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Fujii K, Yagi T, Nakano H, Sato H, Kimura Y. Experimental and theoretical study on p-aminophenylthyil radical geminate recombination in ionic liquids; analysis using the Smoluchowski-Collins-Kimball equation. J Chem Phys 2021; 154:154504. [PMID: 33887928 DOI: 10.1063/5.0047663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Recombination dynamics of geminate p-aminophenylthiyl (PAPT) radicals produced from the photodissociation of bis(p-aminophenyl) disulfide in ionic liquids (ILs) were investigated by transient absorption spectroscopy. ILs with various cationic species were used to examine the effect of viscosity and polarity on recombination dynamics. Experimentally obtained recombination yields and dynamics were found to be virtually independent of the cation species, despite the viscosity range of the solvent ILs being extensive, spanning from a few tens of mPa s to several hundred mPa s. We applied a theoretical analysis model based on the diffusion equation to the time profiles of the experimentally determined recombination yields of geminate PAPT radicals. The square well potential was incorporated into the diffusion equation to consider the concerted dynamics of solvent cage formation and recombination. A long-time asymptotic expression for the survival probability of the photodissociated products was derived and used to simulate the experimentally obtained time profile of the recombination yield. The time profiles in the range of 20-1000 ps and the final yield were successfully simulated by the asymptotic expression of the square well potential model. The optimized parameters used for the fit, including the mutual diffusion coefficient of the radical pairs, cage radius of the potential well, and well depth, were discussed in terms of the diffusion coefficient conventional theory and the potential mean force estimated from the molecular dynamics simulation for the photodissociation reaction in ILs.
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Affiliation(s)
- Kaori Fujii
- Department of Applied Chemistry, Graduate School of Science and Engineering, Doshisha University, Kyotanabe, Kyoto 610-0321, Japan
| | - Tomoaki Yagi
- Department of Molecular Engineering, Kyoto University, Kyoto Daigaku Katsura, Kyoto 615-8510, Japan
| | - Hiroshi Nakano
- Department of Molecular Engineering, Kyoto University, Kyoto Daigaku Katsura, Kyoto 615-8510, Japan
| | - Hirofumi Sato
- Department of Molecular Engineering, Kyoto University, Kyoto Daigaku Katsura, Kyoto 615-8510, Japan
| | - Yoshifumi Kimura
- Department of Applied Chemistry, Graduate School of Science and Engineering, Doshisha University, Kyotanabe, Kyoto 610-0321, Japan
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The centenary of the Stern-Volmer equation of fluorescence quenching: From the single line plot to the SV quenching map. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY C-PHOTOCHEMISTRY REVIEWS 2020. [DOI: 10.1016/j.jphotochemrev.2019.100338] [Citation(s) in RCA: 118] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Huang J, Chen PX, Wettig S. Fluorescence-based techniques to assess the miscibility and physical stability of a drug–lipid complex. CAN J CHEM 2019. [DOI: 10.1139/cjc-2018-0404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The objective of this study was to evaluate the feasibility of using fluorescence-based techniques to assess the miscibility and physical stability of a drug–lipid complex pharmaceutical dosage form under a solvent-free condition. An indomethacin–phospholipid complex (IDM–DPC) was used as model complex for this study. The miscibility of indomethacin within the phospholipid was assessed by fluorescence spectroscopy, fluorescence microscopy, and infrared spectroscopy. The miscibility limit of the complex system was determined by fluorescence to be 20%–30% drug loading content, showing good correlation with infrared spectroscopy. The physical stability of the IDM–DPC stored at 40 °C was evaluated by fluorescence microscopy. Indomethacin formulated in the lipid complex with an indomethacin loading not more than 30% remained in an amorphous state within a period of 21 days, whereas the samples with a drug loading over 30% started to crystallize earlier with increasing drug content. IDM–DPC having higher miscibilities were found to be more resistant to recrystallization under heating, thus having better physical stability. Fluorescence-based techniques showed convenience and promise in characterizing drug–lipid miscibility and predicting storage stability under a solvent-free condition.
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Affiliation(s)
- Jiahao Huang
- School of Pharmacy, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
| | - Peter X. Chen
- School of Pharmacy, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
- Department of Food Science, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada
| | - Shawn Wettig
- School of Pharmacy, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
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Phillips D, Dhami S, Ostler R, Petrasek Z. The Dimerisation of Phthalocyanines. PROGRESS IN REACTION KINETICS AND MECHANISM 2019. [DOI: 10.3184/007967403322807390] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In this review, we have shown that the dimerisation of phthalocyanine compounds, notably here the sulphonated aluminium phthalocyanines, is dependent upon concentration, on the medium in which the dye is dissolved, and upon pH. Complex equilibria between various monomer and dimer species are observed as a function of pH, and the probable structures of the dimers elucidated by semi-empirical and ab initio calculations. The formation of a red-shifted dimer leads to the quenching of monomer singlet state in concentrated solution, in reverse micelles, and in lipid vesicles, and this behaviour can account for the fluorescence intensity distributions and decay characteristics of phthalocyanine dyes in living cells as a function of irradiation time.
