1
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Asemare S, Belay A, Kebede A, Sherfedin U. Ground and Excited State Dipole Moments of Metformin Hydrochloride using Solvatochromic Effects and Density Functional Theory. J Fluoresc 2024; 34:1207-1217. [PMID: 37505362 DOI: 10.1007/s10895-023-03355-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 07/18/2023] [Indexed: 07/29/2023]
Abstract
In this research, the ground (µg) and excited (µe) state dipole moments of metformin hydrochlorides were determined using Lippert-Mataga, Bakhshiev's, Kawski-Chamma-Viallet, and Reichardt models from fluorescence emission and UV-Vis absorption spectra in various solvents. From solvatochromic effects the calculated excited (µe ) dipole moment of metformin hydrochloride were, 8.55 D, 8.34 D, 6.08 D, and 6.40 D using the Lippert-Mataga, Bakhshiev's, Kawski-Chamma-Viallet and Reichardt models respectively. The results also indicated that the dipole moment at the ground state is smaller than the excited state. This is due to solvent polarity having a stronger effect on fluorescence emission than absorption spectra. Similarly, from density functional theory, the calculated ground and excited states dipole moments of metformin hydrochloride using (DFT-B3LYP- 3-21+G*(μg = 10.02 D and μe = 11.94 D), DFT-B3LYP- 6-31+G (d, p) (μg = 8.44 D and μe = 10.87 D), and DFT-B3LYP- 6-311+G (d, p) (μg = 8.24 D and μe = 18.74 D)) analyzed by Gaussian 09W. From the optimized geometry of the molecule, the HOMO-LUMO energy band gap of metformin hydrochloride were computed using DFT [DFT-B3LYP- 3-21+G*(5.51 eV), DFT-B3LYP- 6-31+G (d, p) (5.66 eV), and DFT-B3LYP- 6-311+G (d, p) (5.70 eV)] respectively.
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Affiliation(s)
- Semahegn Asemare
- Department of Applied Physics, School of Applied Natural Sciences, Adama Science and Technology University, PO Box 1888, Adama, Ethiopia.
| | - Abebe Belay
- Department of Applied Physics, School of Applied Natural Sciences, Adama Science and Technology University, PO Box 1888, Adama, Ethiopia.
| | - Alemu Kebede
- Department of Applied Physics, School of Applied Natural Sciences, Adama Science and Technology University, PO Box 1888, Adama, Ethiopia
| | - Umer Sherfedin
- Department of Applied Physics, School of Applied Natural Sciences, Adama Science and Technology University, PO Box 1888, Adama, Ethiopia
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2
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Stasyuk OA, Voityuk AA, Stasyuk AJ. Facilitating Electron Transfer by Resizing Cyclocarbon Acceptor from C 18 to C 16. Chemistry 2024:e202400215. [PMID: 38530218 DOI: 10.1002/chem.202400215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 03/25/2024] [Accepted: 03/26/2024] [Indexed: 03/27/2024]
Abstract
Recent advances in synthetic methods, combined with tip-induced on-surface chemistry, have enabled the formation of numerous cyclocarbon molecules. Here, we investigate computationally the experimentally studied C16 and C18 molecules as well as their van der Waals (vdW) complexes with several typical donor and acceptor molecules. Our results demonstrate a remarkable electron-withdrawing ability of cyclocarbon molecules. The vdW complexes of C16 and C18 exhibit a thermodynamically favorable photoinduced electron transfer (ET) from the donor partner to the cyclocarbons that occurs on a picosecond time scale. The lower reorganization energy of C16 compared to C18 leads to a significant acceleration of the ET reactions.
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Affiliation(s)
- O A Stasyuk
- Institut de Química Computacional i Catàlisi and Departament de Química, Universitat de Girona, C/ Maria Aurèlia, Capmany 69, 17003, Girona, Catalonia, Spain
| | - A A Voityuk
- Institut de Química Computacional i Catàlisi and Departament de Química, Universitat de Girona, C/ Maria Aurèlia, Capmany 69, 17003, Girona, Catalonia, Spain
| | - A J Stasyuk
- Institut de Química Computacional i Catàlisi and Departament de Química, Universitat de Girona, C/ Maria Aurèlia, Capmany 69, 17003, Girona, Catalonia, Spain
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093, Warsaw, Poland
- Departament de Farmàcia, i Tecnologia Farmacèutica, i Fisicoquímica, Facultat de Farmàcia i Ciències de l'Alimentació, Universitat de Barcelona (UB), Barcelona, Spain
- Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona (UB), Barcelona, Spain
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3
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Gao Q, Grzyb K, Gamon LF, Ogilby PR, Pędziński T, Davies MJ. The structure of model and peptide disulfides markedly affects their reactivity and products formed with singlet oxygen. Free Radic Biol Med 2023; 207:320-329. [PMID: 37633403 DOI: 10.1016/j.freeradbiomed.2023.08.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 08/22/2023] [Accepted: 08/23/2023] [Indexed: 08/28/2023]
Abstract
Disulfide bonds are critical structural elements in proteins and stabilize folded structures. Modification of these linkages is associated with a loss of structure and function. Previous studies have reported large variations in the rate of disulfide oxidation by hypohalous acids, due to stabilization of reaction intermediates. In this study we hypothesized that considerable variation (and hence selective oxidation) would occur with singlet oxygen (1O2), a key intermediate in photo-oxidation reactions. The kinetics of disulfide-mediated 1O2 removal were monitored using the time-resolved 1270 nm phosphorescence of 1O2. Stern-Volmer plots of these data showed a large variation (∼103) in the quenching rate constants kq (from 2 × 107 for α-lipoic acid to 3.6 × 104 M-1s-1 for cystamine). The time course of disulfide loss and product formation (determined by LC-MS) support a role for 1O2, with mono- and di-oxygenated products detected. Elevated levels of these latter species were generated in D2O- compared to H2O buffers, which is consistent with solvent effects on the 1O2 lifetime. These data are interpreted in terms of the intermediacy of a zwitterion [-S+(OO-)-S-], which either isomerizes to a thiosulfonate [-S(O)2-S-] or reacts with another parent molecule to give two thiosulfinates [-S(O)-S-]. The variation in quenching rates and product formation are ascribed to zwitterion stabilization by neighboring, or remote, lone pairs of electrons. These data suggest that some disulfides, including some present within or attached to proteins (e.g., α-lipoic acid), may be selectively modified, and undergo subsequent cleavage, with adverse effects on protein structure and function.
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Affiliation(s)
- Qing Gao
- Department of Biomedical Sciences, Panum Institute, University of Copenhagen, Copenhagen, 2200, Denmark
| | - Katarzyna Grzyb
- Faculty of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznanskiego 8, 61-614, Poznań, Poland
| | - Luke F Gamon
- Department of Biomedical Sciences, Panum Institute, University of Copenhagen, Copenhagen, 2200, Denmark
| | - Peter R Ogilby
- Department of Chemistry, Aarhus University, DK-8000, Aarhus, Denmark
| | - Tomasz Pędziński
- Faculty of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznanskiego 8, 61-614, Poznań, Poland
| | - Michael J Davies
- Department of Biomedical Sciences, Panum Institute, University of Copenhagen, Copenhagen, 2200, Denmark.
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4
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Lv M, Gao Y, Cai Z, Tang Z, Zhang Y, Wang T, Li W. A theoretical study on the excited state behavior of a series of novel triazole pyrimidine group fluorophores: ESIPT or ICT. Spectrochim Acta A Mol Biomol Spectrosc 2023; 297:122706. [PMID: 37054571 DOI: 10.1016/j.saa.2023.122706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 03/30/2023] [Accepted: 04/02/2023] [Indexed: 05/14/2023]
Abstract
Fluoropurine analogues are a kind of unnatural bases, which are widely used in chemistry, biological science, pharmacy and other fields. At the same time, fluoropurine analogues of aza-heterocycles play an important role in medicinals research and development. In this work, the excited state behavior of a group of newly developed fluoropurine analogues of aza-heterocycles, triazole pyrimidinyl fluorophores, was comprehensively studied. The reaction energy profiles indicate that excited state intramolecular proton transfer (ESIPT) is difficult to happen, which is further proved by fluorescent spectra results. This work proposed a new and reasonable fluorescence mechanism based on the original experiment, and found that the large Stokes shift of the triazole pyrimidine fluorophore is due to the intramolecular charge transfer (ICT) process of the excited state. Our new discovery is of great significance for the application of this group of fluorescent compounds in other fields and the regulation of fluorescence properties.
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Affiliation(s)
- Meiheng Lv
- College of Science, Shenyang University of Chemical Technology, Shenyang 110142, PR China; State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, PR China
| | - Yue Gao
- College of Science, Shenyang University of Chemical Technology, Shenyang 110142, PR China
| | - Zexu Cai
- College of Science, Shenyang University of Chemical Technology, Shenyang 110142, PR China
| | - Zhe Tang
- Life and Health Intelligent Research Institute, Tianjin University of Technology, Tianjin 300384, PR China
| | - Yuhang Zhang
- College of Science, Shenyang University of Chemical Technology, Shenyang 110142, PR China
| | - Tingting Wang
- College of Science, Shenyang University of Chemical Technology, Shenyang 110142, PR China
| | - Wenze Li
- College of Science, Shenyang University of Chemical Technology, Shenyang 110142, PR China.
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Liu Y, Wu J, Cheng N, Gan P, Li Y, Liu W, Ye J, Tong M, Liang J. The overlooked role of UV 185 induced high-energy excited states in the dephosphorization of organophosphorus pesticide by VUV/persulfate. Chemosphere 2023:138993. [PMID: 37244548 DOI: 10.1016/j.chemosphere.2023.138993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 04/24/2023] [Accepted: 05/18/2023] [Indexed: 05/29/2023]
Abstract
Vacuum ultraviolet (VUV) based advanced oxidation processes (AOPs) recently attracted widespread interests. However, the role of UV185 in VUV is only considered to be generating a series of active species, while the effect of photoexcitation has long been overlooked. In this work, the role of UV185 induced high-energy excited state for the dephosphorization of organophosphorus pesticides was studied using malathion as a model. Results showed malathion degradation was highly related to radical yield, while its dephosphorization was not. It was UV185 rather than UV254 or radical yield that was responsible for malathion dephosphorization by VUV/persulfate. DFT calculation results demonstrated that the polarity of P-S bond was further increased during UV185 excitation, favoring dephosphorization while UV254 did not. The conclusion was further supported by degradation path identification. Moreover, despite the fact that anions (Cl-, SO42- and NO3-) considerably affected radical yield, only Cl- and NO3- with high molar extinction coefficient at 185 nm significantly affected dephosphorization. This study shed light on the crucial role of excited states in VUV based AOPs and provided a new idea for the development of mineralization technology of organophosphorus pesticides.
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Affiliation(s)
- Yudan Liu
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, PR China
| | - Jingke Wu
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, PR China
| | - Nanchunxiao Cheng
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, PR China
| | - Pengfei Gan
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, PR China
| | - Yunyi Li
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, PR China
| | - Wen Liu
- The Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, PR China
| | - Jiangyu Ye
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, PR China
| | - Meiping Tong
- The Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, PR China
| | - Jialiang Liang
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, PR China.
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Taylor A, Heyes DJ, Scrutton NS. Catalysis by Nature's photoenzymes. Curr Opin Struct Biol 2022; 77:102491. [PMID: 36323132 DOI: 10.1016/j.sbi.2022.102491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 08/22/2022] [Accepted: 10/01/2022] [Indexed: 12/14/2022]
Abstract
Photoenzymes use light to initiate biochemical reactions. Although rarely found in nature, their study has advanced understanding of how light energy can be harnessed to facilitate enzyme catalysis, which is also of importance to the design and engineering of man-made photocatalysts. Natural photoenzymes can be assigned to one of two families, based broadly on the nature of the light-sensing chromophores used, those being chlorophyll-like tetrapyrroles or flavins. In all cases, light absorption leads to excited state electron transfer, which in turn initiates photocatalysis. Reviewed here are recent findings relating to the structures and mechanisms of known photoenzymes. We highlight recent advances that have deepened understanding of mechanisms in biological photocatalysis.
