1
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Rymbai LD, Klausmeyer KK, Farmer PJ. The case for an oxidopyrylium intermediate in the mechanism of quercetin dioxygenases. J Inorg Biochem 2023; 247:112343. [PMID: 37549474 DOI: 10.1016/j.jinorgbio.2023.112343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 06/22/2023] [Accepted: 07/25/2023] [Indexed: 08/09/2023]
Abstract
The quercetin dioxygenases (QDOs) are unusual metalloenzymes in that they display ring-opening dioxygenase activity with several different first-row transition metal ions which do not undergo redox changes during turnover. The QDOs are also unique in that the substrate binds as an η1-flavonolate rather than the η2 -bidentate mode seen in all reported model complexes. The flavonol substrates were early examples of excited state intramolecular proton transfer (ESIPT) phenomena, in which photoexcitation causes an H-atom exchange between the adjacent hydroxyl and ketone, generating an oxidopyrylium emissive state. These oxidopyryliums undergo ring-opening dioxygenations analogous to the enzymatic reactions. Our hypothesis is that lability of the divalent metal ion may allow access to a reactive oxidopyrylium intermediate via coordination switching from the oxy to ketone position, which allows reaction with O2. In this report, we use a straight-forward methylation strategy to generate a panel of flavonol and thioflavonol derivatives modeling several η1- and η2-coordination modes. Methylation of 3-hydroxythioflavone generates an air stable η1 hydroxopyrylium salt, which undergoes rapid ring-opening dioxygenation by deprotonation or photoexcitation. By comparison, the η1-methoxyflavonol does not react with O2 under any condition. We find that any of the studied flavonol derivatives, η1 or η2, which demonstrates ESIPT-like oxidopyrylium emissions undergo QDO-like ring-opening reactions with dioxygen. The implications of these results concerning the mechanism of QDOs and related dioxygenases is discussed.
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Affiliation(s)
- Lasien D Rymbai
- Department of Chemistry and Biochemistry, Baylor University, Waco, TX 76798, United States of America
| | - Kevin K Klausmeyer
- Department of Chemistry and Biochemistry, Baylor University, Waco, TX 76798, United States of America
| | - Patrick J Farmer
- Department of Chemistry and Biochemistry, Baylor University, Waco, TX 76798, United States of America.
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2
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Colín M, Aguilar MÁ, Martín ME. A Theoretical Study of Solvent Effects on the Structure and UV-vis Spectroscopy of 3-Hydroxyflavone (3-HF) and Some Simplified Molecular Models. ACS OMEGA 2023; 8:19939-19949. [PMID: 37305262 PMCID: PMC10249394 DOI: 10.1021/acsomega.3c01906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 05/10/2023] [Indexed: 06/13/2023]
Abstract
Solvent effects on the UV-vis spectra of 3-hydroxyflavone and other structurally related molecules (3-hydroxychromen-4-one, 3-hydroxy-4-pyrone, and 4-pyrone) have been studied by combining time-dependent density functional theory (TDDFT) and the polarizable continuum method (PCM). Among the first five excited states of the four considered molecules, electronic states of n → π* and π → π* nature appear. In general, the stability of the n → π* states decreases as the π space becomes larger in such a way that only for 4-pyrone and 3-hydroxy-4-pyrone are they the first excited states. In addition, they become less stabilized in ethanol solution than the ground state, and this causes blueshift transitions in solution. The opposite trend is found for the π → π* excited states. They are less energetic with the π-system size and when passing from gas phase to solution. The solvent shift also depends strongly on the size of the π systems and on the formation of an intramolecular hydrogen bond; thus, it decreases when going from 4-pyrone to 3-hydroxyflavone. The performance of the three versions (cLR, cLR2, and IBSF) of the specific-state PCM method in predicting transition energies are compared.
