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Fajardo J, Rowen JF, Schleif T, Jariwala P, Garcia-Garibay MA. Elusive Arylalkylcarbenes in Solution and in Crystals: Facile 1,2-R (R = H, Ph) Migrations of 1,2,2-Triphenylethylidene. J Am Chem Soc 2024; 146:23221-23229. [PMID: 39116165 DOI: 10.1021/jacs.4c05452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/10/2024]
Abstract
Highly reactive arylalkylcarbenes generated in solution by photolysis of their aryldiazoalkane precursors tend to undergo competing inter- and intramolecular reactions to yield a complex mixture of products. Having previously shown the use of crystals to effectively control the reactivity of arylalkylcarbenes to afford high yields of a single product, it was of interest to investigate whether the crystalline environment could also enable spectroscopic detection of these intermediates en route to the photoproduct. Using 1,2,2-triphenyldiazoethane (3) as a model substrate to probe the effect of alternative reaction trajectories that yield triphenylethylene (5) by competing 1,2-H shift or 1,2-Ph migration, we report selectivities consistent with reaction from a spin-equilibrated carbene 4 in solution, while reactions in crystals primarily afford alkene 5 via a lattice-controlled 1,2-H shift. Attempts to detect 1,2,2-triphenylethylidene 4 in crystals by nanosecond laser-flash photolysis or by triplet-triplet fluorescence at 77 K were unsuccessful, indicating that arylalkylcarbenes possessing α-H substituents undergo facile 1,2-H shifts both in solution and in the solid state. However, related tert-butylphenylmethylene with no α-H substituents could be observed by triplet-triplet fluorescence at 77 K in glassy matrices.
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Affiliation(s)
- Javier Fajardo
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, United States
| | - Julien F Rowen
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, United States
| | - Tim Schleif
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, United States
| | - Palak Jariwala
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, United States
| | - Miguel A Garcia-Garibay
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, United States
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2
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Mahmoud H, Ismail MA, Medien HAA, Abdel-Samad HS, Abdel-Shafi AA. Unique structural effect on the fluorosolvatochromism and dual fluorescence emission of D-π-A + cationic chromophores with furyl bridge. An approach to white light emitters. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2024; 308:123771. [PMID: 38150988 DOI: 10.1016/j.saa.2023.123771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 11/30/2023] [Accepted: 12/13/2023] [Indexed: 12/29/2023]
Abstract
Photophysical behavior of two D - π - A+ cationic compounds with the same furyl bridge and nicotinamidine group as an electron acceptor moiety and two electron donating groups, namely methoxy (I) and N,N-dimethylamino (II) groups was examined using steady-state and time-resolved techniques in variety of solvents. Time-dependent density functional theory (TDDFT) calculations were performed in some representative solvents and compared with the experimental results. Steady state and time-resolved studies in different solvents reveal that fluorescence emission of (I) is ascribed to an emission from an excited state (ICT) with higher dipole moment than the ground state while the emission of (II) is a dual emission from a state with high charge transfer nature (ICT) in addition to the locally excited state (LE). The fluorescence emission spectra of (II) were found to depend on the excitation wavelength and an increase in the excitation wavelength led to the formation of a longer wavelength emission band with lower quantum yield. It has also been found that the fluorescence excitation spectra were dependent on the emission wavelength. The effect of solvent on the nature of dual emission was examined. Correlation of the photophysical properties of the excited states of (I) and (II) with the solvent polarity, ε, reveals the charge transfer nature of (I) and the long wavelength emission band of (II), while their correlation with the solvent polarity parameter (ETN) shows two different trends when the solvents are divided to aprotic and protic solvents. For precise investigation of the impact of each solvent parameter on each photophysical property, Catalán's and Laurence's four parametric linear solvation energy relationships were studied. We have found that the non-specific interactions of the solvent are primarily responsible for controlling the photophysical properties, as demonstrated by Catalán's and Laurence's treatments. DFT and TDDFT calculations were used to anticipate the dipole moments in the ground and excited states and geometry of both states.
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Affiliation(s)
- Hoda Mahmoud
- Department of Chemistry, Faculty of Science, Ain Shams University, Abbassia, Cairo, 11566, Egypt
| | - Mohamed A Ismail
- Department of Chemistry, Faculty of Science, Mansoura University, 35516 Mansoura, Egypt
| | - Hesham A A Medien
- Department of Chemistry, Faculty of Science, Ain Shams University, Abbassia, Cairo, 11566, Egypt
| | - Hesham S Abdel-Samad
- Department of Chemistry, Faculty of Science, Ain Shams University, Abbassia, Cairo, 11566, Egypt
| | - Ayman A Abdel-Shafi
- Department of Chemistry, Faculty of Science, Ain Shams University, Abbassia, Cairo, 11566, Egypt.
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3
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Memarian HR, Rejali N, Soltani M. Electronic and steric substituent effects on the fluorescence emission of 2-pyrazoline derivatives. LUMINESCENCE 2023. [PMID: 38018279 DOI: 10.1002/bio.4631] [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: 07/28/2023] [Revised: 10/09/2023] [Accepted: 11/04/2023] [Indexed: 11/30/2023]
Abstract
A series of substituted 2-pyrazolines were synthesized, and the steric and electronic effects of substituents on the C3 - and C5 -positions of the heterocyclic ring on their fluorescent ability were investigated. Two different conjugative intramolecular charge transfer (ICT) and intramolecular charge transfer through space (spiro-conjugation) affect the fluorescence intensity of these compounds. The extent of the ICT process and spiro-conjugation depends on the electronic nature of the additional substitution and its position on the attached aryl rings. In addition, the effects of the concentration and the solvent polarity on the fluorescence emission were studied. Density functional theory (DFT) calculations were carried out to gain insight into the geometric, electronic, and spectroscopic properties of the pyrazoline derivatives. The results of both experimental and computational studies explain the effects of the geometrical orientation of the C3 - and C5 -aryl rings toward the heterocyclic ring and also the electronic nature of their additional substitutions on the fluorescence intensity.
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Affiliation(s)
| | - Narges Rejali
- Department of Chemistry, University of Isfahan, Isfahan, Iran
| | - Marzieh Soltani
- Department of Chemistry, University of Isfahan, Isfahan, Iran
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4
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Hamasaki A, Kubo K, Harashima M, Katsuki A, Ozeki S. Reversible Change between Excimer and Monomer Forms of Perylene Induced by Water Absorption and Dehydration of Poly- N-isopropylacrylamide Gel. J Phys Chem B 2021; 125:2987-2993. [PMID: 33724819 DOI: 10.1021/acs.jpcb.0c11418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Several fluorescence patterns derived from the excimer states of perylene have been reported, but most of these have been obtained from rigid forms such as crystals or for perylene embedded in hard polymers. We observed perylene excimer emission on absorption of water by a poly-N-isopropylacrylamide gel containing perylene molecules, which were not fixed to the gel framework by chemical bonding. We propose that this emission arises because the hydrophobic perylene molecules cannot dissolve in water and form aggregates. The perylene aggregation was quickly lost on dehydration of the gel, and the luminescence reverted to that of the monomer. In a dehydrated environment, perylene was rapidly dispersed in the gel network. In other words, solid-liquid phase separation of perylene was induced by uptake of water into the gel, and perylene dissolved in the gel on dehydration. Because the outside of the gel is always in an aqueous environment, perylene will remain semipermanently in the gel. Therefore, monomer emission and excimer emission can be switched reversibly and repeatedly.