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Affiliation(s)
- Aoife Taylor
- Future Biomanufacturing Research Hub, Manchester Institute of Biotechnology and Department of Chemistry, School of Natural Sciences, The University of Manchester, M1 7DN, United Kingdom
| | - Derren J Heyes
- Future Biomanufacturing Research Hub, Manchester Institute of Biotechnology and Department of Chemistry, School of Natural Sciences, The University of Manchester, M1 7DN, United Kingdom. https://twitter.com/DerrenHeyes
| | - Nigel S Scrutton
- Future Biomanufacturing Research Hub, Manchester Institute of Biotechnology and Department of Chemistry, School of Natural Sciences, The University of Manchester, M1 7DN, United Kingdom.
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7
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Zhao Z, Gan P, Zhu C, Li Y, Liu W, Tong M, Ye J, Liang J. Comparative evaluation of MSW incineration leachate treatment by heterogeneous catalytic O 3 and UV/O 3: The unexpected contribution of high salinity and overlooked role of excited state. Chemosphere 2022; 307:136143. [PMID: 36037945 DOI: 10.1016/j.chemosphere.2022.136143] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 08/03/2022] [Accepted: 08/17/2022] [Indexed: 06/15/2023]
Abstract
The efficiency and mechanism of heterogeneous catalytic O3 and UV/O3 for municipal solid waste (MSW) incineration leachate advanced treatment was systematically compared. Prior to comparison, catalyst used in heterogenous catalytic O3 and operation parameters for each technology were optimized. The COD removal of CuO@Al2O3/O3 under its optimal parameters was 57.2%, which failed to meet the standard (≥75%). In contrast, the COD removal by UV/O3 could be 82.3%. The superior efficiency of UV/O3 over CuO@Al2O3/O3 could be summarized into three aspects: (I) Cu bounded ·OH (≡Cu-O·) preferentially attacked hydrophilic groups, while free hydroxyl radical (·OH) was non-selective, thus UV/O3 exhibited a unique three-stage mechanism; (II) The oxidation potential of ≡Cu-O· was higher than that of ·OH, therefore was more vulnerable to the negative effect of radical self-quenching; (III) The existence of UV-induced excited states made organics in UV/O3 more active than in CuO@Al2O3/O3 system, thus high concentration of anions enhanced COD removal in UV/O3 but affected that in CuO@Al2O3/O3. The study further revealed the characteristics of heterogeneous catalytic O3 and UV/O3, and UV induced excited state should be considered in UV-based advanced oxidation processes (AOPs).
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Affiliation(s)
- Zhiwei Zhao
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, PR China
| | - Pengfei Gan
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, PR China
| | - Chengjun Zhu
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, PR China
| | - Yunyi Li
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, PR China
| | - Wen Liu
- The Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, PR China; State Environmental Protection Key Laboratory of All Material Fluxes in River Ecosystems, Peking University, Beijing, 100871, China
| | - Meiping Tong
- The Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, PR China
| | - Jiangyu Ye
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, PR China
| | - Jialiang Liang
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, PR China.
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8
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Li C, Wang Y, Wang Y, Wang Z, Huang Q. Electrochemical oxidation combined with UV irradiation for synergistic removal of perfluorooctane sulfonate (PFOS) in water. J Hazard Mater 2022; 436:129091. [PMID: 35569375 DOI: 10.1016/j.jhazmat.2022.129091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 04/25/2022] [Accepted: 05/04/2022] [Indexed: 06/15/2023]
Abstract
The effect of electrochemical degradation on Magnéli phase Ti4O7 anode combined with UV irradiation on the removal of PFOS was systematically evaluated in the present study. A synergistic effect of electrolysis and UV irradiation rather than a simple additive effect for PFOS degradation was demonstrated experimentally and theoretically. The short wavelength irradiation within 400 nm is the main contribution to enhance the electrochemical degradation of PFOS, while the initial pH of the solution has little effect on the PFOS degradation. The increase of current density accelerates the removal of PFOS either by electrolysis treatment or the joint process. The time-dependent density functional theory (TD-DFT) calculation indicates that the synergistic effect of the electrolysis and UV irradiation is most likely due to the involvement of the excited PFOS induced under UV irradiation in the electrochemical reaction. This study provides the first mechanistic explanation for the electrochemical degradation of PFOS enhanced by UV irradiation.
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Affiliation(s)
- Chenguang Li
- Key Laboratory of Marine Environment and Ecology, Ministry of Education, College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, PR China; College of Agricultural and Environmental Sciences, Department of Crop and Soil Sciences, University of Georgia, Griffin, GA 30223, United States; State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu, Nanjing 210023, PR China
| | - Yifei Wang
- College of Agricultural and Environmental Sciences, Department of Crop and Soil Sciences, University of Georgia, Griffin, GA 30223, United States
| | - Yaye Wang
- College of Agricultural and Environmental Sciences, Department of Crop and Soil Sciences, University of Georgia, Griffin, GA 30223, United States
| | - Zunyao Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu, Nanjing 210023, PR China
| | - Qingguo Huang
- College of Agricultural and Environmental Sciences, Department of Crop and Soil Sciences, University of Georgia, Griffin, GA 30223, United States.
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Fatima A, Rabah J, Allard E, Fensterbank H, Wright K, Burdzinski G, Clavier G, Sliwa M, Pino T, Méallet-Renault R, Steenkeste K, Ha-Thi MH. Selective population of triplet excited states in heavy-atom-free BODIPY-C 60 based molecular assemblies. Photochem Photobiol Sci 2022; 21:1573-1584. [PMID: 35612713 DOI: 10.1007/s43630-022-00241-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 05/02/2022] [Indexed: 12/14/2022]
Abstract
Photophysical studies on a BODIPY-fullerene-distyryl BODIPY triad (BDP-C60-DSBDP) and its reference dyads (BODIPY-fullerene; BDP-C60 and distyryl BODIPY-fullerene; DSBDP-C60) are presented herein. In the triad, the association of the two chromophore units linked by a fullerene moiety leads to strong near UV-Visible light absorption from 300 to 700 nm. The triplet-excited state was observed upon visible excitation in all these assemblies, and shown to be localized on the C60 or BODIPY moieties. Using quantitative nanosecond transient absorption, we provide a complete investigation on the lifetime and formation quantum yield of the triplet-excited state. In the BDP-C60 dyad, the triplet excited state of C60 (τ = 7 ± 1 μs) was obtained with a quantum yield of 40 ± 8%. For the DSBDP-C60 dyad and BDP-C60-DSBDP triad, a longer-lived triplet excited state with a lifetime of around 250 ± 20 μs centered on the DSBDP moiety was formed, with respective quantum yields of 37 ± 8 and 20 ± 4%. Triplet-triplet annihilation up-conversion is characterized in the BDP-C60 dyad and the bichromophoric triad in the presence of perylene and DSBDP-monomer as respective annihilators. The photo-induced formation of a long-lived 3DSBDP* in the triad coupled with panchromatic light absorption offers potential applications as a heavy-atom-free organic triplet photosensitizer.
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Affiliation(s)
- Anam Fatima
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, 91405, Orsay, France
| | - Jad Rabah
- Université Paris-Saclay, UVSQ, CNRS, Institut Lavoisier de Versailles, 78000, Versailles, France
| | - Emmanuel Allard
- Université Paris-Saclay, UVSQ, CNRS, Institut Lavoisier de Versailles, 78000, Versailles, France.
| | - Hélène Fensterbank
- Université Paris-Saclay, UVSQ, CNRS, Institut Lavoisier de Versailles, 78000, Versailles, France
| | - Karen Wright
- Université Paris-Saclay, UVSQ, CNRS, Institut Lavoisier de Versailles, 78000, Versailles, France
| | - Gotard Burdzinski
- Adam Mickiewicz Univ in Poznan, Fac Phys, Quantum Elect Lab, 61614, Poznan, Poland
| | - Gilles Clavier
- Université Paris-Saclay, ENS Paris-Saclay, CNRS, PPSM, 91190, Gif-sur-Yvette, France
| | - Michel Sliwa
- Univ. Lille, CNRS, UMR 8516, LASIRE, Laboratoire de Spectroscopie pour les Interactions, la Réactivité et l'Environnement, 59 000, Lille, France
| | - Thomas Pino
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, 91405, Orsay, France
| | - Rachel Méallet-Renault
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, 91405, Orsay, France.
| | - Karine Steenkeste
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, 91405, Orsay, France.
| | - Minh-Huong Ha-Thi
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, 91405, Orsay, France.
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Liu D, Li PY, Wang SJ, Gong B, Lu T, Li GY. Steric hindrance effect on the excited-state proton transfer process: TDDFT study on the fluorescent sensing mechanism of a fluoride sensor. Spectrochim Acta A Mol Biomol Spectrosc 2022; 271:120872. [PMID: 35042045 DOI: 10.1016/j.saa.2022.120872] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 01/03/2022] [Accepted: 01/06/2022] [Indexed: 06/14/2023]
Abstract
An understanding of the excited-state process and the sensing mechanism for specific anions can be helpful for the design and synthesis of fluorescent sensors in analytical chemistry and biotechnology. Here, we theoretically investigated the fluorescent response mechanism of a reported acylhydrazone-based fluorescent sensor (Soft Matter, 2019, 15, 6690) for fluoride recognition using the time-dependent density functional theory approach. At the M06/TZVP/SCM level, the vertical excitation energies, which were calculated based on the ground state and first singlet-state geometries of the sensor molecule, agreed well with the experimental ultraviolet-visible and fluorescence spectra. Therefore, the time-dependent density functional theory method was considered reasonable and effective. According to the frontier orbital analysis and an excited-state potential energy scan, we proposed an excited-state proton transfer mechanism for the sensor-fluorine complex, where the steric hindrance leads to a high potential barrier. The excited-state proton transfer process facilitates sensor molecule deprotonation, alleviates its steric hindrance effect and expands its conjugated system. As a result, the fluorescence emission band of the sensor molecule was red-shifted significantly with the addition of fluoride anion. Based on this fluorescence difference, the sensor could be used for fluoride anion identification. This work provides a strategy to study sensor-analyte interactions in the excited state and offers an approach to tune the fluorescence emission wavelength of sensor molecules in anionic environments.
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Affiliation(s)
- Dong Liu
- College of Chemical Engineering, North China University of Science and Technology, Tangshan 063210, PR China
| | - Peng-Yuan Li
- College of Chemical Engineering, North China University of Science and Technology, Tangshan 063210, PR China
| | - Si-Jia Wang
- College of Chemical Engineering, North China University of Science and Technology, Tangshan 063210, PR China
| | - Bo Gong
- College of Chemical Engineering, North China University of Science and Technology, Tangshan 063210, PR China
| | - Ting Lu
- College of Chemical Engineering, North China University of Science and Technology, Tangshan 063210, PR China.
| | - Guang-Yue Li
- College of Chemical Engineering, North China University of Science and Technology, Tangshan 063210, PR China.
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Cui M, Cui K, Liu X, Chen X, Chen Y, Guo Z. Roles of alkali metal dopants and surface defects on polymeric carbon nitride in photocatalytic peroxymonosulfate activation towards water decontamination. J Hazard Mater 2022; 424:127292. [PMID: 34583168 DOI: 10.1016/j.jhazmat.2021.127292] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 09/11/2021] [Accepted: 09/17/2021] [Indexed: 06/13/2023]
Abstract
Polymeric carbon nitride (PCN) has been extensively employed in peroxymonosulfate (PMS) activation for water decontamination. However, limited photocatalytic efficiency can be achieved by pristine PCN due to its intrinsic deficiencies like high electron-hole recombination rate and resistance to charge transfer. Herein, in a two-stage thermal treatment process, the nontoxic and stable Na and K were successfully anchored among the PCN skeleton with surface defects created, leading to an elevated photocatalytic activity for PMS activation. The SO4·- and 1O2 were identified as the dominant reactive oxygen species, which were generated from electron transfer processes between PMS and catalyst. Experimental and theoretical analyses suggested that the defective structures and metal dopants improved the optical properties of catalyst, endowing it a wider light absorption range and a lower energy barrier for electron transitions. The modified structures were also beneficial to electron transfer processes due to the weaker electron confinement effect, accelerating the production of SO4·- on the defective sites and 1O2 on the metal sites. The synergy of radical and non-radical species weakened the influence of side reactions between radicals from PMS and coexisting inorganic anions in practical water, hence to promote the resistance of modified catalysts in complex water matrices.
