1051
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Banerjee A, Ganguly G, Tripathi R, Nair NN, Paul A. Unearthing the Mechanism of Prebiotic Nitrile Bond Reduction in Hydrogen Cyanide through a Curious Association of Two Molecular Radical Anions. Chemistry 2014; 20:6348-57. [DOI: 10.1002/chem.201304627] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Revised: 01/24/2014] [Indexed: 11/09/2022]
Affiliation(s)
- Ambar Banerjee
- Raman Centre for Atomic Molecular and Optical Sciences, Indian Association for the Cultivation of Science, 2A/2B Raja S.C. Mullick Road, Kolkata, 700032 (India)
| | - Gaurab Ganguly
- Raman Centre for Atomic Molecular and Optical Sciences, Indian Association for the Cultivation of Science, 2A/2B Raja S.C. Mullick Road, Kolkata, 700032 (India)
| | - Ravi Tripathi
- Department of Chemistry, Indian Institute of Technology Kanpur, IIT Kanpur, Kalyanpur, Kanpur, UP 208016 (India)
| | - Nisanth N. Nair
- Department of Chemistry, Indian Institute of Technology Kanpur, IIT Kanpur, Kalyanpur, Kanpur, UP 208016 (India)
| | - Ankan Paul
- Raman Centre for Atomic Molecular and Optical Sciences, Indian Association for the Cultivation of Science, 2A/2B Raja S.C. Mullick Road, Kolkata, 700032 (India)
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1052
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Isobe H, Tanaka K, Shen JR, Yamaguchi K. Water oxidation chemistry of a synthetic dinuclear ruthenium complex containing redox-active quinone ligands. Inorg Chem 2014; 53:3973-84. [PMID: 24694023 DOI: 10.1021/ic402340d] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
We investigated theoretically the catalytic mechanism of electrochemical water oxidation in aqueous solution by a dinuclear ruthenium complex containing redox-active quinone ligands, [Ru2(X)(Y)(3,6-tBu2Q)2(btpyan)](m+) [X, Y = H2O, OH, O, O2; 3,6-tBu2Q = 3,6-di-tert-butyl-1,2-benzoquinone; btpyan =1,8-bis(2,2':6',2″-terpyrid-4'-yl)anthracene] (m = 2, 3, 4) (1). The reaction involves a series of electron and proton transfers to achieve redox leveling, with intervening chemical transformations in a mesh scheme, and the entire molecular structure and motion of the catalyst 1 work together to drive the catalytic cycle for water oxidation. Two substrate water molecules can bind to 1 with simultaneous loss of one or two proton(s), which allows pH-dependent variability in the proportion of substrate-bound structures and following pathways for oxidative activation of the aqua/hydroxo ligands at low thermodynamic and kinetic costs. The resulting bis-oxo intermediates then undergo endothermic O-O radical coupling between two Ru(III)-O(•) units in an anti-coplanar conformation leading to bridged μ-peroxo or μ-superoxo intermediates. The μ-superoxo species can liberate oxygen with the necessity for the preceding binding of a water molecule, which is possible only after four-electron oxidation is completed. The magnitude of catalytic current would be limited by the inherent sluggishness of the hinge-like bending motion of the bridged μ-superoxo complex that opens up the compact, hydrophobic active site of the catalyst and thereby allows water entry under dynamic conditions. On the basis of a newly proposed mechanism, we rationalize the experimentally observed behavior of electrode kinetics with respect to potential and discuss what causes a high overpotential for water oxidation by 1.
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Affiliation(s)
- Hiroshi Isobe
- Division of Bioscience, Graduate School of Natural Science and Technology/Faculty of Science, Okayama University , Okayama 700-8530, Japan
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1053
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Abstract
Herein, molecular strings of ions built along charge-transporting channels are shown to dramatically increase photocurrents and enable charge transport over long distances, thus confirming the existence and significance of ion-gated photosystems. For their synthesis, ordered and oriented stacks of naphthalenediimides were grown on indium tin oxide by ring-opening disulfide-exchange polymerization. To these charge-transporting channels, coaxial strings of anions or cations-fixed, mobile, complete, partial, pure, or mixed-were added by orthogonal hydrazone exchange. The presence of partially protonated carboxylates was found to most significantly increase activity, implying that they both attract holes and repel electrons, that is, facilitate photoinduced charge separation and hinder charge recombination at the same time. As a result of this quite remarkable situation, photocurrents increased rather than decreased with increasing charge stabilization on their "stepping stones." The presence of mobile anions facilitated long-distance charge transport through thick films. Turned off by inhibited anion mobility, that is, proton hopping, hole/proton antiport is identified to account for long-distance charge transport in ion-gated photosystems.