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Affiliation(s)
- Atom Hamasaki
- Faculty of Science, Shinshu University, Matsumoto, Nagano 390-8621, Japan
| | - Kei Kubo
- Faculty of Science, Shinshu University, Matsumoto, Nagano 390-8621, Japan
| | - Miki Harashima
- Faculty of Science, Shinshu University, Matsumoto, Nagano 390-8621, Japan
| | - Akio Katsuki
- School of General Education, Shinshu University, Matsumoto, Nagano 390-8621, Japan
| | - Sumio Ozeki
- Faculty of Science, Shinshu University, Matsumoto, Nagano 390-8621, Japan
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5
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Masuhara H. From Nanosecond Photochemistry to Optical Force Chemistry: My Journey. CHEM REC 2021; 21:1261-1269. [PMID: 33656242 DOI: 10.1002/tcr.202000159] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 02/18/2021] [Accepted: 02/18/2021] [Indexed: 01/28/2023]
Abstract
Laser was invented in 1960 and soon introduced to chemistry research. We started time-resolved spectroscopy and photochemistry and initial trial was focused to nanosecond and then picosecond electronic absorption spectroscopy for studying molecular electronic excited states, charge separation in molecular complexes, and intermolecular electron transfer in solution. We considered that not only time-resolved but also space-resolved chemistry would be important for future laser-based chemistry and combined pulsed lasers with optical microscopes. Spectroscopy, photochemistry, ablation, and spatial arrangement of single microparticles and microdroplets in solution were carried out. Further we shifted from micro to nano and opened a new field covering spectroscopy, ablation, phase transition, crystallization, patterning, and fabrication. The progress is summarized and discussed as time-resolved nano spectroscopy, ablation nano dynamics, and optical force chemistry.
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Affiliation(s)
- Hiroshi Masuhara
- Department of Applied Chemistry and Center for Emergent Functional Matter Science, National Chiao Tung University, 1001 Ta Hsueh Rd., Hsinchu, 30010, Taiwan
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6
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Bylińska I, Szabelski M, Wiczk W. Unusual Solvatofluorochromism of the Asymmetrically Substituted Aromatic Acetylene Derivative CNAacDMA**. Chemphyschem 2021. [DOI: 10.1002/cphc.202000804] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Irena Bylińska
- University of Gdańsk Faculty of Chemistry Wita Stwosza 63 80-308 Gdańsk Poland
| | - Mariusz Szabelski
- Department of Physics and Biophysics University of Warmia and Mazury in Olsztyn Oczapowskiego 4 10-719 Olsztyn Poland
| | - Wiesław Wiczk
- University of Gdańsk Faculty of Chemistry Wita Stwosza 63 80-308 Gdańsk Poland
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Padrutt R, Babu V, Klingler S, Kalt M, Schumer F, Anania MI, Schneider L, Spingler B. Highly Phototoxic Transplatin-Modified Distyryl-BODIPY Photosensitizers for Photodynamic Therapy. ChemMedChem 2020; 16:694-701. [PMID: 33164336 DOI: 10.1002/cmdc.202000702] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 10/14/2020] [Indexed: 12/16/2022]
Abstract
We report the synthesis of the first transplatin-BODIPY conjugates for application in photodynamic therapy (PDT). The distyryl BODIPYs containing two iodine atoms were designed to absorb in the red region, easily undergo intersystem crossing for efficient singlet oxygen generation, and additionally offer the possibility for coordination with mono-activated transplatin. We were able to demonstrate that coordination of the BODIPYs with a mono-activated transplatin increases the phototoxic index of the photosensitizers significantly, giving rise to highly phototoxic distyryl BODIPY derivatives, of which one was shown to have the highest ever reported phototoxic index against any cell line. Furthermore, the photophysical mechanism of singlet oxygen generation in distyryl BODIPYs undergoing intramolecular charge transfer was studied experimentally and using time-dependent density functional theory.
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Affiliation(s)
- Roxane Padrutt
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Vipin Babu
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Simon Klingler
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Martina Kalt
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Frank Schumer
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Maria I Anania
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Lukas Schneider
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Bernhard Spingler
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
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8
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Hamasaki A, Sato N, Kubo K, Katsuki A, Ozeki S. Switching of Fluorescence Wavelength Caused by Phase Separation of Pyrene in Poly( N-isopropylacrylamide) Gel. CHEM LETT 2019. [DOI: 10.1246/cl.190391] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Atom Hamasaki
- Faculty of Science, Shinshu University, Matsumoto, Nagano 390-8621, Japan
| | - Naoya Sato
- Faculty of Science, Shinshu University, Matsumoto, Nagano 390-8621, Japan
| | - Kei Kubo
- Faculty of Science, Shinshu University, Matsumoto, Nagano 390-8621, Japan
| | - Akio Katsuki
- School of General Education, Shinshu University, Matsumoto, Nagano 390-8621, Japan
| | - Sumio Ozeki
- Faculty of Science, Shinshu University, Matsumoto, Nagano 390-8621, Japan
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9
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Belyaev A, Chen Y, Liu Z, Hindenberg P, Wu C, Chou P, Romero‐Nieto C, Koshevoy IO. Intramolecular Phosphacyclization: Polyaromatic Phosphonium P-Heterocycles with Wide-Tuning Optical Properties. Chemistry 2019; 25:6332-6341. [PMID: 30791177 PMCID: PMC6594060 DOI: 10.1002/chem.201900136] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Indexed: 01/08/2023]
Abstract
Rationally designed cationic phospha-polyaromatic fluorophores were prepared through intramolecular cyclization of the tertiary ortho-(acene)phenylene-phosphines mediated by CuII triflate. As a result of phosphorus quaternization, heterocyclic phosphonium salts 1 c-3 c, derived from naphthalene, phenanthrene, and anthracene cores, exhibited very intense blue to green fluorescence (Φem =0.38-0.99) and high photostability in aqueous medium. The structure-emission relationship was further investigated by tailoring the electron-donating functions to the anthracene moiety to give dyes 4 c-6 c with charge-transfer character. The latter significantly decreases the emission energy to reach near-IR region. Thus, the intramolecular phosphacyclization renders an ultra-wide tuning of fluorescence from 420 nm (1 c) to 780 nm (6 c) in solution, extended to 825 nm for 6 c in the solid state with quantum efficiency of approximately 0.07. The physical behavior of these new dyes was studied spectroscopically, crystallographically, and electrochemically, whereas computational analysis was used to correlate the experimental data with molecular electronic structures. The excellent stability, water solubility, and attractive photophysical characteristics make these phosphonium heterocycles powerful tools in cell imaging.
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Affiliation(s)
- Andrey Belyaev
- Department of ChemistryUniversity of Eastern FinlandYliopistokatu 780101JoensuuFinland
| | - Yi‐Ting Chen
- Department of ChemistryNational (Taiwan) UniversityTaipei106Taiwan
| | - Zong‐Ying Liu
- Department of ChemistryNational (Taiwan) UniversityTaipei106Taiwan
| | - Philip Hindenberg
- Organisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Cheng‐Ham Wu
- Department of ChemistryNational (Taiwan) UniversityTaipei106Taiwan
| | - Pi‐Tai Chou
- Department of ChemistryNational (Taiwan) UniversityTaipei106Taiwan
| | - Carlos Romero‐Nieto
- Organisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
- Faculty of PharmacyUniversity of Castilla-La ManchaCalle Almansa 14 - Edif. Bioincubadora02008AlbaceteSpain
| | - Igor O. Koshevoy
- Department of ChemistryUniversity of Eastern FinlandYliopistokatu 780101JoensuuFinland
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Salim AS, Girgis AS, Basta AH, El-Saied H, Mohamed MA, Bedair AH. Comparative DFT Computational Studies with Experimental Investigations for Novel Synthesized Fluorescent Pyrazoline Derivatives. J Fluoresc 2018; 28:913-931. [PMID: 29959579 DOI: 10.1007/s10895-018-2254-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 06/07/2018] [Indexed: 10/28/2022]
Abstract
A novel series of pyrazoline derivatives were synthesized and their spectral properties were characterized via FT-IR, 1H, and 13C NMR. The electronic transitions and fluorescence properties were tracked via UV-Vis and emission spectrometry. The density functional theory (DFT) calculations have been also computed to get spot onto the geometry, electronic transitions and spectroscopic properties theoretically that has been compared with the encountered experimental ones. Moreover, the dipole moment, optimized energy, HOMO - LUMO energies and band gaps were calculated for novel candidates pyrazoline derivatives with highly fluorescence quantum yield.
