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Zhang XY, Sun SP, Sang YQ, Xue XS, Min QQ, Zhang X. Reductive Catalytic Difluorocarbene Transfer via Palladium Catalysis. Angew Chem Int Ed Engl 2023; 62:e202306501. [PMID: 37365143 DOI: 10.1002/anie.202306501] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 06/21/2023] [Accepted: 06/26/2023] [Indexed: 06/28/2023]
Abstract
A palladium-catalyzed reductive difluorocarbene transfer reaction that tames difluorocarbene to couple with two electrophiles has been developed, representing a new mode of difluorocarbene transfer reaction. The approach uses low-cost and bulk industrial chemical chlorodifluoromethane (ClCF2 H) as the difluorocarbene precursor. It produces a variety of difluoromethylated (hetero)arenes from widely available aryl halides/triflates and proton sources, featuring high functional group tolerance and synthetic convenience without preparing organometallic reagents. Experimental mechanistic studies reveal that an unexpected Pd0/II catalytic cycle is involved in this reductive reaction, wherein the oxidative addition of palladium(0) difluorocarbene ([Pd0 (Ln )]=CF2 ) with aryl electrophile to generate the key intermediate aryldifluoromethylpalladium [ArCF2 Pd(Ln )X], followed by reaction with hydroquinone, is responsible for the reductive difluorocarbene transfer.
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Affiliation(s)
- Xue-Ying Zhang
- Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China
| | - Shi-Ping Sun
- Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China
| | - Yue-Qian Sang
- Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China
| | - Xiao-Song Xue
- Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China
| | - Qiao-Qiao Min
- Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China
| | - Xingang Zhang
- Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China
- School of Chemistry and Material Sciences, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, 1 Sub-lane Xiangshan, Hangzhou, 310024, China
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Kepler S, Zeller M, Rosokha SV. Anion-π Complexes of Halides with p-Benzoquinones: Structures, Thermodynamics, and Criteria of Charge Transfer to Electron Transfer Transition. J Am Chem Soc 2019; 141:9338-9348. [PMID: 31083908 DOI: 10.1021/jacs.9b03277] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Interchange of complex formation and electron-transfer reactions between halide anions and p-benzoquinones were established via UV-vis spectral and X-ray structural measurements and computational analysis. Solution-phase interaction of the p-benzoquinone acceptors with Cl-, Br-, or I- donors led to the formation of anion-π complexes showing strong absorption bands in the UV-vis range. Formation constants and calculated interaction energies of these complexes increased, and donor/acceptor separations decreased with increasing reduction potentials of p-benzoquinones. Mulliken correlation and NBO analysis indicated a charge-transfer nature of these anion-π associates. Most notably, the increase of the acceptor strength led to a transition between the formation of the persistent anion-π complexes and electron-transfer reactions. Thermodynamic analysis accounted for the experimental observations of anion radicals and trihalide anions in solutions of p-benzoquinones with iodide or (for the strongest acceptor) bromide donors. Kinetics of these processes indicated that anion-π complexes represent critical intermediates of the redox reactions. In contrast to Cl-, Br-, or I- anions, interaction of p-benzoquinones with F- anions led to the formation of σ-complexes, and the appearance of anion radicals in such systems was related to the follow-up reactions of these complexes.
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Affiliation(s)
- Slade Kepler
- Department of Chemistry , Ball State University , Muncie , Indiana 47306 , United States
| | - Matthias Zeller
- Department of Chemistry , Purdue University , West Lafayette , Indiana 47907 , United States
| | - Sergiy V Rosokha
- Department of Chemistry , Ball State University , Muncie , Indiana 47306 , United States
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3
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Kurahashi T. Drastic Redox Shift and Electronic Structural Changes of a Manganese(III)-Salen Oxidation Catalyst upon Reaction with Hydroxide and Cyanide Ion. Inorg Chem 2018; 57:1066-1078. [DOI: 10.1021/acs.inorgchem.7b02474] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Takuya Kurahashi
- Institute for Molecular Science, National Institutes of Natural Sciences, Myodaiji, Okazaki, Aichi 444-8787, Japan
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4
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Abstract
Hexachloro[60]fullerene, C60Cl6, was reacted with a mixture of ROH/H2O (R = Me, Et, n-Pr, (CH2)2C≡CH) to form both C60Cl(OH)(OR)4 and C60Cl(OR)5. Only the C60Cl(OH)(OR)4 were isolated with bulky alcohols, ROH (R = (CH2)3C≡CH, (CH2)4C≡CH). Tetrahydro[60]fullerene epoxides, C60(O)(OR)4, were prepared by treating C60Cl(OH)(OR)4 with CuI. The epoxy moiety could be hydrolyzed to the vicinal diol derivatives, C60(OH)2(OR)4, and then oxidized to form dicarbonyl open-cage fullerenes, C60O2(OR)4. CuI was found to convert the terminal alkynyl addends into iodoalkynyl addends on the C60 cage.