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Affiliation(s)
- David Phillips
- Department of Chemistry, Imperial College London, Exhibition Road, London SW7 1AZ, UK
| | - Suman Dhami
- Department of Chemistry, Imperial College London, Exhibition Road, London SW7 1AZ, UK
| | - Richard Ostler
- Department of Chemistry, Imperial College London, Exhibition Road, London SW7 1AZ, UK
| | - Zdenek Petrasek
- Department of Chemistry, Imperial College London, Exhibition Road, London SW7 1AZ, UK
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Fluorescence properties of 1-(silylethynyl)naphthalenes and 1,4-bis(silylethynyl)naphthalenes in solutions, thin films and solid states. J Photochem Photobiol A Chem 2017. [DOI: 10.1016/j.jphotochem.2017.04.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Kumpulainen T, Lang B, Rosspeintner A, Vauthey E. Ultrafast Elementary Photochemical Processes of Organic Molecules in Liquid Solution. Chem Rev 2016; 117:10826-10939. [DOI: 10.1021/acs.chemrev.6b00491] [Citation(s) in RCA: 249] [Impact Index Per Article: 31.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Tatu Kumpulainen
- Department of Physical Chemistry,
Sciences II, University of Geneva, 30 Quai Ernest Ansermet, CH-1211 Geneva 4, Switzerland
| | - Bernhard Lang
- Department of Physical Chemistry,
Sciences II, University of Geneva, 30 Quai Ernest Ansermet, CH-1211 Geneva 4, Switzerland
| | - Arnulf Rosspeintner
- Department of Physical Chemistry,
Sciences II, University of Geneva, 30 Quai Ernest Ansermet, CH-1211 Geneva 4, Switzerland
| | - Eric Vauthey
- Department of Physical Chemistry,
Sciences II, University of Geneva, 30 Quai Ernest Ansermet, CH-1211 Geneva 4, Switzerland
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Skalickova S, Nejdl L, Kudr J, Ruttkay-Nedecky B, Jimenez AMJ, Kopel P, Kremplova M, Masarik M, Stiborova M, Eckschlager T, Adam V, Kizek R. Fluorescence Characterization of Gold Modified Liposomes with Antisense N-myc DNA Bound to the Magnetisable Particles with Encapsulated Anticancer Drugs (Doxorubicin, Ellipticine and Etoposide). SENSORS 2016; 16:290. [PMID: 26927112 PMCID: PMC4813865 DOI: 10.3390/s16030290] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Revised: 02/03/2016] [Accepted: 02/18/2016] [Indexed: 12/17/2022]
Abstract
Liposome-based drug delivery systems hold great potential for cancer therapy. The aim of this study was to design a nanodevice for targeted anchoring of liposomes (with and without cholesterol) with encapsulated anticancer drugs and antisense N-myc gene oligonucleotide attached to its surface. To meet this main aim, liposomes with encapsulated doxorubicin, ellipticine and etoposide were prepared. They were further characterized by measuring their fluorescence intensity, whereas the encapsulation efficiency was estimated to be 16%. The hybridization process of individual oligonucleotides forming the nanoconstruct was investigated spectrophotometrically and electrochemically. The concentrations of ellipticine, doxorubicin and etoposide attached to the nanoconstruct in gold nanoparticle-modified liposomes were found to be 14, 5 and 2 µg·mL−1, respectively. The study succeeded in demonstrating that liposomes are suitable for the transport of anticancer drugs and the antisense oligonucleotide, which can block the expression of the N-myc gene.
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Affiliation(s)
- Sylvie Skalickova
- Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno, Czech Republic.
- Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00 Brno, Czech Republic.
| | - Lukas Nejdl
- Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno, Czech Republic.
- Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00 Brno, Czech Republic.
| | - Jiri Kudr
- Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno, Czech Republic.
- Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00 Brno, Czech Republic.
| | - Branislav Ruttkay-Nedecky
- Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno, Czech Republic.
- Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00 Brno, Czech Republic.
| | - Ana Maria Jimenez Jimenez
- Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno, Czech Republic.
- Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00 Brno, Czech Republic.
| | - Pavel Kopel
- Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno, Czech Republic.
- Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00 Brno, Czech Republic.
| | - Monika Kremplova
- Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno, Czech Republic.
- Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00 Brno, Czech Republic.
| | - Michal Masarik
- Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno, Czech Republic.
- Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00 Brno, Czech Republic.
| | - Marie Stiborova
- Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030, CZ-12840 Prague, Czech Republic.
| | - Tomas Eckschlager
- Department of Paediatric Haematology and Oncology, 2nd Faculty of Medicine, Charles University, and University Hospital, Motol V Uvalu 84, CZ-15006 Prague, Czech Republic.
| | - Vojtech Adam
- Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno, Czech Republic.
- Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00 Brno, Czech Republic.
| | - Rene Kizek
- Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno, Czech Republic.
- Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00 Brno, Czech Republic.
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Rusu MC, Dută I, Didilescu AC, Vrapciu AD, Hostiuc S, Anton E. Precursor and interstitial Cajal cells in the human embryo liver. ROMANIAN JOURNAL OF MORPHOLOGY AND EMBRYOLOGY 2015; 13:1093-105. [PMID: 24969977 DOI: 10.1039/c4pp00073k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Interstitial Cajal Cells (ICCs) were only proven in human adult hepatic tissue. The immune phenotypes of various cell types in the human embryonic liver (HEL) are scarcely described. It was hypothesized that in HEL ICCs are present and distinctive to the precursor/progenitor cells populations. It was aimed and performed a qualitative study of HEL by use of antibodies against CD117/c-kit, CD31, CD34, CD90, CD105, DOG1, Ki67, and adiponectin. Five human embryos of 23-29 mm were used. Blasts and hematopoietic cells were comprising the two major cell populations in late stage embryos. The general population of blasts in the HEL was CD34-/CD105, although scarce CD117/c-kit+ and CD90+ such cells were found. Hematopoietic precursors were Ki67+. Adiponectin-positive plasmalemmas were found mostly in blasts. Endothelia were CD31+/CD34+. Interstitial cells with moniliform prolongations were found; such cells were scarcely CD117/c-kit+ but consistently DOG1+. They were diagnosed as ICCs but based on the morphology of their prolongations they can be equally viewed as being telocytes (TCs). Further studies should better correlate the precursor cell-types and immune phenotypes during human liver organogenesis. Liver ICCs and/or TCs should be also investigated in the human fetal liver.
