1
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Minezawa N, Suzuki K, Okazaki S. A density functional study of the photocatalytic degradation of polycaprolactone by the decatungstate anion in acetonitrile solution. Phys Chem Chem Phys 2024; 26:11746-11754. [PMID: 38563826 DOI: 10.1039/d4cp00362d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
A recent experimental study has reported that decatungstate [W10O32]4- can degrade various polyesters in the presence of light and molecular oxygen [Li et al., Nanoscale, 2023, 15, 15038]. We apply density functional theory to the photocatalyst-polycaprolactone model complex in acetonitrile solution and elucidate the degradation mechanisms and catalytic cycle. We consider hydrogen atom transfer (HAT) and single electron transfer (SET) mechanisms. The potential energy profiles show that the former proceeds exergonically in a single step but that the latter involves a subsequent proton transfer and finally yields HAT products as well. Oxygenated polymer species can regain the transferred hydrogen and regenerate the reduced photocatalyst. We propose a photocatalytic cycle that realizes both the photocatalyst regeneration and the polymer degradation.
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Affiliation(s)
- Noriyuki Minezawa
- Department of Applied Materials Science, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Chiba 277-8589, Japan.
| | - Kosuke Suzuki
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Susumu Okazaki
- Department of Applied Materials Science, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Chiba 277-8589, Japan.
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2
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Didarataee S, Suprun A, Joshi N, Scaiano JC. NIR phosphorescence from decatungstate anions allows the conclusive characterization of its elusive excited triplet behaviour and kinetics. Chem Commun (Camb) 2024. [PMID: 38258882 DOI: 10.1039/d3cc06282a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
The characterization of the triplet state of decatungstate (3DT*) and its NIR phosphorescence with lifetimes ∼100 ns in acetonitrile allow the easy determination of rate constants that are key to understanding its role in catalysis. The absence of oxygen quenching can now be understood as the excitation energy of 3DT* is lower than the energy of singlet oxygen.
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Affiliation(s)
- Saba Didarataee
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada.
| | - Anastasiia Suprun
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada.
| | - Neeraj Joshi
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada.
| | - Juan C Scaiano
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada.
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3
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Repp S, Remmers M, Rein ASJ, Sorsche D, Gao D, Anjass M, Mondeshki M, Carrella LM, Rentschler E, Streb C. Coupled reaction equilibria enable the light-driven formation of metal-functionalized molecular vanadium oxides. Nat Commun 2023; 14:5563. [PMID: 37689696 PMCID: PMC10492840 DOI: 10.1038/s41467-023-41257-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Accepted: 08/29/2023] [Indexed: 09/11/2023] Open
Abstract
The introduction of metal sites into molecular metal oxides, so-called polyoxometalates, is key for tuning their structure and reactivity. The complex mechanisms which govern metal-functionalization of polyoxometalates are still poorly understood. Here, we report a coupled set of light-dependent and light-independent reaction equilibria controlling the mono- and di-metal-functionalization of a prototype molecular vanadium oxide cluster. Comprehensive mechanistic analyses show that coordination of a Mg2+ ion to the species {(NMe2H2)2[VV12O32Cl]}3- results in formation of the mono-functionalized {(NMe2H2)[(MgCl)VV12O32Cl]}3- with simultaneous release of a NMe2H2+ placeholder cation. Irradiation of this species with visible light results in one-electron reduction of the vanadate, exchange of the second NMe2H2+ with Mg2+, and formation/crystallization of the di-metal-functionalized [(MgCl)2VIVVV11O32Cl]4-. Mechanistic studies show how stimuli such as light or competing cations affect the coupled equilibria. Transfer of this synthetic concept to other metal cations is also demonstrated, highlighting the versatility of the approach.
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Affiliation(s)
- Stefan Repp
- Institute of Inorganic Chemistry I, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Moritz Remmers
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128, Mainz, Germany
| | | | - Dieter Sorsche
- Institute of Inorganic Chemistry I, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Dandan Gao
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128, Mainz, Germany
| | - Montaha Anjass
- Institute of Inorganic Chemistry I, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
- Department of Chemistry, University of Sharjah, Sharjah-27272, Sharjah, United Arab Emirates
| | - Mihail Mondeshki
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128, Mainz, Germany
| | - Luca M Carrella
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128, Mainz, Germany
| | - Eva Rentschler
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128, Mainz, Germany
| | - Carsten Streb
- Institute of Inorganic Chemistry I, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany.
