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Chen P, Niu Z, Wang E. Bright ESIPT emission from 2,6-di(thiazol/oxazol/imidazol-2-yl)phenol derivatives in solution, aggregation and solid states. Methods Appl Fluoresc 2024; 12:035009. [PMID: 38838704 DOI: 10.1088/2050-6120/ad5490] [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: 02/05/2024] [Accepted: 06/05/2024] [Indexed: 06/07/2024]
Abstract
Most luminophores often suffer from the problem of aggregation-caused quenching (ACQ) or fluorescence disappearance in dilute solution. It is significant to bridge the gap between ACQ and AIE. In this work, a facile but effective strategy was proposed for the fabrication of always-on luminophores based on the excited state intramolecular proton transfer (ESIPT) mechanism, and six luminophores emitting bright fluorescence in solution, aggregation and solid states were synthesized from 5-tert-butyl-2-hydroxyisophthalaldehyde. All these ESIPT systems show only keto emission owing to their congested structures which block the breakage of intramolecular hydrogen bond (O-H⋯N) by solvation, and subsequently make enol emission impossible. Three of these luminophores are prone to convert into the corresponding phenolate anions emitting blue-shifted emission, which enable them to sense pH variation in the weakly basic range. Furthermore, white-light emission was achieved by combining two of them which show complementary-color fluorescence, and one of them was utilized for bioimaging of living Hela cells and the high-resolution image was obtained.
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Affiliation(s)
- Panpan Chen
- Key Laboratory of Tropical Medicinal Resource Chemistry of Ministry of Education, Key Laboratory of Tropical Medicinal Plant Chemistry of Hainan Province, College of Chemistry & Chemical Engineering, Hainan Normal University, Haikou, 571158, People's Republic of China
| | - Zhigang Niu
- Key Laboratory of Tropical Medicinal Resource Chemistry of Ministry of Education, Key Laboratory of Tropical Medicinal Plant Chemistry of Hainan Province, College of Chemistry & Chemical Engineering, Hainan Normal University, Haikou, 571158, People's Republic of China
| | - Eenju Wang
- Key Laboratory of Tropical Medicinal Resource Chemistry of Ministry of Education, Key Laboratory of Tropical Medicinal Plant Chemistry of Hainan Province, College of Chemistry & Chemical Engineering, Hainan Normal University, Haikou, 571158, People's Republic of China
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2
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Bhattacharyya A, Das A, Guchhait N. Investigating the Photophysical Aspects of a Naphthalene-Based Excited-State Proton Transfer Dye 1-(1 H-Benzo[ d]imidazol-2-yl)naphthalen-2-ol: pH-Dependent Modulation of Photodynamics. J Phys Chem A 2024. [PMID: 38687998 DOI: 10.1021/acs.jpca.3c07420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
The steady state and time-resolved photophysical behavior of a proton transfer dye 1-(1H-benzo[d]imidazol-2-yl)naphthalen-2-ol (H-BINO) was investigated. The excited state intramolecular proton transfer (ESIPT) reaction in H-BINO is predominant in nonpolar solutions (toluene and DCM) with a lifetime of ∼1.0 ns. However, in polar media (DMF and MeOH), the excited state photodynamics is characterized by a complex equilibrium of emission from the locally excited state (0.1-2.3 ns), the phototautomer (0.5-1.2 ns), and the anionic emission (2.1-5.4 ns). In the solid state, emission from the various aggregated states dictates the photobehavior. Interestingly, the photodynamics in aqueous solution changes starkly as a function of pH with the anionic (2.1 ns) and phototautomeric (0.5-1.0 ns) emissions guiding the photodynamics as the pH of the medium increases. Optimized structural parameters at the proton donor and acceptor sites for the enol and keto forms and the calculated potential energy curve along the proton transfer coordinate at the density functional theory (DFT) level with the B3LYP/6-311G++(d,p) theory support a favorable and barrierless ESIPT process. The current results will surely boost the ongoing research on small molecule emissive materials.
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Affiliation(s)
| | - Akash Das
- Department of Chemistry, University of Calcutta, 92, A.P.C. Road, Kolkata 700009, India
| | - Nikhil Guchhait
- Department of Chemistry, University of Calcutta, 92, A.P.C. Road, Kolkata 700009, India
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3
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Zhuang H, Shi W, Zhao G, Li Y. Regulating and controlling the stepwise ESDPT channel of BP(OH) 2DCEt 2 using the strategy of solvent polarity and external electric field. Phys Chem Chem Phys 2024; 26:12016-12026. [PMID: 38576357 DOI: 10.1039/d4cp00989d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/06/2024]
Abstract
Excited state double proton transfer (ESDPT) has attracted great scientific interest because of its excellent luminescent properties. However, the complex process of ESDPT has plagued theoretical and experimental scientists for a long time and has become a hot issue. In this work, the ESDPT process of 2,2'-bipyridine-3,3'-diol-5,5'-dicarboxylic acid ethyl ester (BP(OH)2DCEt2) is systematically studied and the regulation of the ESDPT process is further realized. The potential energy curves indicate that BP(OH)2DCEt2 shows the characteristics of stepwise ESDPT in different polar solvents. The increase in solvent polarity will be beneficial to the stepwise ESDPT reaction. Regrettably, it is not possible to distinguish the specific stepwise transfer path of the BP(OH)2DCEt2 molecule due to the symmetry of the potential energy surface along the diagonal. On this basis, we proposed a method to control and regulate the stepwise ESDPT path using an external electric field. The results show that the increase of external electric field intensity is favorable to stepwise ESDPT. It is interesting to note that applying an external electric field in a specific direction will effectively distinguish stepwise ESDPT reaction paths. Therefore, this work not only helps to understand the mechanism of ESDPT, but also contributes to regulation and design of new luminescent materials with excellent luminescent properties.