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Affiliation(s)
- María
Jesús Colín
- Área
de Química-Física, Facultad de Ciencias, Universidad de Extremadura, Avda. de Elvas, 06006 Badajoz, Spain
| | - Manuel Ángel Aguilar
- Área
de Química-Física, Facultad de Ciencias, Universidad de Extremadura, Avda. de Elvas, 06006 Badajoz, Spain
- Instituto
de Computación Científica Avanzada (ICCAEx), Universidad
de Extremadura, Avda.
de Elvas, 06006 Badajoz, Spain
| | - M. Elena Martín
- Área
de Química-Física, Facultad de Ciencias, Universidad de Extremadura, Avda. de Elvas, 06006 Badajoz, Spain
- Instituto
de Computación Científica Avanzada (ICCAEx), Universidad
de Extremadura, Avda.
de Elvas, 06006 Badajoz, Spain
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3
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Frutos-Puerto S, Jesús Colín M, Corchado JC, Luz Sánchez M, Elena Martín M, Aguilar MA. Photophysical and photochemical properties of 3-hydroxyflavone in ethanol solution: implicit vs explicit solvent models. J Mol Liq 2023. [DOI: 10.1016/j.molliq.2023.121783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
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4
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Excited-state proton transfer reaction of a pyrenylurea derivative in the ionic liquid 1-ethyl-3-methylimidazolium acetate. Chem Phys Lett 2023. [DOI: 10.1016/j.cplett.2023.140342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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5
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Solomon G, Landström A, Rotta Loria S, Bolli E, Mezzetti A, Facibeni A, Cattarin S, Mezzi A, Protti S, Kaciulis S, Zavelani-Rossi M, Concina I. Tunable physics through coordination chemistry: formation on oxide surface of Ti and Al chelates with 3-hydroxyflavone capable of electron injection and light emission. Dalton Trans 2022; 51:18489-18501. [PMID: 36421057 DOI: 10.1039/d2dt02195a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The optoelectronic features of 3-hydroxyflavone (3HF) self-assembled on the surface of an n-type semiconducting metal oxide (TiO2) and an insulator (Al2O3) are herein investigated. 3HF molecules use the coordinatively unsaturated metal ions present on the oxide surface to form metal complexes, which exhibit different behaviors upon light irradiation, depending on the nature of the metal ion. Specifically, we show that the photoluminescence of the surface species can be modulated according to the chemical properties of the complex (i.e. the binding metal ion), resulting in solid-state emitters in a high quantum yield (about 15%). Furthermore, photoinduced charge injection can be promoted or inhibited, providing a multifunctional hybrid system.
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Affiliation(s)
- Getachew Solomon
- Department of Engineering Sciences and Mathematics, Luleå University of Technology, 97187 Luleå, Sweden.
| | - Anton Landström
- Department of Engineering Sciences and Mathematics, Luleå University of Technology, 97187 Luleå, Sweden.
| | - Silvia Rotta Loria
- Dipartimento di Fisica, Politecnico di Milano, piazza L. da Vinci 32, 20133 Milano, Italy
| | - Eleonora Bolli
- Institute for the Study of Nanostructured Materials, ISMN-CNR, 00015 Monterotondo Stazione, Roma, Italy
| | - Alberto Mezzetti
- Laboratoire de Réactivité de Surface (LRS), Sorbonne Université, CNRS, 4 Place Jussieu, Paris 75005, France
| | - Anna Facibeni
- Dipartimento di Energia, Politecnico di Milano, via G. Ponzio 34/3, 20133 Milano, Italy.,IFN-CNR, piazza L. da Vinci 32, 20133 Milano, Italy
| | - Sandro Cattarin
- Istituto di Chimica della Materia Condensata e di Tecnologie per l'Energia, ICMATE-CNR, C.so Stati Uniti 4, 35127, Padova, Italy
| | - Alessio Mezzi
- Institute for the Study of Nanostructured Materials, ISMN-CNR, 00015 Monterotondo Stazione, Roma, Italy
| | - Stefano Protti
- Photogreen Lab, Department of Chemistry, University of Pavia, Viale Taramelli 10, 27100 Pavia, Italy
| | - Saulius Kaciulis
- Institute for the Study of Nanostructured Materials, ISMN-CNR, 00015 Monterotondo Stazione, Roma, Italy
| | - Margherita Zavelani-Rossi
- Dipartimento di Energia, Politecnico di Milano, via G. Ponzio 34/3, 20133 Milano, Italy.,IFN-CNR, piazza L. da Vinci 32, 20133 Milano, Italy
| | - Isabella Concina
- Department of Engineering Sciences and Mathematics, Luleå University of Technology, 97187 Luleå, Sweden.
