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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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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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Brotherton AR, Shibu A, Meadows JC, Sayresmith NA, Brown CE, Ledezma AM, Schmedake TA, Walter MG. Leveraging Coupled Solvatofluorochromism and Fluorescence Quenching in Nitrophenyl-Containing Thiazolothiazoles for Efficient Organic Vapor Sensing. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023:e2205729. [PMID: 37186373 DOI: 10.1002/advs.202205729] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 02/26/2023] [Indexed: 05/17/2023]
Abstract
Solvatofluorochromic molecules provide strikingly high fluorescent outputs to monitor a wide range of biological, environmental, or materials-related sensing processes. Here, thiazolo[5,4-d]thiazole (TTz) fluorophores equipped with simple alkylamino and nitrophenyl substituents for solid-state, high-performance chemo-responsive sensing applications are reported. Nitroaromatic substituents are known to strongly quench dye fluorescence, however, the TTz core subtly modulates intramolecular charge transfer (ICT) enabling strong, locally excited-state fluorescence in non-polar conditions. In polar media, a planar ICT excited-state shows near complete quenching, enabling a twisted excited-state emission to be observed. These unique fluorescent properties (spectral shifts of 0.13 - 0.87 eV and large transition dipole moments Δµ = 20.4 - 21.3 D) are leveraged to develop highly sought-after chemo-responsive, organic vapor optical sensors. The sensors are developed by embedding the TTz fluorophores within a poly(styrene-isoprene-styrene) block copolymer to form fluorescent dye/polymer composites (ΦF = 70 - 97%). The composites respond reversibly to a comprehensive list of organic solvents and show low vapor concentration sensing (e.g., 0.04% solvent saturation vapor pressure of THF - 66 ppm). The composite films can distinguish between solvent vapors with near complete fluorescent quenching observed when exposed to their saturated solvent vapor pressures, making this an extremely promising material for optical chemo-responsive sensing.
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Affiliation(s)
- Andrew R Brotherton
- Department of Chemistry, University of North Carolina at Charlotte, Charlotte, NC, 28223, USA
| | - Abhishek Shibu
- Department of Chemistry, University of North Carolina at Charlotte, Charlotte, NC, 28223, USA
| | - Jared C Meadows
- Department of Chemistry, University of North Carolina at Charlotte, Charlotte, NC, 28223, USA
| | - Nickolas A Sayresmith
- Department of Chemistry, University of North Carolina at Charlotte, Charlotte, NC, 28223, USA
| | - Chloe E Brown
- Department of Chemistry, University of North Carolina at Charlotte, Charlotte, NC, 28223, USA
| | - Ana Montoya Ledezma
- Department of Chemistry, University of North Carolina at Charlotte, Charlotte, NC, 28223, USA
| | - Thomas A Schmedake
- Department of Chemistry, University of North Carolina at Charlotte, Charlotte, NC, 28223, USA
| | - Michael G Walter
- Department of Chemistry, University of North Carolina at Charlotte, Charlotte, NC, 28223, USA
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4
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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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Sahu S, Parthasarathy V, Mishra AK. Phenylethynylanthracene based push-pull molecular systems: tuning the photophysics through para-substituents on the phenyl ring. Phys Chem Chem Phys 2023; 25:1957-1969. [PMID: 36541448 DOI: 10.1039/d2cp05074a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Organic push-pull molecules contain donor and acceptor moieties connected via π-linkages through which intramolecular electron charge transfer (ICT) can occur in the ground and excited states; giving these molecules interesting photophysical properties. The molecules chosen in this work are some basic phenylethynylanthracene derivatives to show that with just a change of substituents this class of small molecules can show dramatic changes in their photophysical properties. The emission properties and ICT abilities of these molecules are compared with regards to various electron donating and withdrawing substituents. Substituents such as cyano and methoxycarbonyl groups do not induce any ICT character whereas substituents like aldehyde, N,N-dimethylamino and nitro groups cause appreciable ICT character in this class of molecules and their emission spectra extend almost throughout the whole visible region. The comparative ICT character was correlated with the results of electron density difference calculations. Computational studies show that the molecules are planar in their ground as well as excited states; except the nitro group containing molecule, which has an orthogonally twisted structure in the excited state. The emission properties of this molecule led to its inclusion into a class of nitroaromatics which shows maximum emission intensity in moderately polar solvents and the emission is quenched drastically by either decreasing or increasing solvent polarity. Fluorescence anisotropy studies show very good sensitivity of these compounds towards microviscosity of their immediate molecular environment. A white light emitting (WLE) gel was prepared using 4-(anthracen-9-ylethynyl)benzonitrile (AnPCN) and 4-(anthracen-9-ylethynyl)-N,N-dimethylaniline (AnPNMe2) by taking polyvinyl alcohol (PVA) as the gelator and the resulting gel exhibited very good CIE (0.31, 0.33) with CCT (6598 K) and CRI (87). As an example, the use of the gel was also demonstrated by applying it to a commercial UV LED which showed satisfactory results. AnPNMe2 was used to sense polar solvent vapors in TLC plates and Whatman paper due to its good solvatochromic behavior.
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Affiliation(s)
- Sonali Sahu
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, Tamil Nadu, India.
| | | | - Ashok Kumar Mishra
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, Tamil Nadu, India.
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6
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Revealing how proton transfer process of 2-hydroxylbenzophenones affected by the intermolecular hydrogen bond with different para-substituted groups. J Photochem Photobiol A Chem 2022. [DOI: 10.1016/j.jphotochem.2021.113553] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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7
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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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8
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Sadowski B, Kaliszewska M, Poronik YM, Czichy M, Janasik P, Banasiewicz M, Mierzwa D, Gadomski W, Lohrey TD, Clark JA, Łapkowski M, Kozankiewicz B, Vullev VI, Sobolewski AL, Piatkowski P, Gryko DT. Potent strategy towards strongly emissive nitroaromatics through a weakly electron-deficient core. Chem Sci 2021; 12:14039-14049. [PMID: 34760187 PMCID: PMC8565362 DOI: 10.1039/d1sc03670j] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 09/05/2021] [Indexed: 01/16/2023] Open
Abstract
Nitroaromatics seldom fluoresce. The importance of electron-deficient (n-type) conjugates, however, has inspired a number of strategies for suppressing the emission-quenching effects of the strongly electron-withdrawing nitro group. Here, we demonstrate how such strategies yield fluorescent nitroaryl derivatives of dipyrrolonaphthyridinedione (DPND). Nitro groups near the DPND core quench its fluorescence. Conversely, nitro groups placed farther from the core allow some of the highest fluorescence quantum yields ever recorded for nitroaromatics. This strategy of preventing the known processes that compete with photoemission, however, leads to the emergence of unprecedented alternative mechanisms for fluorescence quenching, involving transitions to dark nπ* singlet states and aborted photochemistry. Forming nπ* triplet states from ππ* singlets is a classical pathway for fluorescence quenching. In nitro-DPNDs, however, these ππ* and nπ* excited states are both singlets, and they are common for nitroaryl conjugates. Understanding the excited-state dynamics of such nitroaromatics is crucial for designing strongly fluorescent electron-deficient conjugates.