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Affiliation(s)
- Ning Lou
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of the Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Liangbing Gan
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of the Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Shanghai 200032, China
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Kurahashi T. Reverse Catalase Reaction: Dioxygen Activation via Two-Electron Transfer from Hydroxide to Dioxygen Mediated By a Manganese(III) Salen Complex. Inorg Chem 2015; 54:8356-66. [PMID: 26347290 DOI: 10.1021/acs.inorgchem.5b01025] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Although atmospheric dioxygen is regarded as the most ideal oxidant, O2 activation for use in oxygenation reactions intrinsically requires a costly sacrificial reductant. The present study investigated the use of aqueous alkaline solution for O2 activation. A manganese(III) salen complex, Mn(III)(salen)(Cl), in toluene reacts with aqueous KOH solution under aerobic conditions, which yields a di-μ-oxo dimanganese(IV) salen complex, [Mn(IV)(salen)]2(μ-O)2. The (18)O isotope experiments show that (18)O2 is indeed activated to give [Mn(IV)(salen)]2(μ-(18)O)2 via a peroxide intermediate. Interestingly, the (18)OH(-) ion in H2(18)O was also incorporated to yield [Mn(IV)(salen)]2(μ-(18)O)2, which implies that a peroxide species is also generated from (18)OH(-). The addition of benzyl alcohol as a stoichiometric reductant selectively inhibits the (18)O incorporation from (18)OH(-), indicating that the reaction of Mn(III)(salen)(Cl) with OH(-) supplies the electrons for O2 reduction. The conversion of both O2 and OH(-) to a peroxide species is exactly the reverse of a catalase-like reaction, which has a great potential as the most efficient O2 activation. Mechanistic investigations revealed that the reaction of Mn(III)(salen)(Cl) with OH(-) generates a transient species with strong reducing ability, which effects the reduction of O2 by means of a manganese(II) intermediate.
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Affiliation(s)
- Takuya Kurahashi
- Institute for Molecular Science, National Institutes of Natural Sciences , Myodaiji, Okazaki, Aichi 444-8787, Japan
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D'Souza F, Imahori H. Preface — Special Issue in Honor of Professor Shunichi Fukuzumi. J PORPHYR PHTHALOCYA 2015. [DOI: 10.1142/s1088424615020010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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8
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Mulyana Y, Alley KG, Davies KM, Abrahams BF, Moubaraki B, Murray KS, Boskovic C. Dinuclear cobalt(ii) and cobalt(iii) complexes of bis-bidentate napthoquinone ligands. Dalton Trans 2014; 43:2499-511. [DOI: 10.1039/c3dt52811a] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Seven dinuclear cobalt complexes with bridging bis-bidentate naphthoquinone ligands reveal the steric influence of the ancillary capping ligand on the redox potential of the cobalt centres, with metal-catalysed derivatisation of the bridging ligand also observed.
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Affiliation(s)
- Yanyan Mulyana
- School of Chemistry
- University of Melbourne
- Melbourne, Australia
| | - Kerwyn G. Alley
- School of Chemistry
- University of Melbourne
- Melbourne, Australia
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Kim YR, Kim RS, Kang SK, Choi MG, Kim HY, Cho D, Lee JY, Chang SK, Chung TD. Modulation of Quinone PCET Reaction by Ca2+ Ion Captured by Calix[4]quinone in Water. J Am Chem Soc 2013; 135:18957-67. [DOI: 10.1021/ja410406e] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Yang-Rae Kim
- Department
of Chemistry, Seoul National University, Seoul 151-747, Korea
| | - R. Soyoung Kim
- Department
of Chemistry, Seoul National University, Seoul 151-747, Korea
| | - Sun Kil Kang
- Department
of Chemistry, Seoul National University, Seoul 151-747, Korea
| | - Myung Gil Choi
- Department
of Chemistry, Chung-Ang University, Seoul 156-756, Korea
| | - Hong Yeong Kim
- Department
of Chemistry, Chung-Ang University, Seoul 156-756, Korea
| | - Daeheum Cho
- Department
of Chemistry, Sungkyunkwan University, Suwon 440-746, Korea
| | - Jin Yong Lee
- Department
of Chemistry, Sungkyunkwan University, Suwon 440-746, Korea
| | - Suk-Kyu Chang
- Department
of Chemistry, Chung-Ang University, Seoul 156-756, Korea
| | - Taek Dong Chung
- Department
of Chemistry, Seoul National University, Seoul 151-747, Korea
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Hou HL, Li ZJ, Li SH, Chen S, Gao X. Hydroxide-Initiated Conversion of Aromatic Nitriles to Imidazolines: Fullerenes vs TCNE. Org Lett 2013; 15:4646-9. [DOI: 10.1021/ol401834j] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Hui-Lei Hou
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, University of the Chinese Academy of Sciences, Chinese Academy of Sciences, 5625 Renmin Street, Changchun, Jilin 130022, China
| | - Zong-Jun Li
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, University of the Chinese Academy of Sciences, Chinese Academy of Sciences, 5625 Renmin Street, Changchun, Jilin 130022, China
| | - Shu-Hui Li
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, University of the Chinese Academy of Sciences, Chinese Academy of Sciences, 5625 Renmin Street, Changchun, Jilin 130022, China
| | - Si Chen
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, University of the Chinese Academy of Sciences, Chinese Academy of Sciences, 5625 Renmin Street, Changchun, Jilin 130022, China
| | - Xiang Gao
