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Csekő G, Horváth AK. Bromide Ion Impurity-Induced Reaction between Selenium(IV) and Acidic Bromate: Prototype of a Cycle with Autocatalytic Behavior. Inorg Chem 2024; 63:2053-2059. [PMID: 38227950 PMCID: PMC10828994 DOI: 10.1021/acs.inorgchem.3c03833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 12/22/2023] [Accepted: 01/02/2024] [Indexed: 01/18/2024]
Abstract
The selenium(IV)-bromate reaction in an acidic medium using phosphoric acid/phosphate buffer was investigated by UV-vis spectroscopy monitoring the formation of bromine. In an excess of bromate, the absorbance-time curves measured at 450 nm display a characteristic sigmoidal shape having a fairly long induction period, while in the opposite case, when selenium(IV) species is used in excess, the measured data follow the rise and fall behavior. Depending on the excess of Se(IV) the final bromine-containing product is either an elementary bromine or bromide ion. Simultaneous evaluation of the measured kinetic traces clearly indicated that, surprisingly, no direct reaction takes place between the reactants. Instead of that, a trace amount of bromide ion impurity in the stock bromate solution is sufficient to drive the system via the oxidation of the bromide ion by bromate producing elementary bromine followed by the subsequent selenite-bromine reaction reestablishing the bromide ion to open a new cycle. As a result, the concentration of bromide ions increases in a sigmoidal fashion during the course of the reaction unless enough selenium(IV) species is present; hence, the overall synergetic effect observed is the autocatalytic rise of bromide ions. Therefore, the cycle mentioned above may be considered as a prototype of autocatalytic cycles. This observation prompted us to clarify the explicit difference between an autocatalytic cycle and an autocatalytic reaction.
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Affiliation(s)
- György Csekő
- Department of General and Inorganic
Chemistry, Faculty of Sciences, University
of Pécs, Ifjúság útja 6, H-7624 Pécs, Hungary
| | - Attila K. Horváth
- Department of General and Inorganic
Chemistry, Faculty of Sciences, University
of Pécs, Ifjúság útja 6, H-7624 Pécs, Hungary
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2
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Wu T, Li XY. An instrument-free visual quantitative detection method based on clock reaction: the detection of thrombin as an example. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2022; 15:48-55. [PMID: 36448577 DOI: 10.1039/d2ay01786e] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Instrument-free visual quantitative detection in chemical and biochemical analysis is of great significance in practical applications especially in point-of-care testing and in places where resources are limited. In this paper, we report the development of a time-based instrument-free visual quantitative detection method by employing a clock reaction, a type of chemical reaction displaying characteristic clocking behavior. The feasibility of the method was illustrated by the quantitative detection of thrombin in buffer solution using the lapse of time as the readout signal. The linear range of detection was from 1.3 to 43 nM (r2 = 0.990, n = 3) with a LOD of 0.9 nM, which is lower than the physiological concentrations of thrombin in the resting and activated blood, which range from low nanomolar to low micromolar, respectively. This method was also validated by detecting thrombin in the serum and a good recovery of nearly 100 ± 8.0% was obtained. To the best of our knowledge, this work is the first report that uses the characteristic time of a clock reaction as the readout signal in instrument-free colorimetry for quantitative bioanalysis.
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Affiliation(s)
- Tianxiang Wu
- Department of Chemistry, The Hong Kong University of Science and Technology, ClearWater Bay, Kowloon, Hong Kong S.A.R., People's Republic of China.
| | - Xiao-Yuan Li
- Department of Chemistry, The Hong Kong University of Science and Technology, ClearWater Bay, Kowloon, Hong Kong S.A.R., People's Republic of China.
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3
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Pires RO, Faria RB. The Photochemical Chlorate-Iodide Clock Reaction. Inorg Chem 2021; 61:1178-1187. [PMID: 34965359 DOI: 10.1021/acs.inorgchem.1c03522] [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
Mixing iodide and perchloric acid solutions with an excess of chlorate inside a diode-array spectrophotometer led to the observation of an abrupt decrease of the absorbance at the 215 nm isosbestic point after an induction period. The clock time decreases by increasing the initial concentrations of chlorate and acid, but increasing the initial iodide concentration has an opposite effect. The proposed mechanism simulates the experimental results and considers the interaction of UV light with iodide, producing iodine and triiodide ion. The autocatalytic core of this mechanism is the same as that employed to explain the autocatalytic behavior of chlorine dioxide-iodine reaction, but considering H2IO+ as the reactive species rather than HOI, being a more realistic mechanism for acid conditions.
