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Raghava T, Chattopadhyay A, Bhavana P, Banerjee S. Amino-Terephthalonitrile-Based Single Benzene Fluorophores with Large Stokes Shifts and Solvatochromic Behavior. Chem Asian J 2023; 18:e202201314. [PMID: 36892161 DOI: 10.1002/asia.202201314] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Revised: 02/25/2023] [Indexed: 03/03/2023]
Abstract
We have synthesized a small library of blue-to-green emissive single benzene-based fluorophores (SBFs) in a short synthetic sequence. The molecules exhibit good Stokes shift in the range of 60-110 nm and select examples also possess very high fluorescence quantum yields of up to 87%. Theoretical investigations into the ground state and excited state geometries of many of these compounds reveal that good degree of planarization between the electron donor secondary amines and electron accepting benzodinitrile units can be achieved under certain solvatochromic conditions, giving rise to the strongly fluorescent behavior. On the other hand, the excited state geometry which lacks co-planarity of the donor amine and the single benzene moiety can open up a non-fluorescent channel. Additionally, in molecules with a dinitrobenzene acceptor, the perpendicular nitro moieties render the molecules completely non-emissive.
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Affiliation(s)
- Tanya Raghava
- Department of Chemistry, BITS Pilani K.K. Birla Goa Campus, NH 17B, Bypass Road, Zuarinagar, Goa, 403726, India
| | - Anjan Chattopadhyay
- Department of Chemistry, BITS Pilani K.K. Birla Goa Campus, NH 17B, Bypass Road, Zuarinagar, Goa, 403726, India
| | - Purushothaman Bhavana
- Department of Chemistry, BITS Pilani K.K. Birla Goa Campus, NH 17B, Bypass Road, Zuarinagar, Goa, 403726, India
| | - Subhadeep Banerjee
- Department of Chemistry, BITS Pilani K.K. Birla Goa Campus, NH 17B, Bypass Road, Zuarinagar, Goa, 403726, India
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2
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Ultrafast Spectroscopies of Nitrophenols and Nitrophenolates in Solution: From Electronic Dynamics and Vibrational Structures to Photochemical and Environmental Implications. Molecules 2023; 28:molecules28020601. [PMID: 36677656 PMCID: PMC9866910 DOI: 10.3390/molecules28020601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 12/27/2022] [Accepted: 01/04/2023] [Indexed: 01/11/2023] Open
Abstract
Nitrophenols are a group of small organic molecules with significant environmental implications from the atmosphere to waterways. In this work, we investigate a series of nitrophenols and nitrophenolates, with the contrasting ortho-, meta-, and para-substituted nitro group to the phenolic hydroxy or phenolate oxygen site (2/3/4NP or NP-), implementing a suite of steady-state and time-resolved spectroscopic techniques that include UV/Visible spectroscopy, femtosecond transient absorption (fs-TA) spectroscopy with probe-dependent and global analysis, and femtosecond stimulated Raman spectroscopy (FSRS), aided by quantum calculations. The excitation-dependent (400 and 267 nm) electronic dynamics in water and methanol, for six protonated or deprotonated nitrophenol molecules (three regioisomers in each set), enable a systematic investigation of the excited-state dynamics of these functional "nanomachines" that can undergo nitro-group twisting (as a rotor), excited-state intramolecular or intermolecular proton transfer (donor-acceptor, ESIPT, or ESPT), solvation, and cooling (chromophore) events on molecular timescales. In particular, the meta-substituted compound 3NP or 3NP- exhibits the strongest charge-transfer character with FSRS signatures (e.g., C-N peak frequency), and thus, does not favor nitroaromatic twist in the excited state, while the ortho-substituted compound 2NP can undergo ESIPT in water and likely generate nitrous acid (HONO) after 267 nm excitation. The delineated mechanistic insights into the nitro-substituent-location-, protonation-, solvent-, and excitation-wavelength-dependent effects on nitrophenols, in conjunction with the ultraviolet-light-induced degradation of 2NP in water, substantiates an appealing discovery loop to characterize and engineer functional molecules for environmental applications.