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Affiliation(s)
- Hongbin Zhuang
- School of Physics, Liaoning University, Shenyang 110036, P. R. China.
| | - Wei Shi
- School of Physics, Liaoning University, Shenyang 110036, P. R. China.
| | - Guijie Zhao
- School of Physics, Liaoning University, Shenyang 110036, P. R. China.
| | - Yongqing Li
- School of Physics, Liaoning University, Shenyang 110036, P. R. China.
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4
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Wang Y, Mu H, Sun Y, Gao J, Zhu X, Li H. Modulating the ESIPT Mechanism and Luminescence Characteristics of Two Reversible Fluorescent Probes by Solvent Polarity: A Novel Perspective. Molecules 2024; 29:1629. [PMID: 38611908 PMCID: PMC11013693 DOI: 10.3390/molecules29071629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 03/29/2024] [Accepted: 03/30/2024] [Indexed: 04/14/2024] Open
Abstract
As reversible fluorescent probes, HTP-1 and HTP-2 have favourable applications for the detection of Zn2+ and H2S. Herein, the impact of solvent on the excited-state intramolecular proton transfer (ESIPT) of HTP-1 and HTP-2 was comprehensively investigated. The obtained geometric parameters and infrared (IR) vibrational analysis associated with the intramolecular hydrogen bond (IHB) indicated that the strength of IHB for HTP-1 was weakened in the excited state. Moreover, structural torsion and almost no ICT behaviour indicated that the ESIPT process did not occur in HTP-1. Nevertheless, when the 7-nitro-1,2,3-benzoxadiazole (NBD) group replaced the H atom, the IHB strength of HTP-2 was enhanced after photoexcitation, which inhibited the twisting of tetraphenylethylene, thereby opening the ESIPT channel. Notably, hole-electron analysis and frontier molecular orbitals revealed that the charge decoupling effect was the reason for the fluorescence quenching of HTP-2. Furthermore, the potential energy curves (PECs) revealed that HTP-2 was more inclined to the ESIPT process in polar solvents than in nonpolar solvents. With a decrease in solvent polarity, it was more conducive to the ESIPT process. Our study systematically presents the ESIPT process and different detection mechanisms of the two reversible probe molecules regulated by solvent polarity, providing new insights into the design and development of novel fluorescent probes.
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Affiliation(s)
| | | | | | | | | | - Hui Li
- Jilin Key Laboratory of Solid-State Laser Technology and Application, School of Physics, Changchun University of Science and Technology, Changchun 130022, China; (Y.W.); (H.M.); (Y.S.); (J.G.); (X.Z.)
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Reimann LK, Dalberto BT, Schneider PH, de Castro Silva Junior H, Rodembusch FS. Benzazole-Based ESIPT Fluorophores: Proton Transfer from the Chalcogen Perspective. A Combined Theoretical and Experimental Study. J Fluoresc 2024:10.1007/s10895-024-03595-y. [PMID: 38507128 DOI: 10.1007/s10895-024-03595-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Accepted: 01/23/2024] [Indexed: 03/22/2024]
Abstract
In this study, we present a comprehensive photophysical investigation of ESIPT-reactive benzazole derivatives in both solution and the solid state. These derivatives incorporate different chalcogen atoms (O, S, and Se) into their structures, and we explore how these variations impact their electronic properties in both ground and excited states. Changes in the UV-Vis absorption and fluorescence emission spectra were analyzed and correlated with the chalcogen atom and solvent polarity. In general, the spectral band of the benzazole derivative containing selenium was redshifted in both the ground and excited states compared to that of its oxygen and sulfur counterparts. Furthermore, we observed that the solvent played a distinctive role in influencing the ESIPT process within these compounds, underscoring once again the significant influence of the chalcogen atom on their photophysical behavior. Theoretical calculations provided a deeper understanding of the molecular dynamics, electronic structures, and photophysical properties of these compounds. These calculations highlighted the effect of chalcogen atoms on the molecular geometry, absorption and emission characteristics, and intramolecular hydrogen bonding, revealing intricate details of the ESIPT mechanism. The integration of experimental and computational data offers a detailed view of the structural and electronic factors governing the photophysical behavior of benzazole derivatives.
