nitrated Push−Pull Molecules: The Importance of the Relative Energy of the Singlet and Triplet Manifolds. J Phys Chem A 2009; 113:13498-508. [PMID: 19839627 DOI: 10.1021/jp905379y] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Elisa Collado-Fregoso
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, México, 04510, D.F., Mexico
| | - Jimena S. Zugazagoitia
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, México, 04510, D.F., Mexico
| | - Eddy F. Plaza-Medina
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, México, 04510, D.F., Mexico
| | - Jorge Peon
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, México, 04510, D.F., Mexico
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