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128, Mainz, Germany.
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4
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Etim UJ, Bai P, Gazit OM, Zhong Z. Low-Temperature Heterogeneous Oxidation Catalysis and Molecular Oxygen Activation. CATALYSIS REVIEWS 2021. [DOI: 10.1080/01614940.2021.1919044] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Ubong J. Etim
- Department of Chemical Engineering, Guangdong Technion-Israel Institute of Technology (GTIIT), Shantou, Guangdong, China
| | - Peng Bai
- College of Chemical Engineering, China University of Petroleum, Qingdao, China
| | - Oz M. Gazit
- Wolfson Faculty of Chemical Engineering, Technion – Israel Institute of Technology, Haifa, Israel
| | - Ziyi Zhong
- Department of Chemical Engineering, Guangdong Technion-Israel Institute of Technology (GTIIT), Shantou, Guangdong, China
- Technion Israel Institute of Technology (IIT), Haifa, Israel
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5
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Capaldo L, Ravelli D, Fagnoni M. Direct Photocatalyzed Hydrogen Atom Transfer (HAT) for Aliphatic C-H Bonds Elaboration. Chem Rev 2021; 122:1875-1924. [PMID: 34355884 PMCID: PMC8796199 DOI: 10.1021/acs.chemrev.1c00263] [Citation(s) in RCA: 338] [Impact Index Per Article: 112.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
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Direct photocatalyzed
hydrogen atom transfer (d-HAT) can be considered
a method of choice for the elaboration of
aliphatic C–H bonds. In this manifold, a photocatalyst (PCHAT) exploits the energy of a photon to trigger the homolytic
cleavage of such bonds in organic compounds. Selective C–H
bond elaboration may be achieved by a judicious choice of the hydrogen
abstractor (key parameters are the electronic character and the molecular
structure), as well as reaction additives. Different are the classes
of PCsHAT available, including aromatic ketones, xanthene
dyes (Eosin Y), polyoxometalates, uranyl salts, a metal-oxo porphyrin
and a tris(amino)cyclopropenium radical dication. The processes (mainly
C–C bond formation) are in most cases carried out under mild
conditions with the help of visible light. The aim of this review
is to offer a comprehensive survey of the synthetic applications of
photocatalyzed d-HAT.
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Affiliation(s)
- Luca Capaldo
- Flow Chemistry Group, Van't Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Davide Ravelli
- PhotoGreen Lab, Department of Chemistry, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy
| | - Maurizio Fagnoni
- PhotoGreen Lab, Department of Chemistry, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy
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6
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Yang B, Zhang H, Wan F, Deng Y, Jiang D, Zhang Q, Liu Y, Zhang C, Fu Z. Molybdenum Isomorphously Substituted Decatungstates as Robust and Renewable Photocatalysts for Visible Light‐Driven Oxidation of Hydrocarbons by Molecular Oxygen. ChemCatChem 2021. [DOI: 10.1002/cctc.202002037] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Bo Yang
- National & Local United Engineering Laboratory for New Petrochemical Materials & Fine Utilization of Resources Key Laboratory of Resource Fine-Processing and advanced materials of Hunan Province and Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China) College of Chemistry and Chemical Engineering Hunan Normal University Changsha 410081 P.R. China
| | - Huanhuan Zhang
- National & Local United Engineering Laboratory for New Petrochemical Materials & Fine Utilization of Resources Key Laboratory of Resource Fine-Processing and advanced materials of Hunan Province and Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China) College of Chemistry and Chemical Engineering Hunan Normal University Changsha 410081 P.R. China
| | - Feifei Wan
- National & Local United Engineering Laboratory for New Petrochemical Materials & Fine Utilization of Resources Key Laboratory of Resource Fine-Processing and advanced materials of Hunan Province and Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China) College of Chemistry and Chemical Engineering Hunan Normal University Changsha 410081 P.R. China
| | - Youer Deng