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Affiliation(s)
- Minshu Cui
- School of Resources and Environmental Engineering, Hefei University of Technology, Hefei 230009, China; Key Laboratory of Nanominerals and Pollution Control of Higher Education Institutes, Hefei University of Technology, Hefei 230009, China
| | - Kangping Cui
- School of Resources and Environmental Engineering, Hefei University of Technology, Hefei 230009, China; Key Laboratory of Nanominerals and Pollution Control of Higher Education Institutes, Hefei University of Technology, Hefei 230009, China.
| | - Xueyan Liu
- School of Resources and Environmental Engineering, Hefei University of Technology, Hefei 230009, China; Key Laboratory of Nanominerals and Pollution Control of Higher Education Institutes, Hefei University of Technology, Hefei 230009, China
| | - Xing Chen
- School of Resources and Environmental Engineering, Hefei University of Technology, Hefei 230009, China; Key Laboratory of Nanominerals and Pollution Control of Higher Education Institutes, Hefei University of Technology, Hefei 230009, China
| | - Yihan Chen
- School of Resources and Environmental Engineering, Hefei University of Technology, Hefei 230009, China; Key Laboratory of Nanominerals and Pollution Control of Higher Education Institutes, Hefei University of Technology, Hefei 230009, China
| | - Zhi Guo
- School of Resources and Environmental Engineering, Hefei University of Technology, Hefei 230009, China; Key Laboratory of Nanominerals and Pollution Control of Higher Education Institutes, Hefei University of Technology, Hefei 230009, China
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12
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Yang Y, Liu Y, Jiang K, Liu Y. Fluorescent detection mechanism of CO-releasing molecule-3: Competition of inter-/intra-molecular hydrogen bonds. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 2021; 263:120227. [PMID: 34332242 DOI: 10.1016/j.saa.2021.120227] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 07/14/2021] [Accepted: 07/23/2021] [Indexed: 06/13/2023]
Abstract
The fluorescent detection mechanism of 2-(4-nitro-1,3-dioxoisoindolin-2-yl) acetic acid (CORM3-green) on CO-Releasing Molecule-3 (CORM-3) is theoretically studied. Upon reaction with CORM-3, the non-fluorescent CORM3-green is transferred to the keto form of 2-(4-amino-1,3-dioxoisoindolin-2-yl)acetic acid (PTI) to produce strong fluorescence peak located at 423 nm. This peak red-shifts to 489 nm, which is induced by the strengthening of intermolecular hydrogen bond (HB) between PTI and water molecules and attributed to the experimentally observed fluorescence emission at 503 nm. This result is dramatically different from previous reports that the experimental fluorescence corresponds to the proton transferred enol form of PTI. To illustrate this confusion, the calculated fluorescence peak of PTI-Enol is located at 689 nm, which is much larger than that of experimental result. This result excludes the occurrence of excited state intramolecular proton transfer (ESIPT). It is concluded that intermolecular HBs hinders the formation of intramolecular HB and the ESIPT of the keto form of PTI. This conclusion confirms that experimental Stokes shift of 113 nm is mainly caused by the intermolecular hydrogen bonding rather than by ESIPT process. This work proposes a reasonable explanation for the detection mechanism of CORM3-green and experimental fluorescence phenomenon.
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Affiliation(s)
- Yonggang Yang
- Henan Key Laboratory of Infrared Materials & Spectrum Measures and Applications, School of Physics, Henan Normal University, Xinxiang 453007, China.
| | - Yang Liu
- Henan Key Laboratory of Infrared Materials & Spectrum Measures and Applications, School of Physics, Henan Normal University, Xinxiang 453007, China
| | - Kai Jiang
- School of Environment, Henan Normal University, Xinxiang 453007, China
| | - Yufang Liu
- Henan Key Laboratory of Infrared Materials & Spectrum Measures and Applications, School of Physics, Henan Normal University, Xinxiang 453007, China.
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13
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Vladislav Victorovich K, Tatyana Aleksandrovna K, Victor Vitoldovich P, Aleksander Nicolaevich S, Larisa Valentinovna K, Anastasia Aleksandrovna A. Spectra of tryptophan fluorescence are the result of co-existence of certain most abundant stabilized excited state and certain most abundant destabilized excited state. Spectrochim Acta A Mol Biomol Spectrosc 2021; 257:119784. [PMID: 33892250 DOI: 10.1016/j.saa.2021.119784] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 02/28/2021] [Accepted: 04/01/2021] [Indexed: 06/12/2023]
Abstract
Fluorescence spectra of proteins and peptides are traditionally used to get an information on self-association of proteins and peptides, on their tertiary and quaternary structure. In this study it was shown that there are just three peaks of tryptophan fluorescence (at ∼308, at ∼330, and at ∼360 nm) in rough unsmoothed spectra of fluorescence of pure tryptophan in different solvents that change their heights depending on the polarity of a solvent. Two separate peaks at ∼330 nm and ∼360 nm are especially prominent in the spectrum of human epidermal growth factor. In contrast, in smoothed (either mathematically, or physically) spectra of Trp-containing proteins a single maximum of fluorescence varies between 330 and 360 nm. The theory of tryptophan fluorescence is discussed in light of three discrete peaks existence. A stabilizing hydrogen bond with aromatic system of benzene ring in the excited state is proposed as the cause of emission at ∼360 nm bringing Trp to the destabilized ground state. Emission from the destabilized excited state has a maximum at ∼330 nm if the ground state is destabilized, as well as if both states are stabilized. If the excited state is destabilized, while the ground state is stabilized by purely hydrophobic interactions, emitted light should have a maximum at ∼308 nm. The degree of hydrophilicity of tryptophan microenvironment is proposed to be measured as the ratio between the peak at 360 nm and the peak at 330 nm if the observed shifts are not "horizontal", but "vertical". The process of dissociation of hemagglutinin trimers from pandemic Influenza A(H1N1) virus is described as an example of the advantages of the proposed method.
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Affiliation(s)
| | - Khrustaleva Tatyana Aleksandrovna
- Biochemical Group of the Multidisciplinary Diagnostic Laboratory, Institute of Physiology of the National Academy of Sciences of Belarus, Minsk, Belarus
| | | | | | - Kordyukova Larisa Valentinovna
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory 1-40, Moscow 119991, Russia
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14
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Kim MS, Lee C, Kim JH. Occurrence of unknown reactive species in UV/H 2O 2 system leading to false interpretation of hydroxyl radical probe reactions. Water Res 2021; 201:117338. [PMID: 34171647 DOI: 10.1016/j.watres.2021.117338] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 04/29/2021] [Accepted: 06/03/2021] [Indexed: 06/13/2023]
Abstract
The UV/H2O2 process is a benchmark advanced oxidation process (AOP) that in situ generates highly reactive and nonselective hydroxyl radical (•OH) to oxidatively destroy a wide range of organic compounds. Accurately quantifying the concentration of short-lived •OH is essential to predict process performance, optimize the operation parameters, and compare with other process options. The •OH concentration is typically measured using organic probe molecules that react with •OH but not with other oxidants. In the extremely well-characterized UV/H2O2 system in which •OH is proven to be the dominant oxidant, using photolysis-resistant probes such as benzoic acid and its derivatives is a widely agreed and practiced norm. We herein report that certain •OH probe compounds can be degraded in UV/H2O2 system by unknown reactive species that has not been reported in the past. Several common organic probes, particularly p-substituted benzoic acid compounds (i.e., p-hydroxybenzoic acid, p-chlorobenzoic acid, and p-phthalic acid), were found to be vulnerable to attack by the unknown reactive species, leading to false quantification of •OH concentration under high radical scavenging conditions. Lines of evidence obtained from a series of •OH scavenging experiments performed under various conditions (i.e., different concentrations of H2O2, •OH probe compounds, and dissolved oxygen) point toward excited state H2O2. The results from this study suggest the importance of using appropriate •OH probe compounds in mechanistic studies and needs for considering the unidentified role of excited state of H2O2 on the UV/H2O2 process and related AOPs.
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Affiliation(s)
- Min Sik Kim
- Department of Environmental Engineering and Soil Environment Research Center, Jeonbuk National University, Jeonju, Jeollabukdo 54896, Republic of Korea; School of Chemical and Biological Engineering, Institute of Chemical Process (ICP), Institute of Engineering Research, Seoul National University, Seoul 08826, Republic of Korea; Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06511, United States
| | - Changha Lee
- School of Chemical and Biological Engineering, Institute of Chemical Process (ICP), Institute of Engineering Research, Seoul National University, Seoul 08826, Republic of Korea.
| | - Jae-Hong Kim
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06511, United States.
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15
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Oftadeh M, Barfarakh Z, Ravari F. Luminescent excited-state intramolecular proton-transfer dyes based on 4-functionalized 6,6'-dimethyl-3,3'-dihydroxy-2,2'-bipyridine (BP(OH)2-Rs); DFT simulation study. J Mol Graph Model 2021; 107:107948. [PMID: 34082341 DOI: 10.1016/j.jmgm.2021.107948] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Revised: 05/04/2021] [Accepted: 05/20/2021] [Indexed: 01/28/2023]
Abstract
The 4-functionalized 6,6'-dimethyl-3,3'-dihydroxy-2,2'-bipyridine dyes (BP(OH)2-Rs) have exhibited dienol and diketo emissions. The optimum geometrical structures for ground, singlet and triplet excited states are computed by DFT/B3LYP/6-31++G that showed the planarity of BP(OH)2-Rs structure. The emission spectra of the molecules are determined in the gas-phase at singlet and triplet excited states using CIS/6-31++G. The theoretical calculations are carried out for BP(OH)2-Rs to understand the impact of different substituents (R = -H (I), -Br (II), -TMS (III), -C2H (IV), -terpyridine (V) and -bodipy (diazaboraindacene) (VI)) on excited-state intramolecular proton transfer (ESIPT) in singlet and triplet excited states. Based on the calculations, the concerted diproton transfer proceeds in the triplet excited state, in which nπ* state has a significant participation in ESIPT. The spectral variation at ESIPT emission of BP(OH)2-Rs is influenced by the electron-acceptor ability of the substituents. The compound V revealed a higher spectral intensity compared to the others. From the comparison with the experimental data, the molecule V is almost planar agreed with the X-ray structure and trend variation of wavelengths. The molecule VI contains bodipy chromophore that excitation energy transfers completely from BP(OH)2 core to a bodipy substituent, leading to emission from the lowest-lying bodipy substituent, and consequently, ESIPT does not occur for this dye.
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16
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Delesma C, Amador-Bedolla C, Robles M, Muñiz J. Electronic structure data at ground and excited state of the structural and opto-electronic properties of organic photovoltaic materials. Data Brief 2021; 35:106952. [PMID: 33850983 PMCID: PMC8039554 DOI: 10.1016/j.dib.2021.106952] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 03/05/2021] [Accepted: 03/08/2021] [Indexed: 11/11/2022] Open
Abstract
This work presents data coming from electronic structure calculations at the Density Functional Theory level, performed in a series of organic photovoltaic materials. The data represents the Cartesian coordinates of such molecular systems at the lowest energy geometry and at the first excited state. Data evidencing the nature of the photo-isomerization in the OPV systems was also obtained. Additionally, the highest probabilities of the molecular electronic transitions giving rise to the absorption spectra observed in excited state were also computed. These data may aid to estimate photovoltaic parameters, and to tailor materials intended to be implemented in solar cell devices. They may also be used as input to design a training set for machine learning analysis and artificial intelligence.