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3
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Ran G, Zeb J, Lu H, Liu Y, Zhang A, Wang L, Bo Z, Zhang W. Ultrafast Carrier Dynamics of Non-fullerene Acceptors with Different Planarity: Impact of Steric Hindrance. J Phys Chem Lett 2022; 13:5860-5866. [PMID: 35727229 DOI: 10.1021/acs.jpclett.2c01281] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Most high-performance non-fullerene acceptors are of the acceptor-donor-acceptor (A-D-A)-type structure. Under photoexcitation, the intramolecular charge transfer effect on the A-D-A framework results in a large dipole moment change, facilitating the efficient generation of charge carriers. Achieving more efficient intramolecular charge transfer by adjusting the molecular structure is one of the current research ideas. Recently, we found that the power conversion efficiency can be improved from 4.41 to 13.13% by tuning the planarity of the non-fused ring electron acceptor backbone through steric hindrance of lateral substituents. We found that the planar backbone can effectively improve the intramolecular charge transfer, which has a great influence on the power conversion efficiency of the device. Our results demonstrate that charge transfer dynamics can be controlled by optimizing steric hindrance, which plays a crucial role in the photovoltaic performance of organic solar cells.
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Affiliation(s)
- Guangliu Ran
- Department of Physics and Applied Optics Beijing Area Major Laboratory, Center for Advanced Quantum Studies, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Johar Zeb
- Department of Physics and Applied Optics Beijing Area Major Laboratory, Center for Advanced Quantum Studies, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Hao Lu
- Beijing Key Laboratory of Energy Conversion and Storage Materials, College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Yahui Liu
- College of Textiles & Clothing, Qingdao University, Qingdao, Shandong 266071, People's Republic of China
| | - Andong Zhang
- College of Textiles & Clothing, Qingdao University, Qingdao, Shandong 266071, People's Republic of China
| | - Lexuan Wang
- Department of Physics and Applied Optics Beijing Area Major Laboratory, Center for Advanced Quantum Studies, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Zhishan Bo
- Beijing Key Laboratory of Energy Conversion and Storage Materials, College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
- College of Textiles & Clothing, Qingdao University, Qingdao, Shandong 266071, People's Republic of China
| | - Wenkai Zhang
- Department of Physics and Applied Optics Beijing Area Major Laboratory, Center for Advanced Quantum Studies, Beijing Normal University, Beijing 100875, People's Republic of China
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Mazumder A, Sebastian E, Hariharan M. Solvent dielectric delimited nitro–nitrito photorearrangement in a perylenediimide derivative. Chem Sci 2022; 13:8860-8870. [PMID: 35975155 PMCID: PMC9350666 DOI: 10.1039/d2sc02979k] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Accepted: 07/04/2022] [Indexed: 12/04/2022] Open
Abstract
The discovery of vibrant excited-state dynamics and distinctive photochemistry has established nitrated polycyclic aromatic hydrocarbons as an exhilarating class of organic compounds. Herein, we report the atypical photorearrangement of nitro-perylenediimide (NO2-PDI) to nitrito-perylenediimide (ONO-PDI), triggered by visible-light excitation and giving rise to linkage isomers in the polar aprotic solvent acetonitrile. ONO-PDI has been isolated and unambiguously characterized using standard spectroscopic, spectrometric, and elemental composition techniques. Although nitritoaromatic compounds are conventionally considered to be crucial intermediates in the photodissociation of nitroaromatics, experimental evidence for this has not been observed heretofore. Ultrafast transient absorption spectroscopy combined with computational investigations revealed the prominence of a conformationally relaxed singlet excited-state (SCR1) of NO2-PDI in the photoisomerization pathway. Theoretical transition state (TS) analysis indicated the presence of a six-membered cyclic TS, which is pivotal in connecting the SCR1 state to the photoproduct state. This article addresses prevailing knowledge gaps in the field of organic linkage isomers and provides a comprehensive understanding of the unprecedented photoisomerization mechanism operating in the case of NO2-PDI. The unprecedented photorearrangement of nitro-perylenediimide (NO2-PDI) to nitrito-perylenediimide (ONO-PDI) is shown to occur through a cyclic six-membered transition state triggered by visible-light excitation.![]()