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Affiliation(s)
- Ahmad Saed Salim
- Forgery Research Department, Forensic Medicine Authority, Ministry of Justice, Cairo, 11381, Egypt.
| | - Adel S Girgis
- Pesticide Chemistry Department, National Research Center, Dokki, Giza, 12622, Egypt
| | - Altaf H Basta
- Cellulose and Paper Department, National Research Center, Dokki, Giza, 12622, Egypt
| | - Houssni El-Saied
- Cellulose and Paper Department, National Research Center, Dokki, Giza, 12622, Egypt
| | - Mohamed A Mohamed
- Forgery Research Department, Forensic Medicine Authority, Ministry of Justice, Cairo, 11381, Egypt
| | - Ahmad H Bedair
- Chemistry Department, Faculty of Science, Al-Azhar University, Cairo, Egypt
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11
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Sirbu D, Woodford OJ, Benniston AC, Harriman A. Photocatalysis and self-catalyzed photobleaching with covalently-linked chromophore-quencher conjugates built around BOPHY. Photochem Photobiol Sci 2018; 17:750-762. [DOI: 10.1039/c8pp00162f] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Two Chromophore-Quencher Conjugates (CQCs) have been synthesized by covalent attachment of the anti-oxidant dibutylated-hydroxytoluene (BHT) to a pyrrole-BF2 chromophore (BOPHY) in an effort to protect the latter against photofading.
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Affiliation(s)
- Dumitru Sirbu
- Molecular Photonics Laboratory
- School of Natural and Environmental Sciences (Chemistry)
- Bedson Building
- Newcastle University
- Newcastle upon Tyne
| | - Owen J. Woodford
- Molecular Photonics Laboratory
- School of Natural and Environmental Sciences (Chemistry)
- Bedson Building
- Newcastle University
- Newcastle upon Tyne
| | - Andrew C. Benniston
- Molecular Photonics Laboratory
- School of Natural and Environmental Sciences (Chemistry)
- Bedson Building
- Newcastle University
- Newcastle upon Tyne
| | - Anthony Harriman
- Molecular Photonics Laboratory
- School of Natural and Environmental Sciences (Chemistry)
- Bedson Building
- Newcastle University
- Newcastle upon Tyne
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12
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Luo Y, Wang Y, Chen S, Wang N, Qi Y, Zhang X, Yang M, Huang Y, Li M, Yu J, Luo D, Lu Z. Facile Access to Twisted Intramolecular Charge-Transfer Fluorogens Bearing Highly Pretwisted Donor-Acceptor Systems Together with Readily Fine-Tuned Charge-Transfer Characters. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2017; 13:1604113. [PMID: 28387442 DOI: 10.1002/smll.201604113] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 02/21/2017] [Indexed: 06/07/2023]
Abstract
Twisted intramolecular charge-transfer (TICT) fluorogens bearing highly pretwisted geometries and readily-fine-tuned charge-transfer characters are quite promising sensor and electroluminescence (EL) materials. In this study, by using 4-aryloxy-1,8-naphthalimide derivatives as the molecular framework, it is demonstrated for the first time that a CO bond could serve as the central bond to construct new TICT D-A systems. Photophysical and quantum chemical studies confirm that rotation around central CO bonds is responsible for the formation of a stable TICT state in these compounds. More importantly, owing to the structural adjustability of the aryl moiety and the strong steric interactions between the naphthalimide and the aryl ring systems, these compounds can display readily-fine-tuned TICT characters, hence exhibiting an adjustable solvent polarity threshold for aggregation-induced emission (AIE) activity, and could be AIE-active even in less-polar toluene and nonpolar cyclohexane. Furthermore, these compounds could possess highly-pretwisted ground-state geometries, hence could show good EL performance. The findings reveal a facile but effective molecular constructive strategy for versatile, high-performance optoelectronic TICT compounds.
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Affiliation(s)
- Yanju Luo
- College of Chemistry, Sichuan University, Chengdu, 610064, P. R. China
| | - Yan Wang
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, 430071, P. R. China
| | - Shiqi Chen
- College of Chemistry, Sichuan University, Chengdu, 610064, P. R. China
| | - Ning Wang
- College of Chemistry, Sichuan University, Chengdu, 610064, P. R. China
| | - Yige Qi
- School of Optoelectronic Information, University of Electronic Science and Technology of China College of Chemistry, Chengdu, 610054, P. R. China
| | - Xiaogen Zhang
- College of Chemistry, Sichuan University, Chengdu, 610064, P. R. China
| | - Minghui Yang
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, 430071, P. R. China
| | - Yan Huang
- College of Chemistry, Sichuan University, Chengdu, 610064, P. R. China
| | - Ming Li
- College of Chemistry, Sichuan University, Chengdu, 610064, P. R. China
| | - Junsheng Yu
- School of Optoelectronic Information, University of Electronic Science and Technology of China College of Chemistry, Chengdu, 610054, P. R. China
| | - Daibing Luo
- Analytical and Testing Center, Sichuan University, Chengdu, 610064, P. R. China
| | - Zhiyun Lu
- College of Chemistry, Sichuan University, Chengdu, 610064, P. R. China
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13
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Garakyaraghi S, Danilov EO, McCusker CE, Castellano FN. Transient absorption dynamics of sterically congested Cu(I) MLCT excited states. J Phys Chem A 2015; 119:3181-93. [PMID: 25751569 DOI: 10.1021/acs.jpca.5b00901] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Subpicosecond through supra-nanosecond transient absorption dynamics of the homoleptic Cu(I) metal-to-ligand charge transfer (MLCT) photosensitizers including the benchmark [Cu(dmp)2](+) (dmp =2,9-dimethyl-1,10-phenanthroline) chromophore, as well as [Cu(dsbp)2](+) (dsbp =2,9-di(sec-butyl)-1,10-phenanthroline and [Cu(dsbtmp)2](+) (dsbtmp =2,9-di(sec-butyl)-3,4,7,8-tetramethyl-1,10-phenanthroline) were investigated in dichloromethane and tetrahydrofuran solutions. Visible and near-IR spectroelectrochemical measurements of the singly reduced [Cu(dsbp)2](+) and [Cu(dsbtmp)2](+) species were determined in tetrahydrofuran, allowing for the identification of redox-specific phenanthroline-based radical anion spectroscopic signatures prevalent in the respective transient absorption experiments. This study utilized four different excitation wavelengths (418, 470, 500, and 530 nm) to elucidate dynamics on ultrafast times scales spanning probe wavelengths ranging from the UV to the near-IR (350 to 1450 nm). With the current time resolution of ∼150 fs, initial excited state decay in all three compounds was found to be independent of excitation wavelength. Not surprisingly, there was little to no observed influence of solvent in the initial stages of excited state decay in any of these molecules including [Cu(dmp)2](+), consistent with results from previous investigators. The combined experimental data revealed two ranges of time constants observed on short time scales in all three MLCT chromophores and both components lengthen as a function of structure in the following manner: [Cu(dsbtmp)2](+) < [Cu(dsbp)2](+) < [Cu(dmp)2](+). The molecule with the most inhibited potential for distortion, [Cu(dsbtmp)2](+), possessed the fastest ultrafast dynamics as well as the longest excited state lifetimes in both solvents. These results are consistent with a small degree of excited state distortion, rapid intersystem crossing, and weak vibronic coupling to the ground state. The concomitant systematic variation in both initial time constants, assigned to pseudo-Jahn-Teller distortion and intersystem crossing, suggest that both processes are intimately coupled in all molecules in the series. The variability in these time scales illustrate that strongly impeded structural distortion in Cu(I) MLCT excited state enables more rapid surface crossings in the initial deactivation dynamics.