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Affiliation(s)
- Cornelio Delesma
- Instituto de Energías Renovables, Universidad Nacional Autónoma de México, Priv. Xochicalco s/n, Col. Centro, Temixco, Morelos CP 62580, México
| | - Carlos Amador-Bedolla
- Facultad de Química, Universidad Nacional Autónoma de México, Ciudad de México, CP 04510, México
| | - Miguel Robles
- Instituto de Energías Renovables, Universidad Nacional Autónoma de México, Priv. Xochicalco s/n, Col. Centro, Temixco, Morelos CP 62580, México
| | - Jesús Muñiz
- Instituto de Energías Renovables, Universidad Nacional Autónoma de México, Priv. Xochicalco s/n, Col. Centro, Temixco, Morelos CP 62580, México
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17
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Togasaki K, Arai T, Nishimura Y. Opposite substituent effects in the ground and excited states on the acidity of N-H fragments involved in proton transfer reaction in aromatic urea compounds. Photochem Photobiol Sci 2021; 20:523-532. [PMID: 33772478 DOI: 10.1007/s43630-021-00035-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 03/19/2021] [Indexed: 10/21/2022]
Abstract
To investigate substitution effects on excited-state intermolecular proton transfer (ESPT) reactions as well as acidity of proton donating fragments in the ground state, we synthesized substituted anthracen-2-yl-3-phenylurea derivatives that form a hydrogen bonds with acetate anions and undergo ESPT reaction. Fluorescence lifetime measurements and their kinetic analyses revealed that the trifluoromethyl group on the phenyl ring as an electron-withdrawing group caused a slow ESPT reaction despite an increase in the acidity of the N-H fragment in the ground state. In contrast, the methoxy group as a donating group leads to a fast ESPT reaction despite a reduction of the acidity of the N-H fragment in the ground state. These effects of substituents on ESPT reaction are due to their influence on the charge transfer reaction, which occurs from the N-H fragment to the anthryl ring to increase the acidity of N-H followed by ESPT reaction, over the urea unit by a combination of resonance and inductive effects. These opposing effects of substituents on the acidity of the urea unit in the ground and excited states provide an important insight in balancing the reactivity of proton transfer reaction in both the excited and ground states.
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Affiliation(s)
- Kei Togasaki
- Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Japan
| | - Tatsuo Arai
- Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Japan
| | - Yoshinobu Nishimura
- Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Japan.
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18
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Zhao L, Zhou P, Liu X, Zheng H, Zhan K, Luo J, Liu B. Theoretical studies of the ultrafast deactivation mechanism of 8-oxo-guanine on the S 1 and S 2 electronic states in gas phase. Spectrochim Acta A Mol Biomol Spectrosc 2021; 244:118884. [PMID: 32898726 DOI: 10.1016/j.saa.2020.118884] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 08/18/2020] [Accepted: 08/22/2020] [Indexed: 06/11/2023]
Abstract
The 8-oxo-deoxyguanosine is the most abundant specie of the DNA oxidative damage. Despite the deleterious effects such as gene mutation it may cause, the 8-oxodG was also reported to have beneficial effect such as repairing the nearby cyclobutane pyrimidine dimer (CPD) after photoexcitation. Due to its strong biological relevance, the photoinduced excited state dynamics behavior of 8-oxo-deoxyguanosine is of particular interest. In this work, a theoretical investigation by combination of complete active space self-consistent field (CASSCF) ab initio calculations and on-the-fly nonadiabatic dynamics simulations are implemented to provide intrinsic deactivation mechanism of its free base 8-oxoguanine after being excited to the S1 and S2 states. Two minimum energy conical intersections (MECIs) characterized by the C3-puckered motion with attractive chiral character are located, which contribute appreciably to the S1 state deactivation process. When the system is being excited to the S2 state directly, a S2 → S1 → S0 two-step decay pattern is proposed. A nearly planar S2/S1 intersection plays a significant role in the S2 → S1 decay process. The subsequent S1 state relaxation process is also dominated by the C3-puckered deformation motion. One decay time is estimated to be 704 fs, which compares well with the experimental observation of 0.9 ± 0.1 ps in solvents. Particular illustration is the fact that the MECIs configurations we located bear an exceptional resemblance with previous reported thymine, cytosine and guanine, suggesting that the current work could lend support for better understanding of the non-natural nucleobases and derivatives.
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Affiliation(s)
- Li Zhao
- College of Science, China University of Petroleum (East China), Qingdao 266580, Shandong, PR China.
| | - Panwang Zhou
- Institute of Molecular Sciences and Engineering, Shandong University, Qingdao 266235, PR China
| | - Xiaoxu Liu
- College of Science, China University of Petroleum (East China), Qingdao 266580, Shandong, PR China
| | - Haixia Zheng
- College of Science, China University of Petroleum (East China), Qingdao 266580, Shandong, PR China
| | - Kaiyun Zhan
- College of Science, China University of Petroleum (East China), Qingdao 266580, Shandong, PR China
| | - Jianhui Luo
- Research Institute of Petroleum Exploration & Development (RIPED), PetroChina, Beijing 100083, PR China
| | - Bing Liu
- College of Science, China University of Petroleum (East China), Qingdao 266580, Shandong, PR China.
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19
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Liu Y, Xu J, Han L, Liu Q, Yang Y, Li Z, Lu Z, Zhang H, Guo T, Liu Q. Ultra-Fast Computation of Excited-States Spectra for Large Systems: Ultraviolet and Fluorescence Spectra of Proteins. Interdiscip Sci 2020; 13:140-146. [PMID: 33185845 DOI: 10.1007/s12539-020-00402-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 10/04/2020] [Accepted: 10/29/2020] [Indexed: 11/26/2022]
Abstract
A workable approach named xTB-sTDDFT was selected to investigate the excited-state spectra of oxytocin (135 atoms), GHRP-6 (120 atoms) and insulin (793 atoms). Three different Hartree-Fock components functionals (wB97XD3: 51%, LC-BLYP: 53%, wB97X: 57%) were used to calculate the excitation spectra, and the results calculated by wB97XD3 functional well agree with the experiments. It's a deep impression that computed time cost reduced by more than 80%. For polypeptide (oxytocin and GHRP-6), both UV and fluorescence spectra were obtained, and the errors between the calculated and experimental values approximately were 20 nm. For Insulin, the errors are within 15 nm. UV spectrum peak is λcal = 262 nm (λexp = 277 nm, Δλ = 15 nm), and fluorescence spectrum peak is λcal = 294 nm (λexp = 304 nm, Δλ = 10 nm). In summary, a suitable theoretical model is established to ultra-fast calculate the electronic excitation spectra of large systems, such as proteins and biomacromolecules, with good calculation accuracy, fast calculation speed and low cost.
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Affiliation(s)
- Yonggang Liu
- Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang, 621010, China.
- State Key Laboratory of Environment-Friendly Energy Materials, Southwest University of Science and Technology, Mianyang, 621010, China.
| | - Jianjie Xu
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China
| | - Li Han
- Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing, 102205, China
| | - Qiangqiang Liu
- School of Chemistry and Environmental Engineering, Sichuan University of Science and Engineering, Zigong, 643000, China
| | - Yunfan Yang
- State Key Laboratory of Environment-Friendly Energy Materials, Southwest University of Science and Technology, Mianyang, 621010, China
| | - Zeren Li
- National Key Laboratory for Shock Wave and Detonation Physics, Institute of Fluid Physics, Chinese Academy of Engineering Physics, Mianyang, 621010, China
| | - Zhongyuan Lu
- State Key Laboratory of Environment-Friendly Energy Materials, Southwest University of Science and Technology, Mianyang, 621010, China.
| | - Hang Zhang
- National Key Laboratory for Shock Wave and Detonation Physics, Institute of Fluid Physics, Chinese Academy of Engineering Physics, Mianyang, 621010, China
| | - Tengxiao Guo
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China
| | - Qiao Liu
- National Key Laboratory for Shock Wave and Detonation Physics, Institute of Fluid Physics, Chinese Academy of Engineering Physics, Mianyang, 621010, China
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20
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Cao CN, Liu CF, Zhao L, Rao GW. New insight into the photoinduced wavelength dependent decay mechanisms of the ferulic acid system on the excited states. Spectrochim Acta A Mol Biomol Spectrosc 2020; 240:118565. [PMID: 32554260 DOI: 10.1016/j.saa.2020.118565] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 05/28/2020] [Accepted: 05/29/2020] [Indexed: 06/11/2023]
Abstract
The ferulic acid (FA) is a kind of phenolic acid widely exists in nature plants. Apart from its medicinal values, the FA is also widely applied in cosmetic industry. Recently, it was found to have potential applications in commercial sunscreens for its strong photostability and photoprotection property from harmful UV rays. Such excellent property lies in the ultrafast decay process of the FA system when exposure to the UV light, but the underlying detailed relaxation pathway is still less clear-cut. In the current work, high-level ab initio electronic structure calculations and on-the-fly surface hopping dynamics simulations were employed to explore the photoinduced decay mechanism of the FA system both on the S1 and S3 states in the gas phase. The results provide a reasonable explanation for the wavelength dependent decay patterns of FA system. The S1 state decay pathway is driven by a re-emission process to dissipate excess energy. While for the S3 state deactivation process, the pathway is dominated by a non-adiabatic process driven by the internal conversion process through the conical intersection regions. A S3-S1-S0 two step decay pattern is proposed, and the pathways are mainly driven by a puckering distortion motion of the aromatic ring and a twisting motion around the bridging double bond. The calculation results contribute to a better understanding of detailed dynamics behavior of the FA deactivation process, and provide theoretical guidance for further design of efficient and environmentally friendly sunscreens.
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Affiliation(s)
- Cong-Neng Cao
- College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou 310014, PR China; Institute of Drug Development & Chemical Biology, Zhejiang University of Technology, Hangzhou 310014, PR China
| | - Cheng-Fu Liu
- School of Pharmaceutical Sciences, Gannan Medical University, Ganzhou 341000, PR China
| | - Li Zhao
- School of Science, China University of Petroleum (East China), Qingdao 266580, Shandong, PR China
| | - Guo-Wu Rao
- College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou 310014, PR China; Institute of Drug Development & Chemical Biology, Zhejiang University of Technology, Hangzhou 310014, PR China.
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21
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Feng W, Wang T, Testoff TT, Bridgmohan CN, Zhao C, Sun H, Hu W, Li W, Liu D, Wang L, Zhou X. Exploiting singlet excited state conformation for rational design of highly efficient photoinduced electron transfer molecules. Spectrochim Acta A Mol Biomol Spectrosc 2020; 229:118016. [PMID: 31923789 DOI: 10.1016/j.saa.2019.118016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 12/26/2019] [Accepted: 12/27/2019] [Indexed: 06/10/2023]
Abstract
In spite of the pivotal role of excited state electronic structures as regulation of photoinduced electron transfer (PET) process, the effect of excited state conformation on PET remains elusive. Here we exploit distinguishable emission characters of trans and cis singlet excited states of donor-acceptor-donor ensemble MTPAAZO to reveal that its PET efficiency and rate are closely depended on its singlet excited state conformation. The PET process occurs solely in cis conformation of MTPAAZO singlet excited states. Novel molecule (MTPA)2Ab as-designed with similar structure of MTPAAZO cis singlet excited states shows high PET efficacy and rate, leading to long-lived CS states. Our findings enable the rational design of the novel molecules with highly efficient PET process suitable for charge separation applications.
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Affiliation(s)
- Wenhui Feng
- School of Chemical Engineering and Technology, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin Engineering Research Center of Functional Fine Chemicals, Tianjin University, Tianjin 300354, PR China
| | - Tianyang Wang
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, School of Science, Tianjin University, Tianjin 300072, PR China
| | - Thomas T Testoff
- Department of Chemistry and Biochemistry and the Materials Technology Center, Southern Illinois University, Carbondale, IL 62901, United States
| | - Chelsea N Bridgmohan
- Department of Chemistry and Biochemistry and the Materials Technology Center, Southern Illinois University, Carbondale, IL 62901, United States
| | - Chuanwu Zhao
- School of Chemical Engineering and Technology, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin Engineering Research Center of Functional Fine Chemicals, Tianjin University, Tianjin 300354, PR China
| | - Haiya Sun
- School of Chemical Engineering and Technology, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin Engineering Research Center of Functional Fine Chemicals, Tianjin University, Tianjin 300354, PR China
| | - Wenping Hu
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, School of Science, Tianjin University, Tianjin 300072, PR China
| | - Wei Li
- School of Chemical Engineering and Technology, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin Engineering Research Center of Functional Fine Chemicals, Tianjin University, Tianjin 300354, PR China
| | - Dongzhi Liu
- School of Chemical Engineering and Technology, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin Engineering Research Center of Functional Fine Chemicals, Tianjin University, Tianjin 300354, PR China
| | - Lichang Wang
- School of Chemical Engineering and Technology, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin Engineering Research Center of Functional Fine Chemicals, Tianjin University, Tianjin 300354, PR China; Department of Chemistry and Biochemistry and the Materials Technology Center, Southern Illinois University, Carbondale, IL 62901, United States.
| | - Xueqin Zhou
- School of Chemical Engineering and Technology, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin Engineering Research Center of Functional Fine Chemicals, Tianjin University, Tianjin 300354, PR China.