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Affiliation(s)
- Aniruddha Mazumder
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Maruthamala P.O., Vithura, Thiruvananthapuram, Kerala, India 695551
| | - Ebin Sebastian
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Maruthamala P.O., Vithura, Thiruvananthapuram, Kerala, India 695551
| | - Mahesh Hariharan
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Maruthamala P.O., Vithura, Thiruvananthapuram, Kerala, India 695551
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5
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Wałęsa-Chorab M, Yao C, Tuner G, Skene WG. Electrochemical and Solvent-Mediated Visible-to-Near-Infrared Spectroscopic Switching of Benzoselenadiazole Fluorophores. Chemistry 2020; 26:17416-17427. [PMID: 33259139 DOI: 10.1002/chem.201903291] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 02/12/2020] [Indexed: 11/06/2022]
Abstract
A series of electronic push-pull, pull-pull, and push fluorophores has been prepared from a benzoselenadiazole core so that their spectroscopic, electrochemical, spectro-electrochemical, and spectro-electrofluorescence properties could be examined. The emission wavelengths and fluorescence quantum yields (Φfl ) of the N,N-dimethyl fluorophores were contingent on the solvent polarity and they ranged from 615 to 850 nm in aprotic solvents. The positive solvatochromism and the quenched Φfl in polar solvents were consistent with an intramolecular charge-transfer state (ICT). Meanwhile, a locally excited state (LE) was assigned in nonpolar solvents from the blue-shifted emission and high Φfl . The N,N-dimethylamine fluorophores examined could be both electrochemically oxidized and reduced, whereas the symmetric dinitro pull-pull derivative could be only reversibly reduced. Courtesy of their electrochemical reversibility, the fluorophores could reversibly change color from yellow to blue with an applied potential in addition to switching off their emission. The absorption of the electrochemically generated intermediates of the N,N-dimethyl derivatives spanned 500 nm over the visible and the NIR regions. The colors could be switched for upwards of two hours with applied potential, illustrating their potential use as electroactive materials in electrochromic devices.
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Affiliation(s)
- Monika Wałęsa-Chorab
- Laboratoire de caractérisation photophysique des matériaux conjugués, Département de Chimie, Pavillon JA Bombardier, Université de Montréal, CP 6128, succ. Centre-ville, Montréal, Québec, H3C 3J7, Canada.,Current address: Faculty of Chemistry, Adam Mickiewicz University in Poznań, Uniwersytetu Poznanskiego 8, 61-614, Poznań, Poland
| | - Chengzhang Yao
- Laboratoire de caractérisation photophysique des matériaux conjugués, Département de Chimie, Pavillon JA Bombardier, Université de Montréal, CP 6128, succ. Centre-ville, Montréal, Québec, H3C 3J7, Canada
| | - Georges Tuner
- Laboratoire de caractérisation photophysique des matériaux conjugués, Département de Chimie, Pavillon JA Bombardier, Université de Montréal, CP 6128, succ. Centre-ville, Montréal, Québec, H3C 3J7, Canada
| | - William G Skene
- Laboratoire de caractérisation photophysique des matériaux conjugués, Département de Chimie, Pavillon JA Bombardier, Université de Montréal, CP 6128, succ. Centre-ville, Montréal, Québec, H3C 3J7, Canada
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Ashok Phadte A, Chattopadhyay A, Banerjee S, Singh Sisodiya D, Raghava T. Synthesis of Green Emitting Multi‐substituted Dibenzodioxins and Related Heteroacenes and Computational Investigation of Substituent Effects on Emission Spectra. ChemistrySelect 2020. [DOI: 10.1002/slct.202001999] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Apeksha Ashok Phadte
- Department of Chemistry BITS Pilani KK Birla Goa Campus NH 17B, Bypass Road Zuarinagar, Goa 403726 India
| | - Anjan Chattopadhyay
- Department of Chemistry BITS Pilani KK Birla Goa Campus NH 17B, Bypass Road Zuarinagar, Goa 403726 India
| | - Subhadeep Banerjee
- Department of Chemistry BITS Pilani KK Birla Goa Campus NH 17B, Bypass Road Zuarinagar, Goa 403726 India
| | - Dilawar Singh Sisodiya
- Department of Chemistry BITS Pilani KK Birla Goa Campus NH 17B, Bypass Road Zuarinagar, Goa 403726 India
| | - Tanya Raghava
- Department of Chemistry BITS Pilani KK Birla Goa Campus NH 17B, Bypass Road Zuarinagar, Goa 403726 India