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Affiliation(s)
- Bartłomiej Sadowski
- Institute of Organic Chemistry, Polish Academy of Sciences Kasprzaka 44/52 01-224 Warsaw Poland
| | - Marzena Kaliszewska
- Faculty of Chemistry, University of Warsaw Zwirki i Wigury 101 02-089 Warsaw Poland
| | - Yevgen M Poronik
- Institute of Organic Chemistry, Polish Academy of Sciences Kasprzaka 44/52 01-224 Warsaw Poland
| | - Małgorzata Czichy
- Faculty of Chemistry, Silesian University of Technology Strzody 9 44-100 Gliwice Poland
| | - Patryk Janasik
- Faculty of Chemistry, Silesian University of Technology Strzody 9 44-100 Gliwice Poland
| | - Marzena Banasiewicz
- Institute of Physics, Polish Academy of Sciences Aleja Lotnikow 32/46 02-668 Warsaw Poland
| | - Dominik Mierzwa
- Institute of Organic Chemistry, Polish Academy of Sciences Kasprzaka 44/52 01-224 Warsaw Poland
| | - Wojciech Gadomski
- Faculty of Chemistry, University of Warsaw Zwirki i Wigury 101 02-089 Warsaw Poland
| | - Trevor D Lohrey
- Department of Chemistry, University of California Berkeley, 420 Latimer Hall Berkeley CA USA
- Chemical Sciences Division, Lawrence Berkeley National Laboratory 1 Cyclotron Road Berkeley CA USA
| | - John A Clark
- Department of Bioengineering, University of California Riverside, 900 University Ave. Riverside CA 92521 USA
| | - Mieczysław Łapkowski
- Faculty of Chemistry, Silesian University of Technology Strzody 9 44-100 Gliwice Poland
| | - Bolesław Kozankiewicz
- Institute of Physics, Polish Academy of Sciences Aleja Lotnikow 32/46 02-668 Warsaw Poland
| | - Valentine I Vullev
- Department of Bioengineering, University of California Riverside, 900 University Ave. Riverside CA 92521 USA
- Department of Chemistry, University of California Riverside, 900 University Ave. Riverside CA 92521 USA
- Department of Biochemistry, University of California Riverside, 900 University Ave. Riverside CA 92521 USA
- Materials Science and Engineering Program, University of California Riverside, 900 University Ave. Riverside CA 92521 USA
| | - Andrzej L Sobolewski
- Institute of Physics, Polish Academy of Sciences Aleja Lotnikow 32/46 02-668 Warsaw Poland
| | - Piotr Piatkowski
- Faculty of Chemistry, University of Warsaw Zwirki i Wigury 101 02-089 Warsaw Poland
| | - Daniel T Gryko
- Institute of Organic Chemistry, Polish Academy of Sciences Kasprzaka 44/52 01-224 Warsaw Poland
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Rybicka-Jasińska K, Espinoza EM, Clark JA, Derr JB, Carlos G, Morales M, Billones MK, O'Mari O, Ågren H, Baryshnikov GV, Vullev VI. Making Nitronaphthalene Fluoresce. J Phys Chem Lett 2021; 12:10295-10303. [PMID: 34653339 PMCID: PMC8800371 DOI: 10.1021/acs.jpclett.1c02155] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Nitroaromatic compounds are inherently nonfluorescent, and the subpicosecond lifetimes of the singlet excited states of many small nitrated polycyclic aromatic hydrocarbons, such as nitronaphthalenes, render them unfeasible for photosensitizers and photo-oxidants, despite their immensely beneficial reduction potentials. This article reports up to a 7000-fold increase in the singlet-excited-state lifetime of 1-nitronaphthalene upon attaching an amine or an N-amide to the ring lacking the nitro group. Varying the charge-transfer (CT) character of the excited states and the medium polarity balances the decay rates along the radiative and the two nonradiative pathways and can make these nitronaphthalene derivatives fluoresce. The strong electron-donating amine suppresses intersystem crossing (ISC) but accommodates CT pathways of nonradiate deactivation. Conversely, the N-amide does not induce a pronounced CT character but slows down ISC enough to achieve relatively long lifetimes of the singlet excited state. These paradigms are key for the pursuit of electron-deficient (n-type) organic conjugates with promising optical characteristics.
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Affiliation(s)
| | - Eli M Espinoza
- Department of Chemistry, University of California, Riverside, California 92521, United States
| | - John A Clark
- Department of Bioengineering, University of California, Riverside, California 92521, United States
| | - James B Derr
- Department of Biochemistry, University of California, Riverside, California 92521, United States
| | - Gregory Carlos
- Department of Biology, University of California, Riverside, California 92521, United States
| | - Maryann Morales
- Department of Chemistry, University of California, Riverside, California 92521, United States
| | - Mimi Karen Billones
- Department of Biology, University of California, Riverside, California 92521, United States
| | - Omar O'Mari
- Department of Bioengineering, University of California, Riverside, California 92521, United States
| | - Hans Ågren
- Department of Physics and Astronomy, Uppsala University, SE-751 20 Uppsala, Sweden
| | - Glib V Baryshnikov
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, SE-60174 Norrköping, Sweden
| | - Valentine I Vullev
- Department of Bioengineering, University of California, Riverside, California 92521, United States
- Department of Chemistry, University of California, Riverside, California 92521, United States
- Department of Biochemistry, University of California, Riverside, California 92521, United States
- Materials Science and Engineering Program, University of California, Riverside, California 92521, United States
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10
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Poronik YM, Baryshnikov GV, Deperasińska I, Espinoza EM, Clark JA, Ågren H, Gryko DT, Vullev VI. Deciphering the unusual fluorescence in weakly coupled bis-nitro-pyrrolo[3,2-b]pyrroles. Commun Chem 2020; 3:190. [PMID: 36703353 PMCID: PMC9814504 DOI: 10.1038/s42004-020-00434-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 11/13/2020] [Indexed: 01/29/2023] Open
Abstract
Electron-deficient π-conjugated functional dyes lie at the heart of organic optoelectronics. Adding nitro groups to aromatic compounds usually quenches their fluorescence via inter-system crossing (ISC) or internal conversion (IC). While strong electronic coupling of the nitro groups with the dyes ensures the benefits from these electron-withdrawing substituents, it also leads to fluorescence quenching. Here, we demonstrate how such electronic coupling affects the photophysics of acceptor-donor-acceptor fluorescent dyes, with nitrophenyl acceptors and a pyrrolo[3,2-b]pyrrole donor. The position of the nitro groups and the donor-acceptor distance strongly affect the fluorescence properties of the bis-nitrotetraphenylpyrrolopyrroles. Concurrently, increasing solvent polarity quenches the emission that recovers upon solidifying the media. Intramolecular charge transfer (CT) and molecular dynamics, therefore, govern the fluorescence of these nitro-aromatics. While balanced donor-acceptor coupling ensures fast radiative deactivation and slow ISC essential for large fluorescence quantum yields, vibronic borrowing accounts for medium dependent IC via back CT. These mechanistic paradigms set important design principles for molecular photonics and electronics.