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6
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Ushakou D, Wróblewski T. Scutellarein in organic solvents: changes in spectroscopic properties caused by solute-solvent interactions. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 273:121027. [PMID: 35182824 DOI: 10.1016/j.saa.2022.121027] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 02/07/2022] [Accepted: 02/09/2022] [Indexed: 06/14/2023]
Abstract
In this work, the spectroscopic properties of scutellarein (6-hydroxyapigenin) were studied in three organic solvents (methanol, acetonitrile and N,N-dimethylformamide) taking into account possible ionization and isomerization (tautomerization) processes. Significant visible colour changes were reported in the case of scutellarein in N,N-dimethylformamide. It was shown that isomerization processes can be one of the reasons for the observed changes in absorption spectrum, because some scutellarein isomers have an absorption band at about 623 nm while other forms of scutellarein show no absorption in this region. Moreover, spectroscopic properties were studied for cases of scutellarein in acetonitrile and methanol. The molar extinction coefficient has been found in the case of methanol solution which could be used to determine scutellarein concentration in this solvent using spectroscopic methods in future studies. The quantum-chemical calculations were performed for neutral and anionic forms and for two types of possible isomers of scutellarein in each solvent. The results help explain the experimentally observed rising absorption in the 500-750 nm wavelength range. Another important result of the quantum-chemical calculations is a prediction of excited state intramolecular proton transfer (ESIPT) in scutellarein. This result has been obtained for free molecule in vacuum and in the cases of methanol, acetonitrile and N,N-dimethylformamide solution. It was found that the excited state energy of the normal molecular form is higher than the excited state energy of the tautomer form of scutellarein.
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Affiliation(s)
- Dzmitryi Ushakou
- Pomeranian University in Słupsk, str. Arciszewskiego 22b, 76-200 Słupsk, Poland.
| | - Tomasz Wróblewski
- Pomeranian University in Słupsk, str. Arciszewskiego 22b, 76-200 Słupsk, Poland
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7
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Li H, Mu H, Xin C, Cai J, Yuan B, Jin G. Turning ON/OFF the fluorescence of the ESIPT state by changing the hydrogen bond distance and orientation in quinoline–pyrazole derivatives. J Mol Struct 2022. [DOI: 10.1016/j.molstruc.2021.132146] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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8
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Kim S, Choi J, Cho DW, Ahn M, Eom S, Kim J, Wee KR, Ihee H. Solvent-modulated proton-coupled electron transfer in an iridium complex with an ESIPT ligand. Chem Sci 2022; 13:3809-3818. [PMID: 35432886 PMCID: PMC8966730 DOI: 10.1039/d1sc07250a] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 03/03/2022] [Indexed: 11/21/2022] Open
Abstract
Proton-coupled electron transfer (PCET), an essential process in nature with a well-known example of photosynthesis, has recently been employed in metal complexes to improve the energy conversion efficiency; however, a profound understanding of the mechanism of PCET in metal complexes is still lacking. In this study, we synthesized cyclometalated Ir complexes strategically designed to exploit the excited-state intramolecular proton transfer (ESIPT) of the ancillary ligand and studied their photoinduced PCET in both aprotic and protic solvent environments using femtosecond transient absorption spectroscopy and density functional theory (DFT) and time-dependent DFT calculations. The data reveal solvent-modulated PCET, where charge transfer follows proton transfer in an aprotic solvent and the temporal order of charge transfer and proton transfer is reversed in a protic solvent. In the former case, ESIPT from the enol form to the keto form, which precedes the charge transfer from Ir to the ESIPT ligand, improves the efficiency of metal-to-ligand charge transfer. This finding demonstrates the potential to control the PCET reaction in the desired direction and the efficiency of charge transfer by simply perturbing the external hydrogen-bonding network with the solvent. The iridium complex with an ESIPT ligand shows solvent-modulated proton-coupled electron transfer, in which the temporal order of proton transfer and charge transfer is altered by the solvent environment.![]()