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Affiliation(s)
- Sofia Garakyaraghi
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
| | - Evgeny O Danilov
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
| | - Catherine E McCusker
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
| | - Felix N Castellano
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
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14
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Liang CK, Desvergne JP, Bassani DM. Anthracene photodimerization in a bis-chromophoric hydrogen-bonding receptor. Photochem Photobiol Sci 2014; 13:316-23. [DOI: 10.1039/c3pp50322d] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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15
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Gao S, Hao L, Li J, Lin P, Li D, Shuang S, Dong C. Photophysical processes of an intramolecular charge transfer fluorescent dye with carbazole units. LUMINESCENCE 2012; 28:412-8. [PMID: 22753316 DOI: 10.1002/bio.2400] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2012] [Revised: 05/20/2012] [Accepted: 05/22/2012] [Indexed: 12/17/2022]
Abstract
A carbazole-based compound with intramolecular charge transfer (ICT) characteristics, 3,6-bis-((N-ethylcarbazole-3-)-propene-1-keto)-N-ethylcarbazole (BCzPCz) was synthesized by N-alkylation, acetylation and aldol condensation. BCzPCz was further confirmed by IR and (1)H NMR. The central N-ethylcarbazole was connected with two N-ethylcarbazole units through the propenone group in BCzPCz. N-ethylcarbazole and carbonyl groups were electron donors (D) and acceptors (A), respectively. The UV-vis absorption and fluorescence characteristics of BCzPCz were also investigated in different solvents. Solvatochromism was attributed to ICT complex formation in singlet excited state. Magnitude of the change in the dipole moment was 24.78 D according to Lippert-Mataga equation. Fluorescence of BCzPCz was significantly affected by pH and was quenched in acidic medium. Fluorescence quantum yield of BCzPCz was 0.516 in ethanol. Experimental results showed its potential use as a fluorescence probe and as two-photon absorption material.
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Affiliation(s)
- Shouqin Gao
- Research Center of Environmental Science and Engineering, Department of Chemistry, Shanxi University, Taiyuan, China
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16
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Inoue H, Katayama K, Iwai K, Miura A, Masuhara H. Conformational relaxation dynamics of a poly(N-isopropylacrylamide) aqueous solution measured using the laser temperature jump transient grating method. Phys Chem Chem Phys 2012; 14:5620-7. [DOI: 10.1039/c2cp40243b] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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17
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Sánchez FG, Díaz AN, Algarra M, Lovillo J, Aguilar A. Time resolved spectroscopy of 2-(dimethylamine)fluorene. Solvent effects and photophysical behavior. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2011; 83:88-93. [PMID: 21920807 DOI: 10.1016/j.saa.2011.07.083] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2010] [Accepted: 07/25/2011] [Indexed: 05/31/2023]
Abstract
The effect of different solvents on the fluorescent properties of 2-(dimethylamine)fluorene (DAF) were studied. In aprotic solvents we detected a strongly emissive intramolecular charge transfer (ICT) state that decayed by intersystem crossing to triplet. In proton-accepting solvents DAF exhibits in the excited state an intramolecular proton transfer. An ionized species is postulated, which simultaneously twists to a rotated conformation in the excited state. Thus, the specific solvent interactions supplement but do not replace the twist mechanism and accompany the charge transfer accepted as the prerequisite for twisted intramolecular charged transfer (TICT) state formation.
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Affiliation(s)
- Francisco G Sánchez
- Department of Analytical Chemistry, Faculty of Sciences, University of Málaga, Málaga, Spain.
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18
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HUANG YAO, LI XIANGYUAN, FU KEXIANG, ZHU QUAN. NEW FORMULATION FOR NON-EQUILIBRIUM SOLVATION: SPECTRAL SHIFTS AND CAVITY RADII OF 6-PROPANOYL-2-(N,N-DIMETHYLAMINO) NAPHTHALENE AND 4-(N,N-DIMETHYLAMINO) BENZONITRILE. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2011. [DOI: 10.1142/s0219633606002313] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In the present work, the new formulations describing spectral shifts by the authors have been introduced and employed to investigate two dye molecules, 6-propanoyl-2-(N,N-dimethylamino) naphthalene and 4-(N,N-dimethylamino) benzonitrile. From the viewpoints of the authors, the cavity radii were overestimated owing to the errors existing in the traditional models. Slightly differing from the results by other authors in the past, this work fits the cavity radii to the values of ~4.5 Å for 6-propanoyl-2-(N,N-dimethylamino) naphthalene and ~3.2 Å for 4-(N,N-dimethylamino) benzonitrile. In the fittings, both point dipole approximation and multipole expansion methods are employed. The calculations of the excited states are performed by means of the time-dependent density functional theory. Comparing the fitted cavity radii from the experimental spectra with those estimated from the molecular volumes by some well-known procedures such as COSMO and PCM, we find that the new formulations give fairly satisfactory results. By taking an atomic ion as an example, the authors argue that the Onsager radii recommended by some popular procedures are greatly exaggerated. The cavity radius derived simply from the volume encompassed by the solvent-accessible surface, without any addition of other parts, is suggested for application.