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Affiliation(s)
- Yevgen M. Poronik
- grid.413454.30000 0001 1958 0162Institute of Organic Chemistry, Polish Academy of Sciences, Warsaw, Poland
| | - Glib V. Baryshnikov
- grid.8993.b0000 0004 1936 9457Department of Physics and Astronomy, Uppsala University, Uppsala, Sweden
| | - Irena Deperasińska
- grid.413454.30000 0001 1958 0162Institute of Physics, Polish Academy of Sciences, Warsaw, Poland
| | - Eli M. Espinoza
- grid.266097.c0000 0001 2222 1582Department of Chemistry, University of California, Riverside, CA USA ,grid.47840.3f0000 0001 2181 7878Present Address: College of Bioengineering, University of California, Berkeley, CA 94720 USA
| | - John A. Clark
- grid.266097.c0000 0001 2222 1582Department of Bioengineering, University of California, Riverside, CA USA
| | - Hans Ågren
- grid.8993.b0000 0004 1936 9457Department of Physics and Astronomy, Uppsala University, Uppsala, Sweden ,grid.77602.340000 0001 1088 3909Department of Physics, Tomsk State University, 36 Lenin Avenue, Tomsk, 634050 Russian Federation
| | - Daniel T. Gryko
- grid.413454.30000 0001 1958 0162Institute of Organic Chemistry, Polish Academy of Sciences, Warsaw, Poland
| | - Valentine I. Vullev
- grid.266097.c0000 0001 2222 1582Department of Chemistry, University of California, Riverside, CA USA ,grid.266097.c0000 0001 2222 1582Department of Bioengineering, University of California, Riverside, CA USA ,grid.266097.c0000 0001 2222 1582Department of Biochemistry, University of California, Riverside, CA USA ,grid.266097.c0000 0001 2222 1582Materials Science and Engineering Program, University of California, Riverside, CA USA
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Chen MC, Chen DG, Chou PT. Fluorescent Chromophores Containing the Nitro Group: Relatively Unexplored Emissive Properties. Chempluschem 2020; 86:11-27. [PMID: 33094565 DOI: 10.1002/cplu.202000592] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 10/05/2020] [Indexed: 12/13/2022]
Abstract
Apart from numerous applications, for example in azo dye precursors, explosives, and industrial processes, the nitro group (-NO2 ) appears on countless molecules in photochemical research owing to its unique characteristics such as a strong electron-withdrawing ability and facile conversion to the reduced substituent. Although it is well known as a fluorescence quencher, fluorescent chromophores that contain the nitro group have also emerged, with 3-nitrophenothiazine being recently reported to have 100 % emission quantum yield in nonpolar solvents. The diverse characters of nitro-containing chromophores motivated us to systematically review those chromophores with nitro substituents, their associated photophysical properties, and applications. In this Review, we succinctly elaborate the advance of the fluorescent nitro chromophores in fields of intramolecular charge transfer, fluorescent probes and nonlinear properties. Special attention is paid to the rationalization of the associated emission spectroscopy, so that the readers can gain insights into the structure-photophysics relationship and hence gain insights for the strategic design of nitro chromophores.
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Affiliation(s)
- Meng-Chi Chen
- Department of Chemistry, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei, 10617, Taiwan
| | - Deng-Gao Chen
- Department of Chemistry, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei, 10617, Taiwan
| | - Pi-Tai Chou
- Department of Chemistry, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei, 10617, Taiwan
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12
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Li B, Zhang TS, Xue J, Xie BB, Fang WH, Shen L. Theoretical studies on the photochemistry of 2-nitrofluorene in the gas phase and acetonitrile solution. Phys Chem Chem Phys 2020; 22:16772-16782. [PMID: 32662496 DOI: 10.1039/d0cp01969k] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The photophysical and photochemical mechanisms of 2-nitrofluorene (2-NF) in the gas phase and acetonitrile solution have been studied theoretically. Upon ∼330 nm irradiation to the first bright state (1ππ*), the 2-NF system can decay to triplet excited states via rapid intersystem crossing (ISC) processes through different surface crossing points or to the ground state via an ultrafast internal conversion (IC) process through the S1/S0 conical intersection. The 1nπ* dark state will serve as a bridge when the system leaves the Franck-Condon (FC) region and approaches to the S1 minimum. The molecule maintains a planar geometry during the excited-state relaxation processes. The differences on excitation properties such as electronic configurations and spin-orbit coupling (SOC) interactions between those in the gas phase and acetonitrile solution cannot be neglected, indicating possible changes on the efficiency of the related ISC processes for the 2-NF system in solution. Once arrived at the T1 state, it would further decay to the S0 state or photodegrade into the Ar-O˙ and NO˙ free radicals. During the intramolecular rearrangement process, the twisting of the nitro group out of the aromatic-ring plane is regarded as a critical structural variation for the photodegradation of the 2-NF system. The free radicals finally form through oxaziridine-type intermediate and transition state structures. The present work provides important mechanistic insights to the photochemistry of nitro-substituted polyaromatic compounds.
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Affiliation(s)
- Bo Li
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou 311231, Zhejiang, P. R. China.