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Affiliation(s)
- Siin Kim
- Department of Chemistry and KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 Republic of Korea
- Center for Advanced Reaction Dynamics, Institute for Basic Science Daejeon 34141 Republic of Korea
| | - Jungkweon Choi
- Department of Chemistry and KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 Republic of Korea
- Center for Advanced Reaction Dynamics, Institute for Basic Science Daejeon 34141 Republic of Korea
| | - Dae Won Cho
- Department of Advanced Materials Chemistry, Korea University, Sejong Campus Sejong 30019 Korea
| | - Mina Ahn
- Department of Chemistry and Institute of Natural Science, Daegu University Gyeongsan 38453 Republic of Korea
| | - Seunghwan Eom
- Department of Chemistry and KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 Republic of Korea
- Center for Advanced Reaction Dynamics, Institute for Basic Science Daejeon 34141 Republic of Korea
| | - Jungmin Kim
- Department of Chemistry and KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 Republic of Korea
- Center for Advanced Reaction Dynamics, Institute for Basic Science Daejeon 34141 Republic of Korea
| | - Kyung-Ryang Wee
- Department of Chemistry and Institute of Natural Science, Daegu University Gyeongsan 38453 Republic of Korea
| | - Hyotcherl Ihee
- Department of Chemistry and KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 Republic of Korea
- Center for Advanced Reaction Dynamics, Institute for Basic Science Daejeon 34141 Republic of Korea
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9
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da Silva UP, de Sousa BL, Ferreira BW, Barreto RW, Amarante GW, da Silva RR, Vaz BG, Varejão EVV. Daylight LED promotes photochemical ring contraction of 2-amine-4H-pyran-3-carbonitriles with consequent loss of their antifungal activity. Photochem Photobiol Sci 2021; 20:1309-1321. [PMID: 34562236 DOI: 10.1007/s43630-021-00108-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 09/16/2021] [Indexed: 11/24/2022]
Abstract
The initial objective of our work was to synthesize a series of 2-amino-4H-pyran-3-carbonitriles to be tested for their antifungal activities against economically relevant phytopathogenic fungi. Fourteen compounds were prepared in up to 94% yield and shown percentages of Botrytis cinerea inhibition above 70%. Despite the promising biological results, we observed that stock solutions prepared for biological tests showed color changing when kept for a few days on the laboratory bench, under room conditions, illuminated by common LED daylight tubes (4500-6000 k). This prompted us to investigate the possible photo-induced degradation of our compounds. FT-IR ATR experiments evidenced variations in the expected bands for functional of -amino-4H-pyran-3-carbonitriles stored under LED daylight. Following, HPLC-UV analysis showed reductions in the intensity of chromatographic peaks of 2-amino-4H-pyran-3-carbonitriles, and but not for solutions kept in the dark. A solution of (E)-2-amino-8-(4-nitrobenzylidene)-4-(4-nitrophenyl)-5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile underwent 84.4% of conversion after 72 h of exposure to continuous LED daylight in a BOD chamber, and the reaction product was isolated in 36% yield and characterized as (E)-7-cyano-5-(4-nitrobenzylidene)-8-(4-nitrophenyl)bicyclo[4.2.0]oct-1(6)-ene-7-carboxamide (7*). Despite freshly prepared solutions of 2-amino-4H-pyran-3-carbonitriles produced antifungal activities, these solutions lost biological activity when left on the bench for a week. Besides, compound 7* formed from photo-induced degradation of 7 also showed no antifungal activity. With this, we hope to bring two contributions: (1) production of cyclobutenes through photochemical reactions of 2-amino-4H-pyran-3-carbonitriles can be carried out through exposure to simple white LED daylight; (2) biological applications of such 2-amino-4H-pyran-3-carbonitriles may be impaired by their poor photostability.