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22
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Chen W, Peng S, Zheng S. A theoretical study on electronic spectra of a novel series of metal substituted boron subphthalocyanine chloride. Spectrochim Acta A Mol Biomol Spectrosc 2020; 229:118018. [PMID: 31923793 DOI: 10.1016/j.saa.2019.118018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 12/16/2019] [Accepted: 12/27/2019] [Indexed: 06/10/2023]
Abstract
Boron subphthalocyanine chloride has been extensively studied by experimentalists and computational chemists due to its unique optical and electronic properties. It has been practical to modify the optical and physical properties of subphthalocyanine through axial, peripheral, and center substitutions or ring expansion. However, there have been few investigations on the substitution of central boron atom. In the present work, a new metal-substituted (center substitution of boron atom) series of boron subphthalocyanine chloride (metal = Fe, Co, Ni, Cu, and Zn) are theoretically designed utilizing modern density functional theory. The optimized results of this series in gas phase and with polarizable continuum model show that they may be chemically stable, and the predicted order of the stability of MSubPC is Fe>Cu>Ni>Co>Zn. Also, this new series of MSubPC molecules all becomes more non-planar and has much smaller dipole moments, which imply that they may be feasible for blend with organic acceptors. The HOMO-LUMO energy gaps of MSubPC (M=Co, Ni, Cu) are smaller than that of subPC. Furthermore, the wavelength of simulated absorption peaks of ZnSubPC and NiSubPC is red-shifted with respect to prototype subPC molecule in the visible region, and FeSubPC has noticeably stronger absorption strength than subPC because its excitation involves more orbital transitions and d electrons. The work here shows a new way to design photoelectric materials based on subphthalocyanine with center metal substitution.
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Affiliation(s)
- Wenlan Chen
- Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energies, School of Materials and Energy, Southwest University, Chongqing, China
| | - Suoping Peng
- Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energies, School of Materials and Energy, Southwest University, Chongqing, China
| | - Shaohui Zheng
- Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energies, School of Materials and Energy, Southwest University, Chongqing, China.
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23
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Lindic MM, Zajonz M, Gers-Panther C, Müller TJJ, Schmitt M. The excited state dipole moment of 2-[(4-methoxyphenyl)ethynyl]-3-(1-methyl-1H-indol-3-yl)-quinoxaline from thermochromic shifts. Spectrochim Acta A Mol Biomol Spectrosc 2020; 228:117574. [PMID: 31748161 DOI: 10.1016/j.saa.2019.117574] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 09/16/2019] [Accepted: 09/28/2019] [Indexed: 06/10/2023]
Abstract
The excited state dipole moment of 2-[(4-methoxyphenyl)ethynyl]-3-(1-methyl-1H-indol-3-yl)-quinoxaline has been determined in ethyl acetate solution using the method of thermochromic shifts. Three different models have been tested and are compared to each other and to the results of ab initio calculations at the coupled cluster CC2/cc-pVTZ and SCS-CC2/cc-pVTZ level of theory. Good agreement is obtained for solvent polarity functions as defined by Bilot and Kawski (L. Bilot and A. Kawski, Z. Naturforsch., 1962, 17A, 621-627), while the original Lippert-Mataga type polarity functions fail to describe the excited state dipole moment correctly. We report an excited state dipole moment of the title compound of 8.5 D and a change upon excitation of 5.5 D.
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Affiliation(s)
- Mirko Matthias Lindic
- Heinrich-Heine-Universität, Institut für Physikalische Chemie I, D-40225, Düsseldorf, Germany
| | - Matthias Zajonz
- Heinrich-Heine-Universität, Institut für Physikalische Chemie I, D-40225, Düsseldorf, Germany
| | - Charlotte Gers-Panther
- Heinrich-Heine-Universität, Institut für Organische Chemie und Makromolekulare Chemie, D-40225, Düsseldorf, Germany
| | - Thomas J J Müller
- Heinrich-Heine-Universität, Institut für Organische Chemie und Makromolekulare Chemie, D-40225, Düsseldorf, Germany
| | - Michael Schmitt
- Heinrich-Heine-Universität, Institut für Physikalische Chemie I, D-40225, Düsseldorf, Germany.
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24
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Liu Q, Wang Q, Xu M, Liu J, Liang J. DFT characterization and design of anthracene-based molecules for improving spectra and charge transfer. Spectrochim Acta A Mol Biomol Spectrosc 2020; 227:117627. [PMID: 31703990 DOI: 10.1016/j.saa.2019.117627] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 09/08/2019] [Accepted: 10/06/2019] [Indexed: 06/10/2023]
Abstract
Four anthracene-based dyes (AN-3, AN-11, AN-12, AN-14) are investigated with density functional theory (DFT) and time-dependent density functional theory (TD-DFT) for dye-sensitized solar cells (DSSCs), involving the stable molecular geometries, the electronic structures, the absorption and fluorescence spectra, and the performance of photoelectric properties. For the simulation of the realistic environment, some important parameters, including energy levels, energy gaps, electron density, projected density of states (PDOS), absorption, vertical dipole moment, first hyperpolarizability, light-harvesting efficiency (LHE), evaluation on electron injection, are calculated for each dye molecule. The relevant electron transfer (ET) and dynamic processes were studied by using the charge different density (CDD) and Newns-Anderson model. The relationship between structure and performance are established. Furthermore, six dyes are designed and examined on the basis of AN-11 to improve optical response and electron injection. It is expected that this study will give theoretical guidance and ideas for finding potential solar cell materials.
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Affiliation(s)
- Qian Liu
- Department of Applied Physics, Xi'an University of Technology, Xi'an, Shaanxi, 710054, China; Department of Physics, Kennesaw State University, Marietta, GA, 30060, USA.
| | - Qungui Wang
- College of Physical Science and Technology, Sichuan University, Chengdu, Sichuan, 610065, China
| | - Ming Xu
- Department of Applied Physics, Xi'an University of Technology, Xi'an, Shaanxi, 710054, China
| | - Jinglin Liu
- College of Science, Jiamusi University, Jiamusi, Heilongjiang, 154001, China.
| | - Jianping Liang
- Key Lab of Materials Modification, Ministry of Education, Dalian University of Technology, Dalian, Liaoning, 116024, China
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25
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Feng S, Guo X, Zhang J. An effective strategy for simply varying relative position of two carbazole groups in the thermally activated delayed fluorescence emitters to achieve deep-blue emission. Spectrochim Acta A Mol Biomol Spectrosc 2020; 226:117564. [PMID: 31614274 DOI: 10.1016/j.saa.2019.117564] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 09/16/2019] [Accepted: 09/22/2019] [Indexed: 06/10/2023]
Abstract
The development of efficient deep-blue thermally activated delayed fluorescence (TADF) materials is especially important for organic light-emitting devices as displays and lighting sources. However, finding suitable deep-blue TADF emitters is still challenging. Based on an experimentally reported blue-light TADF emitter DCZ-TTR, two new molecules (DCZ1-TTR and DCZ2-TTR) have been designed to investigate the impact of the change of relative position in two carbazole groups on their TADF properties. Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations coupled with the Marcus rate theory have been performed. It is found that the absorption and emission spectra simulated using the BMK functional can reproduce the available experimental data very well. The fluorescence emissions of DCZ1-TTR and DCZ2-TTR are predicted to show clear blue-shifting in cyclohexane with respect to their analogue DCZ-TTR. Especially, the emission wavelength of DCZ2-TTR is calculated to be 435nm, in the deep-blue light range. According to the Marcus rate theory, the rates of reverse intersystem crossing of DCZ1-TTR and DCZ2-TTR are estimated to be two orders of magnitude larger than that of DCZ-TTR, which is more favorable for the occurrence of delayed fluorescence. This strongly suggests that our newly designed two molecules DCZ1-TTR and DCZ2-TTR can be also expected to be potential blue-light or even deep-blue-light TADF emitters. This may be an effective strategy for realizing deep-blue emission by simply varying relative position of two carbazole groups in the TADF molecules. To our best knowledge, this is a novel finding, which may be useful in preparing highly efficient deep-blue TADF-OLED materials.
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Affiliation(s)
- Songyan Feng
- Institute of Upconversion Nanoscale Materials, Henan Provincial Engineering Research Center of Green Anticorrosion Technology for Magnesium Alloy, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, 475004, PR China
| | - Xugeng Guo
- Institute of Upconversion Nanoscale Materials, Henan Provincial Engineering Research Center of Green Anticorrosion Technology for Magnesium Alloy, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, 475004, PR China.
| | - Jinglai Zhang
- Institute of Upconversion Nanoscale Materials, Henan Provincial Engineering Research Center of Green Anticorrosion Technology for Magnesium Alloy, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, 475004, PR China.
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26
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Zhang M, Hua Z, Liu W, Liu H, He S, Zhu C, Zhu Y. A DFT study on the photoelectric properties of rubrene and its derivatives. J Mol Model 2020; 26:32. [PMID: 31970537 DOI: 10.1007/s00894-020-4295-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 01/13/2020] [Indexed: 10/25/2022]
Abstract
The way to obtain new materials was usually to introduce some groups to molecules. Correlations among the molecular structure and photoelectric properties of rubrene and its eight derivatives have been studied in this paper, and the influences of the introduction of different electron-donating and withdrawing substituents on the molecular orbital, reorganization energies, absorption spectra, and fluorescence spectra of rubrene and its derivatives were discussed. In the present work, density functional theory calculations were performed at the B3LYP/6-311G(d,p) level to optimize the structure, and TD-DFT was used to calculate the absorption and emission spectra. Quantum chemistry calculation results indicated that the maximum absorption wavelengths are redshifted due to the introduction of cyclopentadienyl or furan groups, the maximum absorption wavelengths are blueshifted while methoxy groups substituted on tetracene backbone. We also discussed the influence of substituents on the molecule structure, which suggests that introducing furan and cyclopentadienyl substituents on the tetracene backbone can increase the rigidity of rubrene and improve the fluorescence intensity. The results of reorganization show that the introduction of cyclopentadienyl or furan groups into rubrene is advantageous to the holes transportation, and the introduction of F groups contributes to the electrons transportation. This study provides an insight into the properties of rubrene and its derivatives and supplies an effective method to design new organic semiconductor materials.
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27
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Zhang X, Shi Y, Cai L, Zhou Y, Wang CK, Lin L. Solvent effect on the photophysical properties of thermally activated delayed fluorescence molecules. Spectrochim Acta A Mol Biomol Spectrosc 2020; 225:117473. [PMID: 31470345 DOI: 10.1016/j.saa.2019.117473] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 07/27/2019] [Accepted: 08/15/2019] [Indexed: 06/10/2023]
Abstract
As the third-generation organic electroluminescent materials, thermally activated delayed fluorescence (TADF) molecules have become the research focus recently. Significant solvent effect on TADF molecules were found experimentally, while theoretical investigations are quite limited. In this work, the solvent effect on photophysical properties of DCBPy and DTCBPy are investigated with first-principles calculations. The solvent polarity has slight influence on the molecular geometries and orbitals, while it can decrease the energy gap between the first singlet excited state (S1) and first triplet excited state (T1) significantly. Both the oscillator strength and the radiation rates of S1 increase with larger solvent polarity. The large energy gap between S1 and T1 induce negligible intersystem crossing (ISC) and reverse ISC rates between them, which also indicates higher triplet excited states are involved in the up-conversion process. Our results provide valuable information about solvent influence on the light-emitting properties of TADF molecules, which could help one better understand the light-emitting mechanism of them and favor the design of TADF molecules.
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Affiliation(s)
- Xiaotong Zhang
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, 250014 Jinan, China
| | - Yurong Shi
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, 250014 Jinan, China
| | - Lei Cai
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, 250014 Jinan, China
| | - Yong Zhou
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, 250014 Jinan, China
| | - Chuan-Kui Wang
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, 250014 Jinan, China.
| | - Lili Lin
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, 250014 Jinan, China.