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13
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Cadena-Caicedo A, Gonzalez-Cano B, López-Arteaga R, Esturau-Escofet N, Peon J. Ultrafast Fluorescence Signals from β-Dihydronicotinamide Adenine Dinucleotide: Resonant Energy Transfer in the Folded and Unfolded Forms. J Phys Chem B 2020; 124:519-530. [PMID: 31876417 DOI: 10.1021/acs.jpcb.9b10012] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
β-Dihydronicotinamide adenine dinucleotide (NADH) plays a critical role in biological redox processes. Inside the cell, NADH can be in a folded or an unfolded conformation, depending on the chemical environment that surrounds it. It is known that selective excitation of adenine in NADH can induce energy transfer events from this nucleotide to the reduced nicotinamide chromophore. From the anticipated time scales, this process must compete with adenine's internal conversion channel, which is known to occur in the sub-picosecond time scale. In this work, we studied the dynamics of the excited states of both chromophores in NADH through the time resolution of the spontaneous emission from both nucleotides. Through these experiments, we extend the knowledge about the competition between the different photophysical channels both in the folded and unfolded states. The study involved the folded and unfolded states of NADH by experiments in water and methanol solutions. Our femtosecond fluorescence results were complemented by the first nuclear magnetic resonance through space magnetization transfer measurements on NADH, which establish the solvent-dependent folded versus unfolded states. We determined the dynamics of the excited states by direct excitation of dihydronicotinamide at 380 nm and adenine at 266 nm. From this, we were able to measure for the folded state, a time constant of 90 fs for energy transfer. Additionally, we determined that even in what is referred to as an unfolded state in methanol, non-negligible excitation transfer events do take place. Spontaneous emission anisotropy measurements were used in order to confirm the presence of a minor energy transfer channel in the methanol solutions where the unfolded state dominates.
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Affiliation(s)
- Andrea Cadena-Caicedo
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior , Ciudad Universitaria , Ciudad de México 04510 , Mexico
| | - Beatriz Gonzalez-Cano
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior , Ciudad Universitaria , Ciudad de México 04510 , Mexico
| | - Rafael López-Arteaga
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior , Ciudad Universitaria , Ciudad de México 04510 , Mexico
| | - Nuria Esturau-Escofet
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior , Ciudad Universitaria , Ciudad de México 04510 , Mexico
| | - Jorge Peon
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior , Ciudad Universitaria , Ciudad de México 04510 , Mexico
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14
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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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15
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Flores-Cruz R, López-Arteaga R, Ramírez-Vidal L, López-Casillas F, Jiménez-Sánchez A. Unravelling the modus-operandi of chromenylium-cyanine fluorescent probes: a case study. Phys Chem Chem Phys 2019; 21:15779-15786. [PMID: 31282523 DOI: 10.1039/c9cp03256h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Small-molecule fluorescent probes having optimized optical properties, such as high photostability and brightness, local microenvironment sensitivity and specific subcellular localizations, are increasingly available. Although the basis for designing efficient fluorophores for bioimaging applications is well established, implementing an improvement in a given photophysical characteristic always tends to compromise another optical property. This problem has enormous consequences for in vivo imaging, where ensuring a specific localization and precise control of the probe response is challenging. Herein we discuss a fluorescent probe, CC334, as a case study of the chromenylium-cyanine family that commonly exhibits highly complex photophysical schemes and highly interfered bioanalytical responses. By an exhaustive and concise analysis of the CC334 optical responses including detailed spectroscopic calibrations, steady-state microenvironment effects, ultrafast photophysics analysis and computational studies, we elucidate a new strategy to apply the probe in the singlet oxygen reactive oxygen species (1O2-ROS) monitoring using in vitro and in vivo models. The probe provides a new avenue for designing fluorescent probes to understand the dynamic behavior of subcellular environments.
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Affiliation(s)
- Ricardo Flores-Cruz
- Instituto de Química, Universidad Nacional Autónoma de México, México D.F., No. 04510, Mexico.
| | - Rafael López-Arteaga
- Instituto de Química, Universidad Nacional Autónoma de México, México D.F., No. 04510, Mexico.
| | - Lizbeth Ramírez-Vidal
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México D.F., No. 04510, Mexico
| | - Fernando López-Casillas
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México D.F., No. 04510, Mexico
| | - Arturo Jiménez-Sánchez
- Instituto de Química, Universidad Nacional Autónoma de México, México D.F., No. 04510, Mexico.
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16
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Ciavardini A, Coreno M, Callegari C, Spezzani C, De Ninno G, Ressel B, Grazioli C, de Simone M, Kivimäki A, Miotti P, Frassetto F, Poletto L, Puglia C, Fornarini S, Pezzella M, Bodo E, Piccirillo S. Ultra-Fast-VUV Photoemission Study of UV Excited 2-Nitrophenol. J Phys Chem A 2019; 123:1295-1302. [DOI: 10.1021/acs.jpca.8b10136] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Alessandra Ciavardini
- Dipartimento di Chimica e Tecnologie del Farmaco, Università di Roma “La Sapienza”, Ple A. Moro, 5, 00185 Rome, Italy
- Dipartimento di Scienze e Tecnologie Chimiche, Università di Roma “Tor Vergata”, Via della Ricerca Scientifica, 00133 Rome, Italy
| | - Marcello Coreno
- ISM-CNR, in Basovizza Area Science Park, 34149 Trieste, Italy
- Elettra - Sincrotrone Trieste, ss. 14, Km. 163,5, 34149 Trieste, Italy
| | - Carlo Callegari
- Elettra - Sincrotrone Trieste, ss. 14, Km. 163,5, 34149 Trieste, Italy
| | - Carlo Spezzani
- Elettra - Sincrotrone Trieste, ss. 14, Km. 163,5, 34149 Trieste, Italy