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Affiliation(s)
- Ueveton Pimentel da Silva
- Department of Chemistry, Universidade Federal de Viçosa, Av PH Rolfs sn, Viçosa, MG, 36.570-900, Brazil
| | - Bianca Lana de Sousa
- Department of Chemistry, Universidade Federal de Viçosa, Av PH Rolfs sn, Viçosa, MG, 36.570-900, Brazil
| | - Bruno Wesley Ferreira
- Department of Phytopathology, Universidade Federal de Viçosa, Av PH Rolfs sn, Viçosa, MG, 36.570-900, Brazil
| | - Robert Weingart Barreto
- Department of Phytopathology, Universidade Federal de Viçosa, Av PH Rolfs sn, Viçosa, MG, 36.570-900, Brazil
| | - Giovanni Wilson Amarante
- Department of Chemistry, Universidade Federal de Juiz de Fora, Rua José Lourenço Kelmer sn, Juiz de Fora, MG, 36.036-900, Brazil
| | - Rodolfo Rodrigues da Silva
- Institute of Chemistry, Universidade Federal de Goiás, Av Esperança, sn, Samambaia, Goiânia, 74.690-900, Brazil
| | - Boniek Gontijo Vaz
- Institute of Chemistry, Universidade Federal de Goiás, Av Esperança, sn, Samambaia, Goiânia, 74.690-900, Brazil
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10
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Chansen W, Kungwan N. Theoretical Insights into Excited-State Intermolecular Proton Transfers of 2,7-Diazaindole in Water Using a Microsolvation Approach. J Phys Chem A 2021; 125:5314-5325. [PMID: 34125551 DOI: 10.1021/acs.jpca.1c03120] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The detailed excited-state intermolecular proton transfer (ESInterPT) mechanism of 2,7-diazaindole with water wires consisting of either one or two shells [2,7-DAI(H2O)n; n = 1-5] has been theoretically explored by time-dependent density functional theory using microsolvation with an implicit solvent model. On the basis of the excited-state potential energy surfaces along the proton transfer (PT) coordinates, among all 2,7-DAI(H2O)n, the multiple ESInterPT of 2,7-DAI(H2O)2+3 through the first hydration shell (inner circuit) is the most easy process to occur with the lowest PT barrier and a highly exothermic reaction. The lowest PT barrier resulted from the outer three waters pushing the inner circuit waters to be much closer to 2,7-DAI, leading to the enhanced intermolecular hydrogen-bonding strength of the inner two waters. Moreover, on-the-fly dynamic simulations show that the multiple ESInterPT mechanism of 2,7-DAI(H2O)2+3 is the triple PT in a stepwise mechanism with the highest PT probability. This solvation effect using microsolvation and dynamic simulation is a cost-effect approach to reveal the solvent-assisted multiple proton relay of chromophores based on excited-state proton transfer.