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Affiliation(s)
- Mugurel Constantin Rusu
- Discipline of Anatomy, Faculty of Dental Medicine, "Carol Davila" University of Medicine and Pharmacy, Bucharest, Romania;
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Scully AD, Ohtaka H, Takezaki M, Tominaga T. Diffusion-Facilitated Direct Determination of Intrinsic Parameters for Rapid Photoinduced Bimolecular Electron-Transfer Reactions in Nonpolar Solvents. J Phys Chem A 2015; 119:2770-9. [DOI: 10.1021/jp510383t] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Andrew D. Scully
- CSIRO Manufacturing Flagship, Bayview Avenue, Clayton, Victoria 3168, Australia
| | - Hiroyasu Ohtaka
- Department
of Applied Chemistry, Okayama University of Science, 1-1 Ridai-cho, Okayama 700-0005, Japan
- Department
of Pharmacy, Chiba Institute of Science, 3 Shiomi-cho, Choshi, Chiba 288-0025, Japan
| | - Makoto Takezaki
- Department
of Applied Chemistry, Okayama University of Science, 1-1 Ridai-cho, Okayama 700-0005, Japan
| | - Toshihiro Tominaga
- Department
of Applied Chemistry, Okayama University of Science, 1-1 Ridai-cho, Okayama 700-0005, Japan
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10
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Doktorov AB. Analysis of the methods for the derivation of binary kinetic equations in the theory of fluorescence concentration quenching. J Chem Phys 2014; 141:104104. [PMID: 25217901 DOI: 10.1063/1.4894285] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In the framework of unified many-particle approach the familiar problem of fluorescence concentration quenching in the presence of pumping (light pulse) of arbitrary intensity is considered. This process is a vivid and the simplest example of multistage bulk reaction including bimolecular irreversible quenching reaction and reversible monomolecular transformation as elementary stages. General relation between the kinetics of multistage bulk reaction and that of the elementary stage of quenching has been established. This allows one to derive general kinetic equations (of two types) for the multistage reaction in question on the basis of general kinetic equations (differential and integro-differential) of elementary stage of quenching. Relying on the same unified many-particle approach we have developed binary approximations with the use of two (frequently employed in the literature) many-particle methods (such as simple superposition approximation and the method of extracting pair channels in three-particle correlation evolution) to the derivation of non-Markovian binary kinetic equations. The possibility of reducing the obtained binary equations to the Markovian equations of formal chemical kinetics has been considered. As an example the exact solution of the problem (for the specific case) is examined, and the applicability of two many particle methods of derivation of binary equations is analyzed.
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Affiliation(s)
- A B Doktorov
- Voevodsky Institute of Chemical Kinetics and Combustion, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russia and Physics Department Novosibirsk State University, Novosibirsk 630090, Russia
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11
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Wüstner D, Christensen T, Solanko LM, Sage D. Photobleaching kinetics and time-integrated emission of fluorescent probes in cellular membranes. Molecules 2014; 19:11096-130. [PMID: 25076144 PMCID: PMC6271172 DOI: 10.3390/molecules190811096] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 07/04/2014] [Accepted: 07/10/2014] [Indexed: 12/02/2022] Open
Abstract
Since the pioneering work of Hirschfeld, it is known that time-integrated emission (TiEm) of a fluorophore is independent of fluorescence quantum yield and illumination intensity. Practical implementation of this important result for determining exact probe distribution in living cells is often hampered by the presence of autofluorescence. Using kinetic modelling of photobleaching combined with pixel-wise bleach rate fitting of decay models with an updated plugin to the ImageJ program, it is shown that the TiEm of a fluorophore in living cells can be determined exactly from the product of bleaching amplitude and time constant. This applies to mono-exponential bleaching from the first excited singlet and/or triplet state and to multi-exponential combinations of such processes. The TiEm can be used to correct for illumination shading and background autofluorescence without the need for fluorescent test layers or separate imaging of non-stained cells. We apply the method to simulated images and to images of cells, whose membranes were labelled with fluorescent sterols and sphingolipids. Our bleaching model can be extended to include a probability density function (PDF) of intrinsic bleach rate constants with a memory kernel. This approach results in a time-dependent bleach rate coefficient and is exemplified for fluorescent sterols in restricted intracellular environments, like lipid droplets. We show that for small deviations from the classical exponential bleaching, the TiEm of decay functions with rate coefficients remains largely independent of fluorescence lifetime and illumination, and thereby represents a faithful measure of probe distribution.