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Affiliation(s)
- Louise Kommers Reimann
- Instituto de Química, Departamento de Química Orgânica, Universidade Federal Do Rio Grande Do Sul (UFRGS), PO Box 15003, Porto Alegre, Rio Grande Do Sul, ZIP Code91501-970, Brazil
| | - Bianca Thaís Dalberto
- Instituto de Química, Departamento de Química Orgânica, Universidade Federal Do Rio Grande Do Sul (UFRGS), PO Box 15003, Porto Alegre, Rio Grande Do Sul, ZIP Code91501-970, Brazil
| | - Paulo Henrique Schneider
- Instituto de Química, Departamento de Química Orgânica, Universidade Federal Do Rio Grande Do Sul (UFRGS), PO Box 15003, Porto Alegre, Rio Grande Do Sul, ZIP Code91501-970, Brazil
| | - Henrique de Castro Silva Junior
- Instituto de Química, Departamento de Química Orgânica, Universidade Federal Do Rio Grande Do Sul (UFRGS), PO Box 15003, Porto Alegre, Rio Grande Do Sul, ZIP Code91501-970, Brazil.
| | - Fabiano Severo Rodembusch
- Instituto de Química, Departamento de Química Orgânica, Universidade Federal Do Rio Grande Do Sul (UFRGS), PO Box 15003, Porto Alegre, Rio Grande Do Sul, ZIP Code91501-970, Brazil.
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Halder A, Dinda S, Deb S, Baitalik S, Ghoshal D. Solid-State Solvent-Independent Excited-State Intramolecular Proton Transfer in a Coordination Polymer and Its Temperature Dependence. Inorg Chem 2023; 62:18732-18739. [PMID: 37910665 DOI: 10.1021/acs.inorgchem.3c03162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2023]
Abstract
Increasing demand for futuristic switches and sensors around the world has created an intense interest in smart materials, which can show a rapid but feature-dependent change in the physical properties in the presence of external stimuli. Hitherto such changes in the photophysical property of materials, specifically in the solid state, are projected for the use of smart on-off switches. Materials having an external-stimuli-responsive change in the photophysical properties like excited-state intramolecular proton transfer (ESIPT) can also be utilized for these purposes. Although the event of solid-state ESIPT is not new in the domain of material chemistry, especially for organic molecules, it was never observed for coordination polymers (CPs). Previous instances of ESIPT in CPs have necessitated the presence of a solvent as a suspension medium, driving a solvent-assisted ESIPT phenomenon. However, the emergence of a solvent-independent ESIPT-enabled CP presents unique advantages. The well-defined periodic arrangement ensures reliable property variations, while the robust coordination bonds between the metal nodes and ligands provide durability in harsh environments. Addressing this gap, we present the first ever solid-state, solvent-free, and solvent-independent ESIPT-active CP. Remarkably, this CP exhibits temperature-dependent ESIPT on-off behavior, demonstrating its potential as a cutting-edge material in the field of smart switches and sensors.
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Affiliation(s)
- Arijit Halder
- Department of Chemistry, Jadavpur University, Jadavpur, Kolkata 700 032, India
| | - Susanta Dinda
- Department of Chemistry, Jadavpur University, Jadavpur, Kolkata 700 032, India
| | - Sourav Deb
- Department of Chemistry, Jadavpur University, Jadavpur, Kolkata 700 032, India
| | - Sujoy Baitalik
- Department of Chemistry, Jadavpur University, Jadavpur, Kolkata 700 032, India
| | - Debajyoti Ghoshal
- Department of Chemistry, Jadavpur University, Jadavpur, Kolkata 700 032, India
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7
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Shekhovtsov NA, Nikolaenkova EB, Ryadun AA, Samsonenko DG, Tikhonov AY, Bushuev MB. ESIPT-Capable 4-(2-Hydroxyphenyl)-2-(Pyridin-2-yl)-1 H-Imidazoles with Single and Double Proton Transfer: Synthesis, Selective Reduction of the Imidazolic OH Group and Luminescence. Molecules 2023; 28:molecules28041793. [PMID: 36838780 PMCID: PMC9962989 DOI: 10.3390/molecules28041793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 02/07/2023] [Accepted: 02/09/2023] [Indexed: 02/16/2023] Open
Abstract
1H-Imidazole derivatives establish one of the iconic classes of ESIPT-capable compounds (ESIPT = excited state intramolecular proton transfer). This work presents the synthesis of 1-hydroxy-4-(2-hydroxyphenyl)-5-methyl-2-(pyridin-2-yl)-1H-imidazole (LOH,OH) as the first example of ESIPT-capable imidazole derivatives wherein the imidazole moiety simultaneously acts as a proton acceptor and a proton donor. The reaction of LOH,OH with chloroacetone leads to the selective reduction of the imidazolic OH group (whereas the phenolic OH group remains unaffected) and to the isolation of 4-(2-hydroxyphenyl)-5-methyl-2-(pyridin-2-yl)-1H-imidazole (LH,OH), a monohydroxy congener of LOH,OH. Both LOH,OH and LH,OH demonstrate luminescence in the solid state. The number of OH···N proton transfer sites in these compounds (one for LH,OH and two for LOH,OH) strongly affects the luminescence mechanism and color of the emission: LH,OH emits in the light green region, whereas LOH,OH luminesces in the orange region. According to joint experimental and theoretical studies, the main emission pathway of both compounds is associated with T1 → S0 phosphorescence and not related to ESIPT. At the same time, LOH,OH also exhibits S1 → S0 fluorescence associated with ESIPT with one proton transferred from the hydroxyimidazole moiety to the pyridine moiety, which is not possible for LH,OH due to the absence of the hydroxy group in the imidazole moiety.