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Sun S, Qin C, Liu H, Jiang C. Excitation wavelength dependent ICT character and ISC efficiency in a photocleavage agent of 1-aminoanthraquinone. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2020; 234:118200. [PMID: 32172187 DOI: 10.1016/j.saa.2020.118200] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 02/12/2020] [Accepted: 02/26/2020] [Indexed: 06/10/2023]
Abstract
Anthraquinone derivatives have been widely used as photocleavage agents and dyes. Here, photoinduced excited state intramolecular charge transfer (ICT) dynamics of 1-aminoanthraquinone in ethanol are studied by femtosecond transient absorption (fs-TA) spectroscopy and quantum chemical (QC) calculations. Four decay associated difference spectra and corresponding lifetime components were obtained by singular value decomposition and global fitting analysis from the fs-TA spectra. The QC calculations prove that the S1 state has obvious ICT character. Planar ICT (PICT) and twisted ICT (TICT) reaction coordinates are observed. On the PICT coordinate, vibrational relaxation (VR) and intersystem crossing (ISC) processes are observed. The ISC efficiency is dependent on excitation wavelength, which elucidates that T'2 state participates in the ISC process on a higher-level than the S'1 state. On the TICT coordinate, the TICT process is dependent on excitation wavelength, which elucidates a direct experimental evidence of an energy barrier in excited state TICT potential energy.
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Affiliation(s)
- Simei Sun
- School of Physics, Henan Normal University, Xinxiang 453007, China; Huangshi Key Laboratory of Photoelectric Technology and Materials, College of Physics and Electronic Science, Hubei Normal University, Huangshi 435002, China
| | - Chaochao Qin
- School of Physics, Henan Normal University, Xinxiang 453007, China; Henan Key Laboratory of Infrared Materials & Spectrum Measures and Applications, Henan Normal University, Xinxiang 453007, China.
| | - Hua Liu
- School of Physics, Henan Normal University, Xinxiang 453007, China; Henan Key Laboratory of Infrared Materials & Spectrum Measures and Applications, Henan Normal University, Xinxiang 453007, China
| | - Chao Jiang
- Huangshi Key Laboratory of Photoelectric Technology and Materials, College of Physics and Electronic Science, Hubei Normal University, Huangshi 435002, China
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8
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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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9
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Tang L, Fang C. Nitration of Tyrosine Channels Photoenergy through a Conical Intersection in Water. J Phys Chem B 2019; 123:4915-4928. [PMID: 31094198 DOI: 10.1021/acs.jpcb.9b03464] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Nitration of tyrosine occurs under oxidative stress in vivo. The product, 3-nitrotyrosine (3NY), has a dramatically decreased quantum yield and can be used as a molecular ruler. In this study, femtosecond transient absorption spectroscopy and quantum calculations were implemented to elucidate the photoinduced relaxation processes of anionic 3NY in water. Upon 400 nm excitation into an excited electronic state with notable charge-transfer (CT) character, a barrierless nitro-twisting motion rapidly (<100 fs) guides the chromophore into an adjacent twisted intramolecular CT state, therein reaching a sloped S1/S0 conical intersection on the ∼100 fs time scale. Once in the hot ground state, excess energy is further released through vibrational cooling with biexponential time constants of ∼140 and 680 fs in water. Nitro back-twisting occurs on longer time scales (∼1.1 and 9 ps in water), returning the system to original ground state. Systematic evaluations of excited-state potential energies of anionic 3NY were performed by density functional theory (DFT) and time-dependent DFT calculations, showing that intersystem crossing (ISC) from the first singlet state (S1) to the first or second triplet state (T1 or T2) is unlikely. Inclusion of an explicit water molecule in calculations leads to improved mapping of the excited-state energy ordering of the second singlet state (S2) and T2, further diminishing ISC probability from S1 and favoring an ultrafast internal conversion to S0. These results provide deep insights into the highly efficient nonradiative decay of anionic 3NY in aqueous solution, with nitro-site-specific information that can help infer the characterization and potential optogenetic control of 3NY in protein environment.