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Affiliation(s)
- Romulo O Pires
- Instituto de Química, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-909 Rio de Janeiro, Brazil
| | - Roberto B Faria
- Instituto de Química, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-909 Rio de Janeiro, Brazil
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4
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A kinetic study of the photooxidation of water by aqueous cerium(IV) in sulfuric acid using a diode array spectrophotometer. J Photochem Photobiol A Chem 2021. [DOI: 10.1016/j.jphotochem.2020.113110] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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5
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Some physical parameters influencing the comprehensive evaluation of kinetic data in photochemical reactions and its application in the periodate-chemistry. J Photochem Photobiol A Chem 2020. [DOI: 10.1016/j.jphotochem.2019.112021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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6
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Nassar SJM, Sirbu D, Harriman A. Photocatalysed decolouration of indigo in solution via in situ generation of an organic hydroperoxide. Photochem Photobiol Sci 2019; 18:2875-2883. [PMID: 31720669 DOI: 10.1039/c9pp00355j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Indigo, an emblematic violet dye used for thousands of years to colour fabric, is resistant to fading on exposure to sunlight. Prior work has indicated that indigo is reactive towards both hydroperoxyl radicals and superoxide anions in solution. In order to promote photobleaching of indigo, we have utilised a BOPHY-based (BOPHY = aryl fused symmetrical pyrrole-BF2 complex) chromophore known to form both superoxide ions and a stable alkyl hydroperoxide under illumination in aerated solution. Selective irradiation of the photocatalyst causes relatively fast fading of indigo, with the rate increasing gently with increasing concentration of indigo. Molecular oxygen and light are essential for effective bleaching. One molecule of photocatalyst can bleach more than 40 molecules of indigo. An active component of the photocatalyst is a butylated hydroxytoluene (BHT) residue which itself quenches the triplet excited state of indigo. This provides an ancillary mechanism for effecting photofading of indigo but, because the triplet is formed in very low yield, this route is less practical.
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Affiliation(s)
- Sulafa Jamal M Nassar
- Molecular Photonics Laboratory, School of Natural and Environmental Science, Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK.
| | - Dumitru Sirbu
- Molecular Photonics Laboratory, School of Natural and Environmental Science, Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK.
| | - Anthony Harriman
- Molecular Photonics Laboratory, School of Natural and Environmental Science, Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK.
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7
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Ali B, Imar S, Laffir F, Kailas L, Maccato C, McCormac T. Electrochemical, surface and electrocatalytic properties of layer-by-layer multilayer assemblies composed of silver nanoparticles and a Ni(II)-crown type polyoxometalate. J Electroanal Chem (Lausanne) 2018. [DOI: 10.1016/j.jelechem.2018.07.036] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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8
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9
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Pagnacco MC, Mojović MD, Popović-Bijelić AD, Horváth AK. Investigation of the Halogenate-Hydrogen Peroxide Reactions Using the Electron Paramagnetic Resonance Spin Trapping Technique. J Phys Chem A 2017; 121:3207-3212. [PMID: 28402644 DOI: 10.1021/acs.jpca.7b02035] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The differences in the mechanism of the halogenate reactions with the same oxidizing/reducing agent, such as H2O2 contribute to the better understanding of versatile halogen chemistry. The reaction between iodate, bromate, and chlorate with hydrogen peroxide in acidic medium at 60 °C is investigated by using the electron paramagnetic resonance (EPR) spin trapping technique. Essential differences in the chemistry of iodate, bromate, and chlorate in their reactions with hydrogen peroxide have been evidenced by finding different radicals as governing intermediates. The reaction between KIO3 and H2O2 is supposed to be the source of IO2• radicals. The KBrO3 and H2O2 reaction did not produce any EPR signal, whereas the KClO3-H2O2 system was found to be a source of HO• radical. Moreover, KClO3 dissolved in sulfuric acid without hydrogen peroxide produced HO• radical as well. The minimal-core models explaining the origin of obtained EPR signals are proposed. Current findings suggested the inclusion of IO2• and HOO• radicals, and ClO2• and HO• radicals in the particular kinetic models of iodate-hydrogen peroxide and chlorate-hydrogen peroxide systems, as well as possible exclusion of BrO2• radical from the kinetic scheme of the bromate-hydrogen peroxide system. Obtained results may pave the way for understanding more complex, nonlinear reactions of these halogen-containing species.