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, University of the Chinese Academy of Sciences, Chinese Academy of Sciences, 5625 Renmin Street, Changchun, Jilin 130022, China
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Mbiya W, Chipinda I, Siegel PD, Mhike M, Simoyi RH. Substituent effects on the reactivity of benzoquinone derivatives with thiols. Chem Res Toxicol 2012; 26:112-23. [PMID: 23237669 DOI: 10.1021/tx300417z] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Benzoquinone (BQ) is an extremely potent electrophilic contact allergen that haptenates endogenous proteins through Michael addition (MA). It is also hypothesized that BQ may haptenate proteins via free radical formation. The objective of this study was to assess the inductive effects (activating and deactivating) of substituents on BQ reactivity and the mechanistic pathway of covalent binding to a nucleophilic thiol. The BQ binding of Cys34 on human serum albumin was studied, and for reactivity studies, nitrobenzenethiol (NBT) was used as a surrogate for protein binding of the BQ and benzoquinone derivatives (BQD). Stopped flow techniques were used to determine pseudofirst order rate constants (k) of methyl-, t-butyl-, and chlorine-substituted BQD reactions with NBT, whereas electron pair resonance (EPR) studies were performed to investigate the presence of the free radical mediated binding mechanism of BQD. Characterization of adducts was performed using mass spectrometry and nuclear magnetic resonance spectroscopy (NMR). The rate constant values demonstrated the chlorine-substituted (activated) BQD to be more reactive toward NBT than the methyl and t-butyl-substituted (deactivated) BQD, and this correlated with the respective EPR intensities. The EPR signal, however, was quenched in the presence of NBT suggesting MA as the dominant reaction pathway. MS and NMR results confirmed adduct formation to be a result of MA onto the BQ ring with vinylic substitution also occurring for chlorine-substituted derivatives. The binding positions on BQ and NBT/BQ(D) stoichiometric ratios were affected by whether the inductive effects of the substituents on the ring were positive or negative. The reactivity of BQ and BQD is discussed in terms of the potential relationship to potential allergenic potency.
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Affiliation(s)
- Wilbes Mbiya
- Department of Chemistry, Portland State University , Portland, Oregon 97207-0751, United States
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12
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Chang WW, Li ZJ, Yang WW, Gao X. Reactions of anionic oxygen nucleophiles with C60 revisited. Org Lett 2012; 14:2386-9. [PMID: 22515146 DOI: 10.1021/ol300805p] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Reactions of C(60) with oxygen nucleophiles of HO(-) and CH(3)O(-) are revisited in PhCN in the presence of PhCH(2)Br. Different from previous results that such reactions lead to the formation of complex mixtures, well-structured C(60) oxazolines are obtained when HO(-) is involved, while di- and tetraadducts with methoxy and benzyl addends are obtained when CH(3)O(-) is engaged. The reactions are followed by in situ vis-near-IR spectroscopy, which reveals further information for the reactions.
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Affiliation(s)
- Wei-Wei Chang
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Graduate School of Chinese Academy of Sciences, Chinese Academy of Sciences, 5625 Renmin Street, Changchun, Jilin 130022, China
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13
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Shishlov NM, Khursan SL. On the possibility of single-electron transfer during alkaline hydrolysis of sulfophthalides. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY B 2011. [DOI: 10.1134/s1990793111090223] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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14
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Wang GW, Lu YM, Chen ZX, Wu SH. An Alternative Type of Fullerene Products from the Reaction of [60]Fullerene with Alkoxides and Subsequent Derivatization. J Org Chem 2009; 74:4841-8. [DOI: 10.1021/jo9005848] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Guan-Wu Wang
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, People’s Republic of China, State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou, Gansu 730000, People’s Republic of China, and Department of Chemistry, Fudan University, Shanghai 200433, People’s Republic of China
| | - Yong-Ming Lu
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, People’s Republic of China, State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou, Gansu 730000, People’s Republic of China, and Department of Chemistry, Fudan University, Shanghai 200433, People’s Republic of China
| | - Zhong-Xiu Chen
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, People’s Republic of China, State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou, Gansu 730000, People’s Republic of China, and Department of Chemistry, Fudan University, Shanghai 200433, People’s Republic of China
| | - Shi-Hui Wu
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, People’s Republic of China, State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou, Gansu 730000, People’s Republic of China, and Department of Chemistry, Fudan University, Shanghai 200433, People’s Republic of China
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15