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Affiliation(s)
- Nikita A. Shekhovtsov
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciences, 3, Acad. Lavrentiev Ave., Novosibirsk 630090, Russia
- Correspondence: (N.A.S.); (A.Y.T.); (M.B.B.)
| | - Elena B. Nikolaenkova
- N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of Russian Academy of Sciences, 9, Acad. Lavrentiev Ave., Novosibirsk 630090, Russia
| | - Alexey A. Ryadun
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciences, 3, Acad. Lavrentiev Ave., Novosibirsk 630090, Russia
| | - Denis G. Samsonenko
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciences, 3, Acad. Lavrentiev Ave., Novosibirsk 630090, Russia
| | - Alexsei Ya. Tikhonov
- N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of Russian Academy of Sciences, 9, Acad. Lavrentiev Ave., Novosibirsk 630090, Russia
- Correspondence: (N.A.S.); (A.Y.T.); (M.B.B.)
| | - Mark B. Bushuev
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciences, 3, Acad. Lavrentiev Ave., Novosibirsk 630090, Russia
- Correspondence: (N.A.S.); (A.Y.T.); (M.B.B.)
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8
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Shekhovtsov NA, Nikolaenkova EB, Berezin AS, Plyusnin VF, Vinogradova KA, Naumov DY, Pervukhina NV, Tikhonov AY, Bushuev MB. Tuning ESIPT-coupled luminescence by expanding π-conjugation of a proton acceptor moiety in ESIPT-capable zinc(II) complexes with 1-hydroxy-1 H-imidazole-based ligands. Dalton Trans 2022; 51:15166-15188. [PMID: 36129344 DOI: 10.1039/d2dt02460h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The emission of ESIPT-fluorophores is known to be sensitive to various external and internal stimuli and can be fine-tuned through substitution in the proton-donating and proton-accepting groups. The incorporation of metal ions in the molecules of ESIPT fluorophores without their deprotonation is an emerging area of research in coordination chemistry which provides chemists with a new factor affecting the ESIPT reaction and ESIPT-coupled luminescence. In this paper we present 1-hydroxy-5-methyl-4-(pyridin-2-yl)-2-(quinolin-2-yl)-1H-imidazole (HLq) as a new ESIPT-capable ligand. Due to the spatial separation of metal binding and ESIPT sites this ligand can coordinate metal ions without being deprotonated. The reactions of ZnHal2 with HLq afford ESIPT-capable [Zn(HLq)Hal2] (Hal = Cl, Br, I) complexes. In the solid state HLq and [Zn(HLq)Hal2] luminesce in the orange region (λmax = 600-650 nm). The coordination of HLq by Zn2+ ions leads to the increase in the photoluminescence quantum yield due to the chelation-enhanced fluorescence effect. The ESIPT process is barrierless in the S1 state, leading to the only possible fluorescence channel in the tautomeric form (T), S1T → S0T. The emission of [Zn(HLq)Hal2] in the solid state is blue-shifted as compared with HLq due to the stabilization of the ground state and destabilization of the excited state. In CH2Cl2 solutions, the compounds demonstrate dual emission in the UV (λmax = 358 nm) and green (λmax = 530 nm) regions. This dual emission is associated with two radiative deactivation channels in the normal (N) and tautomeric (T) forms, S1N → S0N and S1T → S0T, originating from two minima on the excited state potential energy surfaces. High energy barriers for the GSIPT process allow the trapping of molecules in the minimum of the tautomeric form, S0T, resulting in the possibility of the S0T → S1T photoexcitation and extraordinarily small Stokes shifts in the solid state. Finally, the π-system of quinolin-2-yl group facilitates the delocalization of the positive charge in the proton-accepting part of the molecule and promotes the ESIPT reaction.
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Affiliation(s)
- Nikita A Shekhovtsov
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, 3, Acad. Lavrentiev Ave., Novosibirsk, 630090, Russia.
| | - Elena B Nikolaenkova
- N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences, 9, Acad. Lavrentiev Ave., Novosibirsk, 630090, Russia
| | - Alexey S Berezin
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, 3, Acad. Lavrentiev Ave., Novosibirsk, 630090, Russia.
| | - Victor F Plyusnin
- Institute of Chemical Kinetics and Combustion, Siberian Branch of the Russian Academy of Sciences, 3, Institutskaya str., Novosibirsk, 630090, Russia
| | - Katerina A Vinogradova
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, 3, Acad. Lavrentiev Ave., Novosibirsk, 630090, Russia.
| | - Dmitry Yu Naumov
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, 3, Acad. Lavrentiev Ave., Novosibirsk, 630090, Russia.
| | - Natalia V Pervukhina
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, 3, Acad. Lavrentiev Ave., Novosibirsk, 630090, Russia.
| | - Alexsei Ya Tikhonov
- N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences, 9, Acad. Lavrentiev Ave., Novosibirsk, 630090, Russia
| | - Mark B Bushuev
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, 3, Acad. Lavrentiev Ave., Novosibirsk, 630090, Russia.