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Affiliation(s)
- YAO HUANG
- College of Chemical Engineering, Sichuan University, Chengdu 610065, P. R. China
| | - XIANG-YUAN LI
- College of Chemical Engineering, Sichuan University, Chengdu 610065, P. R. China
| | - KE-XIANG FU
- College of Chemical Engineering, Sichuan University, Chengdu 610065, P. R. China
| | - QUAN ZHU
- College of Chemical Engineering, Sichuan University, Chengdu 610065, P. R. China
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19
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Li YK, Zhu Q, Li XY, Fu KX, Wang XJ, Cheng XM. Spectral Shift of the n → π* Transition for Acetone and Formic Acid with an Explicit Solvent Model. J Phys Chem A 2010; 115:232-43. [DOI: 10.1021/jp105663g] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Yun-Kui Li
- College of Chemical Engineering, Sichuan University, Chengdu, 610065, People’s Republic of China
| | - Quan Zhu
- College of Chemical Engineering, Sichuan University, Chengdu, 610065, People’s Republic of China
| | - Xiang-Yuan Li
- College of Chemical Engineering, Sichuan University, Chengdu, 610065, People’s Republic of China
| | - Ke-Xiang Fu
- College of Chemical Engineering, Sichuan University, Chengdu, 610065, People’s Republic of China
| | - Xing-Jian Wang
- College of Chemical Engineering, Sichuan University, Chengdu, 610065, People’s Republic of China
| | - Xue-Min Cheng
- College of Chemical Engineering, Sichuan University, Chengdu, 610065, People’s Republic of China
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20
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Danel KS, Gasiorski P, Matusiewicz M, Całus S, Uchacz T, Kityk AV. UV-vis spectroscopy and semiempirical quantum chemical studies on methyl derivatives of annulated analogues of azafluoranthene and azulene dyes. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2010; 77:16-23. [PMID: 20510645 DOI: 10.1016/j.saa.2010.04.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2010] [Revised: 03/16/2010] [Accepted: 04/08/2010] [Indexed: 05/29/2023]
Abstract
Paper reports the measured optical absorption and fluorescence spectra of 4-(2-chlorophenyl)-7-methyl-1,3-diphenyl-1H-pyrazolo[3,4-b]quinoline (MCPDPPQ), as well as 6-methyl-1,3-diphenyl-3H-indeno[1,2,3-de]pyrazolo[3,4-b]quinoline (MDPIPQ) and 9-methyl-6-phenyl-6H-5,6,7-triazadibenzo[f,h]naphtho[3,2,1-cd]azulene (MPTNA) representing cyclized five- or seven-membered regioisomeric products of MCPDPPQ, respectively. The spectra has been recorded in solvents of different polarity and compared with the results of quantum chemical calculations performed by means of the semiempirical method PM3 in combination with molecular dynamics (MD) simulations. Cyclization of MCPDPPQ into MDPIPQ or MPTNA is accompanied by a significant red shift of the first optical absorption and fluorescence bands. While the solvent polarity rises all the dyes exhibit the blue shift of the first absorption band and the red shift of the fluorescence band. These trends have been reproduced within the semiempirical calculations in combination with the Lippert-Mataga dielectric polarization model and explained by specific orientations of the dipole moments in the ground and excited states. All dyes may be considered as candidates for the luminescent or electroluminescent applications. Depending on solvent polarity they emit light in the green-yellow range of the visible spectra.
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Affiliation(s)
- K S Danel
- Department of Chemistry, University of Agriculture, Balicka str. 122, 30-149 Kraków, Poland
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21
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Zhao GJ, Han KL. pH-Controlled twisted intramolecular charge transfer (TICT) excited state via changing the charge transfer direction. Phys Chem Chem Phys 2010; 12:8914-8. [DOI: 10.1039/b924549a] [Citation(s) in RCA: 163] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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22
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Gondek E, Danel A, Kwiecień B, Sanetra J, Kityk AV. Optical absorption of bisphenol A based pyrazoloquinoline dimers. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2009; 74:685-690. [PMID: 19716761 DOI: 10.1016/j.saa.2009.07.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2008] [Revised: 07/09/2009] [Accepted: 07/29/2009] [Indexed: 05/28/2023]
Abstract
The paper presents the measured absorption spectra for several newly synthesized derivatives of bisphenol A based pyrazoloquinoline dimers (BAPQD). The experimental results are compared with quantum chemical calculations performed by semiempirical method AM1 and PM3. Molecular mechanic analysis shows that BAPQD dyes possess by a large number of equilibrium molecular conformations with similar total energies and small energy barriers between these states; thus at room temperature (T=300 K) the molecular dynamics exhibits slow temporal evolution passing a large number of intermediate slightly non-equilibrium conformational states. For this reason the semiempirical quantum chemical methods have been combined with the molecular dynamics simulations. The semiempirical PM3 method exhibits the best agreement with the experimental data, especially in the prediction of the spectral position of the first absorption band (absorption threshold). Taking into account that such good agreement is found for a set of more complex organic systems like BAPQD this may be of substantial interest for chemical engineering which deals with the designing of new efficient organic luminophores for electroluminescent applications.
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Affiliation(s)
- E Gondek
- Institute of Physics, Technical University of Kraków, Podchorazych 1, 30-084 Kraków, Poland
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Koścień E, Gondek E, Jarosz B, Danel A, Nizioł J, Kityk AV. Photoluminescence of 1-phenyl,3-methyl pyrazoloquinoline derivatives. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2009; 72:582-590. [PMID: 19091627 DOI: 10.1016/j.saa.2008.10.048] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2008] [Revised: 10/29/2008] [Accepted: 10/30/2008] [Indexed: 05/27/2023]
Abstract
Paper presents the absorption and photoluminescence of 7-TFM, 6-F, 6-CN, 6-TBu and 6-COOEt derivatives of 1-phenyl-3-methyl-1H-Pyrazolo[3,4-b]quinoline (MPPQ). The measured spectra are compared with the results of the quantum chemical calculations performed by means of the semi-empirical methods (AM1 or PM3) that have been applied either to the equilibrium molecular conformations in vacuo (T=0K) or combined with the MD simulations (T=300 K). The photoluminescent spectra of MPPQ dyes are highly solvatochromic. The emission bands broaden and shift to the red with the increasing of solvent polarity, indicating thus a substantial dipole moment of the excited states. According to the quantum chemical analysis the reason for the strong solvatochromism of MPPQ dyes is related with intramolecular charge transfer (ICT) state. Due to the large dipole moment in the twisted geometry the ICT state is believed to become the lowest excited state in a strongly polar environment. This would explain a considerable solvatochromic shift in the highly polar solvents observed for all MPPQ dyes in the experiment. Such hypothesis is supported by the semi-empirical quantum chemical evaluations.
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Affiliation(s)
- E Koścień
- 1st Liceum, Sobieskiego 22, 42-700 Lubliniec, Poland
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24
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Dekhtyar M, Rettig W, Weigel W. Mesomeric and twisted intramolecular-charge-transfer states as a key to polarity-dependent fluorescence of donor–acceptor-substituted aryl pyrenes. Chem Phys 2008. [DOI: 10.1016/j.chemphys.2008.01.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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25
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Gondek E, Całus S, Danel A, Kityk AV. Photoluminescence and electroluminescence of methoxy and carboethoxy derivatives of 1,3-diphenyl-1H-pyrazolo[3,4-b]quinoline. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2008; 69:22-6. [PMID: 17434336 DOI: 10.1016/j.saa.2007.03.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2006] [Revised: 02/25/2007] [Accepted: 03/07/2007] [Indexed: 05/14/2023]
Abstract
A series of methoxy (MO) and carboethoxy (CE) derivatives of 1,3-diphenyl-1H-pyrazolo[3,4-b]quinoline ([DPPQ]) are characterized by spectroscopic methods. All dyes show the photoluminescent spectra which are highly solvatochromic. In the case of 6MO[DPPQ] and 6CE[DPPQ] the emission bands are broad and shifted to the red with increasing of solvent polarity whereas the dyes 6MO1pMO[DPPQ] and 6MO13pMO[DPPQ] exhibit a reverse solvatochromism. The large difference between the excited- and state-dipole moments indicates a strong electron transfer effects in all dyes. The EL spectra are obtained for the fabricated OLEDs with a general structure of EL device ITO/PVK:6X[DPPQ]/Ca/Al. The blue emission originating from PVK host matrix appears to be quenched in EL spectra of doped PVK matrix giving rise to emission in blue, blue-green or green spectral regions. The obtained results demonstrate that a series of newly synthesized methoxy and carboethoxy [DPPQ]-derivatives may be considered as promising materials for electroluminescent applications.