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Affiliation(s)
- Longteng Tang
- Department of Chemistry , Oregon State University , 153 Gilbert Hall , Corvallis , Oregon 97331-4003 , United States
| | - Chong Fang
- Department of Chemistry , Oregon State University , 153 Gilbert Hall , Corvallis , Oregon 97331-4003 , United States
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10
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Zhou M, Wang L, Zhang S, Zhang B. Ultrafast spectroscopy of the primary charge transfer and ISC processes in 9-anthraldehyde. Chem Phys Lett 2019. [DOI: 10.1016/j.cplett.2018.12.040] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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11
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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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12
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Al-Ansari IAZ. Role of Solvent Polarity and Hydrogen-Bonding on Excited-State Fluorescence of 3-[(E)-{4-[Dimethylamino]benzylidene}amino]-2-naphthoic Acid (DMAMN): Isomerization vs Rotomerization. J Phys Chem A 2018; 122:1838-1854. [PMID: 29381869 DOI: 10.1021/acs.jpca.7b11623] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The present experimental and theoretical study on a new chromophore DMAMN of the type push-π-pull (push = dimethylaniline, π = imine, pull = 2-naphthoic acid), allows understanding of the mechanism by which the molecular conformational undergoes isomerization/rotomerization following electronic excitation. The steady-state fluorescence spectra of this compound, carried out in solvents of different polarities and proticities, showed significant changes in both the shape and peak positions. The wavelength and intensity change depend on the polarity and hydrogen-bonding environment. In highly polar solvents, the emission is weak and red-shifted compared to that for cyclohexane, but it is more red-shifted in moderate aprotic polar solvents. In hydroxyl solvents, a new weak low-energy emission band appears at ∼525 nm, attributed to the intermolecularly H-bonded open conformer. On the basis of the generated potential energy landscapes of the ground state and low-lying excited state in the gas phase and solution, we found that selective photon absorption, brings this molecule to a "bright" state, from which N═C isomerization Z → E, takes place. This isomerization in gas-phase and low-polarity solvents leads to two minima with a barrier, whereas in highly polar-protic media, it gives one minimum on the S1 surface with low ΔES1/T1 (0.17 eV), facilitating deactivation via ISC.
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Affiliation(s)
- Ibrahim Ahmed Z Al-Ansari
- Department of Chemistry & Earth Sciences, College of Arts & Sciences, Qatar University , P.O. Box 2713, Doha, Qatar
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13
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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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14
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Ultrafast investigation of photoinduced charge transfer in aminoanthraquinone pharmaceutical product. Sci Rep 2017; 7:43419. [PMID: 28233835 PMCID: PMC5324068 DOI: 10.1038/srep43419] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Accepted: 01/24/2017] [Indexed: 01/03/2023] Open
Abstract
We investigated the mechanism of intramolecular charge transfer and the following radiationless dynamics of the excited states of 1-aminoanthraquinone using steady state and time-resolved absorption spectroscopy combined with quantum chemical calculations. Following photoexcitation with 460 nm, conformational relaxation via twisting of the amino group, charge transfer and the intersystem crossing (ISC) processes have been established to be the major relaxation pathways responsible for the ultrafast nonradiative of the excited S1 state. Intramolecular proton transfer, which could be induced by intramolecular hydrogen bonding is inspected and excluded. Time-dependent density functional theory (TDDFT) calculations reveal the change of the dipole moments of the S0 and S1 states along the twisted coordinate of the amino group, indicating the mechanism of twisted intra-molecular charge transfer (TICT). The timescale of TICT is measured to be 5 ps due to the conformational relaxation and a barrier on the S1 potential surface. The ISC from the S1 state to the triplet manifold is a main deactivation pathway with the decay time of 28 ps. Our results observed here have yield a physically intuitive and complete picture of the photoinduced charge transfer and radiationless dynamics in anthraquinone pharmaceutial products.