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9
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Shekhovtsov NA, Vinogradova KA, Vorobyova SN, Berezin AS, Plyusnin VF, Naumov DY, Pervukhina NV, Nikolaenkova EB, Tikhonov AY, Bushuev MB. N-Hydroxy- N-oxide photoinduced tautomerization and excitation wavelength dependent luminescence of ESIPT-capable zinc(II) complexes with a rationally designed 1-hydroxy-2,4-di(pyridin-2-yl)-1 H-imidazole ESIPT-ligand. Dalton Trans 2022; 51:9818-9835. [PMID: 35708132 DOI: 10.1039/d2dt01232d] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The ability of 1-hydroxy-1H-imidazoles to undergo proton transfer processes and to exist in N-hydroxy and N-oxide tautomeric forms can be used in coordination chemistry for the design of ESIPT-capable complexes. A series of ESIPT-capable zinc(II) complexes [Zn(HL)Hal2] (Hal = Cl, Br, I) with a rationally designed ESIPT-ligand 1-hydroxy-5-methyl-2,4-di(pyridin-2-yl)-1H-imidazole (HL) featuring spatially separated metal binding and ESIPT sites have been synthesized and characterized. Crystals of these compounds consist of a mixture of two isomers of [Zn(HL)Hal2]. Only a major isomer has a short intramolecular hydrogen bond O-H⋯N as a pre-requisite for ESIPT. In the solid state, the complexes [Zn(HL)Hal2] demonstrate temperature- and excitation wavelength dependent fluorescence in the cyan region due to the interplay of two intraligand fluorescence channels with excited state lifetimes spanning from 0.2 to 4.3 ns. The coordination of HL by Zn2+ ions results in an increase in the photoluminescence efficiency, and the photoluminescence quantum yields (PLQYs) of the complexes reach 12% at λex = 300 nm and 27% at λex = 400 nm in comparison with the PLQY of free HL of ca. 2%. Quantum chemical calculations indicate that N-hydroxy-N-oxide phototautomerization is both thermodynamically and kinetically favourable in the S1 state for [Zn(HL)Hal2]. The proton transfer induces considerable geometrical reorganizations and therefore results in large Stokes shifts of ca. 230 nm. In contrast, auxiliary ESIPT-incapable complexes [ZnL2][Zn(OAc)2]2·2H2O and [ZnL2][ZnCl2]2·4H2O with the deprotonated ligand exhibit excitation wavelength independent emission in the violet region with the Stokes shift reduced to ca. 130 nm.
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Affiliation(s)
- Nikita A Shekhovtsov
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciences, 3, Acad. Lavrentiev Ave., Novosibirsk, 630090, Russia.
| | - Katerina A Vinogradova
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciences, 3, Acad. Lavrentiev Ave., Novosibirsk, 630090, Russia.
| | - Sofia N Vorobyova
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciences, 3, Acad. Lavrentiev Ave., Novosibirsk, 630090, Russia.
| | - Alexey S Berezin
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciences, 3, Acad. Lavrentiev Ave., Novosibirsk, 630090, Russia.
| | - Victor F Plyusnin
- Institute of Chemical Kinetics and Combustion, Siberian Branch of Russian Academy of Sciences, 3, Institutskaya str., Novosibirsk, 630090, Russia
| | - Dmitry Yu Naumov
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciences, 3, Acad. Lavrentiev Ave., Novosibirsk, 630090, Russia.
| | - Natalia V Pervukhina
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciences, 3, Acad. Lavrentiev Ave., Novosibirsk, 630090, Russia.
| | - Elena B Nikolaenkova
- N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of Russian Academy of Sciences, 9, Acad. Lavrentiev Ave., Novosibirsk, 630090, Russia
| | - Alexsei Ya Tikhonov
- N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of Russian Academy of Sciences, 9, Acad. Lavrentiev Ave., Novosibirsk, 630090, Russia
| | - Mark B Bushuev
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciences, 3, Acad. Lavrentiev Ave., Novosibirsk, 630090, Russia.
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10
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Munch M, Ulrich G, Massue J. Synthesis and Optical Properties of Excited-State Intramolecular Proton Transfer (ESIPT) Emitters with Sulfobetaine Fragments. Org Biomol Chem 2022; 20:4640-4649. [PMID: 35612088 DOI: 10.1039/d2ob00691j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This article describes the synthetic efforts towards the solubilization of organic fluorescent emitters based on a 2-(2'-hydroxybenzofuranyl)benzazole (HBBX) scaffold in aqueous media under physiological conditions (PBS, pH 7.4). These dyes are well-known to display the excited-state intramolecular proton transfer (ESIPT) process which leads to a Stokes-shifted fluorescence with enhanced photostability and strong environment dependent features. Organic dyes are hydrophobic by nature and their vectorization into aqueous media usually necessitates amphiphilic polymers. In this study, we show that the incorporation of one or two sulfobetaine fragments, a highly biocompatible zwitterionic unit leads to the vectorization in buffer solution at pH 7.4 while keeping a reasonable ESIPT fluorescence emission. The photophysical properties of all dyes were studied in multiple solvents and showed that, depending on structure and environment, different excited-state species are observed: normal or tautomeric species, as well as a competitive anionic fluorescent derivative. This study shows that it is not only possible to solubilize fluorescent ESIPT dyes in water using sulfobetaine(s) but also that the optical properties can be finely tuned depending on small structural inputs.