| | - Giovanni De Ninno
- Elettra - Sincrotrone Trieste, ss. 14, Km. 163,5, 34149 Trieste, Italy
- Laboratory of Quantum Optics, University of Nova Gorica, Vipavska 11c, SI-5270 Ajdovščina, Slovenia
| | - Barbara Ressel
- Elettra - Sincrotrone Trieste, ss. 14, Km. 163,5, 34149 Trieste, Italy
- Laboratory of Quantum Optics, University of Nova Gorica, Vipavska 11c, SI-5270 Ajdovščina, Slovenia
| | - Cesare Grazioli
- Laboratorio TASV, IOM-CNR, Basovizza SS-14, km 163.5, 34012 Trieste, Italy
| | - Monica de Simone
- Laboratorio TASV, IOM-CNR, Basovizza SS-14, km 163.5, 34012 Trieste, Italy
| | - Antti Kivimäki
- Laboratorio TASV, IOM-CNR, Basovizza SS-14, km 163.5, 34012 Trieste, Italy
| | - Paolo Miotti
- Padova Research Unit, IFN-CNR, Via Trasea 7, I-35131 Padova, Italy
| | - Fabio Frassetto
- Padova Research Unit, IFN-CNR, Via Trasea 7, I-35131 Padova, Italy
| | - Luca Poletto
- Padova Research Unit, IFN-CNR, Via Trasea 7, I-35131 Padova, Italy
| | - Carla Puglia
- Department of Physics and Astronomy, Uppsala University, SE-75120 Uppsala, Sweden
| | - Simonetta Fornarini
- Dipartimento di Chimica e Tecnologie del Farmaco, Università di Roma “La Sapienza”, Ple A. Moro, 5, 00185 Rome, Italy
| | - Marco Pezzella
- Dipartimento di Chimica, Università di Roma “La Sapienza”, Ple A. Moro, 5, 00185 Rome, Italy
| | - Enrico Bodo
- Dipartimento di Chimica, Università di Roma “La Sapienza”, Ple A. Moro, 5, 00185 Rome, Italy
| | - Susanna Piccirillo
- Dipartimento di Scienze e Tecnologie Chimiche, Università di Roma “Tor Vergata”, Via della Ricerca Scientifica, 00133 Rome, Italy
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17
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Kumari B, Paramasivam M, Dutta A, Kanvah S. Emission and Color Tuning of Cyanostilbenes and White Light Emission. ACS OMEGA 2018; 3:17376-17385. [PMID: 31458345 PMCID: PMC6643655 DOI: 10.1021/acsomega.8b02775] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 11/30/2018] [Indexed: 06/10/2023]
Abstract
White-light-emitting diodes are energy efficiency replacement of conventional lighting sources. Herein, we report the luminescent behavior of three simple cyanostilbenes with triphenylamine-donating groups bearing different electron-withdrawing groups (phenyl, pyridyl, and p-nitrophenyl) in a common donor (D)-π-acceptor (A) α-cyanostilbene construct along with their thermal and electrochemical properties. The density functional theory (DFT) studies reveal that aggregation-induced emission characteristic feature of the D-π-A dyes is inversely proportional to the intramolecular charge transfer (ICT) effect, that is, phenyl-and pyridyl-substituted compounds show characteristic aggregation-induced emission in water, whereas the ICT effect is dominant for the nitro derivative. The extent of ICT and the solvatochromic emission shifts, from blue to red, depend on the strength of the electron-withdrawing group. White luminescence and tunable emission colors are obtained by careful admixtures of these cyanostilbenes bearing triphenylamines. The results rationalized through DFT and time-dependent DFT calculations follow a consistent trend with the energy levels measured from the electrochemical and optical studies. Thermogravimetric analysis and differential scanning calorimetry studies showed excellent thermal stability of the compounds. The scanning electron microscopy and dynamic light scattering measurements were performed to reveal the formation of aggregates. This strategy involving synthetically simple and structurally similar molecules with different emission properties has potential applications in the fabrication of multicolor and white-light-emitting materials.
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Affiliation(s)
- Beena Kumari
- Department of Chemistry, Indian
Institute of Technology Gandhinagar,
Palaj, Gandhinagar 382
355, India
| | | | - Arnab Dutta
- Department of Chemistry, Indian
Institute of Technology Gandhinagar,
Palaj, Gandhinagar 382
355, India
| | - Sriram Kanvah
- Department of Chemistry, Indian
Institute of Technology Gandhinagar,
Palaj, Gandhinagar 382
355, India
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18
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Khatun R, Majhi K, Meriga V, Chakraborty AK, Sinha S. Detail Photophysical Studies of Sulfonated Polyaniline in Aqueous Medium. J Phys Chem A 2018; 122:7089-7098. [DOI: 10.1021/acs.jpca.8b06640] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Rijia Khatun
- Integrated Science Education and Research Centre, Siksha Bhavana, Visva-Bharati, Santiniketan 731 235, India
| | - Koushik Majhi
- Integrated Science Education and Research Centre, Siksha Bhavana, Visva-Bharati, Santiniketan 731 235, India
| | - Venkanna Meriga
- Carbon Nanotechnology Laboratory, Department of Physics, National Institute of Technology Durgapur, M. G. Avenue, Durgapur 713 209, India
| | - Amit K. Chakraborty
- Carbon Nanotechnology Laboratory, Department of Physics, National Institute of Technology Durgapur, M. G. Avenue, Durgapur 713 209, India
| | - Subrata Sinha
- Integrated Science Education and Research Centre, Siksha Bhavana, Visva-Bharati, Santiniketan 731 235, India
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19
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Zobel JP, Nogueira JJ, González L. Mechanism of Ultrafast Intersystem Crossing in 2-Nitronaphthalene. Chemistry 2018; 24:5379-5387. [PMID: 29377370 PMCID: PMC5947663 DOI: 10.1002/chem.201705854] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2017] [Indexed: 01/10/2023]
Abstract
Nitronaphthalene derivatives efficiently populate their electronically excited triplet states upon photoexcitation through ultrafast intersystem crossing (ISC). Despite having been studied extensively by time-resolved spectroscopy, the reasons behind their ultrafast ISC remain unknown. Herein, we present the first ab initio nonadiabatic molecular dynamics study of a nitronaphthalene derivative, 2-nitronaphthalene, including singlet and triplet states. We find that there are two distinct ISC reaction pathways involving different electronic states at distinct nuclear configurations. The high ISC efficiency is explained by the very small electronic and nuclear alterations that the chromophore needs to undergo during the singlet-triplet transition in the dominating ISC pathway after initial dynamics in the singlet manifold. The insights gained in this work are expected to shed new light on the photochemistry of other nitro polycyclic aromatic hydrocarbons that exhibit ultrafast intersystem crossing.