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Affiliation(s)
- Warinthon Chansen
- Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand.,Graduate School, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Nawee Kungwan
- Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand.,Center of Excellence in Material Science and Technology, Chiang Mai University, Chiang Mai 50200, Thailand
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11
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Tong C, Shi F, Tong X, Shi S, Ali I, Guo Y. Shining natural flavonols in sensing and bioimaging. Trends Analyt Chem 2021. [DOI: 10.1016/j.trac.2021.116222] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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12
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Sukpattanacharoen C, Kungwan N. Theoretical insights of solvent effect on excited-state proton transfers of 2-aryl-3-hydroxyquinolone. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2020.115035] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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13
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Effect of Water Microsolvation on the Excited-State Proton Transfer of 3-Hydroxyflavone Enclosed in γ-Cyclodextrin. Molecules 2021; 26:molecules26040843. [PMID: 33562757 PMCID: PMC7914428 DOI: 10.3390/molecules26040843] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Revised: 01/31/2021] [Accepted: 02/02/2021] [Indexed: 12/19/2022] Open
Abstract
The effect of microsolvation on excited-state proton transfer (ESPT) reaction of 3-hydroxyflavone (3HF) and its inclusion complex with γ-cyclodextrin (γ-CD) was studied using computational approaches. From molecular dynamics simulations, two possible inclusion complexes formed by the chromone ring (C-ring, Form I) and the phenyl ring (P-ring, Form II) of 3HF insertion to γ-CD were observed. Form II is likely more stable because of lower fluctuation of 3HF inside the hydrophobic cavity and lower water accessibility to the encapsulated 3HF. Next, the conformation analysis of these models in the ground (S0) and the first excited (S1) states was carried out by density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations, respectively, to reveal the photophysical properties of 3HF influenced by the γ-CD. The results show that the intermolecular hydrogen bonding (interHB) between 3HF and γ-CD, and intramolecular hydrogen bonding (intraHB) within 3HF are strengthened in the S1 state confirmed by the shorter interHB and intraHB distances and the red-shift of O–H vibrational modes involving in the ESPT process. The simulated absorption and emission spectra are in good agreement with the experimental data. Significantly, in the S1 state, the keto form of 3HF is stabilized by γ-CD, explaining the increased quantum yield of keto emission of 3HF when complexing with γ-CD in the experiment. In the other word, ESPT of 3HF is more favorable in the γ-CD hydrophobic cavity than in aqueous solution.
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14
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Smortsova Y, Gaillard J, Miannay FA, Cornard JP. A Picosecond Time-Resolved Spectroscopic Investigation of the Effect of pH on Morin Fluorescence. Chemphyschem 2020; 21:2680-2691. [PMID: 32991037 DOI: 10.1002/cphc.202000608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 09/22/2020] [Indexed: 11/10/2022]
Abstract
In this work, we investigated for the first time morin in MeOH at different pH values by picosecond time-resolved fluorescence. We identified the two species responsible for the fluorescence at low and high pH. The solvated morin-solvent hydrogen-bonded complex has been experimentally observed for the first time. We give also the typical fluorescence spectra as well as the fluorescence lifetimes of the probable emitting species. In this work we put forward new insights concerning the contribution of free morin to the fluorescence. We hope that these new data improve the accuracy of the interpretation of the cation:morin complexes titration using fluorescence signal.
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Affiliation(s)
- Yevheniia Smortsova
- Univ. Lille, CNRS, UMR 8516 LASIRE-LAboratoire de Spectroscopie pour les Interactions, la Réactivité et l'Environnement, 59655, Villeneuve d'Ascq Cedex, France
| | - Jérémy Gaillard
- Univ. Lille, CNRS, UMR 8516 LASIRE-LAboratoire de Spectroscopie pour les Interactions, la Réactivité et l'Environnement, 59655, Villeneuve d'Ascq Cedex, France
| | - François-Alexandre Miannay
- Univ. Lille, CNRS, UMR 8516 LASIRE-LAboratoire de Spectroscopie pour les Interactions, la Réactivité et l'Environnement, 59655, Villeneuve d'Ascq Cedex, France
| | - Jean-Paul Cornard
- Univ. Lille, CNRS, UMR 8516 LASIRE-LAboratoire de Spectroscopie pour les Interactions, la Réactivité et l'Environnement, 59655, Villeneuve d'Ascq Cedex, France
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15
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Labarrière L, Moncomble A, Cornard JP. pH dependency of the structural and photophysical properties of the atypical 2′,3-dihydroxyflavone. RSC Adv 2020; 10:35017-35030. [PMID: 35515691 PMCID: PMC9056863 DOI: 10.1039/d0ra06833k] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 09/14/2020] [Indexed: 11/21/2022] Open