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Affiliation(s)
- Maxime Munch
- Institut de Chimie et Procédés pour l'Energie, l'Environnement et la Santé (ICPEES), Equipe Chimie Organique pour la Biologie, les Matériaux et l'Optique (COMBO), UMR CNRS 7515, Ecole Européenne de Chimie, Polymères et Matériaux (ECPM), Université de Strasbourg, 25 Rue Becquerel, 67087 Strasbourg Cedex 02, France.
| | - Gilles Ulrich
- Institut de Chimie et Procédés pour l'Energie, l'Environnement et la Santé (ICPEES), Equipe Chimie Organique pour la Biologie, les Matériaux et l'Optique (COMBO), UMR CNRS 7515, Ecole Européenne de Chimie, Polymères et Matériaux (ECPM), Université de Strasbourg, 25 Rue Becquerel, 67087 Strasbourg Cedex 02, France.
| | - Julien Massue
- Institut de Chimie et Procédés pour l'Energie, l'Environnement et la Santé (ICPEES), Equipe Chimie Organique pour la Biologie, les Matériaux et l'Optique (COMBO), UMR CNRS 7515, Ecole Européenne de Chimie, Polymères et Matériaux (ECPM), Université de Strasbourg, 25 Rue Becquerel, 67087 Strasbourg Cedex 02, France.
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11
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Plaza-Pedroche R, Fernández-Liencres MP, Jiménez-Pulido SB, Illán-Cabeza NA, Achelle S, Navarro A, Rodríguez-López J. Excited-State Intramolecular Proton Transfer in 2-(2'-Hydroxyphenyl)pyrimidines: Synthesis, Optical Properties, and Theoretical Studies. ACS APPLIED MATERIALS & INTERFACES 2022; 14:24964-24979. [PMID: 35579566 PMCID: PMC9164210 DOI: 10.1021/acsami.2c05439] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 05/05/2022] [Indexed: 06/15/2023]
Abstract
The development of fluorescence materials with switched on/off emission has attracted great attention owing to the potential application of these materials in chemical sensing. In this work, the photophysical properties of a series of original 2-(2'-hydroxyphenyl)pyrimidines were thoroughly studied. The compounds were prepared by following well-established and straightforward methodologies and showed very little or null photoluminescence both in solution and in the solid state. This absence of emission can be explained by a fast proton transfer from the OH group to the nitrogen atoms of the pyrimidine ring to yield an excited tautomer that deactivates through a nonradiative pathway. The key role of the OH group in the emission quenching was demonstrated by the preparation of 2'-unsubstituted derivatives, all of which exhibited violet or blue luminescence. Single crystals of some compounds suitable for an X-ray diffraction analysis could be obtained, which permitted us to investigate inter- and intramolecular interactions and molecular packing structures. The protonation of the pyrimidine ring by an addition of trifluoroacetic acid inhibited the excited-state intramolecular proton transfer (ESIPT) process, causing a reversible switch on fluorescence response detectable by the naked eye. This acidochromic behavior allows 2-(2'-hydroxyphenyl)pyrimidines to be used as solid-state acid-base vapor sensors and anticounterfeiting agents. Extensive density functional theory and its time-dependent counterpart calculations at the M06-2X/6-31+G** level of theory were performed to rationalize all the experimental results and understand the impact of protonation on the different optical transitions.
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Affiliation(s)
- Rodrigo Plaza-Pedroche
- Área
de Química Orgánica, Facultad de Ciencias y Tecnologías
Químicas, Universidad de Castilla-La
Mancha, Avda Camilo José Cela 10, 13071 Ciudad Real, Spain
| | - M. Paz Fernández-Liencres
- Dpto.
de Química Física y Analítica, Facultad de Ciencias
Experimentales, Campus Las Lagunillas, Universidad
de Jaén, 23071 Jaén, Spain
| | - Sonia B. Jiménez-Pulido
- Dpto.
de Química Inorgánica y Orgánica, Facultad de
Ciencias Experimentales, Campus Las Lagunillas, Universidad de Jaén, 23071 Jaén, Spain
| | - Nuria A. Illán-Cabeza
- Dpto.
de Química Inorgánica y Orgánica, Facultad de
Ciencias Experimentales, Campus Las Lagunillas, Universidad de Jaén, 23071 Jaén, Spain
| | - Sylvain Achelle
- Univ
Rennes, CNRS, Institut des Sciences Chimiques de Rennes - UMR 6226, F-35000 Rennes, France
| | - Amparo Navarro
- Dpto.