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Affiliation(s)
- Maja C Pagnacco
- Faculty of Physical Chemistry, University of Belgrade , Studentski trg 12-16, P.O. Box 47, 11158 Belgrade, Serbia
| | - Miloš D Mojović
- Faculty of Physical Chemistry, University of Belgrade , Studentski trg 12-16, P.O. Box 47, 11158 Belgrade, Serbia
| | - Ana D Popović-Bijelić
- Faculty of Physical Chemistry, University of Belgrade , Studentski trg 12-16, P.O. Box 47, 11158 Belgrade, Serbia
| | - Attila K Horváth
- Department of Inorganic Chemistry, University of Pécs , Ifjúság u. 6, H-7624 Pécs, Hungary
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Kiss V, Lehoczki G, Ősz K. Mathematical description of pH-stat kinetic traces measured during photochemical quinone decomposition. Photochem Photobiol Sci 2017; 16:519-526. [PMID: 27942682 DOI: 10.1039/c6pp00333h] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Substituted 1,4-benzoquinone (QR) derivatives are photosensitive in aqueous solution and form hydroquinones (QR-H2) and hydroxy-quinones (QR-OH), two weak acids in their photoreaction. For this reason, the kinetics of the photoreaction can be conveniently followed by the pH-stat titration technique. The mathematical description of the kinetic traces measured provides the two main parameters of the photoreaction: the differential quantum yield of the reaction (Φ) and the ratio of the two photo-products, i.e. the fraction of QR that is converted to QR-OH (α). These values are described in this paper for 2,5-dichloro-1,4-benzoquinone at different pH values, together with the detailed mathematical evaluation of the application limits of the pH-stat method for such reactions.
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Affiliation(s)
- Virág Kiss
- Department of Physical Chemistry, University of Debrecen, H-4032 Debrecen, Egyetem tér 1., Hungary.
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11
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Pure gold dissolution in dilute chloric, bromic or iodic acid solution containing abundant halide ions. J Mol Liq 2017. [DOI: 10.1016/j.molliq.2016.12.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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12
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Ditrói T, Kalmár J, Pino-Chamorro JA, Erdei Z, Lente G, Fábián I. Construction of a multipurpose photochemical reactor with on-line spectrophotometric detection. Photochem Photobiol Sci 2016; 15:589-94. [DOI: 10.1039/c5pp00407a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A versatile photoreactor was constructed from commercially available parts, which is capable of recording high quality kinetic traces in homogeneous and heterogeneous photoreactions and also easily adaptable to flow-through operation.
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Affiliation(s)
- Tamás Ditrói
- Department of Inorganic and Analytical Chemistry
- University of Debrecen
- Debrecen
- H-4010 Hungary
| | - József Kalmár
- MTA-DE Homogeneous Catalysis and Reaction Mechanisms Research Group
- Debrecen
- H-4010 Hungary
| | | | - Zsolt Erdei
- Department of Inorganic and Analytical Chemistry
- University of Debrecen
- Debrecen
- H-4010 Hungary
| | - Gábor Lente
- Department of Inorganic and Analytical Chemistry
- University of Debrecen
- Debrecen
- H-4010 Hungary
| | - István Fábián
- Department of Inorganic and Analytical Chemistry
- University of Debrecen
- Debrecen
- H-4010 Hungary
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13
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Valkai L, Csekő G, Horváth AK. Initial inhomogeneity-induced crazy-clock behavior in the iodate-arsenous acid reaction in a buffered medium under stirred batch conditions. Phys Chem Chem Phys 2015; 17:22187-94. [PMID: 26239390 DOI: 10.1039/c5cp02572a] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
It is unambiguously demonstrated that in the case of an autocatalytic reaction, initial inhomogeneities induced by the imperfectly mixed part of the overall volume may result in a serious irreproducibility of the individual kinetic runs. A statistically meaningful number of repetitions, however, gives rise to a reproducible cumulative probability distribution curve often referred to as a support of the stochastic feature. The iodate-arsenous acid reaction being autocatalytic with respect to both iodide and hydrogen ions displays clock behavior. However, the time lag necessary for the appearance of iodine, even in buffered solution, varies in an apparently random manner. Careful analysis of the variation of the different parameters like stirring rate, overall volume, geometry of the reactor and the way of mixing the reactants led us to conclude that the fate of the individual samples is determined at the initial stage when the reacting system is per se inhomogeneous. The place, the size of the so-called ignition volume, where the reacting system is imperfectly stirred, as well as the residence time spent there by the imperfectly mixed reactants all seem to depend on external factors.