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Affiliation(s)
- E Gondek
- Institute of Physics, Technical University of Krakow, Podhorazych 1, 30-084 Krakow, Poland
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26
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Mallick A, Purkayastha P, Chattopadhyay N. Photoprocesses of excited molecules in confined liquid environments: An overview. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY C-PHOTOCHEMISTRY REVIEWS 2007. [DOI: 10.1016/j.jphotochemrev.2007.06.001] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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27
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Li JF, Guan B, Li DX, Dong C. Study on the fluorescence properties of a new intramolecular charge transfer compound 1,5-diphenyl-3-(N-ethylcarbazole-3-yl)-2-pyrazoline. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2007; 68:404-8. [PMID: 17379571 DOI: 10.1016/j.saa.2006.12.010] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2006] [Accepted: 12/08/2006] [Indexed: 05/14/2023]
Abstract
The fluorescence properties of a newly synthesized compound, 1,5-diphenyl-3-(N-ethylcarbazole-3-yl)-2-pyrazoline (DEP) have been studied. On excitation at 352 nm, the fluorescence spectrum exhibits a large red shift with an increase in the polarity of solvents. The intensity of the band is different in different solvents as well. The change in the dipole moment in various solvents at room temperature has been characterized by the absorption and steady state fluorescence techniques and calculated based on the Lippert-Mataga equation. DEP has an increase of dipole moment of 2.83 D units on excitation to the lowest singlet state. It is concluded that photo-induced charge transfer from N (1) to C (3) actually exists in the excited state of the pyrazoline moiety. Its fluorescence property is relative to viscosity and temperature of solvents. The phi(f) of DEP in neutral medium or basic medium is higher than acidic medium. In addition, when the concentration of DEP is higher than 10(-3) M, its fluorescence is quenched by the collision of each molecule. The red shift of the maximum emission of DEP attributes to the formation of aggregates and the conjugate system is strengthened.
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Affiliation(s)
- J F Li
- Institute of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006, People's Republic of China
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28
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Qin W, Baruah M, Van der Auweraer M, De Schryver FC, Boens N. Photophysical properties of borondipyrromethene analogues in solution. J Phys Chem A 2007; 109:7371-84. [PMID: 16834104 DOI: 10.1021/jp052626n] [Citation(s) in RCA: 208] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The photophysical properties of seven new 8-(p-substituted)phenyl analogues of 4,4-difluoro-3,5-dimethyl-8-(aryl)-4-bora-3a,4a-diaza-s-indacene (derivatives of the well-known fluorophore BODIPY) in several solvents have been studied by means of absorption and steady-state and time-resolved fluorimetry. For each compound, the fluorescence quantum yield and lifetime are lower in solvents with higher polarity owing to an increase in the rate of nonradiative deactivation. Increasing the electron withdrawing strength of the p-substituent on the phenyl group in position 8 also leads to lower fluorescence quantum yields and lifetimes. When the p-substituent on the phenyl group in position 8 is a tertiary amine [8-(4-piperidinophenyl), 8-(4-N,N-dimethylaminophenyl), and 8-(4-morpholinophenyl)], the low quantum yields of these compounds in more polar solvents can be rationalized by the inversion of the energy levels of an apolar, highly fluorescent and a polar, nonfluorescent excited state, where charge transfer from the tertiary amine to the BODIPY unit occurs. These amine analogues can be protonated at low pH in aqueous solution. Fluorescence titrations yielded pK(a) values of their conjugate ammonium salts which are in agreement with the electron donating tendency of the amine group: piperidino (4.15) > dimethylamino (2.37) > morpholino (1.47), with the pK(a) values in parentheses. The rate constant of radiative deactivation (k(f)) is the same for all compounds in all solvents studied (k(f) = 1.4 x 10(8) s(-1)).
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Affiliation(s)
- Wenwu Qin
- Department of Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200F, 3001 Heverlee, Leuven, Belgium
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29
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Szubiakowski JP, Dale RE, Boens N, Ameloot M. Fluorescence anisotropy decay for intramolecular two-state excited-state processes with added quencher in the presence of rotational diffusion: An identifiability analysis. Chem Phys Lett 2007. [DOI: 10.1016/j.cplett.2007.02.051] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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30
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Goeb S, Ziessel R. Convenient Synthesis of Green Diisoindolodithienylpyrromethene−Dialkynyl Borane Dyes. Org Lett 2007; 9:737-40. [PMID: 17269781 DOI: 10.1021/ol0627404] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
[structure: see text] Versatile dyes based on diisoindolodithienylpyrromethene substituted at the boron center by alkynylaryl chromophores have been developed that efficiently fluorescence in the near infrared. Fast intramolecular energy transfer from the appended alkynyl units to the central core provides Stokes shifts above 16,000 cm(-1).
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Affiliation(s)
- Sébastien Goeb
- Laboratoire de Chimie Moléculaire, Centre National de la Recherche Scientifique (CNRS), Université Louis Pasteur, Ecole de Chimie, Polymères, Matériaux de Strasbourg (ECPM), 25 rue Becquerel, 67087 Strasbourg, Cedex 02, France
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31
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Shaw GB, Grant CD, Shirota H, Castner EW, Meyer GJ, Chen LX. Ultrafast Structural Rearrangements in the MLCT Excited State for Copper(I) bis-Phenanthrolines in Solution. J Am Chem Soc 2007; 129:2147-60. [PMID: 17256860 DOI: 10.1021/ja067271f] [Citation(s) in RCA: 159] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Ultrafast excited-state structural dynamics of [Cu(I)(dmp)(2)](+) (dmp = 2,9-dimethyl-1,10-phenanthroline) have been studied to identify structural origins of transient spectroscopic changes during the photoinduced metal-to-ligand charge-transfer (MLCT) transition that induces an electronic configuration change from Cu(I) (3d(10)) to Cu(II) (3d(9)). This study has important connections with the flattening of the Franck-Condon state tetrahedral geometry and the ligation of Cu(II)* with the solvent observed in the thermally equilibrated MLCT state by our previous laser-initiated time-resolved X-ray absorption spectroscopy (LITR-XAS) results. To better understand the structural photodynamics of Cu(I) complexes, we have studied both [Cu(I)(dmp)(2)](+) and [Cu(I)(dpp)(2)](+) (dpp = 2,9-diphenyl-1,10-phenanthroline) in solvents with different dielectric constants, viscosities, and thermal diffusivities by transient absorption spectroscopy. The observed spectral dynamics suggest that a solvent-independent inner-sphere relaxation process is occurring despite the large amplitude motions due to the flattening of the tetrahedral coordinated geometry. The singlet fluorescence dynamics of photoexcited [Cu(I)(dmp)(2)](+) were measured in the coordinating solvent acetonitrile, using the fluorescence upconversion method at different emission wavelengths. At the bluest emission wavelengths, a prompt fluorescence lifetime of 77 fs is attributed to the excited-state deactivation processes due to the internal conversion and intersystem crossing at the Franck-Condon state geometry. The differentiation between the prompt fluorescence lifetime with the tetrahedral Franck-Condon geometry and that with the flattened tetrahedral geometry uncovers an unexpected ultrafast flattening process in the MLCT state of [Cu(I)(dmp)(2)](+). These results provide guidance for future X-ray structural studies on ultrafast time scale, as well as for synthesis toward its applications in solar energy conversion.