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28
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Deng Q, Zhu Z, Shu X. Spectrally resolved luminescence lifetime detection for measuring the energy splitting of the long-lived excited states. Spectrochim Acta A Mol Biomol Spectrosc 2020; 224:117434. [PMID: 31394392 DOI: 10.1016/j.saa.2019.117434] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 07/26/2019] [Accepted: 07/27/2019] [Indexed: 06/10/2023]
Abstract
Molecular motion plays an important role in the reverse intersystem crossing of thermally activated delayed fluorescence (TADF) materials, since the conformation varies as the molecule vibrates, leading to potential changes in the energies of excited states. Although many theoretical simulations have researched the relationship between the excited states and the molecular conformations, there are still few experimental results showing the energy level difference between different long-lived excited states. Herein, a novel method for measuring spectrally resolved luminescence lifetimes is proposed to detect the energy splitting of the long-lived excited states of a classical TADF molecule, BTZ-DMAC. A set of the time-gated luminescence spectra with different delay times were captured by a spectrograph equipped on an auto-phase-locked system, and then used for lifetime analysis at each wavelength. Unlike traditional measurement techniques, the proposed novel method does not require ultrafast laser, high-speed detector and any phase matching circuitry, thus significantly reducing the cost. This method revealed a definite energy gap between the two excited states of BTZ-DMAC with different lifetimes, indicating different conformations caused by molecular vibration. This low-cost method could be also used to detect many other luminescence materials for investigating the detail mechanisms of multiple excited states.
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Affiliation(s)
- Qisheng Deng
- Wuhan National Laboratory for Optoelectronics & School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Zece Zhu
- Wuhan National Laboratory for Optoelectronics & School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China.
| | - Xuewen Shu
- Wuhan National Laboratory for Optoelectronics & School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China.
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29
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Li G, Zheng S. A computational study of the effects of axial halogen substitutions of boron subphthalocyanines on their electronic spectra in solution and in the solid state. Spectrochim Acta A Mol Biomol Spectrosc 2019; 222:117180. [PMID: 31185442 DOI: 10.1016/j.saa.2019.117180] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 04/22/2019] [Accepted: 05/26/2019] [Indexed: 06/09/2023]
Abstract
Non-planar boron subphthalocyanine chloride is a talented photoelectric material and has been widely applied. In this paper, we have investigated the effects of axial halogen substitutions on electronic spectra of boron subphthalocyanines by combining DFT/TDDFT calculations and available experimental data in solution and in the solid state. We utilize long range separated density functional and polarizable continuum model to obtain the electronic structure and absorption spectra. The computed frontier molecular orbital energy matches well with experiment in dichloromethane and the simulated spectra correctly reproduce the trend of experiment in toluene. Furthermore, we model two configurations (convex-to-convex and concave-to-concave) of dimers of boron subphthalocyanines based on experimental structures in thin film: From F to Cl to Br substitution, the simulated wavelength of absorption peaks in the visible region slightly increases; in contrast, the absorption strength decreases. Moreover, our calculated results suggest that the convex-to-convex configurations of dimers may be the main contributors to the absorption spectra of X-BsubPC (X = F, Cl, Br) in thin film, though no experimental spectra of thin film of X-BsubPC (X = F, Br) yet. Finally, we find that CAM-B3LYP is able to reproduce the energy of frontier molecular orbitals quite well.
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Affiliation(s)
- Guo Li
- Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energies, Faculty of Materials and Energy, Southwest University, Chongqing, China
| | - Shaohui Zheng
- Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energies, Faculty of Materials and Energy, Southwest University, Chongqing, China.
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30
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Abstract
A variational solution to the eigenvalue problem for the Hamiltonian H, with orthogonality restrictions on eigenvectors of H to the vector H ∣ Φ0〉, where ∣Φ0〉 is an approximate ground-state vector, is proposed as a means to calculate excited states. The asymptotic projection (AP) method proposed previously is further developed and applied to solve this problem in a simple way. We demonstrate that the AP methodology does not require an evaluation of the matrix elements of operator H2, whereas conventional approaches-such as the elimination of off-diagonal Lagrange multipliers method, projection operator techniques, and other methods-do. It is shown, based on the results obtained for the single-electron molecular ions H2+, HeH2+, and H32+, that applying the new method to determine excited-state wavefunctions yields the upper bounds for excited-state energies. We demonstrate that regardless of whether the orthogonality constraint for states (〈Φ| Φ0〉 = 0) is applied, the zero-coupling constraint (〈Φ| H| Φ0〉 = 0) is imposed, or both of these restrictions are enforced simultaneously, practically the same excited-state energy is obtained if the basis set is almost complete. For the systems considered here, all schemes are capable of giving a sub-μhartree level of accuracy for the ground and excited states computed with different basis sets.
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Affiliation(s)
- V N Glushkov
- Department of Chemistry, Dnipropetrovsk National University, Dnipropetrovsk, Ukraine.
| | - X Assfeld
- CNRS, Laboratoire de Physique et Chimie Théoriques, UMR 7019, Université de Lorraine, 54506, Vandoeuvre-les-Nancy Cedex, France
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31
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Liu D, Wang JP, Li GY, Zhou CH. TDDFT study on aluminum and fluoride dual-sensing mechanism of a Schiff-Base sensor. Spectrochim Acta A Mol Biomol Spectrosc 2019; 211:44-51. [PMID: 30503987 DOI: 10.1016/j.saa.2018.11.043] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 11/13/2018] [Accepted: 11/15/2018] [Indexed: 06/09/2023]
Abstract
The aluminum and fluoride dual-sensing mechanism of a previously reported sensor with a Schiff-base moiety (Spectrochim. Acta A, 2017, 183, 267-274) has been investigated by density functional theory (DFT) and time-dependent DFT (TDDFT) methods. The present calculations reproduce the photoproperties of the sensor as well as its aluminum and fluoride complexes, which illustrates that DFT and TDDFT constitute a reliable tool for uncovering detailed fluorescence-based sensing mechanisms in diverse electronic states. Theoretical results indicate that there are two OH⋯N hydrogen bonds in the sensor and two OH⋯F hydrogen bonds in its F¯ complex. Different degrees of coplanarity caused by these hydrogen bonds are responsible for their distinct absorption wavelengths. However, excited-state geometry optimization and a scan of the potential-energy surface show that there is twisted intramolecular charge transfer about the CN bond in the sensor molecule and an excited-state proton-transfer process from the fluoride anion to the neighboring N atom in the fluoride-sensor complex, whereby the fluorescence is quenched. A chelation-enhanced fluorescence effect associated with the aluminum-sensor complex shows a different excited-state process. The local excitation and emission occur exclusively within the planar fluorophore, and negligible structural change upon excitation of the aluminum-sensor complex leads to its strong fluorescence. Therefore, it is theoretically explained why the sensor may be successfully used to analyze the fluoride anion by absorption spectroscopy and the aluminum cation by emission spectroscopy.
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Affiliation(s)
- Dong Liu
- College of Chemical Engineering, North China University of Science and Technology, Tangshan 063009, PR China; State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, PR China
| | - Jie-Ping Wang
- College of Chemical Engineering, North China University of Science and Technology, Tangshan 063009, PR China
| | - Guang-Yue Li
- College of Chemical Engineering, North China University of Science and Technology, Tangshan 063009, PR China.
| | - Can-Hua Zhou
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, PR China.
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32
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Yang Y, Li D, Li C, Liu Y, Jiang K. Asymmetric substitution changes the UV-induced nonradiative decay pathway and the spectra behaviors of β-diketones. Spectrochim Acta A Mol Biomol Spectrosc 2019; 207:209-215. [PMID: 30240982 DOI: 10.1016/j.saa.2018.09.026] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2018] [Revised: 09/13/2018] [Accepted: 09/14/2018] [Indexed: 06/08/2023]
Abstract
Asymmetric substitution has not been termed as an essential factor in studying photo-induced ultrafast dynamics of molecular system. Asymmetric 4-hydroxybut-3-en-2-one (HEO), together with symmetric malonaldehyde (MA) and acetylacetone (AA), have been provided as target sample to study the nonradiative decay (ND) processes of β-diketones. An effective ND pathway of the three molecules is presented that their excited second (S2) states transfer to first (S1) state by nonadiabatic surface hopping, and then transfer to triplet (T1) state by crossing minimum energy crossing point (MECP), after which decay to ground (S0) state through MECP. More importantly, the asymmetric substitution of HEO induces the proton transfer in the S1 state and generates a proton-transferred conformer with lowest energy, which does not occur for MA and AA. This change exploits a new ND pathway that the S1 state decays to the proton transferred T1 state and then undergoes reverse proton transfer to S0 state through the MECPs between the three states. The two pathways of HEO give detailed energy and geometric information on surface hopping of S2/S1 and MECPs of S1/T1/S0, and interpret the reason of the ND pathway while not spectra emission. This result is significantly different from the previous reported ND pathway of photoisomerization or conical intersection between different states. This work shows that asymmetric substitution changes the molecular structure and then changes their spectra behaviors.
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Affiliation(s)
- Yonggang Yang
- College of Physics and Materials Science, Henan Normal University, Xinxiang 453007, China
| | - Donglin Li
- College of Physics and Materials Science, Henan Normal University, Xinxiang 453007, China
| | - Chaozheng Li
- College of Physics and Materials Science, Henan Normal University, Xinxiang 453007, China
| | - Yufang Liu
- College of Physics and Materials Science, Henan Normal University, Xinxiang 453007, China.
| | - Kai Jiang
- School of Environment, Henan Normal University, Xinxiang 453007, China
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33
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Talbert LE, Julian RR. Directed-Backbone Dissociation Following Bond-Specific Carbon-Sulfur UVPD at 213 nm. J Am Soc Mass Spectrom 2018; 29:1760-1767. [PMID: 29623659 PMCID: PMC6087500 DOI: 10.1007/s13361-018-1934-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 02/16/2018] [Accepted: 02/23/2018] [Indexed: 05/22/2023]
Abstract
Ultraviolet photodissociation or UVPD is an increasingly popular option for tandem-mass spectrometry experiments. UVPD can be carried out at many wavelengths, and it is important to understand how the results will be impacted by this choice. Here, we explore the utility of 213 nm photons for initiating bond-selective fragmentation. It is found that bonds previously determined to be labile at 266 nm, including carbon-iodine and sulfur-sulfur bonds, can also be cleaved with high selectivity at 213 nm. In addition, many carbon-sulfur bonds that are not subject to direct dissociation at 266 nm can be selectively fragmented at 213 nm. This capability can be used to site-specifically create alaninyl radicals that direct backbone dissociation at the radical site, creating diagnostic d-ions. Furthermore, the additional carbon-sulfur bond fragmentation capability leads to signature triplets for fragmentation of disulfide bonds. Absorption of amide bonds can enhance dissociation of nearby labile carbon-sulfur bonds and can be used for stochastic backbone fragmentation typical of UVPD experiments at shorter wavelengths. Several potential applications of the bond-selective fragmentation chemistry observed at 213 nm are discussed. Graphical Abstract ᅟ.
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Affiliation(s)
- Lance E Talbert
- Department of Chemistry, University of California, Riverside, 501 Big Springs Road, Riverside, CA, 92521, USA
| | - Ryan R Julian
- Department of Chemistry, University of California, Riverside, 501 Big Springs Road, Riverside, CA, 92521, USA.