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Affiliation(s)
- J. Patrick Zobel
- Institute of Theoretical Chemistry, Faculty of ChemistryUniversity of ViennaWähringer Straße 171090ViennaAustria
| | - Juan J. Nogueira
- Institute of Theoretical Chemistry, Faculty of ChemistryUniversity of ViennaWähringer Straße 171090ViennaAustria
| | - Leticia González
- Institute of Theoretical Chemistry, Faculty of ChemistryUniversity of ViennaWähringer Straße 171090ViennaAustria
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20
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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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21
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Stepwise photoinduced transformation of fused aziridines via stable biradicals and azomethine ylides. J Photochem Photobiol A Chem 2018. [DOI: 10.1016/j.jphotochem.2017.11.053] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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22
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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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23
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Gutiérrez-Arzaluz L, López-Arteaga R, Cortés-Guzmán F, Peon J. Nitrated Fluorophore Formation upon Two-Photon Excitation of an Azide with Extended Conjugation. J Phys Chem B 2017; 121:9910-9919. [PMID: 28981286 DOI: 10.1021/acs.jpcb.7b09446] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The transformation of an aromatic azide into a highly fluorescent species through a nonlinear optical process was studied. The azide system was designed to undergo N2 release and nitrene to nitro conversion upon two-photon electronic excitation. The formation of the nitro form of the compound through reactions with O2 and its high radiative quantum yield implies that the azide can be used as a biphotonic activatable fluorogen. The electronic state in which the azide to nitrene transformation takes place can be accessed nonlinearly with near-infrared light which allows for photoactivation with commonly available lasers. Furthermore, the system was built with a sulfonate functionality which allows for the molecule to be adsorbed at surfaces like that of cadmium sulfide nanocrystals which further improves the nonlinear optical absorption properties in the composite, through an energy transfer mechanism. The yield of the process as a function of the excitation photon energy together with computational studies indicate that the N2 release in this azide is due to a reactive channel in the second singlet excited state of the molecule. This feature implies that the system is intrinsically photostable for excitation below and above a certain wavelength and that the system can be phototriggered selectively by the nonlinear optical process.
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Affiliation(s)
- Luis Gutiérrez-Arzaluz
- Instituto de Química, Universidad Nacional Autónoma de México , Circuito Exterior, Ciudad Universitaria, México, 04510, México
| | - Rafael López-Arteaga
- Instituto de Química, Universidad Nacional Autónoma de México , Circuito Exterior, Ciudad Universitaria, México, 04510, México
| | - Fernando Cortés-Guzmán
- Instituto de Química, Universidad Nacional Autónoma de México , Circuito Exterior, Ciudad Universitaria, México, 04510, México
| | - Jorge Peon
- Instituto de Química, Universidad Nacional Autónoma de México , Circuito Exterior, Ciudad Universitaria, México, 04510, México
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24
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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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25
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Stephansen AB, Sølling TI. Distortion dependent intersystem crossing: A femtosecond time-resolved photoelectron spectroscopy study of benzene, toluene, and p-xylene. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2017; 4:044008. [PMID: 28345010 PMCID: PMC5336472 DOI: 10.1063/1.4977735] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 02/16/2017] [Indexed: 05/05/2023]
Abstract
The competition between ultrafast intersystem crossing and internal conversion in benzene, toluene, and p-xylene is investigated with time-resolved photoelectron spectroscopy and quantum chemical calculations. By exciting to S2 out-of-plane symmetry breaking, distortions are activated at early times whereupon spin-forbidden intersystem crossing becomes (partly) allowed. Natural bond orbital analysis suggests that the pinnacle carbon atoms distorting from the aromatic plane change hybridization between the planar Franck-Condon geometry and the deformed (boat-shaped) S2 equilibrium geometry. The effect is observed to increase in the presence of methyl-groups on the pinnacle carbon-atoms, where largest extents of σ and π orbital-mixing are observed. This is fully consistent with the time-resolved spectroscopy data: Toluene and p-xylene show evidence for ultrafast triplet formation competing with internal conversion, while benzene appears to only decay via internal conversion within the singlet manifold. For toluene and p-xylene, internal conversion to S1 and intersystem crossing to T3 occur within the time-resolution of our instrument. The receiver triplet state (T3) is found to undergo internal conversion in the triplet manifold within ≈100-150 fs (toluene) or ≈180-200 fs (p-xylene) as demonstrated by matching rise and decay components of upper and lower triplet states. Overall, the effect of methylation is found to both increase the intersystem crossing probability and direct the molecular axis of the excited state dynamics.
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Affiliation(s)
- Anne B Stephansen
- Department of Chemistry, University of Copenhagen , Universitetsparken 5, DK-2100 København Ø, Denmark
| | - Theis I Sølling
- Department of Chemistry, University of Copenhagen , Universitetsparken 5, DK-2100 København Ø, Denmark
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26
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Kumpulainen T, Lang B, Rosspeintner A, Vauthey E. Ultrafast Elementary Photochemical Processes of Organic Molecules in Liquid Solution. Chem Rev 2016; 117:10826-10939. [DOI: 10.1021/acs.chemrev.6b00491] [Citation(s) in RCA: 249] [Impact Index Per Article: 31.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Tatu Kumpulainen
- Department of Physical Chemistry,
Sciences II, University of Geneva, 30 Quai Ernest Ansermet, CH-1211 Geneva 4, Switzerland
| | - Bernhard Lang
- Department of Physical Chemistry,
Sciences II, University of Geneva, 30 Quai Ernest Ansermet, CH-1211 Geneva 4, Switzerland
| | - Arnulf Rosspeintner
- Department of Physical Chemistry,
Sciences II, University of Geneva, 30 Quai Ernest Ansermet, CH-1211 Geneva 4, Switzerland
| | - Eric Vauthey
- Department of Physical Chemistry,
Sciences II, University of Geneva, 30 Quai Ernest Ansermet, CH-1211 Geneva 4, Switzerland
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27
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Le VS, Jeong JE, Huynh HT, Lee J, Woo HY. An Ionic 1,4-Bis(styryl)benzene-Based Fluorescent Probe for Mercury(II) Detection in Water via Deprotection of the Thioacetal Group. SENSORS 2016; 16:s16122082. [PMID: 27941624 PMCID: PMC5191063 DOI: 10.3390/s16122082] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 11/30/2016] [Accepted: 12/05/2016] [Indexed: 11/24/2022]
Abstract
Highly sensitive and selective mercury detection in aqueous media is urgently needed because mercury poisoning usually results from exposure to water-soluble forms of mercury by inhalation and/or ingesting. An ionic conjugated oligoelectrolye (M1Q) based on 1,4-bis(styryl)benzene was synthesized as a fluorescent mercury(II) probe. The thioacetal moiety and quaternized ammonium group were incorporated for Hg2+ recognition and water solubility. A neutral Hg2+ probe (M1) was also prepared based on the same molecular backbone, and their sensor characteristics were investigated in a mixture of acetonitrile/water and in water. In the presence of Hg2+, the thioacetal group was converted to aldehyde functionality, and the resulting photoluminescence intensity decreased. In water, M1Q successfully demonstrated highly sensitive detection, showing a binding toward Hg2+ that was ~15 times stronger and a signal on/off ratio twice as high, compared to M1 in acetonitrile/water. The thioacetal deprotection by Hg2+ ions was substantially facilitated in water without an organic cosolvent. The limit of detection was measured to be 7 nM with a detection range of 10–180 nM in 100% aqueous medium.