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Fukuzumi S. Roles of Metal Ions in Controlling Bioinspired Electron-Transfer Systems. Metal Ion-Coupled Electron Transfer. PROGRESS IN INORGANIC CHEMISTRY 2009. [DOI: 10.1002/9780470440124.ch2] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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16
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Izquierdo M, Osuna S, Filippone S, Martín-Domenech A, Solà M, Martín N. H-Bond-Assisted Regioselective (cis-1) Intramolecular Nucleophilic Addition of the Hydroxyl Group to [60]Fullerene. J Org Chem 2009; 74:1480-7. [DOI: 10.1021/jo802152x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Marta Izquierdo
- Departamento de Química Orgánica, Facultad de Química, Universidad Complutense, E-28040 Madrid, Spain, and Institut de Química Computacional and Departament de Química, Universidad de Girona, E-17071 Girona, Catalonia, Spain
| | - Sílvia Osuna
- Departamento de Química Orgánica, Facultad de Química, Universidad Complutense, E-28040 Madrid, Spain, and Institut de Química Computacional and Departament de Química, Universidad de Girona, E-17071 Girona, Catalonia, Spain
| | - Salvatore Filippone
- Departamento de Química Orgánica, Facultad de Química, Universidad Complutense, E-28040 Madrid, Spain, and Institut de Química Computacional and Departament de Química, Universidad de Girona, E-17071 Girona, Catalonia, Spain
| | - Angel Martín-Domenech
- Departamento de Química Orgánica, Facultad de Química, Universidad Complutense, E-28040 Madrid, Spain, and Institut de Química Computacional and Departament de Química, Universidad de Girona, E-17071 Girona, Catalonia, Spain
| | - Miquel Solà
- Departamento de Química Orgánica, Facultad de Química, Universidad Complutense, E-28040 Madrid, Spain, and Institut de Química Computacional and Departament de Química, Universidad de Girona, E-17071 Girona, Catalonia, Spain
| | - Nazario Martín
- Departamento de Química Orgánica, Facultad de Química, Universidad Complutense, E-28040 Madrid, Spain, and Institut de Química Computacional and Departament de Química, Universidad de Girona, E-17071 Girona, Catalonia, Spain
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Murakami M, Ohkubo K, Mandal P, Ganguly T, Fukuzumi S. Does Bimolecular Charge Recombination in Highly Exergonic Electron Transfer Afford the Triplet Excited State or the Ground State of a Photosensitizer? J Phys Chem A 2008; 112:635-42. [DOI: 10.1021/jp0767718] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Motonobu Murakami
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, SORST, Japan Science and Technology Agency (JST), Suita, Osaka 565-0871, Japan, and Department of Spectroscopy, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032,West Bengal, India
| | - Kei Ohkubo
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, SORST, Japan Science and Technology Agency (JST), Suita, Osaka 565-0871, Japan, and Department of Spectroscopy, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032,West Bengal, India
| | - Paulami Mandal
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, SORST, Japan Science and Technology Agency (JST), Suita, Osaka 565-0871, Japan, and Department of Spectroscopy, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032,West Bengal, India
| | - Tapan Ganguly
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, SORST, Japan Science and Technology Agency (JST), Suita, Osaka 565-0871, Japan, and Department of Spectroscopy, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032,West Bengal, India
| | - Shunichi Fukuzumi
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, SORST, Japan Science and Technology Agency (JST), Suita, Osaka 565-0871, Japan, and Department of Spectroscopy, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032,West Bengal, India
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18
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C–S bond cleavage in the sensitized photooxygenation of tert-alkyl phenyl sulfides. The role of superoxide anion. Tetrahedron 2006. [DOI: 10.1016/j.tet.2005.09.154] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Okamoto K, Fukuzumi S. Hydrogen Bonds Not Only Provide a Structural Scaffold to Assemble Donor and Acceptor Moieties of Zinc Porphyrin−Quinone Dyads but Also Control the Photoinduced Electron Transfer to Afford the Long-Lived Charge-Separated States. J Phys Chem B 2005; 109:7713-23. [PMID: 16851896 DOI: 10.1021/jp050352y] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
A series of zinc porphyrin-quinone linked dyads [ZnP-CONH-Q, ZnP-NHCO-Q, and ZnP-n-Q (n = 3, 6, 10)] were designed and synthesized to investigate the effects of hydrogen bonds which can not only provide a structural scaffold to assemble donor and acceptor moieties but also control the photoinduced electron-transfer process. In the case of ZnP-CONH-Q and ZnP-NHCO-Q, the hydrogen bond between the N-H proton and the carbonyl oxygen of Q results in the change in the reduction potential of Q. The strong hydrogen bond between the N-H proton and the carbonyl oxygen of Q*- in ZnP-CONH-Q*-,ZnP-NHCO-Q*-, and ZnP-n-Q*- (n = 3, 6, 10) generated by the chemical reduction has been confirmed by the ESR spectra, which exhibit hyperfine coupling constants in agreement those predicted by the density functional calculations. In the case of ZnP-n-Q (n = 3, 6, 10), on the other hand, the hydrogen bond between two amide groups provides a structural scaffold to assemble the donor (ZnP) and the acceptor (Q) moiety together with the hydrogen bond between the N-H proton and the carbonyl oxygen of Q, leading to attainment of the charge-separated state with a long lifetime up to a microsecond.