Abstract
2′,3-Dihydroxyflavone (2′3HF) is a natural flavonol that has barely ever been studied, however the scarce studies of its physico-chemical properties have highlighted its atypical behaviour. We present a structural and spectral study of 2′3HF, performed using UV-visible absorption and fluorescence spectroscopies, coupled with DFT and TD-DFT calculations. Although its structure is close to that of 3-hydroxyflavone, 2′3HF shows a much lower pKa value. We show that the origin of this particularity is the substitution by a hydroxyl group on position 2′, that induces a stronger inter-ring interaction weakening the bonding of the proton at position 3. The main absorption band of the is red-shifted upon deprotonation. The remaining proton is highly bonded in between oxygen atoms 3 and 2′, making the second deprotonation unattainable in methanol. The neutral form can undergo an excited-state intramolecular proton transfer to emit dual fluorescence by the normal and tautomer forms. We suggested five geometries to be the sources of the emission bands, and showed that the energy barriers to interconversions were almost null. The anion is also fluorescent. The Stokes shifts for the neutral normal and anion species are extremely high, that can be explained by the conformational rearrangement, as the species go from twisted in the ground-state, to planar in the excited-state. Finally, another emission band is evidenced when exciting in the vicinity of the absorption maximum of the anion species in acidic medium. We suggest an aggregate with the solvent to be the origin of the emission. The assignment of the multiple fluorescence emission wavelengths of 2′,3-dihydroxyflavone highlights its particular properties compared to analogues.![]()
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Affiliation(s)
- Luc Labarrière
- Univ. Lille
- CNRS
- UMR 8516 – LASIRE – Laboratoire avancé de spectroscopie pour les interactions, la réactivité et l'environnement
- F-59000 Lille
- France
| | - Aurélien Moncomble
- Univ. Lille
- CNRS
- UMR 8516 – LASIRE – Laboratoire avancé de spectroscopie pour les interactions, la réactivité et l'environnement
- F-59000 Lille
- France
| | - Jean-Paul Cornard
- Univ. Lille
- CNRS
- UMR 8516 – LASIRE – Laboratoire avancé de spectroscopie pour les interactions, la réactivité et l'environnement
- F-59000 Lille
- France
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16
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Das K, Sappati S, Hazra P. Peculiar hydrogen bonding behaviour of water molecules inside the aqueous nanochannels of lyotropic liquid crystals. Phys Chem Chem Phys 2020; 22:6210-6221. [DOI: 10.1039/c9cp06405b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The hydrogen bonding abilities of the LLC water molecules and their effects on intramolecular hydrogen bonds of the target probe molecules.
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Affiliation(s)
- Konoya Das
- Department of Chemistry
- Indian Institute of Science Education and Research (IISER)
- Pune
- India
| | - Subrahmanyam Sappati
- Department of Chemistry
- Indian Institute of Science Education and Research (IISER)
- Pune
- India
| | - Partha Hazra
- Department of Chemistry
- Indian Institute of Science Education and Research (IISER)
- Pune
- India
- Centre for Energy Science
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17
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Das S, Chakrabarty S, Chattopadhyay N. Origin of Unusually High Fluorescence Anisotropy of 3-Hydroxyflavone in Water: Formation of Probe-Solvent Cage-like Cluster. J Phys Chem B 2019; 124:173-180. [PMID: 31622100 DOI: 10.1021/acs.jpcb.9b07526] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Based on the unusually high fluorescence anisotropy (FA) of 3-hydroxyflavone (3HF) in water medium in contrast to the very low FA of its methoxy counterpart (3MF), our proposition invoked formation of an intermolecular hydrogen-bonded cage-like probe-solvent cluster of 3HF in water. In the present work, ab-initio DFT-based quantum chemical calculations have been exploited to provide a foundation for our interpretation. Ground-state optimization of 3HF with varying numbers of water molecules leads to the formation of a cage-like or loop-like probe-water cluster. Our calculations reveal that the structures with four to five water molecules are stabilized to the maximum extent. Classical molecular dynamics simulations reveal that the rotational dynamics of 3HF is much slower in water compared to that in alkane medium, which also goes in favor of the probe-solvent cluster formation in water medium. Apart from the theoretical studies, an indirect experimental approach has been adopted to substantiate formation of the probe-water cluster. The atypical observation of reduced FA of 3HF entrapped in micelles relative to that of the fluorophore in water implies disruption of the probe-water cluster with the addition of micelles, corroborating our original proposition of formation of an intermolecularly hydrogen-bonded 3HF-water cluster.