de Química Física y Analítica, Facultad de Ciencias
Experimentales, Campus Las Lagunillas, Universidad
de Jaén, 23071 Jaén, Spain
| | - Julián Rodríguez-López
- Área
de Química Orgánica, Facultad de Ciencias y Tecnologías
Químicas, Universidad de Castilla-La
Mancha, Avda Camilo José Cela 10, 13071 Ciudad Real, Spain
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12
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Li W, Chasing P, Nalaoh P, Chawanpunyawat T, Sukpattanacharoen C, Kungwan N, Sudyoadsuk T, Promarak V. Hydroxy‐Tetraphenylimidazole Derivatives as Efficient Blue Emissive Materials for Electroluminescent Devices. Chem Asian J 2022; 17:e202200266. [DOI: 10.1002/asia.202200266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 04/18/2022] [Indexed: 11/07/2022]
Affiliation(s)
- Wan Li
- Department of Materials Science and Engineering School of Molecular Science and Engineering Vidyasirimedhi Institute of Science and Technology 21210 Wangchan Rayong Thailand
| | - Pongsakorn Chasing
- Department of Materials Science and Engineering School of Molecular Science and Engineering Vidyasirimedhi Institute of Science and Technology 21210 Wangchan Rayong Thailand
| | - Phattananawee Nalaoh
- Department of Materials Science and Engineering School of Molecular Science and Engineering Vidyasirimedhi Institute of Science and Technology 21210 Wangchan Rayong Thailand
| | - Thanyarat Chawanpunyawat
- Department of Materials Science and Engineering School of Molecular Science and Engineering Vidyasirimedhi Institute of Science and Technology 21210 Wangchan Rayong Thailand
| | | | - Nawee Kungwan
- Department of Chemistry Faculty of Science Chiang Mai University Muang District 50200 Chiang Mai Thailand
| | - Taweesak Sudyoadsuk
- Department of Materials Science and Engineering School of Molecular Science and Engineering Vidyasirimedhi Institute of Science and Technology 21210 Wangchan Rayong Thailand
| | - Vinich Promarak
- Department of Materials Science and Engineering School of Molecular Science and Engineering Vidyasirimedhi Institute of Science and Technology 21210 Wangchan Rayong Thailand
- Research Network of NANOTEC-VISTEC on Nanotechnology for Energy Vidyasirimedhi Institute of Science and Technology 21210 Wangchan Rayong Thailand
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13
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Stoerkler T, Pariat T, Laurent AD, Jacquemin D, Ulrich G, Massue J. Excited-State Intramolecular Proton Transfer Dyes with Dual-State Emission Properties: Concept, Examples and Applications. Molecules 2022; 27:molecules27082443. [PMID: 35458640 PMCID: PMC9024454 DOI: 10.3390/molecules27082443] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Revised: 04/08/2022] [Accepted: 04/08/2022] [Indexed: 11/30/2022] Open
Abstract
Dual-state emissive (DSE) fluorophores are organic dyes displaying fluorescence emission both in dilute and concentrated solution and in the solid-state, as amorphous, single crystal, polycrystalline samples or thin films. This comes in contrast to the vast majority of organic fluorescent dyes which typically show intense fluorescence in solution but are quenched in concentrated media and in the solid-state owing to π-stacking interactions; a well-known phenomenon called aggregation-caused quenching (ACQ). On the contrary, molecular rotors with a significant number of free rotations have been engineered to show quenched emission in solution but strong fluorescence in the aggregated-state thanks to restriction of the intramolecular motions. This is the concept of aggregation-induced emission (AIE). DSE fluorophores have been far less explored despite the fact that they are at the crossroad of ACQ and AIE phenomena and allow targeting applications both in solution (bio-conjugation, sensing, imaging) and solid-state (organic electronics, data encryption, lasing, luminescent displays). Excited-State Intramolecular Proton Transfer (ESIPT) fluorescence is particularly suitable to engineer DSE dyes. Indeed, ESIPT fluorescence, which relies on a phototautomerism between normal and tautomeric species, is characterized by a strong emission in the solid-state along with a large Stokes’ shift, an enhanced photostability and a strong sensitivity to the close environment, a feature prone to be used in bio-sensing. A drawback that needs to be overcome is their weak emission intensity in solution, owing to detrimental molecular motions in the excited-state. Several strategies have been proposed in that regard. In the past few years, a growing number of examples of DSE-ESIPT dyes have indeed emerged in the literature, enriching the database of such attractive dyes. This review aims at a brief but concise overview on the exploitation of ESIPT luminescence for the optimization of DSE dyes properties. In that perspective, a synergistic approach between organic synthesis, fluorescence spectroscopy and ab initio calculations has proven to be an efficient tool for the construction and optimization of DSE-ESIPT fluorophores.
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Affiliation(s)
- Timothée Stoerkler
- Institut de Chimie et Procédés pour l’Energie, l’Environnement et la Santé (ICPEES), Equipe Chimie Organique pour la Biologie, les Matériaux et l’Optique (COMBO), UMR CNRS 7515, Ecole Européenne de Chimie, Polymères et Matériaux (ECPM), Université de Strasbourg, 25 Rue Becquerel, CEDEX 02, 67087 Strasbourg, France; (T.S.); (T.P.); (G.U.)
| | - Thibault Pariat
- Institut de Chimie et Procédés pour l’Energie, l’Environnement et la Santé (ICPEES), Equipe Chimie Organique pour la Biologie, les Matériaux et l’Optique (COMBO), UMR CNRS 7515, Ecole Européenne de Chimie, Polymères et Matériaux (ECPM), Université de Strasbourg, 25 Rue Becquerel, CEDEX 02, 67087 Strasbourg, France; (T.S.); (T.P.); (G.U.)