- National & Local United Engineering Laboratory for New Petrochemical Materials & Fine Utilization of Resources Key Laboratory of Resource Fine-Processing and advanced materials of Hunan Province and Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China) College of Chemistry and Chemical Engineering Hunan Normal University Changsha 410081 P.R. China
| | - Dabo Jiang
- National & Local United Engineering Laboratory for New Petrochemical Materials & Fine Utilization of Resources Key Laboratory of Resource Fine-Processing and advanced materials of Hunan Province and Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China) College of Chemistry and Chemical Engineering Hunan Normal University Changsha 410081 P.R. China
| | - Qiao Zhang
- National & Local United Engineering Laboratory for New Petrochemical Materials & Fine Utilization of Resources Key Laboratory of Resource Fine-Processing and advanced materials of Hunan Province and Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China) College of Chemistry and Chemical Engineering Hunan Normal University Changsha 410081 P.R. China
| | - Yachun Liu
- National & Local United Engineering Laboratory for New Petrochemical Materials & Fine Utilization of Resources Key Laboratory of Resource Fine-Processing and advanced materials of Hunan Province and Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China) College of Chemistry and Chemical Engineering Hunan Normal University Changsha 410081 P.R. China
| | - Chao Zhang
- National & Local United Engineering Laboratory for New Petrochemical Materials & Fine Utilization of Resources Key Laboratory of Resource Fine-Processing and advanced materials of Hunan Province and Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China) College of Chemistry and Chemical Engineering Hunan Normal University Changsha 410081 P.R. China
| | - Zaihui Fu
- National & Local United Engineering Laboratory for New Petrochemical Materials & Fine Utilization of Resources Key Laboratory of Resource Fine-Processing and advanced materials of Hunan Province and Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China) College of Chemistry and Chemical Engineering Hunan Normal University Changsha 410081 P.R. China
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7
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Sousa Da Silva E, Sarakha M, Burrows HD, Wong-Wah-Chung P. Decatungstate anion as an efficient photocatalytic species for the transformation of the pesticide 2-(1-naphthyl)acetamide in aqueous solution. J Photochem Photobiol A Chem 2017. [DOI: 10.1016/j.jphotochem.2016.10.036] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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8
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Waele VD, Poizat O, Fagnoni M, Bagno A, Ravelli D. Unraveling the Key Features of the Reactive State of Decatungstate Anion in Hydrogen Atom Transfer (HAT) Photocatalysis. ACS Catal 2016. [DOI: 10.1021/acscatal.6b01984] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Vincent De Waele
- Université de Lille, CNRS, UMR 8516, LASIR, Laboratoire
de Spectrochimie et Raman, F59000 Lille, France
| | - Olivier Poizat
- Université de Lille, CNRS, UMR 8516, LASIR, Laboratoire
de Spectrochimie et Raman, F59000 Lille, France
| | - Maurizio Fagnoni
- PhotoGreen
Lab, Department of Chemistry, University of Pavia, viale Taramelli
12, 27100 Pavia, Italy
| | - Alessandro Bagno
- Department
of Chemistry, University of Padova, via Marzolo 1, 35131 Padova, Italy
| | - Davide Ravelli
- PhotoGreen
Lab, Department of Chemistry, University of Pavia, viale Taramelli
12, 27100 Pavia, Italy
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9
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Kathuria S, Dhamiwal N. Methylene blue sensitized oxidation of ethylene thiourea in cationic micellar medium. ARAB J CHEM 2016. [DOI: 10.1016/j.arabjc.2011.06.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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10
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Lacombe S, Pigot T. Materials for selective photo-oxygenation vs. photocatalysis: preparation, properties and applications in environmental and health fields. Catal Sci Technol 2016. [DOI: 10.1039/c5cy01929j] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Photosensitizing materials made of organic dyes embedded in various supports are compared to usual supported TiO2-based photocatalysts.