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34
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Yang Y, Li D, Li C, Liu Y, Jiang K. Hydrogen bond strengthening induces fluorescence quenching of PRODAN derivative by turning on twisted intramolecular charge transfer. Spectrochim Acta A Mol Biomol Spectrosc 2017; 187:68-74. [PMID: 28654834 DOI: 10.1016/j.saa.2017.06.029] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 06/21/2017] [Accepted: 06/22/2017] [Indexed: 06/07/2023]
Abstract
Researchers have proposed different effective mechanisms of hydrogen bonding (HB) on the fluorescence of 6-propionyl-2-dimethylaminonaphthalene (PRODAN) and its derivatives. Herein, excited state transition and dynamics analysis confirm that the fluorescence of PD (a derivative of PRODAN with ethyl replaced by 3-hydroxy-2,2-dimethylpropan) emits from the planar intramolecular charge transfer (PICT) state rather than twist ICT (TICT) state, because the fluorescence emission and surface hopping from the TICT state to the twist ground (T-S0) state is energy forbidden. Nevertheless, the strengthening of intramolecular-HB (intra-HB) and intermolecular-HB (inter-HB) of PD-(methanol)2 smooth the pathway of surface hopping from TICT to T-S0 state and the external conversion going to planar ground state by decreasing the energy difference of the two states. This smoothing changes the fluorescence state of PD-(methanol)2 to the TICT state in which fluorescence emission does not occur but surface hopping, leading to the partial fluorescence quenching of PD in methanol solvent. This conclusion is different from previous related reports. Moreover, the inter-HB strengthening of PD-methanol in PICT state induces the cleavage of intra-HB and a fluorescence red-shift of 54nm compared to PD. This red-shift increases to 66nm for PD-(methanol)2 for the strengthening of the one intra-HB and two inter-HBs. The dipole moments of PD-methanol and PD-(methanol)2 respectively increase about 10.3D and 8.1D in PICT state compared to PD. The synergistic effect of intra-HB and inter-HB induces partial quenching of PD in methanol solvent by turning on the TICT state and fluorescence red-shift. This work gives a reasonable description on the fluorescence red-shift and partial quenching of PD in methanol solvent, which will bring insight into the study of spectroscopic properties of molecules owning better spectral characteristics.
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Affiliation(s)
- Yonggang Yang
- College of Physics and Materials Science, Henan Normal University, Xinxiang 453007, China
| | - Donglin Li
- College of Physics and Materials Science, Henan Normal University, Xinxiang 453007, China
| | - Chaozheng Li
- College of Physics and Materials Science, Henan Normal University, Xinxiang 453007, China
| | - YuFang Liu
- College of Physics and Materials Science, Henan Normal University, Xinxiang 453007, China.
| | - Kai Jiang
- School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang 453007, China
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Tong H, Zhao Z, Li G, Gao L, Zhao N, Li P, Jia Y, Zhou C, Zhang M, Wang Y, Hao C, Tang X. TDDFT study on recognition mechanism for the oxygen sensing of the cyclometalated platinum (II) complex. Spectrochim Acta A Mol Biomol Spectrosc 2017; 183:371-377. [PMID: 28463776 DOI: 10.1016/j.saa.2017.04.048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 04/07/2017] [Accepted: 04/18/2017] [Indexed: 06/07/2023]
Abstract
The influence of oxygen molecule on the luminescent properties of a cyclometalated Pt(II) complex Lxp1, was investigated using density functional theory (DFT) and time-dependent density functional theory (TDDFT) methods. Analysis of frontier molecular orbitals and electronic configuration indicated that the highest-occupied molecular orbital of the Lxp1 has a significant mixture of metal Pt (d) as well as 2-phenylpyridine and acetyl acetone(π). The lowest-unoccupied orbital of the Lxp1 primarily locates on π* of 2-phenylpyridineligands. The emission mechanism of the cyclometalated Pt(II) complex Lxp1 is assigned to the mixing of ligand-to-metal charge transfer and ligand-to-ligand charge transfer. The emission mechanism of the Lxp1-O2 complex can be attributed to the charge transfer from the oxygen molecule to the luminescent material Lxp1. Our study showed that intermolecular hydrogen bonding between the Lxp1 and oxygen molecule was strengthened by the calculation of electronic excitation, leading to a luminescence-decreasing phenomenon. The calculation of the radiative and non-radiative decay rate constants of the Lxp1 and the Lxp1-O2 complex demonstrates that the phosphorescence from T1-S0 of the Lxp1 would alter to the internal conversion from T1-T0 of the Lxp1-O2 complex. This alteration further explains the luminescence quenching phenomenon of the cyclometalated Pt(II) complex Lxp1 after interacting with oxygen molecule.
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Affiliation(s)
- Huan Tong
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Panjin 124221, China; State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Zhengyan Zhao
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Panjin 124221, China
| | - Guanglan Li
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Panjin 124221, China
| | - Liguo Gao
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Panjin 124221, China
| | - Ningjiu Zhao
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Peng Li
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
| | - Yan Jia
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Chenyang Zhou
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Institute of Chemistry, Department of Chemistry, School of Science, Tianjin University, Tianjin 300354, China
| | - Mingzhen Zhang
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Institute of Chemistry, Department of Chemistry, School of Science, Tianjin University, Tianjin 300354, China.
| | - Yong Wang
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Institute of Chemistry, Department of Chemistry, School of Science, Tianjin University, Tianjin 300354, China
| | - Ce Hao
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Panjin 124221, China.
| | - Xiaoying Tang
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Institute of Chemistry, Department of Chemistry, School of Science, Tianjin University, Tianjin 300354, China
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Cartwright SJ. Interaction of homeopathic potencies with the water soluble solvatochromic dye bis-dimethylaminofuchsone. Part 1: pH studies. HOMEOPATHY 2017; 106:37-46. [PMID: 28325223 DOI: 10.1016/j.homp.2017.01.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 12/06/2016] [Accepted: 01/06/2017] [Indexed: 11/29/2022]
Abstract
INTRODUCTION Previous studies have demonstrated the potential of solvatochromic dyes for investigating the physical chemistry of homeopathic potencies. RESULTS Following examination of this class of dyes in organic solvents, results obtained using the positively solvatochromic dye Bis-dimethylaminofuchsone (BDF) in aqueous solution are now reported. Spectral changes observed with this dye in the presence of potencies are both substantial and reproducible. Studies across a wide range of pH values reveal an unusual pH dependence for the dye's interaction with homeopathic potencies. Results indicate potency enhances dye protonation at pH values below c. 7.0, whilst protecting the dye from attack by hydroxyl ions above c. pH 7.5. CONCLUSION A possible explanation for these observations is offered in terms of a potency - induced electron density shift in BDF. The interaction of homeopathic potencies with solvatochromic dyes, particularly BDF, points towards a possible physico-chemical model for the nature of potencies, how they may be interacting with this class of dyes, and moreover how their biological effects may be mediated.
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Affiliation(s)
- Steven J Cartwright
- DiagnOx Laboratory, Cherwell Innovation Centre, Upper Heyford, Oxon, OX25 5HD, UK.
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Racine J, Touadjine MA, Rahmouni A, Humbel S. Methylenecyclopropene: local vision of the first 1B 2 excited state. J Mol Model 2017; 23:22. [PMID: 28064374 DOI: 10.1007/s00894-016-3191-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 12/15/2016] [Indexed: 10/20/2022]
Abstract
The 1A1 ground and the first 1B2 excited states of the methylenecyclopropene (triafulvene) are described by localized wave functions, based on 20 structures valence bond structures. The results are compared to CASSCF(4,4) calculations for both the energetics and the dipole moment. Additional calculations with partial electronic delocalization are presented, and it is shown that the dipole moment modification does not correspond to a situation where the antiaromatic situation prevails (with 4n electrons in the cycle). Part of the analysis uses a "trust factor" that helps to decide if a wave function is appropriate to describe a given state. The trust factor compares the VB wave function to the CASSCF's with their overlap. Finally, the valence bond density is used to produce density maps that illustrate the electron transfer upon excitation. Graphical Abstract A projector-based method compares CASSCF wave functions to local wave functions, including Lewis structures as shown in the picture. A "trust factor" (τ) is obtained. Both the ground state and the first excited state of the methylenecyclopropene are discussed.
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Katsukura H, Miyata T, Tomita K, Mizoguchi T. Effect of the van der Waals interaction on the electron energy-loss near edge structure theoretical calculation. Ultramicroscopy 2016; 178:88-95. [PMID: 27477916 DOI: 10.1016/j.ultramic.2016.07.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 07/07/2016] [Accepted: 07/18/2016] [Indexed: 11/28/2022]
Abstract
The effect of the van der Waals (vdW) interaction on the simulation of the electron energy-loss near edge structure (ELNES) by a first-principles band-structure calculation is reported. The effect of the vdW interaction is considered by the Tkatchenko-Scheffler scheme, and the change of the spectrum profile and the energy shift are discussed. We perform calculations on systems in the solid, liquid and gaseous states. The transition energy shifts to lower energy by approximately 0.1eV in the condensed (solid and liquid) systems by introducing the vdW effect into the calculation, whereas the energy shift in the gaseous models is negligible owing to the long intermolecular distance. We reveal that the vdW interaction exhibits a larger effect on the excited state than the ground state owing to the presence of an excited electron in the unoccupied band. Moreover, the vdW effect is found to depend on the local electron density and the molecular coordination. In addition, this study suggests that the detection of the vdW interactions exhibited within materials is possible by a very stable and high resolution observation.
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Affiliation(s)
- Hirotaka Katsukura
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8505, Japan
| | - Tomohiro Miyata
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8505, Japan
| | - Kota Tomita
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8505, Japan
| | - Teruyasu Mizoguchi
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8505, Japan.
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Pizarro S, Gallardo M, Leyton C, Castro E, Gajardo F, Delgadillo A. Effect of pH in the photoluminescence of a ruthenium complex featuring a derivative of the ligand pyrazine[2,3-f][1,10]-phenanthroline. Spectrochim Acta A Mol Biomol Spectrosc 2015; 146:61-65. [PMID: 25813163 DOI: 10.1016/j.saa.2015.03.067] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Revised: 03/03/2015] [Accepted: 03/04/2015] [Indexed: 06/04/2023]
Abstract
A new ruthenium complex, [Ru(bpy)2(dbe-ppl)](PF6)2 (bpy=2,2'-bipyridine and dbe-ppl=dimethyl 4,4'-(pyrazino[2,3-f][1,10]phenanthroline-2,3-diyl)dibenzoate, has been synthesized and characterized by (1)H NMR spectroscopy, UV-Vis, IR, and cyclic voltammetry. Irradiation on the MLCT band results in photoluminescence in both protic and aprotic solvents. The photoluminescence in water is pH dependent, it shows a behavior which can be described by the Henderson-Hasselbalch assuming the protonation/deprotonation of the excited state with a pKa of 2.40±0.01.
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Affiliation(s)
- Sebastián Pizarro
- Departamento de Química, Facultad de Ciencias, Universidad de La Serena, Casilla 599, Benavente 980, La Serena, Chile
| | - Miguel Gallardo
- Departamento de Química, Facultad de Ciencias, Universidad de La Serena, Casilla 599, Benavente 980, La Serena, Chile
| | - Constanza Leyton
- Departamento de Química, Facultad de Ciencias, Universidad de La Serena, Casilla 599, Benavente 980, La Serena, Chile
| | - Eileen Castro
- Departamento de Química, Facultad de Ciencias, Universidad de La Serena, Casilla 599, Benavente 980, La Serena, Chile
| | - Francisco Gajardo
- Departamento de Química, Facultad de Ciencias, Universidad de La Serena, Casilla 599, Benavente 980, La Serena, Chile
| | - Alvaro Delgadillo
- Departamento de Química, Facultad de Ciencias, Universidad de La Serena, Casilla 599, Benavente 980, La Serena, Chile.
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Song MX, Wang GF, Wang J, Wang YH, Bai FQ, Qin ZK. Theoretical study on a series of iridium complexes with low efficiency roll-off property. Spectrochim Acta A Mol Biomol Spectrosc 2015; 134:406-412. [PMID: 25025313 DOI: 10.1016/j.saa.2014.06.088] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 05/26/2014] [Accepted: 06/01/2014] [Indexed: 06/03/2023]
Abstract
A series of heteroleptic cyclometalated Ir (III) complexes for OLEDs application have been investigated theoretically to explore their electronic structures and spectroscopic properties. The geometries, electronic structures, and the lowest-lying singlet absorptions and triplet emissions of (piq)₂Ir(acac) (labeled 1) and theoretically designed models (piq)₂Ir(dpis) (labeled 2), (4Fpiq)₂Ir(dpis) (labeled 3), (4F5M-piq)₂Ir(dpis) (labeled 4), (4,5-2F-piq)₂Ir(dpis) (labeled 5) and (5-F-piq)₂Ir(dpis) (labeled 6) were investigated with density functional theory (DFT)-based approaches, where, piq=1-phenylisoquinolato, acac=acetylacetonate and dpis=diphenylimidodisilicate. Their structures in the ground and excited states have been optimized at the DFT/B3LYP/LANL2DZ and TDDFT/B3LYP/LANL2DZ levels, and the lowest absorptions and emissions were evaluated at B3LYP and M062X level of theory, respectively. Furthermore, the energy-transfer mechanism of these complexes also be analyzed here, and the result shown that the complexes 1-6 are having the low efficiency roll-off property. Except that, the oscillator strength analyze shown that the complexes 2-6, which were designed by theory, are suitable for OLED since their high oscillator strength property.