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Affiliation(s)
- Ken Okamoto
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, SORST, Japan Science and Technology Agency, Suita, Osaka 565-0871, Japan
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Lee Y, Kitagawa T, Komatsu K. Electron-Transfer-Induced Substitution of Alkylated C60Chlorides with Proton Sponge. J Org Chem 2004; 69:263-9. [PMID: 14725437 DOI: 10.1021/jo0351421] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A series of alkylated C(60) chlorides 1,4-RC(60)Cl (1) were found to undergo nucleophilic substitution with 1,8-bis(dimethylamino)naphthalene (2), affording 1,4-RC(60)Ar [3, Ar = 4,5-bis(dimethylamino)-1-naphthyl] in good yields. An S(RN)1 mechanism, initiated by a single-electron transfer from 2 to 1, is proposed on the basis of the enhanced rates compared with the rate of the S(N)1 reaction of 1 with anisole. The involvement of free radicals in the reaction is supported by the formation of a small amount of dimer RC(60)-C(60)R (4) as a byproduct. The enhanced ability of C(60) chlorides 1 to accept an electron, attributable to the inductive effect of the directly attached chlorine atom, was demonstrated by its reduction potential and calculated LUMO energy.
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Affiliation(s)
- Yangsoo Lee
- Institute for Chemical Research, Kyoto University, and CREST, Japan Science and Technology Corporation, Uji, Kyoto 611-0011, Japan
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Ohkubo K, Suga K, Morikawa K, Fukuzumi S. Selective Oxygenation of Ring-Substituted Toluenes with Electron-Donating and -Withdrawing Substituents by Molecular Oxygen via Photoinduced Electron Transfer. J Am Chem Soc 2003; 125:12850-9. [PMID: 14558834 DOI: 10.1021/ja036645r] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A ring-substituted toluene with an electron-withdrawing substituent, p-tolunitrile, is oxygenated by molecular oxygen to yield the corresponding aldehyde with tetrafluoro-p-dicyanobenzene as a photocatalyst under photoirradiation with an Hg lamp (lambda > 300 nm). The oxygenation of a ring-substituted toluene with an electron-donating substituent, p-xylene, by molecular oxygen is also achieved with 10-methyl-9-phenylacridinium ion as a photocatalyst under visible light irradiation, yielding p-tolualdehyde exclusively as the final oxygenated product. Both the oxygenation reactions are initiated by photoinduced electron transfer from the ring-substituted toluene to the singlet excited state of the photocatalyst. The reason for the high selectivity in the photocatalytic oxygenation of various toluene derivatives by molecular oxygen is discussed on the basis of the photoinduced electron transfer mechanism that does not involve the autoxidation process (radical chain reactions). The reactive intermediates in the photocatalytic cycle are successfully detected as the transient absorption spectra and the electron spin resonance spectra.
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Affiliation(s)
- Kei Ohkubo
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, CREST, Japan Science and Technology Corporation, Suita, Osaka 565-0871, Japan
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22
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Song F, Echegoyen L. In Situ Spectroelectrochemistry and Electrochemical Quartz Crystal Microbalance (EQCM) Characterization of C60 Embedded in a Tetraoctylammonium Bromide Film in Aqueous Solution. J Phys Chem B 2003. [DOI: 10.1021/jp0278420] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Fayi Song
- Department of Chemistry, Clemson University, Clemson, South Carolina 29634
| | - Luis Echegoyen
- Department of Chemistry, Clemson University, Clemson, South Carolina 29634
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Kesti T, Tkachenko N, Yamada H, Imahori H, Fukuzumi S, Lemmetyinen H. C70 vs. C60 in zinc porphyrin-fullerene dyads: prolonged charge separation and ultrafast energy transfer from the second excited singlet state of porphyrin. Photochem Photobiol Sci 2003; 2:251-8. [PMID: 12713225 DOI: 10.1039/b210127k] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The second excited singlet (S2) state of porphyrin was efficiently quenched by the attached fullerene C70 moiety in a zinc porphyrin-C70 dyad. The quenching is largely explained by energy transfer to C70, but the possibility of additional reactions involving the S2 state of porphyrin is discussed. Singlet energy transfer was found to be an important decay pathway also for the first excited singlet (S1) state of porphyrin. In the polar solvent benzonitrile a charge-separated state was formed, and its lifetime was 890 ps, 50% longer than in the analogous porphyrin-C60 dyad.
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Affiliation(s)
- Tero Kesti
- Institute of Materials Chemistry, Tampere University of Technology, PO Box 541, 33101 Tampere, Finland.