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Affiliation(s)
- S. Lacombe
- IPREM UMR CNRS 5254
- Université de Pau et des Pays de l'Adour
- 64053 Pau Cedex
- France
| | - T. Pigot
- IPREM UMR CNRS 5254
- Université de Pau et des Pays de l'Adour
- 64053 Pau Cedex
- France
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11
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Tanielian C, Seghrouchni R. Decatungstate photocatalyzed oxygenation of methanol in acetonitrile under photostationary state conditions. CR CHIM 2014. [DOI: 10.1016/j.crci.2013.10.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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12
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Tucher J, Streb C. Visible light photooxidative performance of a high-nuclearity molecular bismuth vanadium oxide cluster. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2014; 5:711-716. [PMID: 24991508 PMCID: PMC4077371 DOI: 10.3762/bjnano.5.83] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 05/01/2014] [Indexed: 06/03/2023]
Abstract
The visible light photooxidative performance of a new high-nuclearity molecular bismuth vanadium oxide cluster, H3[{Bi(dmso)3}4V13O40], is reported. Photocatalytic activity studies show faster reaction kinetics under anaerobic conditions, suggesting an oxygen-dependent quenching of the photoexcited cluster species. Further mechanistic analysis shows that the reaction proceeds via the intermediate formation of hydroxyl radicals which act as oxidant. Trapping experiments using ethanol as a hydroxyl radical scavenger show significantly decreased photocatalytic substrate oxidation in the presence of EtOH. Photocatalytic performance analyses using monochromatic visible light irradiation show that the quantum efficiency Φ for indigo photooxidation is strongly dependent on the irradiation wavelength, with higher quantum efficiencies being observed at shorter wavelengths (Φ395nm ca. 15%). Recycling tests show that the compound can be employed as homogeneous photooxidation catalyst multiple times without loss of catalytic activity. High turnover numbers (TON ca. 1200) and turnover frequencies up to TOF ca. 3.44 min(-1) are observed, illustrating the practical applicability of the cluster species.
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Affiliation(s)
- Johannes Tucher
- Ulm University, Institute of Inorganic Chemistry I, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Carsten Streb
- Ulm University, Institute of Inorganic Chemistry I, Albert-Einstein-Allee 11, 89081 Ulm, Germany
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13
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Montanaro S, Ravelli D, Merli D, Fagnoni M, Albini A. Decatungstate As Photoredox Catalyst: Benzylation of Electron-Poor Olefins. Org Lett 2012; 14:4218-21. [DOI: 10.1021/ol301900p] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Sara Montanaro
- PhotoGreen Lab, Department of Chemistry, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy
| | - Davide Ravelli
- PhotoGreen Lab, Department of Chemistry, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy
| | - Daniele Merli
- PhotoGreen Lab, Department of Chemistry, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy
| | - Maurizio Fagnoni
- PhotoGreen Lab, Department of Chemistry, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy
| | - Angelo Albini
- PhotoGreen Lab, Department of Chemistry, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy
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14
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Alberti MN, Vougioukalakis GC, Orfanopoulos M. Photosensitized Oxidations of Substituted Pyrroles: Unanticipated Radical-Derived Oxygenated Products. J Org Chem 2009; 74:7274-82. [DOI: 10.1021/jo9012942] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mariza N. Alberti
- Department of Chemistry, University of Crete, 71003 Voutes, Heraklion, Crete, Greece
| | | | - Michael Orfanopoulos
- Department of Chemistry, University of Crete, 71003 Voutes, Heraklion, Crete, Greece
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15
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Affiliation(s)
- Norbert Hoffmann
- Laboratoire des Réactions Sélectives et Applications, UMR 6519 CNRS et Université de Reims Champagne-Ardenne, UFR Sciences, B.P. 1039, F-51687 Reims, Cedex 02, France
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16
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Clemente-Juan JM, Coronado E, Gaita-Ariño A, Suaud N. Mixed-valence polyoxometalates: spin-coupling and electron distribution in the decawolframate anion reduced by two electrons. J Phys Chem A 2007; 111:9969-77. [PMID: 17845013 DOI: 10.1021/jp073433y] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The decawolframate anion reduced by two electrons, W10O326-, is diamagnetic, and its two "extra" electrons delocalize mainly among its eight equatorial wolfram sites. In this work, we combine a phenomenological Hamiltonian with first-principles calculations to explain the origin of these properties. Through ab initio calculations and effective Hamiltonians on fragments, we determine the values of the magnetic exchange parameters, J, the transfer integrals, t, the Coulombic repulsions, V, and the orbital energies, epsilon. Then, by introducing these parameters in a model Hamiltonian simulating the whole molecule, one obtains that the singlet-triplet gap is 780 meV and that more than a 90% of the "extra" electron density resides on the eight equatorial wolfram ions. An analysis of the interplay between these parameters indicates that electron-transfer processes play a dominant role while magnetic exchange has only a minor influence.