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Affiliation(s)
- László Valkai
- Department of Inorganic Chemistry, University of Pécs, Ifjúság útja 6, Pécs, Hungary.
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14
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Horváth AK, Nagypál I. Classification of Clock Reactions. Chemphyschem 2014; 16:588-94. [DOI: 10.1002/cphc.201402806] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Indexed: 11/10/2022]
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15
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Sant'Anna RTP, Faria RB. The chlorate-iodine-nitrous acid clock reaction. PLoS One 2014; 9:e109899. [PMID: 25313803 PMCID: PMC4196969 DOI: 10.1371/journal.pone.0109899] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2014] [Accepted: 09/10/2014] [Indexed: 11/18/2022] Open
Abstract
A new clock reaction based on chlorate, iodine and nitrous acid is presented. The induction period of this new clock reaction decreases when the initial concentrations of chlorate, nitrous acid and perchloric acid increase, but it is independent on the initial iodine concentration. The proposed mechanism is based on the LLKE autocatalytic mechanism for the chlorite-iodide reaction and the initial reaction between chlorate and nitrous acid to produce nitrate and chlorite. This new clock reaction opens the possibility for a new family of oscillating reactions containing chlorate or nitrous acid, which in both cases has not been observed until now.
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Affiliation(s)
| | - Roberto B. Faria
- Instituto de Química, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
- * E-mail:
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16
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Kalmár J, Dóka É, Lente G, Fábián I. Aqueous photochemical reactions of chloride, bromide, and iodide ions in a diode-array spectrophotometer. Autoinhibition in the photolysis of iodide ions. Dalton Trans 2014; 43:4862-70. [DOI: 10.1039/c3dt53255k] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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17
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Sant'Anna RTP, Monteiro EV, Pereira JRT, Faria RB. The ozone-iodine-chlorate clock reaction. PLoS One 2013; 8:e83706. [PMID: 24386257 PMCID: PMC3873335 DOI: 10.1371/journal.pone.0083706] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Accepted: 11/06/2013] [Indexed: 11/19/2022] Open
Abstract
This work presents a new clock reaction based on ozone, iodine, and chlorate that differs from the known chlorate-iodine clock reaction because it does not require UV light. The induction period for this new clock reaction depends inversely on the initial concentrations of ozone, chlorate, and perchloric acid but is independent of the initial iodine concentration. The proposed mechanism considers the reaction of ozone and iodide to form HOI, which is a key species for producing non-linear autocatalytic behavior. The novelty of this system lies in the presence of ozone, whose participation has never been observed in complex systems such as clock or oscillating reactions. Thus, the autocatalysis demonstrated in this new clock reaction should open the possibility for a new family of oscillating reactions.
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Affiliation(s)
| | - Emily V. Monteiro
- Instituto de Química, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Juliano R. T. Pereira
- Instituto de Química, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Roberto B. Faria
- Instituto de Química, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
- * E-mail:
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18
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Lehóczki T, Józsa É, Ősz K. Ferrioxalate actinometry with online spectrophotometric detection. J Photochem Photobiol A Chem 2013. [DOI: 10.1016/j.jphotochem.2012.10.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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19
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Gombár M, Józsa É, Braun M, Ősz K. Construction of a photochemical reactor combining a CCD spectrophotometer and a LED radiation source. Photochem Photobiol Sci 2012; 11:1592-5. [DOI: 10.1039/c2pp25166c] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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20
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Nakata S, Matsushita M, Sato T, Suematsu NJ, Kitahata H, Amemiya T, Mori Y. Photoexcited Chemical Wave in the Ruthenium-Catalyzed Belousov–Zhabotinsky Reaction. J Phys Chem A 2011; 115:7406-12. [PMID: 21563834 DOI: 10.1021/jp2012057] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Satoshi Nakata
- Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Japan
- Department of Chemistry, Nara University of Education, Takabatake-cho, Nara 630-8528, Japan
| | - Mariko Matsushita