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Affiliation(s)
- Daniel Wüstner
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense M, Denmark.
| | - Tanja Christensen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense M, Denmark.
| | - Lukasz M Solanko
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense M, Denmark.
| | - Daniel Sage
- Biomedical Imaging Group, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
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12
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Photoinduced electron transfer between coumarin dyes and N,N-dimethylaniline in imidazolium based room temperature ionic liquids: Effect of the cation's alkyl chain length on the bimolecular photoinduced electron transfer process. J Photochem Photobiol A Chem 2013. [DOI: 10.1016/j.jphotochem.2013.03.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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13
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Methenni A, Mighri F, Elkoun S, Fang H, Cassagnau P. Fluorescence quenching of fluoranthene by maleic anhydride in solution and during nonreactive and reactive twin-screw extrusion. POLYM ENG SCI 2013. [DOI: 10.1002/pen.23263] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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14
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Cox MJ, Timmer RLA, Bakker HJ, Park S, Agmon N. Distance-dependent proton transfer along water wires connecting acid-base pairs. J Phys Chem A 2009; 113:6599-606. [PMID: 19449829 DOI: 10.1021/jp9004778] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
We report time-resolved mid-IR kinetics for the ultrafast acid-base reaction between photoexcited 8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt (HPTS), and acetate at three concentrations (0.5, 1.0, and 2.0 M) and three temperatures (5, 30, and 65 degrees C) in liquid D(2)O. The observed proton-transfer kinetics agree quantitatively, over all times (200 fs-500 ps), with an extended Smoluchowski model which includes distance-dependent reactivity in the form of a Gaussian rate function, k(r). This distance dependence contrasts with the exponential k(r) that is typically observed for electron-transfer reactions. The width of k(r) is essentially the only parameter varied in fitting the proton-transfer kinetics at each concentration and temperature. We find that k(r) likely represents the rate of concerted (multi)proton hopping across "proton wires" of different length r that connect acid-base pairs in solution. The concerted nature of the proton transfer is supported by the fact that k(r) shows a steeper dependence on r at higher temperatures.
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Affiliation(s)
- M Jocelyn Cox
- FOM-institute for Atomic and Molecular Physics, Kruislaan 407, 1098 SJ Amsterdam, The Netherlands
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Sreearunothai P, Asaoka S, Cook AR, Miller JR. Length and Time-Dependent Rates in Diffusion-Controlled Reactions with Conjugated Polymers. J Phys Chem A 2009; 113:2786-95. [DOI: 10.1021/jp809413x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Paiboon Sreearunothai
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11793–5000 and Chemical Resources Laboratory, Tokyo Institute of Technology, Yokohama, 226–8503, Japan
| | - Sadayuki Asaoka
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11793–5000 and Chemical Resources Laboratory, Tokyo Institute of Technology, Yokohama, 226–8503, Japan
| | - Andrew R. Cook
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11793–5000 and Chemical Resources Laboratory, Tokyo Institute of Technology, Yokohama, 226–8503, Japan
| | - John R. Miller
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11793–5000 and Chemical Resources Laboratory, Tokyo Institute of Technology, Yokohama, 226–8503, Japan
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Samori S, Fujitsuka M, Majima T. Properties of Excited Radical Cations of Substituted Oligothiophenes. J Phys Chem A 2008; 112:11312-8. [DOI: 10.1021/jp804369e] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Shingo Samori
- The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan
| | - Mamoru Fujitsuka
- The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan
| | - Tetsuro Majima
- The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan
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Takahashi F, Jin J. Electrochemiluminescence of Tris(2,2′‐bipyridine)ruthenium with Various Co‐reactants under Ultrasound Irradiation. ELECTROANAL 2008. [DOI: 10.1002/elan.200804214] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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18
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Pant S, Ohtaka-Saiki H, Takezaki M, Scully AD, Hirayama S, Tominaga T. Effect of Diffusion on the Photoinduced Reaction between a Tetra-Anionic Porphyrin and Methylviologen Cation in Methanol. J Phys Chem A 2008; 112:5378-84. [DOI: 10.1021/jp800538e] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Sanjay Pant
- Department of Applied Chemistry, Okayama University of Science, 1-1 Ridai-cho, Okayama 700-0005 Japan, Department of Physics, Kumaun University, Nainital 263 002, India, Department of Pharmacy, Chiba Institute of Science, 3 Shiomi-cho, Choshi, Chiba 288-0025 Japan, CSIRO Materials Science and Engineering, Gate 5 Normanby Road, Clayton South, Victoria 3169, Australia, and Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585 Japan
| | - Hiroyasu Ohtaka-Saiki
- Department of Applied Chemistry, Okayama University of Science, 1-1 Ridai-cho, Okayama 700-0005 Japan, Department of Physics, Kumaun University, Nainital 263 002, India, Department of Pharmacy, Chiba Institute of Science, 3 Shiomi-cho, Choshi, Chiba 288-0025 Japan, CSIRO Materials Science and Engineering, Gate 5 Normanby Road, Clayton South, Victoria 3169, Australia, and Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585 Japan
| | - Makoto Takezaki
- Department of Applied Chemistry, Okayama University of Science, 1-1 Ridai-cho, Okayama 700-0005 Japan, Department of Physics, Kumaun University, Nainital 263 002, India, Department of Pharmacy, Chiba Institute of Science, 3 Shiomi-cho, Choshi, Chiba 288-0025 Japan, CSIRO Materials Science and Engineering, Gate 5 Normanby Road, Clayton South, Victoria 3169, Australia, and Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585 Japan