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Affiliation(s)
- Juan M Clemente-Juan
- Instituto de Ciencia Molecular, Universitat de Valencia, Polígono de La Coma s/n, E-46980 Paterna, Spain
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17
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Fornal E, Giannotti C. Photocatalyzed oxidation of cyclohexane with heterogenized decatungstate. J Photochem Photobiol A Chem 2007. [DOI: 10.1016/j.jphotochem.2006.12.023] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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18
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Lykakis IN, Vougioukalakis GC, Orfanopoulos M. Homogeneous Decatungstate-Catalyzed Photooxygenation of Tetrasubstituted Alkenes: A Deuterium Kinetic Isotope Effect Study. J Org Chem 2006; 71:8740-7. [PMID: 17081001 DOI: 10.1021/jo061238u] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The decatungstate W10O32(4-) homogeneous photocatalyzed oxygenation of tetrasubstituted alkenes has been mechanistically studied. In all cases, allylic hydroperoxides are the major products. The primary inter- and intramolecular as well as the remote delta-secondary deuterium kinetic isotope effects for the photooxidation of the 2,3-dimethyl-2-butene and 1,1,1-trideuterio-7-methyl-2-(trideuteriomethyl)octa-2,6-diene along with product analysis suggest a hydrogen abstraction in the rate-determining step. For comparison, singlet oxygen photosensitized oxidations of the above substrates were also studied.
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Affiliation(s)
- Ioannis N Lykakis
- Department of Chemistry, University of Crete, Iraklion, Voutes 71003, Crete, Greece
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19
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Lykakis IN, Orfanopoulos M. Deuterium kinetic isotope effects in homogeneous decatungstate catalyzed photooxygenation of 1,1-diphenylethane and 9-methyl-9H-fluorene: evidence for a hydrogen abstraction mechanism. Tetrahedron Lett 2005. [DOI: 10.1016/j.tetlet.2005.09.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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20
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Latour V, Pigot T, Simon M, Cardy H, Lacombe S. Photo-oxidation of di-n-butylsulfide by various electron transfer sensitizers in oxygenated acetonitrile. Photochem Photobiol Sci 2005; 4:221-9. [PMID: 15696241 DOI: 10.1039/b413865c] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The selective activation of different photosensitizers has been carried out under comparable conditions and their efficiency towards di-n-butylsulfide oxidation in oxygenated acetonitrile compared from the product distribution after 150 minutes of irradiation. As expected, the best selectivity towards sulfoxide is obtained with a conventional energy transfer sensitizer such as Rose Bengal (RB), but also with a quinone with a low-lying triplet state, 2,3,5,6-tetrachloro-1,4-benzoquinone (chloranil or CHLO) and with 9,10-dicyanoanthracene (DCA). More significant yields in sulfonic and sulfuric acids are obtained under sensitization with 9,10-anthraquinone (ANT) or a derivative of benzophenone, 4-benzoyl benzoic acid (4-BB), with which additional experiments were carried out in order to discuss the involvement of either singlet oxygen or superoxide radical anion. Triphenyl pyrylium tetrafluoroborate (TPT+) is inefficient under the selected conditions and sulfide photo-oxidation can only be achieved with higher TPT+ concentrations with simultaneous total TPT+ bleaching. With TPT+, 1,2,4,5-tetracyanobenzene (TCNB) and TiO2, the product distribution and the low selectivity as well as the formation of numerous common by-products are indicative of radical mechanisms. All these results are discussed according to the possible formation of activated oxygen species, such as singlet oxygen, superoxide radical anion or alkylperoxy radicals.
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Affiliation(s)
- Virginie Latour
- Laboratoire de Chimie Theorique et de Physico-Chimie Moleculaire, UMR CNRS 5624, Universite de Pau, BP 1155, 64013, Pau cedex, France
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21
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Photooxidation of aryl alkanes by a decatungstate/triethylsilane system in the presence of molecular oxygen. Tetrahedron Lett 2004. [DOI: 10.1016/j.tetlet.2004.08.096] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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22
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Lykakis IN, Tanielian C, Orfanopoulos M. Decatungstate photocatalyzed oxidation of aryl alkanols. Electron transfer or hydrogen abstraction mechanism? Org Lett 2003; 5:2875-8. [PMID: 12889897 DOI: 10.1021/ol0349211] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
[reaction: see text] Decatungstate W(10)O(32)(4-) photosensitized oxidation of a series of para-X-substituted 1-aryl-1-alkanols was investigated. The only oxidation product of the side-chain of the 1-aryl-1-alkanol was the aryl ketone. The product analysis and kinetic data of the title reaction support a hydrogen atom transfer mechanism in the rate-determining step.
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Affiliation(s)
- Ioannis N Lykakis
- Department of Chemistry, University of Crete, 71409 Iraklion, Greece
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