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Affiliation(s)
- Ming-Xing Song
- College of Information Technology, Jilin Normal University, Siping 136000, People's Republic of China
| | - Guo-Feng Wang
- College of Information Technology, Jilin Normal University, Siping 136000, People's Republic of China
| | - Jin Wang
- College of Information Technology, Jilin Normal University, Siping 136000, People's Republic of China
| | - Yu-Hai Wang
- College of Information Technology, Jilin Normal University, Siping 136000, People's Republic of China
| | - Fu-Quan Bai
- Institute of Theoretical Chemistry, State Key Laboratory of Theoretical and Computational Chemistry, Jilin University, Changchun 130023, People's Republic of China.
| | - Zheng-Kun Qin
- College of Information Technology, Jilin Normal University, Siping 136000, People's Republic of China.
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Abstract
The use of visible light to produce highly selective and potent drugs through photodynamic therapy (PDT) holds much potential in the treatment of cancer. PDT agents can be designed to follow an O2-dependent mechanism by producing highly reactive species such as 1O2 and/or an O2 independent mechanism through processes such as excited state electron transfer, covalent binding to DNA or photoinduced drug delivery. Ru(II)-polypyridyl and Rh2(II,II) complexes represent an important class of compounds that can be tailored to exhibit desired photophysical properties and photochemical reactivity by judicious selection of the ligand set. Complexes with relatively long-lived excited states and planar, intercalating ligands localize on the DNA strand and photocleave DNA through 1O2 production or guanine oxidation by the excited state of the chromophore. Photoinduced ligand substitution occurs through the population of triplet metal centered (3MC) excited states and facilitates covalent binding of the metal complex to DNA in a mode similar to cisplatin. Ligand photodissociation also provides a route to selective drug delivery. The ability to construct metal complexes with desired light absorbing and excited state properties by ligand variation enables the design of PDT agents that can potentially provide combination therapy from a single metal complex.
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Affiliation(s)
- Jessica D. Knoll
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Claudia Turro
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
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42
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Li H, Liu Y, Yang Y, Yang D, Sun J. Excited-state intramolecular hydrogen bonding of compounds based on 2-(2-hydroxyphenyl)-1,3-benzoxazole in solution: a TDDFT study. Spectrochim Acta A Mol Biomol Spectrosc 2014; 133:818-824. [PMID: 25000569 DOI: 10.1016/j.saa.2014.06.072] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Revised: 04/25/2014] [Accepted: 06/01/2014] [Indexed: 06/03/2023]
Abstract
The excited-state properties of intramolecular hydrogen bonding in the compounds based on 2-(2-hydroxyphenyl)-1,3-benzoxazole (6 and its tautomers 6a and 6b) have been investigated using theoretical methods. According to the geometric optimization and IR spectra in the ground and excited states calculated by density functional theory (DFT) and time-dependent DFT (TD-DFT) methods respectively, the type of intramolecular hydrogen bonding N⋯HO in 6 and 6a is demonstrated to be significantly strengthened, while NH⋯O in the tautomers 6a and 6b are proved to be sharply weakened upon excitation to excited state S1. The calculated absorption peaks of 6 are in good accordance with the experimental results. Moreover, other compounds based on 6 that R1 and R2 are both substituted as well as that only R1 is substituted are investigated to understand the effect of substituent on intramolecular hydrogen bonding. It is found that the hydrogen bond strength can be controlled by the inductive field effect of the substituent. In addition, the intramolecular charge transfers (ICT) of the S1 state for 6 and its tautomers 6a and 6b were theoretically investigated by analyses of molecular orbital.
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Affiliation(s)
- Hui Li
- Department of Physics, Henan Normal University, Xinxiang 453007, China
| | - Yufang Liu
- Department of Physics, Henan Normal University, Xinxiang 453007, China.
| | - Yonggang Yang
- Department of Physics, Henan Normal University, Xinxiang 453007, China
| | - Dapeng Yang
- Physics Laboratory, North China University of Water Resources and Electric Power, Zhengzhou 450045, China
| | - Jinfeng Sun
- Department of Physics, Henan Normal University, Xinxiang 453007, China
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43
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Liu YH, Mehata MS, Lan SC. TDDFT study of the polarity controlled ion-pair separation in an excited-state proton transfer reaction. Spectrochim Acta A Mol Biomol Spectrosc 2014; 128:280-284. [PMID: 24681312 DOI: 10.1016/j.saa.2014.02.149] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Revised: 02/09/2014] [Accepted: 02/24/2014] [Indexed: 06/03/2023]
Abstract
6-Hydroxyquinoline (6HQ) is an ideal photoacid system for exploring excited-state proton transfer (ESPT) reactions. We have previously (Mahata et al. (2002)) shown that the ESPT reaction between 6HQ and trimethylamine (TMA) leads to an "unusual" emission in the 440-450 nm range, containing two decay components (∼5 ns and ∼12 ns). The observed results suggest the presence of a contact ion-pair and a solvent separated ion-pair. In this work, density functional theory (DFT) and time-dependent density functional theory (TD-DFT) have been employed to study the nature of the contact ion-pair formed between 6HQ and TMA and to determine why the decay component ∼12 ns is absent in a non-polar solvent. Calculations of the hydrogen-bonded complexes formed between 6HQ and TMA and its ESPT reaction product, namely 6HQ-TMA and 6HQ-TMA-PT, respectively, have been carried out, both in the electronic ground and excited states. Moreover, by using the CPCM model, different dielectric constants have been introduced into the calculations. On increasing the dielectric constant, the hydrogen bond in 6HQ-TMA-PT becomes weaker and the hydrogen bond length becomes larger; this effectively facilitates the proton transfer reaction and formation of separated ion-pair. Thus, the separation and diffusion of the contact ion-pair can be controlled by changing the polarity of the surroundings.
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Affiliation(s)
- Yu-Hui Liu
- Department of Physics, College of Mathematics and Physics, Bohai University, Jinzhou 121013, China.
| | - Mohan Singh Mehata
- Department of Applied Physics, Delhi Technological University, Bawana Road, Delhi 110042, India
| | - Sheng-Cheng Lan
- Department of Physics, College of Mathematics and Physics, Bohai University, Jinzhou 121013, China
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Bothe JR, Stein ZW, Al-Hashimi HM. Evaluating the uncertainty in exchange parameters determined from off-resonance R1ρ relaxation dispersion for systems in fast exchange. J Magn Reson 2014; 244:18-29. [PMID: 24819426 PMCID: PMC4222517 DOI: 10.1016/j.jmr.2014.04.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 04/08/2014] [Accepted: 04/09/2014] [Indexed: 05/25/2023]
Abstract
Spin relaxation in the rotating frame (R1ρ) is a powerful NMR technique for characterizing fast microsecond timescale exchange processes directed toward short-lived excited states in biomolecules. At the limit of fast exchange, only k(ex)=k(1)+k(-1) and Φex=p(G)p(E)(Δω)(2) can be determined from R1ρ data limiting the ability to characterize the structure and energetics of the excited state conformation. Here, we use simulations to examine the uncertainty with which exchange parameters can be determined for two state systems in intermediate-to-fast exchange using off-resonance R1ρ relaxation dispersion. R1ρ data computed by solving the Bloch-McConnell equations reveals small but significant asymmetry with respect to offset (R1ρ (ΔΩ)≠R1ρ (-ΔΩ)), which is a hallmark of slow-to-intermediate exchange, even under conditions of fast exchange for free precession chemical exchange line broadening (k(ex)/Δω>10). A grid search analysis combined with bootstrap and Monte-Carlo based statistical approaches for estimating uncertainty in exchange parameters reveals that both the sign and magnitude of Δω can be determined at a useful level of uncertainty for systems in fast exchange (k(ex)/Δω<10) but that this depends on the uncertainty in the R1ρ data and requires a thorough examination of the multidimensional variation of χ(2) as a function of exchange parameters. Results from simulations are complemented by analysis of experimental R1ρ data measured in three nucleic acid systems with exchange processes occurring on the slow (k(ex)/Δω=0.2; pE=∼0.7%), fast (k(ex)/Δω=∼10-16; p(E)=∼13%) and very fast (k(ex)=39,000 s(-1)) chemical shift timescales.
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Affiliation(s)
- Jameson R Bothe
- Department of Chemistry and Biophysics, University of Michigan, Ann Arbor, MI 48109, United States
| | - Zachary W Stein
- Department of Chemistry and Biophysics, University of Michigan, Ann Arbor, MI 48109, United States
| | - Hashim M Al-Hashimi
- Department of Biochemistry and Chemistry, Duke University School of Medicine, Durham, NC 27710, United States.
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Wang D, Lü R, Yuan M, Fu A, Chu T. A DFT/TD-DFT study of thiazolidinedione derivative in dimethylformamide: cooperative roles of hydrogen bondings, electronic and vibrational spectra. Spectrochim Acta A Mol Biomol Spectrosc 2014; 125:131-137. [PMID: 24531543 DOI: 10.1016/j.saa.2014.01.094] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Revised: 12/05/2013] [Accepted: 01/19/2014] [Indexed: 06/03/2023]
Abstract
The time-dependent density functional theory (TDDFT) method has been applied to investigate the thiazolidinedione (TZD) derivative A and its hydrogen-bonded complexes with dimethylformamide (DMF) (A-DMF and A-2DMF). The calculation results showed that the excited-state hydrogen bondings of O-H⋯O=C and N-H⋯O=C are strengthened and weakened in the hydrogen-bonded trimer A-2DMF, and their cooperation effect caused a blue shift in the electronic spectrum of A-2DMF. This modulation mechanism of the hydrogen-bond strengthening and weakening and its role in influencing the spectroscopy property of the TZD derivative A in DMF have been analyzed and showed in details.
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Affiliation(s)
- Dandan Wang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People's Republic of China
| | - Rui Lü
- Laboratory of Pathogenic Biology, Medical College, Qingdao University, Qingdao 266071, People's Republic of China
| | - Minghu Yuan
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People's Republic of China
| | - Aiping Fu
- Institute for Computational Sciences and Engineering, Laboratory of New Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao 266071, People's Republic of China
| | - Tianshu Chu
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People's Republic of China; Institute for Computational Sciences and Engineering, Laboratory of New Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao 266071, People's Republic of China.
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46
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Poorabdollah H, Omidyan R, Solimannejad M, Azimi G. Hydrogen bond strengthening of cis-trans glyoxal dimers in electronic excited states: a theoretical study. Spectrochim Acta A Mol Biomol Spectrosc 2014; 122:337-342. [PMID: 24317260 DOI: 10.1016/j.saa.2013.11.034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Revised: 10/02/2013] [Accepted: 11/02/2013] [Indexed: 06/02/2023]
Abstract
The second-order approximate coupled-cluster (CC2) method was performed to investigate the excited state hydrogen-bonding properties of Glyoxal (C2H2O2, Gl) dimers. Since the strengthening and weakening of hydrogen bonds can be investigated by monitoring the vibrational absorption spectra of some hydrogen-bonded groups in different electronic states, the infrared spectra of the hydrogen-bonded Gl-Gl complexes in both of the ground state and the S1 electronically excited state are calculated using the MP2/CC2 methods respectively. We demonstrated that the intermolecular hydrogen bond C=O⋯H-C between two glyoxal molecules is significantly strengthened in the electronically excited S1 state upon photoexcitation of the hydrogen-bonded Gl-Gl complexes.
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Affiliation(s)
| | - Reza Omidyan
- Department of Chemistry, University of Isfahan, 81746-7344 Isfahan, Iran.
| | - Mohammad Solimannejad
- Quantum Chemistry Group, Department of Chemistry, Faculty of Sciences, Arak University, Arak 38156-8-8349, Iran
| | - Gholamhasan Azimi
- Department of Chemistry, University of Isfahan, 81746-7344 Isfahan, Iran
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