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24
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Fukuzumi S, Okamoto K, Yoshida Y, Imahori H, Araki Y, Ito O. Effects of hydrogen bonding on metal ion-promoted intramolecular electron transfer and photoinduced electron transfer in a ferrocene-quinone dyad with a rigid amide spacer. J Am Chem Soc 2003; 125:1007-13. [PMID: 12537500 DOI: 10.1021/ja026441v] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A ferrocene-quinone dyad (Fc-Q) with a rigid amide spacer and Fc-(Me)Q dyad, in which the amide proton acting as a hydrogen-bonding acceptor is replaced by the methyl group, are employed to examine the effects of hydrogen bonding on both the thermal and the photoinduced electron-transfer reactions. The hydrogen bonding of the semiquinone radical anion with the amide proton in Fc-Q(.-) produced by the electron-transfer reduction of Fc-Q is indicated by the significant positive shift of the one-electron reduction potential of Fc-Q. The hyperfine coupling constants of Fc-Q(.-) also indicate the existence of hydrogen bonding, agreeing with those predicted by the density functional calculation. The hydrogen-bonding dynamics in the photoinduced electron transfer from the ferrocene (Fc) to the quinone moiety (Q) in Fc-Q have been successfully detected in the femtosecond laser flash photolysis experiments. Thermal intramolecular electron transfer from Fc to Q in Fc-Q and Fc-(Me)Q also occurs efficiently in the presence of metal ions in acetonitrile at 298 K. The hydrogen bond formed between the semiquinone radical anion and the amide proton in Fc-Q results in remarkable acceleration of the rate of metal ion-promoted electron transfer as compared to the rate of Fc-(Me)Q in which hydrogen bonding is prohibited. The metal ion-promoted electron-transfer rates are well correlated with the binding energies of superoxide ion-metal ion complexes, which are derived from the g(zz) values of the ESR spectra.
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Affiliation(s)
- Shunichi Fukuzumi
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan.
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25
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Vehmanen V, Tkachenko NV, Efimov A, Damlin P, Ivaska A, Lemmetyinen H. The Role of the Exciplex State in Photoinduced Electron Transfer of Phytochlorin−[60]Fullerene Dyads. J Phys Chem A 2002. [DOI: 10.1021/jp0260595] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Visa Vehmanen
- Institute of Materials Chemistry, Tampere University of Technology, P.O. Box 541, FIN-33101 Tampere, Finland, and Process Chemistry Group c/o Laboratory of Analytical Chemistry, Åbo Akademi University, FIN-20500 Turku-Åbo, Finland
| | - Nikolai V. Tkachenko
- Institute of Materials Chemistry, Tampere University of Technology, P.O. Box 541, FIN-33101 Tampere, Finland, and Process Chemistry Group c/o Laboratory of Analytical Chemistry, Åbo Akademi University, FIN-20500 Turku-Åbo, Finland
| | - Alexander Efimov
- Institute of Materials Chemistry, Tampere University of Technology, P.O. Box 541, FIN-33101 Tampere, Finland, and Process Chemistry Group c/o Laboratory of Analytical Chemistry, Åbo Akademi University, FIN-20500 Turku-Åbo, Finland
| | - Pia Damlin
- Institute of Materials Chemistry, Tampere University of Technology, P.O. Box 541, FIN-33101 Tampere, Finland, and Process Chemistry Group c/o Laboratory of Analytical Chemistry, Åbo Akademi University, FIN-20500 Turku-Åbo, Finland
| | - Ari Ivaska
- Institute of Materials Chemistry, Tampere University of Technology, P.O. Box 541, FIN-33101 Tampere, Finland, and Process Chemistry Group c/o Laboratory of Analytical Chemistry, Åbo Akademi University, FIN-20500 Turku-Åbo, Finland
| | - Helge Lemmetyinen
- Institute of Materials Chemistry, Tampere University of Technology, P.O. Box 541, FIN-33101 Tampere, Finland, and Process Chemistry Group c/o Laboratory of Analytical Chemistry, Åbo Akademi University, FIN-20500 Turku-Åbo, Finland
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Fukuzumi S, Yoshida Y, Okamoto K, Imahori H, Araki Y, Ito O. Hydrogen-bonding dynamics in photoinduced electron transfer in a ferrocene-quinone linked dyad with a rigid amide spacer. J Am Chem Soc 2002; 124:6794-5. [PMID: 12059178 DOI: 10.1021/ja0157604] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A newly designed ferrocene-quinone dyad with an amide space (Fc-Q) is employed to examine formation of the hydrogen bonding in the one-electron reduced form (Q*-) and the dynamics in the photoinduced electron-transfer reaction from the ferrocene to the quinone moiety. Photoexcitation of the Q moiety in Fc-Q in deaerated PhCN with 388 nm results in intramolecular electron transfer from Fc to the singlet excited state of Q to produce Fc+-Q*- without changing the conformation (<1 ps), followed by hydrogen bond formation with the amide proton of the spacer (tau = approximately 5 ps). The resulting radical ion pair decays via a back electron transfer to the ground state at a longer time scale with a rate constant of 2.6 x 108 s-1.
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Affiliation(s)
- Shunichi Fukuzumi
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, CREST, Japan Science and Technology Corporation (JST), 2-1, Yamada-oka, Suita, Osaka 565-0871, Japan.