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Affiliation(s)
- Van Sang Le
- Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 46241, Korea.
| | - Ji-Eun Jeong
- Department of Chemistry, Korea University, Seoul 02841, Korea.
| | - Huy Tuan Huynh
- Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 46241, Korea.
| | - Jiae Lee
- Department of Chemistry, Korea University, Seoul 02841, Korea.
| | - Han Young Woo
- Department of Chemistry, Korea University, Seoul 02841, Korea.
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28
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Zhu H, Li M, Hu J, Wang X, Jie J, Guo Q, Chen C, Xia A. Ultrafast Investigation of Intramolecular Charge Transfer and Solvation Dynamics of Tetrahydro[5]-helicene-Based Imide Derivatives. Sci Rep 2016; 6:24313. [PMID: 27074814 PMCID: PMC4830958 DOI: 10.1038/srep24313] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 03/24/2016] [Indexed: 11/09/2022] Open
Abstract
We report the excited-state intramolecular charge transfer (ICT) characteristics of four tetrahydro[5] helicene-based imide (THHBI) derivatives with various electron-donating substitutes in different polarity of solvents using steady-state, time-resolved transient absorption (TA) spectroscopy. It is found that, the small bathochromic-shift of the absorption spectra but large red shift of the emission spectra for all dyes with increasing solvent polarity indicates the larger dipole moment of the excited state compared to ground state. The results of theoretical calculations exhibit the charge transfer from the terminal donors to helical backbone, which accounts for the degrees of red shift of the emission spectra from different extent of ICT nature. Time-resolved TA spectra recorded as a function of electron-donating substitutes and solvent polarity show the dye with stronger donors (THHBI-PhNPh2) in more polar solvent behaves faster excited-state ICT relaxation, leading to the formation of solvent-stabilized ICT state (ICT' state) from the excited ICT state; The dyes (THHBI-Ph, THHBI-PhCF3 and THHBI-PhOMe) with relative weaker donors show weaker dependence on solvent polarity, and instead of that intersystem crossing (ISC) becomes possible from ICT state to triplet state.
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Affiliation(s)
- Huaning Zhu
- Key Laboratory of Photochemistry, Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Meng Li
- Key Laboratory of Molecular Recognition and Function, Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Jiangpu Hu
- Key Laboratory of Photochemistry, Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Xian Wang
- Key Laboratory of Photochemistry, Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Jialong Jie
- Key Laboratory of Photochemistry, Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Qianjin Guo
- Key Laboratory of Photochemistry, Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Chuanfeng Chen
- Key Laboratory of Molecular Recognition and Function, Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Andong Xia
- Key Laboratory of Photochemistry, Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
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29
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Talone CJ, Gao J, Lynch JR, Tanu RM, Deyrup ST. Determination of the ground- and excited-state dipole moments of bromocresol purple in protic and aprotic solvents. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2016; 156:138-42. [PMID: 26684025 DOI: 10.1016/j.saa.2015.11.034] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 11/24/2015] [Accepted: 11/28/2015] [Indexed: 05/26/2023]
Abstract
Although it has been widely recognized that hydrogen bonds play a significant role in the photophysics of molecules, this phenomenon has rarely been applied to the solvatochromic method for determination of dipole moments. The difference in the dipole moment between the ground and excited state was determined in protic and aprotic solvents using both the Lippert-Mataga equation and the Bilot-Kawski equation for bromocresol purple, a molecule capable of hydrogen-bond donation and acceptance. The dipole change in protic environments was determined to be 15.2 ± 1.0 D for the Lippert-Mataga method and 9.2 ± 1.0 D for the Bilot-Kawski method, while the change in aprotic environments was 10.4 ± 1.0 D and 6.7 ± 1.0 D, respectively. Both methods highlighted the importance of hydrogen bonding in stabilizing increased charge-separation of the excited state, allowing for larger changes in dipole moments in protic environments. This study further validates a simple, rational modification to the commonly used methods that allows access to dipole-moment data on dyes with hydrogen-bonding capabilities through solvatochromic experiments.
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Affiliation(s)
- Christopher J Talone
- Department of Chemistry and Biochemistry, Siena College, Loudonville, NY 12211, USA
| | - Jingya Gao
- Department of Chemistry and Biochemistry, Siena College, Loudonville, NY 12211, USA
| | - James R Lynch
- Department of Chemistry and Biochemistry, Siena College, Loudonville, NY 12211, USA
| | - Rhoda M Tanu
- Department of Chemistry and Biochemistry, Siena College, Loudonville, NY 12211, USA
| | - Stephen T Deyrup
- Department of Chemistry and Biochemistry, Siena College, Loudonville, NY 12211, USA.
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30
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Yi J, Xiong Y, Cheng K, Li M, Chu G, Pu X, Xu T. A Combination of Chemometrics and Quantum Mechanics Methods Applied to Analysis of Femtosecond Transient Absorption Spectrum of Ortho-Nitroaniline. Sci Rep 2016; 6:19364. [PMID: 26781083 PMCID: PMC4726040 DOI: 10.1038/srep19364] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 12/11/2015] [Indexed: 12/19/2022] Open
Abstract
A combination of the advanced chemometrics method with quantum mechanics calculation was for the first time applied to explore a facile yet efficient analysis strategy to thoroughly resolve femtosecond transient absorption spectroscopy of ortho-nitroaniline (ONA), served as a model compound of important nitroaromatics and explosives. The result revealed that the ONA molecule is primarily excited to S3 excited state from the ground state and then ultrafast relaxes to S2 state. The internal conversion from S2 to S1 occurs within 0.9 ps. One intermediate state S* was identified in the intersystem crossing (ISC) process, which is different from the specific upper triplet receiver state proposed in some other nitroaromatics systems. The S1 state decays to the S* one within 6.4 ps and then intersystem crossing to the lowest triplet state within 19.6 ps. T1 was estimated to have a lifetime up to 2 ns. The relatively long S* state and very long-lived T1 one should play a vital role as precursors to various nitroaromatic and explosive photoproducts.