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Affiliation(s)
- Sinjan Das
- Department of Chemistry , Jadavpur University , Kolkata 700 032 , India
| | - Suman Chakrabarty
- Department of Chemical, Biological & Macromolecular Sciences , S. N. Bose National Centre for Basic Sciences , Kolkata 700 106 , India
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18
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4’-Methoxy-3-hydroxyflavone excited state intramolecular proton transfer reaction in alcoholic solutions: Intermolecular versus intramolecular hydrogen bonding effect. J Photochem Photobiol A Chem 2019. [DOI: 10.1016/j.jphotochem.2019.111964] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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19
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Loco D, Protti S, Mennucci B, Mezzetti A. Critical assessment of solvent effects on absorption and fluorescence of 3HF in acetonitrile in the QM/PCM framework: A synergic computational and experimental study. J Mol Struct 2019. [DOI: 10.1016/j.molstruc.2018.12.085] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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20
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21
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Das M, Sahu S, Krishnamoorthy G. Tweaking the proton transfer triggered proton transfer of 3,5-bis(2-hydroxyphenyl)-1H-1,2,4-triazole. Phys Chem Chem Phys 2019; 21:15669-15677. [DOI: 10.1039/c9cp02281c] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Proton transfer triggered proton transfer (PTTPT) of the molecule is completely altered by dimethylformamide and the proton transfer paths are changed. The process can be reversed by silver particle.
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Affiliation(s)
- Minati Das
- Department of Chemistry
- Indian Institute of Technology Guwahati
- Guwahati
- India
| | - Saugata Sahu
- Department of Chemistry
- Indian Institute of Technology Guwahati
- Guwahati
- India
| | - G. Krishnamoorthy
- Department of Chemistry
- Indian Institute of Technology Guwahati
- Guwahati
- India
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22
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Wang M, Cheng C, Li C, Wu D, Song J, Wang J, Zhou X, Xiang H, Liu J. Smart, chiral, and nonconjugated cyclohexane-based bis-salicylaldehyde hydrazides: multi-stimuli-responsive, turn-on, ratiometric, and thermochromic fluorescence, single-crystal structures via DFT calculations. JOURNAL OF MATERIALS CHEMISTRY C 2019. [DOI: 10.1039/c9tc01337g] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Multidentate and environmentally sensitive dyes show turn-on, ratiometric, and thermochromic fluorescence.
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Affiliation(s)
- Man Wang
- College of Chemistry
- Sichuan University
- Chengdu
- China
| | - Caiqi Cheng
- State Key Laboratory of Oral Diseases
- Department of Orthodontics
- West China Hospital of Stomatology
- Sichuan University
- Chengdu
| | - Chunbo Li
- College of Chemistry
- Sichuan University
- Chengdu
- China
| | - Dehua Wu
- College of Chemistry
- Sichuan University
- Chengdu
- China
| | - Jintong Song
- College of Chemistry
- Sichuan University
- Chengdu
- China
| | - Jun Wang
- State Key Laboratory of Oral Diseases
- Department of Orthodontics
- West China Hospital of Stomatology
- Sichuan University
- Chengdu
| | - Xiangge Zhou
- College of Chemistry
- Sichuan University
- Chengdu
- China
| | | | - Jin Liu
- Laboratory of Stem Cell Biology
- State Key Laboratory of Biotherapy
- West China Hospital
- Sichuan University
- Chengdu
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23
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Das S, Chattopadhyay N. Heteroatom controlled probe-water cluster formation of a series of ESIPT probes: An exploration with fluorescence anisotropy. Chem Phys Lett 2018. [DOI: 10.1016/j.cplett.2018.07.065] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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