| | - Andrew D. Scully
- Department of Applied Chemistry, Okayama University of Science, 1-1 Ridai-cho, Okayama 700-0005 Japan, Department of Physics, Kumaun University, Nainital 263 002, India, Department of Pharmacy, Chiba Institute of Science, 3 Shiomi-cho, Choshi, Chiba 288-0025 Japan, CSIRO Materials Science and Engineering, Gate 5 Normanby Road, Clayton South, Victoria 3169, Australia, and Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585 Japan
| | - Satoshi Hirayama
- Department of Applied Chemistry, Okayama University of Science, 1-1 Ridai-cho, Okayama 700-0005 Japan, Department of Physics, Kumaun University, Nainital 263 002, India, Department of Pharmacy, Chiba Institute of Science, 3 Shiomi-cho, Choshi, Chiba 288-0025 Japan, CSIRO Materials Science and Engineering, Gate 5 Normanby Road, Clayton South, Victoria 3169, Australia, and Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585 Japan
| | - Toshihiro Tominaga
- Department of Applied Chemistry, Okayama University of Science, 1-1 Ridai-cho, Okayama 700-0005 Japan, Department of Physics, Kumaun University, Nainital 263 002, India, Department of Pharmacy, Chiba Institute of Science, 3 Shiomi-cho, Choshi, Chiba 288-0025 Japan, CSIRO Materials Science and Engineering, Gate 5 Normanby Road, Clayton South, Victoria 3169, Australia, and Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585 Japan
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Paulo PMR, Costa SMB. Interactions in noncovalent PAMAM/TMPyP systems studied by fluorescence spectroscopy. J Phys Chem B 2007; 109:13928-40. [PMID: 16852748 DOI: 10.1021/jp050894f] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Steady-state absorption and emission spectroscopy and time-resolved fluorescence measurements were employed in the study of meso-tetrakis(4-N-methylpyridinium)porphine (TMPyP) interactions with half-generation carboxyl-terminated poly(amidoamine) (PAMAM) dendrimers in water. TMPyP experiences a less polar environment and a strong fluorescence quenching effect upon dendrimer association. The tertiary amine functional groups in PAMAM dendrimers are likely to be responsible for the fluorescence quenching of TMPyP through an electron-transfer mechanism. The Stern-Volmer plots achieve a plateau at high dendrimer concentrations that was attributed to full porphyrin-dendrimer association, and an average fluorescence quantum yield of 15-20% relative to aqueous TMPyP was estimated. The association constant for the 1:1 complex with generation 2.5 at dendrimer-porphyrin ratio D/P = 1 is 5.75 x 10(7) M(-1), indicating a strong binding affinity. The dissociation of the complex with increasing ionic strength reinforces the role of electrostatic forces in porphyrin-dendrimer association. Comparison of Stern-Volmer plots obtained from quantum yields or lifetimes showed the importance of a static effect in these systems. The fluorescence decays of the porphyrin-dendrimer complex were fitted with a dispersed kinetics model. At intermediate dendrimer-porphyrin ratios (D/P approximately 1), diffusional quenching processes between free porphyrin and dendrimer were modeled with the Sano-Tachiya pair survival probability equation. Transient diffusional effects were dismissed as a possible explanation for the static effect detected.
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Affiliation(s)
- Pedro M R Paulo
- Centro de Química Estrutural, Complexo 1, Instituto Superior Técnico, Av. Rovisco Pais, 1049-001 Lisboa, Portugal.
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21
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Sakamoto M, Cai X, Hara M, Fujitsuka M, Majima T. Significant effects of substituents on substituted naphthalenes in the higher triplet excited state. J Phys Chem A 2007; 109:4657-61. [PMID: 16833806 DOI: 10.1021/jp045608z] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Substituent effect on the lifetimes of a series of substituted naphthalenes (Np) in the higher triplet excited state (Tn) was studied with transient absorption measurements using the two-color two-laser flash photolysis technique. Lifetimes of Np(Tn) in cyclohexane solution were determined from the triplet energy transfer quenching by carbon tetrachloride to be 0.98-63 ps. The different lifetimes of Np(Tn) were explained by the energy gap law for the internal conversion from Np(Tn) to Np(T1), indicating that Np(Tn) quenched by carbon tetrachloride is assigned to Np(T2) with the longest lifetime among Np(Tn). The lifetime of Np(Tn) was correlative with the Hammett sigmap constant. Electronic characters of substituents showed a more significant influence on the energy of the T2 state than that of the T1 state.
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Affiliation(s)
- Masanori Sakamoto
- The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan
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22
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Laia CAT, Costa SMB, Vieira Ferreira LF. Electron-transfer mechanism of the triplet state quenching of aluminium tetrasulfonated phthalocyanine by cytochrome c. Biophys Chem 2006; 122:143-55. [PMID: 16624476 DOI: 10.1016/j.bpc.2006.03.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2005] [Revised: 03/09/2006] [Accepted: 03/09/2006] [Indexed: 11/19/2022]
Abstract
The mechanism of electron-transfer from aluminium tetrasulfonated phthalocyanine triplet state to cytochrome c was investigated in this work. This reaction successfully quenches the dye triplet state due to the formation of complexes between the solute and the protein at the active site. The electron-transfer rate constant is around 3x10(7) s(-1), and is in accordance with previous results for the singlet excited state quenching [C.A.T. Laia, S.M.B. Costa, D. Phillips, A. Beeby. Electron-transfer kinetics in sulfonated aluminum phthalocyanines/cytochrome c complexes, J. Phys. Chem. B 108 (2004) 7506-7514.] in the framework of the Marcus theory, with a reorganization energy equal to 0.94 eV. The complex formation is diffusion controlled, but heterogeneities of the protein surface charge distribution lead to quenching rate constants smaller than predicted on a hard-spheres model with electrostatic interactions. Also the binding equilibrium constant is strongly affected by this phenomenon. Ionic strength plays an important role on the complex formation, but its effect on the unimolecular electron-transfer rate constant is negligible within experimental error.