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27
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Vehmanen V, Tkachenko NV, Imahori H, Fukuzumi S, Lemmetyinen H. Charge-transfer emission of compact porphyrin-fullerene dyad analyzed by Marcus theory of electron-transfer. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2001; 57:2229-2244. [PMID: 11603840 DOI: 10.1016/s1386-1425(01)00496-6] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A porphyrin-fullerene dyad, which is characterized by a close proximity of the porphyrin donor and the fullerene acceptor, was found to undergo a photoinduced electron transfer both in solutions and in solid films. Near-infrared charge-transfer (CT) emission was observed and analyzed in frame of the semi-classical Marcus electron-transfer theory yielding values for the reaction free energy, -deltaG degrees = 1.75 eV, the internal reorganization energy, lambdav = 0.05 eV, and the donor-acceptor vibrational energy, hv(v) = 0.14 eV, both in solution and in solid film. The influence of the environment on the CT properties of the dyad is described by a single parameter, the outer-sphere reorganization energy, lambdas, which varies from 0.05 eV in non-polar solvents and films to 0.13 eV in solvents of moderate polarity. At low temperatures (T< 200 K), the CT emission consists of distinct bands shifted from each other by value hv(v). This is the first direct observation of the vibrational frequencies of a porphyrin-fullerene donor-acceptor system.
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Affiliation(s)
- V Vehmanen
- Institute of Materials Chemistry, Tampere University of Technology, Finland.
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Del Giacco T, Baciocchi E, Lanzalunga O, Elisei F. Competitive decay pathways of the radical ions formed by photoinduced electron transfer between quinones and 4,4'-dimethoxydiphenylmethane in acetonitrile. Chemistry 2001; 7:3005-13. [PMID: 11495427 DOI: 10.1002/1521-3765(20010716)7:14<3005::aid-chem3005>3.0.co;2-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The reactivity of the cation radical of (4-MeOC6H4)2CH2 photosensitized by 1,4-benzoquinone (BQ), 2,5-dichloro-1,4-benzoquinone (Cl2BQ), and tetrachloro-1,4-benzoquinone (chloranil, CA) was investigated in acetonitrile. The main photoreaction products obtained by steady-state irradiation were identified to be: (4-MeOC6H4)2-CHOC6H4OH, sensitized by BQ; (4-MeOC6H4)2CHCl, sensitized by Cl2BQ; (4-MeOC6H4)2CHOH, sensitized by CA. The mechanism of their formation was investigated by nanosecond laser flash photolysis that allowed transient species (radical ions, neutral radicals, and ions) to be detected and characterized in terms of absorption spectra, formation quantum yields, and decay rate constants. For all systems, the interaction between the triplet quinone (Q) and (4-MeOC6H4)2CH2 produced the corresponding radical ions (quantum yield phi > or = 0.72) which mainly decay by back electron transfer processes. Less efficient reaction routes for the radical ions Q*- and (4-MeOC6H4)2CH2*+ were also: i) the proton-transfer process with the formation of the radical (4-MeOC6H4)2CH* by use of Cl2BQ; ii) the hydrogen-transfer process with the formation of the cation (4-MeOC6H4)2CH+ in the case of CA. Instead. BQ sensitized a much higher yield of BOH* and (4-MeOC6H4)2CH*, mainly by the direct interaction of triplet BQ with (4-MeOC6H4)2CH2. It was also shown that the presence of salts decreases significantly the rate of the back electron transfer process and enhances the quantum yields of formation of the neutral radicals and ions when Cl2BQ and CA are used, respectively. The behavior of BQ*-, Cl2BQ*-, and CA*- appears to be mainly determined by the Mulliken charges on the oxygen atom obtained from quantum mechanical calculations with the model B3LYP/6-311G(d,p). Spin densities seem to be much less important.