| | - Adèle D. Laurent
- Chimie et Interdisciplinarités: Synthèse, Analyse et Modélisation (CEISAM), UMR CNRS 6230, Nantes University, 44322 Nantes, France;
| | - Denis Jacquemin
- Chimie et Interdisciplinarités: Synthèse, Analyse et Modélisation (CEISAM), UMR CNRS 6230, Nantes University, 44322 Nantes, France;
- Correspondence: (D.J.); (J.M.)
| | - Gilles Ulrich
- Institut de Chimie et Procédés pour l’Energie, l’Environnement et la Santé (ICPEES), Equipe Chimie Organique pour la Biologie, les Matériaux et l’Optique (COMBO), UMR CNRS 7515, Ecole Européenne de Chimie, Polymères et Matériaux (ECPM), Université de Strasbourg, 25 Rue Becquerel, CEDEX 02, 67087 Strasbourg, France; (T.S.); (T.P.); (G.U.)
| | - Julien Massue
- Institut de Chimie et Procédés pour l’Energie, l’Environnement et la Santé (ICPEES), Equipe Chimie Organique pour la Biologie, les Matériaux et l’Optique (COMBO), UMR CNRS 7515, Ecole Européenne de Chimie, Polymères et Matériaux (ECPM), Université de Strasbourg, 25 Rue Becquerel, CEDEX 02, 67087 Strasbourg, France; (T.S.); (T.P.); (G.U.)
- Correspondence: (D.J.); (J.M.)
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14
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Suzuki N, Kubota T, Ando N, Yamaguchi S. Photobase-Driven Excited-State Intramolecular Proton Transfer (ESIPT) in a Strapped π-Electron System. Chemistry 2021; 28:e202103584. [PMID: 34841575 DOI: 10.1002/chem.202103584] [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: 10/04/2021] [Indexed: 11/09/2022]
Abstract
We report a new design strategy for an excited-state intramolecular proton transfer (ESIPT) fluorophore that can be used in acidic media. A photobasic pyridine-centered donor-acceptor-donor-type fluorophore is combined with a basic trialkylamine "strap". In the presence of an acid, protonation occurs predominantly at the amine moiety in the ground state. A single-crystal X-ray diffraction analysis confirmed the formation of a pre-organized intramolecular hydrogen-bonded structure between the resulting ammonium moiety and the pyridine ring. Upon excitation, the intramolecular charge-transfer transition increases the basicity of the pyridine moiety in the excited state, resulting in proton transfer from the amine to the pyridine moiety. Consequently, the fluorophore takes on a polymethine-dye character in the ESIPT state, which gives rise to significantly red-shifted emission with an increased fluorescence quantum yield.
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Affiliation(s)
- Naoya Suzuki
- Department of Chemistry, Graduate School of Science, and Integrated Research Consortium on Chemical Sciences (IRCCS), Nagoya University, Furo, Chikusa, Nagoya, 464-8602, Japan
| | - Tomoya Kubota
- Department of Chemistry, Graduate School of Science, and Integrated Research Consortium on Chemical Sciences (IRCCS), Nagoya University, Furo, Chikusa, Nagoya, 464-8602, Japan
| | - Naoki Ando
- Department of Chemistry, Graduate School of Science, and Integrated Research Consortium on Chemical Sciences (IRCCS), Nagoya University, Furo, Chikusa, Nagoya, 464-8602, Japan
| | - Shigehiro Yamaguchi
- Department of Chemistry, Graduate School of Science, and Integrated Research Consortium on Chemical Sciences (IRCCS), Nagoya University, Furo, Chikusa, Nagoya, 464-8602, Japan.,Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Furo, Chikusa, Nagoya, 464-8601, Japan
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15
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Jankowska J, Sobolewski AL. Modern Theoretical Approaches to Modeling the Excited-State Intramolecular Proton Transfer: An Overview. Molecules 2021; 26:molecules26175140. [PMID: 34500574 PMCID: PMC8434569 DOI: 10.3390/molecules26175140] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 08/20/2021] [Accepted: 08/23/2021] [Indexed: 02/02/2023] Open
Abstract
The excited-state intramolecular proton transfer (ESIPT) phenomenon is nowadays widely acknowledged to play a crucial role in many photobiological and photochemical processes. It is an extremely fast transformation, often taking place at sub-100 fs timescales. While its experimental characterization can be highly challenging, a rich manifold of theoretical approaches at different levels is nowadays available to support and guide experimental investigations. In this perspective, we summarize the state-of-the-art quantum-chemical methods, as well as molecular- and quantum-dynamics tools successfully applied in ESIPT process studies, focusing on a critical comparison of their specific properties.
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Affiliation(s)
- Joanna Jankowska
- Faculty of Chemistry, University of Warsaw, 02-093 Warsaw, Poland
- Correspondence:
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16
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Feng X, Becke AD, Johnson ER. Theoretical investigation of polymorph- and coformer-dependent photoluminescence in molecular crystals. CrystEngComm 2021. [DOI: 10.1039/d1ce00383f] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
A novel density-functional approach provides accurate predictions for the colour zoning of ROY polymorphs and the fluorescence energies of a family of 9-acetylanthracene cocrystals.
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Affiliation(s)
- Xibo Feng
- Department of Chemistry
- Dalhousie University
- Halifax
- Canada
| | - Axel D. Becke
- Department of Chemistry
- Dalhousie University
- Halifax
- Canada
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