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Affiliation(s)
- César A T Laia
- Centro de Química-Estrutural, Complexo 1, Instituto Superior Técnico, 1049-001 Lisboa, Portugal.
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23
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Andrews SS, Bray D. Stochastic simulation of chemical reactions with spatial resolution and single molecule detail. Phys Biol 2005; 1:137-51. [PMID: 16204833 DOI: 10.1088/1478-3967/1/3/001] [Citation(s) in RCA: 282] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Methods are presented for simulating chemical reaction networks with a spatial resolution that is accurate to nearly the size scale of individual molecules. Using an intuitive picture of chemical reaction systems, each molecule is treated as a point-like particle that diffuses freely in three-dimensional space. When a pair of reactive molecules collide, such as an enzyme and its substrate, a reaction occurs and the simulated reactants are replaced by products. Achieving accurate bimolecular reaction kinetics is surprisingly difficult, requiring a careful consideration of reaction processes that are often overlooked. This includes whether the rate of a reaction is at steady-state and the probability that multiple reaction products collide with each other to yield a back reaction. Inputs to the simulation are experimental reaction rates, diffusion coefficients and the simulation time step. From these are calculated the simulation parameters, including the 'binding radius' and the 'unbinding radius', where the former defines the separation for a molecular collision and the latter is the initial separation between a pair of reaction products. Analytic solutions are presented for some simulation parameters while others are calculated using look-up tables. Capabilities of these methods are demonstrated with simulations of a simple bimolecular reaction and the Lotka-Volterra system.
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24
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Park S, Shin KJ, Popov AV, Agmon N. Diffusion-influenced excited-state reversible transfer reactions, A*+B⇌C*+D, with two different lifetimes: Theories and simulations. J Chem Phys 2005; 123:34507. [PMID: 16080744 DOI: 10.1063/1.1948369] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We report accurate Brownian simulation results for the kinetics of the pseudo-first-order diffusion-influenced excited-state reversible transfer reaction A(*) + Bright harpoon over left harpoonC(*) + D with two different lifetimes using two different propagation algorithms. The results are used to test approximate solutions for this many-particle problem. Available theories fail when one of the two reactions or (decay) rate constants is large. To remedy this situation, we develop two uniform approximations, which are based on introducing a generalized Smoluchowski term into the relaxation-time approximation. The best of these is the extended unified theory of reversible target reactions, which reduces correctly in all limits and exhibits superior agreement with simulations.
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Affiliation(s)
- Soohyung Park
- School of Chemistry, Seoul National University, Korea
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25
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Litniewski M, Gorecki J. Kinetics of fluorescence quenching for electron transfer and for energy transfer: Molecular dynamics tests for spherical molecules. J Chem Phys 2005; 122:204504. [PMID: 15945749 DOI: 10.1063/1.1901657] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The Smoluchowski approach to description of fluorescence quenching is tested by comparing the theory with computer simulations for the case of spherical molecules. The distance dependent sink terms describing the electron transfer mechanism and the Forster model for the energy transfer are considered. It is shown that the agreement between the rate coefficient from the model and from simulations depends on the strength of the solute-solvent interactions as well as on the speed of reaction itself. Comparing results of simulations for different quencher concentrations we estimate the strength of quencher concentration dependence effect and the range of times the effect may be significant. In the long time limit the increase in quencher concentration decreased the rate coefficient.
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Affiliation(s)
- Marek Litniewski
- Institute of Physical Chemistry of the Polish Academy of Science, Kasprzaka 44/52, 01-224 Warszawa, Poland
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26
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Abstract
The absorption of a photon by a hydroxy-aromatic photoacid triggers a cascade of events contributing to the overall phenomenon of intermolecular excited-state proton transfer. The fundamental steps involved were studied over the last 20 years using a combination of theoretical and experimental techniques. They are surveyed in this sequel in sequential order, from fast to slow. The excitation triggers an intramolecular charge transfer to the ring system, which is more prominent for the anionic base than the acid. The charge redistribution, in turn, triggers changes in hydrogen-bond strengths that set the stage for the proton-transfer step itself. This step is strongly influenced by the solvent, resulting in unusual dependence of the dissociation rate coefficient on water content, temperature, and isotopic substitution. The photolyzed proton can diffuse in the aqueous solution in a mechanism that involves collective changes in hydrogen-bonding. On longer times, it may recombine adiabatically with the excited base or quench it. The theory for these diffusion-influenced geminate reactions has been developed, showing nice agreement with experiment. Finally, the effect of inert salts, bases, and acids on these reactions is analyzed.
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Affiliation(s)
- Noam Agmon
- Department of Physical Chemistry and the Fritz Haber Research Center, The Hebrew University, Jerusalem 91904, Israel.