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Affiliation(s)
- Jing Yi
- College of Chemistry, Sichuan University, Chengdu 610064, People's Republic of China
| | - Ying Xiong
- Institute of Chemical Material, China Academy of Engineering Physics (CAEP), Mianyang 621900, People's Republic of China
| | - Kemei Cheng
- Institute of Chemical Material, China Academy of Engineering Physics (CAEP), Mianyang 621900, People's Republic of China
| | - Menglong Li
- College of Chemistry, Sichuan University, Chengdu 610064, People's Republic of China
| | - Genbai Chu
- Science and Technology on Plasma Physics Laboratory, Research Center of Laser Fusion, CAEP, Mianyang 621900, People's Republic of China
| | - Xuemei Pu
- College of Chemistry, Sichuan University, Chengdu 610064, People's Republic of China
| | - Tao Xu
- Institute of Chemical Material, China Academy of Engineering Physics (CAEP), Mianyang 621900, People's Republic of China
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31
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Stephansen AB, Larsen MAB, Sølling TI. The involvement of triplet receiver states in the ultrafast excited state processes of small esters. Phys Chem Chem Phys 2016; 18:24484-97. [DOI: 10.1039/c6cp04046b] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The photoinduced processes of methyl formate and methyl acetate have been probed by femtosecond time-resolved mass spectrometry and photoelectron spectroscopy experiments supported by quantum chemical calculations.
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Affiliation(s)
- A. B. Stephansen
- Department of Chemistry
- Københavns Universitet Det Natur- og Biovidenskabelige Fakultet
- København Ø
- Denmark
| | - M. A. B. Larsen
- Department of Chemistry
- Københavns Universitet Det Natur- og Biovidenskabelige Fakultet
- København Ø
- Denmark
| | - T. I. Sølling
- Department of Chemistry
- Københavns Universitet Det Natur- og Biovidenskabelige Fakultet
- København Ø
- Denmark
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32
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Larsen MAB, Thøgersen J, Stephansen AB, Peon J, Sølling TI, Keiding SR. Transient IR Spectroscopic Observation of Singlet and Triplet States of 2-Nitrofluorene: Revisiting the Photophysics of Nitroaromatics. J Phys Chem A 2015; 120:28-35. [DOI: 10.1021/acs.jpca.5b09125] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Martin A. B. Larsen
- Department
of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen Ø, Denmark
| | - Jan Thøgersen
- Department
of Chemistry, Aarhus University, Langelandsgade 140, DK-8000 Aarhus C, Denmark
| | - Anne B. Stephansen
- 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 04510, D.F. México
| | - Theis I. Sølling
- Department
of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen Ø, Denmark
| | - Søren R. Keiding
- Department
of Chemistry, Aarhus University, Langelandsgade 140, DK-8000 Aarhus C, Denmark
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33
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Carlotti B, Elisei F, Mazzucato U, Spalletti A. Unusual high fluorescence of two nitro-distyrylbenzene-like compounds induced by CT processes affecting the fluorescence/intersystem-crossing competition. Phys Chem Chem Phys 2015; 17:14740-9. [DOI: 10.1039/c5cp00291e] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Fluorescence/intersystem crossing/photoisomerization competition in the relaxation of nitro-substituted distyrylbenzene-like compounds: charge transfer induced, unusually high, fluorescence yield in polar solvents.
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Affiliation(s)
- B. Carlotti
- Department of Chemistry
- Biology and Biotechnology and Centro di Eccellenza sui Materiali Innovativi Nanostrutturati (CEMIN)
- University of Perugia
- 06123 Perugia
- Italy
| | - F. Elisei
- Department of Chemistry
- Biology and Biotechnology and Centro di Eccellenza sui Materiali Innovativi Nanostrutturati (CEMIN)
- University of Perugia
- 06123 Perugia
- Italy
| | - U. Mazzucato
- Department of Chemistry
- Biology and Biotechnology and Centro di Eccellenza sui Materiali Innovativi Nanostrutturati (CEMIN)
- University of Perugia
- 06123 Perugia
- Italy
| | - A. Spalletti
- Department of Chemistry
- Biology and Biotechnology and Centro di Eccellenza sui Materiali Innovativi Nanostrutturati (CEMIN)
- University of Perugia
- 06123 Perugia
- Italy
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34
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Richter M, Mai S, Marquetand P, González L. Ultrafast intersystem crossing dynamics in uracil unravelled by ab initio molecular dynamics. Phys Chem Chem Phys 2014; 16:24423-36. [PMID: 25301389 PMCID: PMC4391640 DOI: 10.1039/c4cp04158e] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 10/03/2014] [Indexed: 11/21/2022]
Abstract
Ab initio molecular dynamics simulations have been performed in order to investigate the relaxation dynamics of uracil after UV excitation in gas phase. Intersystem crossing (ISC) has been included for the first time into time-dependent simulations of uracil, allowing the system to relax in the singlet as well as in the triplet states. The results show a qualitatively different picture than similar simulations that include singlet states only. The inclusion of ISC effectively quenches the relaxation to the singlet ground state and instead privileges transitions from the low-lying nπ* state (S1) to a ππ* triplet state (T2) followed by rapid internal conversion to the lowest triplet state.
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Affiliation(s)
- Martin Richter
- Institute of Theoretical Chemistry , Währinger Str. 17 , 1090 Vienna , Austria .
| | - Sebastian Mai
- Institute of Theoretical Chemistry , Währinger Str. 17 , 1090 Vienna , Austria .
| | - Philipp Marquetand
- Institute of Theoretical Chemistry , Währinger Str. 17 , 1090 Vienna , Austria .
| | - Leticia González
- Institute of Theoretical Chemistry , Währinger Str. 17 , 1090 Vienna , Austria .
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35
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Czerwińska M, Wierzbicka M, Guzow K, Bylińska I, Wiczk W. Solvatochromic properties of 3,6-di-tert-butyl-8H-indolo[3,2,1-de]acridin-8-one. RSC Adv 2014. [DOI: 10.1039/c4ra00787e] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The spectral and photophysical properties of newly synthesized 3,6-di-tert-butyl-8H-indolo[3,2,1-de]acridin-8-one were studied.
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Affiliation(s)
- Marlena Czerwińska
- Faculty of Chemistry
- University of Gdańsk, Wita Stwosza 63
- 80-308 Gdańsk, Poland
| | | | - Katarzyna Guzow
- Faculty of Chemistry
- University of Gdańsk, Wita Stwosza 63
- 80-308 Gdańsk, Poland
| | - Irena Bylińska
- Faculty of Chemistry
- University of Gdańsk, Wita Stwosza 63
- 80-308 Gdańsk, Poland
| | - Wiesław Wiczk
- Faculty of Chemistry
- University of Gdańsk, Wita Stwosza 63
- 80-308 Gdańsk, Poland
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36
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Sølling TI, Kuhlman TS, Stephansen AB, Klein LB, Møller KB. The Non-Ergodic Nature of Internal Conversion. Chemphyschem 2013; 15:249-59. [DOI: 10.1002/cphc.201300926] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 11/22/2013] [Indexed: 11/08/2022]
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