- Department of Chemistry, Nara University of Education, Takabatake-cho, Nara 630-8528, Japan
- Hikuma Junior High School, 4-2-15 Hikuma, Naka-ku, Hamamatsu 430-0901, Japan
| | - Taisuke Sato
- Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Japan
| | - Nobuhiko J. Suematsu
- Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Japan
- Meiji University, 1-1-1 Higashi-mita, Tama-ku, Kawasaki 214-8571, Japan
| | - Hiroyuki Kitahata
- Department of Physics, Graduate School of Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan, and PRESTO, JST, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Takashi Amemiya
- Graduate School of Environment and Information Sciences, Yokohama National University, 79-7 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan
| | - Yoshihito Mori
- Graduate School of Humanities and Sciences, Ochanomizu University, 2-1-1 Ohtsuka, Bunkyo-ku, Tokyo 112-8610, Japan
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Filáry Á, Horváth AK. Photochemically induced catalysis of iodide ion and iodine in the tetrathionate–periodate reaction. Phys Chem Chem Phys 2010; 12:6742-9. [DOI: 10.1039/b921858k] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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22
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Zidki T, Cohen H, Meyerstein D. Photochemical induced growth and aggregation of metal nanoparticles in diode-array spectrophotometer via excited dimethyl-sulfoxide. Phys Chem Chem Phys 2010; 12:12862-7. [DOI: 10.1039/c0cp01037e] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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23
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Rudzinski DM, Priefer R. Photolytic, autocatalyzed decomposition of benzylic dialkoxy disulfides. Tetrahedron Lett 2009. [DOI: 10.1016/j.tetlet.2009.01.115] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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24
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Lente G, Kalmár J, Baranyai Z, Kun A, Kék I, Bajusz D, Takács M, Veres L, Fábián I. One- Versus Two-Electron Oxidation with Peroxomonosulfate Ion: Reactions with Iron(II), Vanadium(IV), Halide Ions, and Photoreaction with Cerium(III). Inorg Chem 2009; 48:1763-73. [DOI: 10.1021/ic801569k] [Citation(s) in RCA: 159] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Gábor Lente
- University of Debrecen, Department of Inorganic and Analytical Chemistry, Debrecen 10, POB 21, Hungary, H-4010
| | - József Kalmár
- University of Debrecen, Department of Inorganic and Analytical Chemistry, Debrecen 10, POB 21, Hungary, H-4010
| | - Zsuzsa Baranyai
- University of Debrecen, Department of Inorganic and Analytical Chemistry, Debrecen 10, POB 21, Hungary, H-4010
| | - Alíz Kun
- University of Debrecen, Department of Inorganic and Analytical Chemistry, Debrecen 10, POB 21, Hungary, H-4010
| | - Ildikó Kék
- University of Debrecen, Department of Inorganic and Analytical Chemistry, Debrecen 10, POB 21, Hungary, H-4010
| | - Dávid Bajusz
- University of Debrecen, Department of Inorganic and Analytical Chemistry, Debrecen 10, POB 21, Hungary, H-4010
| | - Marcell Takács
- University of Debrecen, Department of Inorganic and Analytical Chemistry, Debrecen 10, POB 21, Hungary, H-4010
| | - Lilla Veres
- University of Debrecen, Department of Inorganic and Analytical Chemistry, Debrecen 10, POB 21, Hungary, H-4010
| | - István Fábián
- University of Debrecen, Department of Inorganic and Analytical Chemistry, Debrecen 10, POB 21, Hungary, H-4010
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Lente G, Fábián I. Kinetics and mechanism of the oxidation of water soluble porphyrin FeIIITPPS with hydrogen peroxide and the peroxomonosulfate ion. Dalton Trans 2007:4268-75. [PMID: 17893816 DOI: 10.1039/b708961a] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The overall six-electron oxidation of water soluble porphyrin Fe(III)TPPS by hydrogen peroxide and peroxomonosulfate ion was studied by the stopped-flow method with UV-vis detection. A three-step consecutive reaction was observed with two intermediates: Fe(III)TPPS --> Int(1)--> Int(2)--> products. The products were identified as the iron(iii) complex of the biliverdin analog formed from TPPS and 4-sulfobenzoic acid. All the rate constants with both oxidizing agents were determined. Intermediate Int(1) is proposed to be the species (TPPS (+))Fe(IV)=O. Although no unambiguous proposal for the structure of Int(2) can be made, it is most probably the product of the four-electron oxidation of the original Fe(III)TPPS, contains an iron-oxo center and has a dissociable proton with a pK of around 3.1. In spite of the protolytic equilibria occuring in the pH region 2-4, the kinetic observations do not show pH dependence.
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Affiliation(s)
- Gábor Lente
- University of Debrecen, Department of Inorganic and Analytical Chemistry, Debrecen 10, P.O.B. 21, Hungary, H-4010.
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