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27
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Rini M, Pines D, Magnes BZ, Pines E, Nibbering ETJ. Bimodal proton transfer in acid-base reactions in water. J Chem Phys 2004; 121:9593-610. [PMID: 15538881 DOI: 10.1063/1.1804172] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We investigate one of the fundamental reactions in solutions, the neutralization of an acid by a base. We use a photoacid, 8-hydroxy-1,3,6-trisulfonate-pyrene (HPTS; pyranine), which upon photoexcitation reacts with acetate under transfer of a deuteron (solvent: deuterated water). We analyze in detail the resulting bimodal reaction dynamics between the photoacid and the base, the first report on which was recently published. We have ascribed the bimodal proton-transfer dynamics to contributions from preformed hydrogen bonding complexes and from initially uncomplexed acid and base. We report on the observation of an additional (6 ps)(-1) contribution to the reaction rate constant. As before, we analyze the slower part of the reaction within the framework of the diffusion model and the fastest part by a static, sub-150 fs reaction rate. Adding the second static term considerably improves the overall modeling of the experimental results. It also allows to connect experimentally the diffusion controlled bimolecular reaction models as defined by Eigen-Weller and by Collins-Kimball. Our findings are in agreement with a three-stage mechanism for liquid phase intermolecular proton transfer: mutual diffusion of acid and base to form a "loose" encounter complex, followed by reorganization of the solvent shells and by "tightening" of the acid-base encounter complex. These rearrangements last a few picoseconds and enable a prompt proton transfer along the reaction coordinate, which occurs faster than our time resolution of 150 fs. Alternative models for the explanation of the slower "on-contact" reaction time of the loose encounter complex in terms of proton transmission through a von Grotthuss mechanism are also discussed.
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Affiliation(s)
- Matteo Rini
- Max Born Institut fuer Nichtlineare Optik und Kurzzeitspektroskopie, Max Born Strasse 2A, D-12489 Berlin, Germany
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28
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Satzger H, Schmidt B, Root C, Zinth W, Fierz B, Krieger F, Kiefhaber T, Gilch P. Ultrafast Quenching of the Xanthone Triplet by Energy Transfer: New Insight into the Intersystem Crossing Kinetics. J Phys Chem A 2004. [DOI: 10.1021/jp047583+] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Krystkowiak E. Rapid fluorescence quenching of S2-xanthione by 3,3-diethylpentane in perfluorohydrocarbons. J Chem Phys 2004; 120:8166-71. [PMID: 15267736 DOI: 10.1063/1.1695325] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Rapid fluorescence quenching of S2-xanthione by 3,3-diethylpentane has been studied in three perfluorohydrocarbons of different viscosities. The donor fluorescence decay in the presence of a quencher was fitted using the Smoluchowski-Collins-Kimball (SCK) model. The molecular parameters, R (the sum of the molecular radii), D (the sum of diffusion coefficients), and the specific rate constant of the process, kappa, were determined. The values of parameter D for all systems studied differed from the sum of the macroscopic diffusion coefficients Dx measured independently. This behavior is explained by the dependence of the molecular diffusion coefficient (as determined from the SCK model) on the distance traveled by the donor and quencher molecules during the excited donor lifetime.
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Affiliation(s)
- Ewa Krystkowiak
- Faculty of Photochemistry, Department of Chemistry, Adam Mickiewicz University, Grunwaldzka 6, 60-780 Poznan, Poland
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30
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Laia CAT, Costa SMB, Phillips D, Beeby A. Electron-Transfer Kinetics in Sulfonated Aluminum Phthalocyanines/Cytochrome c Complexes. J Phys Chem B 2004. [DOI: 10.1021/jp036675g] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- César A. T. Laia
- Centro de Química-Estrutural, Complexo 1, Instituto Superior Técnico, 1049-001 LISBOA, Portugal, Department of Chemistry, Imperial College, Exhibition Road, London SW7 2AY, U.K., and Chemistry Department, University of Durham, South Road, Durham DH1 3LE, U.K
| | - Sílvia M. B. Costa
- Centro de Química-Estrutural, Complexo 1, Instituto Superior Técnico, 1049-001 LISBOA, Portugal, Department of Chemistry, Imperial College, Exhibition Road, London SW7 2AY, U.K., and Chemistry Department, University of Durham, South Road, Durham DH1 3LE, U.K
| | - David Phillips
- Centro de Química-Estrutural, Complexo 1, Instituto Superior Técnico, 1049-001 LISBOA, Portugal, Department of Chemistry, Imperial College, Exhibition Road, London SW7 2AY, U.K., and Chemistry Department, University of Durham, South Road, Durham DH1 3LE, U.K
| | - Andrew Beeby
- Centro de Química-Estrutural, Complexo 1, Instituto Superior Técnico, 1049-001 LISBOA, Portugal, Department of Chemistry, Imperial College, Exhibition Road, London SW7 2AY, U.K., and Chemistry Department, University of Durham, South Road, Durham DH1 3LE, U.K
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31
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Litniewski M, Gorecki J. Molecular dynamics tests of the Smoluchowski–Collins–Kimball model for fluorescence quenching of spherical molecules. Phys Chem Chem Phys 2004. [DOI: 10.1039/b308680a] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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32
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Litniewski M, Gorecki J. On the applicability of the step function nonradiative lifetime model for diffusion controlled reactions. J Chem Phys 2003. [DOI: 10.1063/1.1612471] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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33
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Laia CAT, Costa SMB, Phillips D, Parker AW. Spectroscopy of photoinduced charge-transfer reactions between tetrasulfonated aluminium phthalocyanine and methyl viologen. Photochem Photobiol Sci 2003; 2:555-62. [PMID: 12803078 DOI: 10.1039/b301036h] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Interactions between tetrasulfonated aluminium phthalocyanine (AlPcTS4-) and methyl viologen (Mv2+) have been studied in water and ethanol solutions using several experimental techniques. UV-visible absorption and fluorescence spectroscopies show that ion-pair complexes occur in ethanol, disappearing in more polar environments such as water. Time-resolved fluorescence spectroscopy (picosecond timescale) reveals the existence of several emissive species in ethanol solutions, of which one of the components is attributed to the charge-transfer complex (AlPcTS4-)(Mv2+)2, another to higher-order aggregates and yet another to the isolated AlPcTS4- molecule. The AlPcTS4- emission is quenched by Mv2+, leading to transient diffusion in the fluorescence decay kinetics. On the other hand, the emissive complex has an exponential decay with a relatively long lifetime (above 1 ns). Time-resolved absorption measurements did not reveal the existence of radicals in aqueous solution, even on the picosecond timescale. The spectra reveal the presence of excited singlet state AlPcTS4-, which decays via the triplet excited state back to the ground state.