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Affiliation(s)
- George B Shaw
- Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
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Iwai K, Matsumoto N, Niki M, Yamamoto M. Fluorescence Probe Studies of Thermosensitive N−Isopropylacrylamide Copolymers in Aqueous Solutions. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/10587259808044310] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Kaoru Iwai
- a Department of Chemistry, Faculty of Science , Nara Women's University , Kitauoya-Nishimachi, Nara , 630 , Japan
| | - Naomi Matsumoto
- a Department of Chemistry, Faculty of Science , Nara Women's University , Kitauoya-Nishimachi, Nara , 630 , Japan
| | - Makiko Niki
- a Department of Chemistry, Faculty of Science , Nara Women's University , Kitauoya-Nishimachi, Nara , 630 , Japan
| | - Masao Yamamoto
- a Department of Chemistry, Faculty of Science , Nara Women's University , Kitauoya-Nishimachi, Nara , 630 , Japan
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33
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Osawa M, Hoshino M, Wada T, Araki Y, Ito O. Phosphorous atom induced intramolecular charge transfer fluorescence in 9-diphenylphosphinophenanthrene. Chem Phys Lett 2006. [DOI: 10.1016/j.cplett.2006.07.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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34
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Amthor S, Lambert C, Dümmler S, Fischer I, Schelter J. Excited Mixed-Valence States of Symmetrical Donor−Acceptor−Donor π Systems. J Phys Chem A 2006; 110:5204-14. [PMID: 16610844 DOI: 10.1021/jp056728p] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We investigated the spectroscopic properties of a series of four bistriarylamine donor-pi-bridge-donor D-pi-D compounds (dimers), composed of two asymmetric triarylamine chromophores (monomers). UV/vis, fluorescence, and transient absorption spectra were recorded and compared with those of the corresponding D-pi monomers. Bilinear Lippert-Mataga plots indicate a major molecular reorganization of the excited state in polar media for all compounds. The excited states of the dimers are described as mixed-valence states that show, depending on the chemical nature of the pi bridge, a varying amount of interactions (couplings). We found that superradiant emission, that is, an enhancement of the fluorescence rate in the dimer, is observed only in the case of weak and medium coupling. Whether the first excited-state potential energy surface of the dimers is described by single minimum or a double minimum potential depends on the solvent polarity and the electronic coupling. In the latter case, the dimer relaxes in a symmetry broken CT state with partial positive charge at the triarylamine donor and negative charge at the pi bridge. The [2.2]paracyclophane bridged dimer is an example of a weakly coupled system because the spectroscopic behavior is very similar to the corresponding p-xylene monomer. In contrast, anthracene as well as p-xylene bridges mediate a stronger coupling and reveal a significant cooperative influence on the optical properties.
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Affiliation(s)
- Stephan Amthor
- Institut für Organische Chemie, Bayerische Julius-Maximilans-Universität Würzburg, Am Hubland, D-97074 Würzburg
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35
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Ziessel R, Bonardi L, Retailleau P, Ulrich G. Isocyanate-, Isothiocyanate-, Urea-, and Thiourea-Substituted Boron Dipyrromethene Dyes as Fluorescent Probes. J Org Chem 2006; 71:3093-102. [PMID: 16599605 DOI: 10.1021/jo0600151] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Boron dipyrromethene dyes (Bodipy) bearing a meso-phenyl substituent carrying a variety of functional groups can be prepared under mild conditions. A single-crystal X-ray structure determination for the 3,5-dinitrophenyl compound shows the phenyl ring to be almost orthogonal (dihedral angle 84 degrees) to the plane of the Bodipy core, with one nitro group almost coplanar with the ring and the other tilted by approximately 21 degrees. Nitro substituents at the 3-, 4-, and 5- positions of the phenyl group are readily reduced to the corresponding amino groups and then converted to isocyanato, isothiocyanato, urea, thiourea, and some polyimine derivatives, the last providing additional functionality (phenazine and pyridylindole units) suitable for chelation of metal ions. All compounds are redox active, the electron-transfer processes being assigned on the basis of comparisons with model compounds. Their fluorescence properties are sensitive to the phenyl group substituents. The Bodipy unit excited state appears to be a strong reductant (Eo approximately -1.4 V) and a modest oxidant (Eo approximately +1.0 V). Quenching processes in the nitro and phenazine derivatives appear to involve intramolecular photoinduced electron transfer.
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Affiliation(s)
- Raymond Ziessel
- Laboratoire de Chimie Moléculaire, Ecole de Chimie, Polymères, Matériaux, Université Louis Pasteur, 25 rue Becquerel, 67087 Strasbourg Cedex 02, France.
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Ziessel R, Bonardi L, Ulrich G. Boron dipyrromethene dyes: a rational avenue for sensing and light emitting devices. Dalton Trans 2006:2913-8. [PMID: 16751901 DOI: 10.1039/b516222j] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Boron dipyrromethene dyes bearing nitro, amino, isocyanate and isothiocyanate functions were readily prepared under mild conditions. Various combinations allow to produce urea, diurea, thiourea, dithiourea in the 3, 4 and 5-substitution positions of the appended phenyl group. Condensation of the 3,4-substituted diamino derivative with 1,10-phenanthroline-5,6-dione and 6-formyl-2-methylpyridine allow to prepare dipyridophenazine and indole derivatives. The 3,5-dinitro-substituted indacene dye was characterized by an X-ray molecular structure showing a pronounced tilt angle of the dinitrophenyl group relative to the indacene core (approximately 84 degrees) whereas one nitro groups is basically coplanar with the phenyl ring and the second titled by approximately 21 degrees. The optical properties of these dyes reveals on/off switching of the fluorescence from the nitro to the amino compounds and further to the urea likely understood in the framework of an photoinduced electron transfer process.
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Affiliation(s)
- Raymond Ziessel
- Laboratoire de Chimie Moléculaire, Ecole de Chimie, Polymères, Matériaux (ECPM), 25 rue Becquerel, 67087, Strasbourg Cedex 02, France.
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Ulrich G, Goze C, Goeb S, Retailleau P, Ziessel R. New fluorescent aryl- or ethynylaryl-boron-substituted indacenes as promising dyes. NEW J CHEM 2006. [DOI: 10.1039/b604830g] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Matsumura Y, Iwai K. Synthesis and thermo-responsive behavior of fluorescent labeled microgel particles based on poly(N-isopropylacrylamide) and its related polymers. POLYMER 2005. [DOI: 10.1016/j.polymer.2005.08.050] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Liu T, Wei YG, Yuan YQ, Guo QX. Charge Transfer in Excited Donor-acceptor Phenothiazine Derivatives. CHINESE J CHEM 2005. [DOI: 10.1002/cjoc.200591430] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Ho TI, Elangovan A, Hsu HY, Yang SW. Highly Fluorescent N,N-Dimethylaminophenylethynylarenes: Synthesis, Photophysical Properties, and Electrochemiluminescence. J Phys Chem B 2005; 109:8626-33. [PMID: 16852021 DOI: 10.1021/jp0444518] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A new family of aryl-pi-donor-aryl molecules has been synthesized and studied with respect to their photophysical properties and electrogenerated chemiluminscence (ECL) for the first time. Anthracene, phenanthrene, naphthalene, biphenyl, and fluorene were coupled with N,N-dimethylanilino moiety via a C-C triple bond (1-7). Introduction of such a strong electron-donating moiety as N,N-dimethylanilino group through a triple bond imparts new properties to the resultant molecules that are not commonly observed for the parent arenes. All molecules show absorption in the near-visible region and emission totally in the visible region with high fluorescence quantum yields. Bright solid-state photoluminescence has also been noticed for all the compounds in the visible region. 9-Anthryl- and 1-naphthyl- derivatives exhibited blue-shifted electrochemiluminescence (ECL) relative to their photoluminescence because of aggregation. 9-Phenanthryl- and 2-naphthyl- derivatives did not show ECL. 2-Biphenyl derivative showed monomeric ECL while 4-biphenyl counterpart exhibited excimer ECL. No ECL was observed for 2-fluorenyl derivative. The observed electronic properties are discussed with regard to the structure of the molecules. The characteristics of the molecules chosen in the present study open up new prospects and promises for novel tunable organic materials, on the basis of simple extension of conjugation to promote intramolecular communication, for ECL, OLED, and other optoelectronic applications.