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Affiliation(s)
- T Del Giacco
- Dipartimento di Chimica, Università di Perugia, Italy
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Kitagawa T, Takeuchi K. Monofunctionalized C60Ions: Their Generation, Stability, and Reactions. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2001. [DOI: 10.1246/bcsj.74.785] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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30
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Konishi T, Fujitsuka M, Ito O, Toba Y, Usui Y. The C60-Photosensitized Reduction of Methyl Viologen Through the Intermediary of O2. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2001. [DOI: 10.1246/bcsj.74.39] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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31
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Konishi T, Fujitsuka M, Ito O, Toba Y, Usui Y. C60 as Photosensitizing Electron-Transfer Mediator for Ion-Pair Charge-Transfer Complexes between Borate Anions and Methyl Viologen Dication. J Phys Chem A 1999. [DOI: 10.1021/jp9921856] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Toshifumi Konishi
- Institute for Chemical Reaction Science, Tohoku University, Katahira, Aoba-ku, Sendai, 980-8577, Japan, Tsukuba Research Laboratory, Toyo Ink, 27, Wadai, Tsukuba, 300-4247, Japan, and Graduate School of Science and Engineering, Ibaraki University, Bunkyo, Mito, 310-8512, Japan
| | - Mamoru Fujitsuka
- Institute for Chemical Reaction Science, Tohoku University, Katahira, Aoba-ku, Sendai, 980-8577, Japan, Tsukuba Research Laboratory, Toyo Ink, 27, Wadai, Tsukuba, 300-4247, Japan, and Graduate School of Science and Engineering, Ibaraki University, Bunkyo, Mito, 310-8512, Japan
| | - Osamu Ito
- Institute for Chemical Reaction Science, Tohoku University, Katahira, Aoba-ku, Sendai, 980-8577, Japan, Tsukuba Research Laboratory, Toyo Ink, 27, Wadai, Tsukuba, 300-4247, Japan, and Graduate School of Science and Engineering, Ibaraki University, Bunkyo, Mito, 310-8512, Japan
| | - Yasumasa Toba
- Institute for Chemical Reaction Science, Tohoku University, Katahira, Aoba-ku, Sendai, 980-8577, Japan, Tsukuba Research Laboratory, Toyo Ink, 27, Wadai, Tsukuba, 300-4247, Japan, and Graduate School of Science and Engineering, Ibaraki University, Bunkyo, Mito, 310-8512, Japan
| | - Yoshiharu Usui
- Institute for Chemical Reaction Science, Tohoku University, Katahira, Aoba-ku, Sendai, 980-8577, Japan, Tsukuba Research Laboratory, Toyo Ink, 27, Wadai, Tsukuba, 300-4247, Japan, and Graduate School of Science and Engineering, Ibaraki University, Bunkyo, Mito, 310-8512, Japan
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32
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Tkachenko NV, Rantala L, Tauber AY, Helaja J, Hynninen PH, Lemmetyinen H. Photoinduced Electron Transfer in Phytochlorin−[60]Fullerene Dyads. J Am Chem Soc 1999. [DOI: 10.1021/ja9915605] [Citation(s) in RCA: 255] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Nikolai V. Tkachenko
- Contribution from the Institute of Materials Chemistry, Tampere University of Technology, P.O. Box 541, FIN-33101 Tampere, Finland, and Department of Chemistry, University of Helsinki, P.O. Box 55, FIN-00014 Helsinki, Finland
| | - Lasse Rantala
- Contribution from the Institute of Materials Chemistry, Tampere University of Technology, P.O. Box 541, FIN-33101 Tampere, Finland, and Department of Chemistry, University of Helsinki, P.O. Box 55, FIN-00014 Helsinki, Finland
| | - Andrei Y. Tauber
- Contribution from the Institute of Materials Chemistry, Tampere University of Technology, P.O. Box 541, FIN-33101 Tampere, Finland, and Department of Chemistry, University of Helsinki, P.O. Box 55, FIN-00014 Helsinki, Finland
| | - Juho Helaja
- Contribution from the Institute of Materials Chemistry, Tampere University of Technology, P.O. Box 541, FIN-33101 Tampere, Finland, and Department of Chemistry, University of Helsinki, P.O. Box 55, FIN-00014 Helsinki, Finland
| | - Paavo H. Hynninen
- Contribution from the Institute of Materials Chemistry, Tampere University of Technology, P.O. Box 541, FIN-33101 Tampere, Finland, and Department of Chemistry, University of Helsinki, P.O. Box 55, FIN-00014 Helsinki, Finland
| | - Helge Lemmetyinen
- Contribution from the Institute of Materials Chemistry, Tampere University of Technology, P.O. Box 541, FIN-33101 Tampere, Finland, and Department of Chemistry, University of Helsinki, P.O. Box 55, FIN-00014 Helsinki, Finland
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Tanemura K, Nishida Y, Suzuki T, Satsumabayashi K, Horaguchi T. Cleavage of Protecting Groups Catalysed by π-Acceptors. JOURNAL OF CHEMICAL RESEARCH 1999. [DOI: 10.1177/174751989902300126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The cleavage of protecting groups is caused by the acidic adducts produced from the methanolysis of acceptors.
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Affiliation(s)
- Kiyoshi Tanemura
- School of Dentistry at Niigata, The Nippon Dental University, Hamaura-cho, Niigata 951-8580, Japan
| | - Yoko Nishida
- School of Dentistry at Niigata, The Nippon Dental University, Hamaura-cho, Niigata 951-8580, Japan
| | - Tsuneo Suzuki
- School of Dentistry at Niigata, The Nippon Dental University, Hamaura-cho, Niigata 951-8580, Japan
| | - Koko Satsumabayashi
- School of Dentistry at Niigata, The Nippon Dental University, Hamaura-cho, Niigata 951-8580, Japan
| | - Takaaki Horaguchi
- Department of Chemistry, Faculty of Science, Niigata University, Ikarashi, Nigata 950-2181, Japan
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Tanemura K, Nishida Y, Suzuki T, Satsumabayashi K, Horaguchi T. Cleavage of Protecting Groups Catalysed by π-Acceptors. JOURNAL OF CHEMICAL RESEARCH 1999. [DOI: 10.1039/a807416j] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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