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Affiliation(s)
- César A T Laia
- Centro de Química-Estrutural, Complexo 1, Instituto Superior Técnico, 1049-001 Lisboa, Portugal.
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34
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Petrásek Z, Phillips D. A time-resolved study of concentration quenching of disulfonated aluminium phthalocyanine fluorescence. Photochem Photobiol Sci 2003; 2:236-44. [PMID: 12713223 DOI: 10.1039/b209906c] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The effects of concentration on the fluorescence decay kinetics of disulfonated aluminium phthalocyanine (AlPcS2) were studied in several solvents. The degree of aggregation, which increased with total dye concentration, was estimated from the absorption spectra. The measured fluorescence decays were shorter and increasingly non-monoexponential with increasing dye concentration. However, stronger quenching was not correlated with higher aggregation. The fluorescence decays were analyzed using a model that assumes excitation energy migration between diffusing monomeric AlPcS2 and quenching by diffusing dimers, both governed by the Förster energy transfer mechanism. The model can explain the observations in three of the four solvents used (phosphate-buffered saline (PBS) pH = 11.5, ethanol, and 67% glycerol-33% water mixture) on the assumption that different dimer configurations are present and not all of them act as quenchers. In PBS at pH = 7.4 the theory predicts much stronger quenching than observed. Excitation energy migration between monomeric species at high dye concentration was confirmed by the observed decrease of the decay time of fluorescence anisotropy in viscous solutions of 67% glycerol, and appears to be a major factor in fluorescence quenching of AlPcS2 at high concentration.
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Affiliation(s)
- Zdenĕk Petrásek
- Department of Chemistry, Imperial College of Science, Technology and Medicine, London, United Kingdom SW7 2AY
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35
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Billard I. Lanthanide and actinide solution chemistry as studied by time-resolved emission spectroscopy. ACTA ACUST UNITED AC 2003. [DOI: 10.1016/s0168-1273(02)33006-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2023]
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36
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Krystkowiak E, Maciejewski A. Examination of the viability of the Smoluchowski–Collins–Kimball model in fluorescence quenching of S2-xanthione. J Chem Phys 2002. [DOI: 10.1063/1.1502253] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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37
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Krystkowiak E, Maciejewski A. Kinetics of fluorescence quenching of S2-thioketones studied by the Smoluchowski–Collins–Kimball model: Standard systems. J Chem Phys 2002. [DOI: 10.1063/1.1488921] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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38
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Dobek K, Maciejewski A, Karolczak J, Augustyniak W. Determination of Reactivities of Primary, Secondary, and Tertiary C−H Bonds in Saturated Hydrocarbons from S2-Xanthione Fluorescence Quenching. J Phys Chem A 2002. [DOI: 10.1021/jp013090i] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Krzysztof Dobek
- Departments of Physics and Chemistry, A. Mickiewicz University, 60-780 Poznań, Poland
| | - Andrzej Maciejewski
- Departments of Physics and Chemistry, A. Mickiewicz University, 60-780 Poznań, Poland
| | - Jerzy Karolczak
- Departments of Physics and Chemistry, A. Mickiewicz University, 60-780 Poznań, Poland
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39
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Popov AV, Agmon N. Three-dimensional simulations of reversible bimolecular reactions: The simple target problem. J Chem Phys 2001. [DOI: 10.1063/1.1412609] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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40
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Karolczak J, Komar D, Kubicki J, Wróżowa T, Dobek K, Ciesielska B, Maciejewski A. The measurements of picosecond fluorescence lifetimes with high accuracy and subpicosecond precision. Chem Phys Lett 2001. [DOI: 10.1016/s0009-2614(01)00689-3] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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41
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Affiliation(s)
- Boiko Cohen
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel-Aviv University, Ramat-Aviv, Tel-Aviv 69978, Israel
| | - Dan Huppert
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel-Aviv University, Ramat-Aviv, Tel-Aviv 69978, Israel
| | - Noam Agmon
- The Fritz Haber Research Center, Department of Physical Chemistry, The Hebrew University, Jerusalem 91904, Israel
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42
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Cohen B, Huppert D, Agmon N. Non-Exponential Smoluchowski Dynamics in Fast Acid−Base Reaction. J Am Chem Soc 2000. [DOI: 10.1021/ja001572m] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Boiko Cohen
- School of Chemistry, Sackler Faculty of Exact Sciences Tel-Aviv University, Tel-Aviv 69978, Israel
| | - Dan Huppert
- School of Chemistry, Sackler Faculty of Exact Sciences Tel-Aviv University, Tel-Aviv 69978, Israel
| | - Noam Agmon
- Department of Physical Chemistry The Hebrew University, Jerusalem 91904, Israel
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