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Affiliation(s)
- Tong-Ing Ho
- Department of Chemistry, National Taiwan University, Taipei - 106, Taiwan.
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41
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López Arbeloa F, Bañuelos J, Martínez V, Arbeloa T, López Arbeloa I. Structural, photophysical and lasing properties of pyrromethene dyes. INT REV PHYS CHEM 2005. [DOI: 10.1080/01442350500270551] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Pang YH, Shuang SM, Wong MS, Li ZH, Dong C. Study on photophysical properties of intramolecular charge transfer (ICT) compound: 4-(diphenylamino)biphenyl-4′-boronic acid. J Photochem Photobiol A Chem 2005. [DOI: 10.1016/j.jphotochem.2004.08.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Fron E, Lor M, Pilot R, Schweitzer G, Dincalp H, De Feyter S, Cremer J, Bauerle P, Mullen K, Van der Auweraer M, De Schryver FC. Photophysical study of photoinduced electron transfer in a bis-thiophene substituted peryleneimide. Photochem Photobiol Sci 2005; 4:61-8. [PMID: 15616693 DOI: 10.1039/b409346c] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Based on femtosecond time-resolved spectroscopy and single photon timing experiments, intramolecular photoinduced charge transfer has been investigated in two systems containing a peryleneimide chromophore (P) and thiophene (T) groups. The first compound bearing a single thiophene ring (PT1) is used as model and shows a behavior similar to P, studied previously, while in the compound with two thiophene rings attached (PT2) electron transfer from the thiophene donor to the peryleneimide acceptor is observed in benzonitrile. Femtosecond fluorescence upconversion and femtosecond transient absorption experiments in benzonitrile indicate that this ion-pair state formation occurs in 19 ps. This ion-pair state then decays with two time constants of 1400 and 820 ps, probably corresponding to different conformations of the thiophene rings.
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Affiliation(s)
- Eduard Fron
- Department of Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200 F, 3001, Heverlee, Belgium
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López Arbeloa F, Bañuelos Prieto J, Martínez Martínez V, Arbeloa López T, López Arbeloa I. Intramolecular Charge Transfer in Pyrromethene Laser Dyes: Photophysical Behaviour of PM650. Chemphyschem 2004; 5:1762-71. [PMID: 15580938 DOI: 10.1002/cphc.200400242] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Absorption and fluorescence (steady-state and time-correlated) techniques are used to study the photophysical characteristics of the pyrromethene 650 (PM650) dye. The presence of the cyano group at the 8 position considerably shifts the absorption and fluorescence bands to lower energies with respect to other related pyrromethene dyes; this is attributed to the strong electron-acceptor character of the cyano group, as is theoretically confirmed by quantum mechanical methods. The fluorescence properties of PM650 are intensively solvent-dependent. The fluorescence band is shifted to lower energies in polar/protic solutions, and the evolution of the corresponding wavelength with the solvent is analysed by a multicomponent linear regression. The fluorescence quantum yield and the lifetime strongly decrease in polar/protic solvents, which can be ascribed to an extra nonradiative deactivation, via an intramolecular charge-transfer state (ICT state), favoured in polar media.
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Affiliation(s)
- F López Arbeloa
- Departamento de Química Física, Universidad del Pais Vasco-EHU, Apartado 644, 48080 Bilbao, Spain.
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von Seggern D, Modrakowski C, Spitz C, Dieter Schlüter A, Menzel R. Charge transfer initiated by optical excitation in diester substituted biphenylpyrene as a function of the solvent characterized by excited state absorption spectroscopy. Chem Phys 2004. [DOI: 10.1016/j.chemphys.2004.04.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Li XY, Fu KX, Zhu Q, Shan MH. Continuous medium theory for nonequilibrium solvation: II. Interaction energy between solute charge and reaction field and single-sphere model for spectral shift. J Comput Chem 2004; 25:835-42. [PMID: 15011255 DOI: 10.1002/jcc.20015] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
On the basis of continuous medium theory, a model for evaluation of spectral shifts in solution has been developed in this work. The interaction energy between solute dipole and reaction field and the self-energy of the reaction field have been formulated through derivations. Applying the interaction energy expression together with the point dipole approximation to the case of spherical cavity produces new formulations of spectral shifts. The same expression of electrostatic free energy of the nonequilibrium state is achieved by integrating the change of the electrostatic free energy for a charging process. Moreover, generalized formulations evaluating spectral shifts have been established in the charge-potential notation, and the reduction of them to the point dipole case consistently leads to the same formulations of spectral shifts as those by interaction energy approach. Mutual supports provide convincing evidences for the reliability of the present results. In this work, attentions are particularly paid to the conclusion of zero self-energy of the reaction field, which is different from the previous theory. Reasoning and arguments are given on this point. From the present derivations, it is concluded that the spectral shifts of light absorption and emission were theoretically exaggerated in the past, in particular, by a factor of 2 for the spectral shift sum.
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Affiliation(s)
- Xiang-Yuan Li
- College of Chemical Engineering, Sichuan University, Chengdu, 610065, People's Republic of China.
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Chen LX, Shaw GB, Novozhilova I, Liu T, Jennings G, Attenkofer K, Meyer GJ, Coppens P. MLCT state structure and dynamics of a copper(I) diimine complex characterized by pump-probe X-ray and laser spectroscopies and DFT calculations. J Am Chem Soc 2003; 125:7022-34. [PMID: 12783557 DOI: 10.1021/ja0294663] [Citation(s) in RCA: 218] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The molecular structure and dynamics of the photoexcited metal-to-ligand-charge-transfer (MLCT) state of [Cu(I)(dmp)(2)](+), where dmp is 2,9-dimethyl-1,10-phenanthroline, in acetonitrile have been investigated by time-domain pump-probe X-ray absorption spectroscopy, femtosecond optical transient spectroscopy, and density functional theory (DFT). The time resolution for the excited state structural determination was 100 ps, provided by single X-ray pulses from a third generation synchrotron source. The copper ion in the thermally equilibrated MLCT state has the same oxidation state as the corresponding copper(II) complex in the ground state and was found to be penta-coordinate with an average nearest neighbor Cu-N distance 0.04 A shorter than that of the ground state [Cu(I)(dmp)(2)](+). The results confirm the previously proposed "exciplex" structure of the MLCT state in Lewis basic solvents. The evolution from the photoexcited Franck-Condon MLCT state to the thermally equilibrated MLCT state was followed by femtosecond optical transient spectroscopy, revealing three time constants of 500-700 fs, 10-20 ps, and 1.6-1.7 ns, likely related to the kinetics for the formation of the triplet MLCT state, structural relaxation, and the MLCT excited-state decay to the ground state, respectively. DFT calculations are used to interpret the spectral shift on structural relaxation and to predict the geometries of the ground state, the tetracoordinate excited state, and the exciplex. The DFT calculations also indicate that the amount of charge transferred from copper to the dmp ligand upon photoexcitation is similar to the charge difference at the copper center between the ground-state copper(I) and copper(II) complexes.
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Affiliation(s)
- Lin X Chen
- Chemistry Division and Material Sciences Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
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Dobkowski J, Rettig W, Waluk J. Intramolecular charge-transfer properties of a molecule with a large donor group: the case of 4′-(pyren-1-yl)benzonitrile. Phys Chem Chem Phys 2002. [DOI: 10.1039/b204749g] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Effect of cyclodextrin encapsulation on the photocyclization of diphenylamine: Cavity imposed restriction on the reaction rate. J Mol Liq 2000. [DOI: 10.1016/s0167-7322(00)90012-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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