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Ghosh R, Manna B. Comparative photophysics and ultrafast dynamics of dimethylaminochalcone and a structurally rigid derivative: experimental identification of TICT coordinate. Phys Chem Chem Phys 2017; 19:23078-23084. [DOI: 10.1039/c7cp03461j] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Restriction of torsional relaxation and solvent dependent competing photophysical dynamics of free and rigid dimethylaminochalcones were investigated by time resolved spectroscopy.
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Affiliation(s)
- Rajib Ghosh
- Radiation and Photochemistry Division
- Bhabha Atomic Research Centre
- Mumbai 400085
- India
| | - Biswajit Manna
- Radiation and Photochemistry Division
- Bhabha Atomic Research Centre
- Mumbai 400085
- India
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16
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Nandi A, Ghosh R, Palit DK. Excited state relaxation pathways of 4-dimethylamino-β-nitrostyrene: Effect of solvent polarity and donor–acceptor conjugation. J Photochem Photobiol A Chem 2016. [DOI: 10.1016/j.jphotochem.2016.02.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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17
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Ghosh R, Nandi A, Palit DK. Solvent sensitive intramolecular charge transfer dynamics in the excited states of 4-N,N-dimethylamino-4′-nitrobiphenyl. Phys Chem Chem Phys 2016; 18:7661-71. [DOI: 10.1039/c5cp07778h] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Solvent sensitive excited state dynamics of DNBP is explored. In polar solvents, the ultrafast barrierless TICT process is the major relaxation pathway, whereas, in nonpolar solvents the excited state undergoes the PICT process, followed by efficient intersystem crossing to the triplet state.
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Affiliation(s)
- Rajib Ghosh
- Radiation & Photochemistry Division
- Bhabha Atomic Research Centre
- Mumbai-400085
- India
| | - Amitabha Nandi
- Radiation & Photochemistry Division
- Bhabha Atomic Research Centre
- Mumbai-400085
- India
| | - Dipak K. Palit
- Radiation & Photochemistry Division
- Bhabha Atomic Research Centre
- Mumbai-400085
- India
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19
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Kanal F, Schleier D, Nuernberger P. Ultrafast Photogeneration of a Tetrazolinyl Radical. Chemphyschem 2015; 16:3143-6. [PMID: 26331990 DOI: 10.1002/cphc.201500628] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Indexed: 11/06/2022]
Abstract
Radicals in solution are crucial for many chemical processes. In this work, we unveil the photoreaction sequence leading to radical formation from tetrazolium salts, which are extensively used in enzyme assays and also exhibit a rich photochemistry. Upon UV irradiation, the tetrazolium ion turns into the tetrazolinyl radical via two intermediates on a nanosecond timescale. The solvent's polarity governs the rate of formation, but the reaction pathway towards the tetrazolinyl radical is identical for aqueous and alcoholic solutions, although the final photoproduct distribution differs. These observations provide new insight into the versatile reactivity of tetrazolium salts and ultrafast radical formation in the liquid phase.
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Affiliation(s)
- Florian Kanal
- Institut für Physikalische und Theoretische Chemie, Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Domenik Schleier
- Institut für Physikalische und Theoretische Chemie, Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Patrick Nuernberger
- Physikalische Chemie II, Ruhr-Universität Bochum, Universitätsstraße 150, 44801, Bochum, Germany.
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20
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Zhang L, Liu ZY, Zhan X, Wang LL, Wang H, Liu HY. Photophysical properties of electron-deficient free-base corroles bearing meso-fluorophenyl substituents. Photochem Photobiol Sci 2015; 14:953-62. [DOI: 10.1039/c5pp00060b] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The ultrafast photophysical behaviors of a series of meso-flurophenyl substituted electron-deficient free base corroles F0C, F5C, F10C and F15C in toluene have been investigated using femtosecond time resolved absorption spectroscopy and steady spectroscopies.
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Affiliation(s)
- Lei Zhang
- State Key Laboratory of Optoelectronics Materials and Technologies
- Sun-Yat Sen University
- Guangzhou 510275
- China
| | - Zi-Yu Liu
- State Key Laboratory of Optoelectronics Materials and Technologies
- Sun-Yat Sen University
- Guangzhou 510275
- China
| | - Xuan Zhan
- Department of Chemistry
- South China University of Technology
- Guangzhou 510641
- China
| | - Li-Li Wang
- State Key Laboratory of Optoelectronics Materials and Technologies
- Sun-Yat Sen University
- Guangzhou 510275
- China
| | - Hui Wang
- State Key Laboratory of Optoelectronics Materials and Technologies
- Sun-Yat Sen University
- Guangzhou 510275
- China
| | - Hai-Yang Liu
- Department of Chemistry
- South China University of Technology
- Guangzhou 510641
- China
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21
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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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22
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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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23
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Singh C, Ghosh R, Mondal JA, Palit DK. Excited state dynamics of a push–pull stilbene: A femtosecond transient absorption spectroscopic study. J Photochem Photobiol A Chem 2013. [DOI: 10.1016/j.jphotochem.2013.04.027] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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24
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Lin CK, Wang YF, Cheng YC, Yang JS. Multisite constrained model of trans-4-(N,N-dimethylamino)-4'-nitrostilbene for structural elucidation of radiative and nonradiative excited states. J Phys Chem A 2013; 117:3158-64. [PMID: 23514591 DOI: 10.1021/jp310770s] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A constrained model compound of trans-4-(N,N-dimethylamino)-4'-nitrostilbene (DNS), namely, compound DNS-B3 that is limited to torsions about the phenyl-nitro C-N bond and the central C═C bond, was prepared to investigate the structural nature of the radiative and nonradiative states of electronically excited DNS. The great similarities in solvent-dependent electronic spectra, fluorescence decay times, and quantum yields for fluorescence (Φf) and trans → cis photoisomerization (Φtc) between DNS and DNS-B3 indicate that the fluorescence is from a planar charge-transfer state and torsion of the nitro group is sufficient to account for the nonradiative decay of DNS. This conclusion is supported by TDDFT calculations on DNS-B3 in dichloromethane. The structure at the conical intersection for internal conversion is associated with not only a twisting but also a pyramidalization of the nitro group. The mechanism of the NO2 torsion is discussed in terms of the effects of solvent polarity, the substituents, and the volume demand. The differences and analogies of the NO2- vs amino-twisted intramolecular charge-transfer (TICT) state of trans-aminostilbenes are also discussed.
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Affiliation(s)
- Cheng-Kai Lin
- Department of Chemistry, National Taiwan University, Taipei, Taiwan 10617
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25
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Ishow E, Clavier G, Miomandre F, Rebarz M, Buntinx G, Poizat O. Comprehensive investigation of the excited-state dynamics of push–pull triphenylamine dyes as models for photonic applications. Phys Chem Chem Phys 2013; 15:13922-39. [DOI: 10.1039/c3cp51480c] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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26
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Richter M, Marquetand P, González-Vázquez J, Sola I, González L. Femtosecond Intersystem Crossing in the DNA Nucleobase Cytosine. J Phys Chem Lett 2012; 3:3090-5. [PMID: 26296011 DOI: 10.1021/jz301312h] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Ab initio molecular dynamics including nonadiabatic and spin-orbit couplings on equal footing is used to unravel the deactivation of cytosine after UV light absorption. Intersystem crossing (ISC) is found to compete directly with internal conversion in tens of femtoseconds, thus making cytosine the organic compound with the fastest triplet population calculated so far. It is found that close degeneracy between singlet and triplet states can more than compensate for very small spin-orbit couplings, leading to efficient ISC. The femtosecond nature of the ISC process highlights its importance in photochemistry and challenges the conventional view that large singlet-triplet couplings are required for an efficient population flow into triplet states. These findings are important to understand DNA photostability and the photochemistry and dynamics of organic molecules in general.
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Affiliation(s)
- Martin Richter
- †Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - Philipp Marquetand
- ‡Institute of Theoretical Chemistry, University of Vienna, Währinger Strasse 17, 1090 Vienna, Austria
| | | | - Ignacio Sola
- ¶Departamento de Química Física I, Universidad Complutense, 28040 Madrid, Spain
| | - Leticia González
- ‡Institute of Theoretical Chemistry, University of Vienna, Währinger Strasse 17, 1090 Vienna, Austria
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