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Affiliation(s)
- Naomi Sakai
- Department of Organic Chemistry, University of Geneva , CH-1211 Geneva, Switzerland
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1054
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Kim JH, Lee M, Park CB. Polydopamine as a Biomimetic Electron Gate for Artificial Photosynthesis. Angew Chem Int Ed Engl 2014; 53:6364-8. [DOI: 10.1002/anie.201402608] [Citation(s) in RCA: 97] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Indexed: 11/10/2022]
Affiliation(s)
- Jae Hong Kim
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, 335 Science Road, Daejeon 305‐701 (Republic of Korea)
| | - Minah Lee
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, 335 Science Road, Daejeon 305‐701 (Republic of Korea)
| | - Chan Beum Park
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, 335 Science Road, Daejeon 305‐701 (Republic of Korea)
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1055
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Kim JH, Lee M, Park CB. Polydopamine as a Biomimetic Electron Gate for Artificial Photosynthesis. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201402608] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Jae Hong Kim
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, 335 Science Road, Daejeon 305‐701 (Republic of Korea)
| | - Minah Lee
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, 335 Science Road, Daejeon 305‐701 (Republic of Korea)
| | - Chan Beum Park
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, 335 Science Road, Daejeon 305‐701 (Republic of Korea)
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1056
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Chen X, Ma G, Sun W, Dai H, Xiao D, Zhang Y, Qin X, Liu Y, Bu Y. Water Promoting Electron Hole Transport between Tyrosine and Cysteine in Proteins via a Special Mechanism: Double Proton Coupled Electron Transfer. J Am Chem Soc 2014; 136:4515-24. [DOI: 10.1021/ja406340z] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Xiaohua Chen
- School
of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 400030, China
| | - Guangcai Ma
- School
of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China
| | - Weichao Sun
- School
of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 400030, China
| | - Hongjing Dai
- School
of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 400030, China
| | - Dong Xiao
- School
of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 400030, China
| | - Yanfang Zhang
- School
of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 400030, China
| | - Xin Qin
- School
of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 400030, China
| | - Yongjun Liu
- School
of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China
| | - Yuxiang Bu
- School
of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China
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1057
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Chen S, Navizet I, Lindh R, Liu Y, Ferré N. Hybrid QM/MM Simulations of the Obelin Bioluminescence and Fluorescence Reveal an Unexpected Light Emitter. J Phys Chem B 2014; 118:2896-903. [DOI: 10.1021/jp412198w] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Shufeng Chen
- Key
Laboratory of Theoretical and Computational Photochemistry, Ministry
of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P.R. China
- Aix-Marseille
Université, CNRS, Institut de Chimie Radicalaire (UMR-7273), Marseille 13397, France
| | - Isabelle Navizet
- Laboratoire
de Modélisation et Simulation Multi Echelle, Université Paris-Est, MSME UMR 8208 CNRS. 5 bd Descartes, 77454 Marne-la-Vallé, France
- Molecular
Sciences Institute, School of Chemistry, University of the Witwatersrand, PO
Wits, Johannesburg 2050, South Africa
| | - Roland Lindh
- Department
of Chemistry − Ångström, Uppsala University, P.O. Box 518, SE-751 20 Uppsala, Sweden
- Uppsala
Center
of Computational Chemistry - UC3, Uppsala University, P.O. Box 518, SE-751 20 Uppsala, Sweden
| | - Yajun Liu
- Key
Laboratory of Theoretical and Computational Photochemistry, Ministry
of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P.R. China
| | - Nicolas Ferré
- Aix-Marseille
Université, CNRS, Institut de Chimie Radicalaire (UMR-7273), Marseille 13397, France
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1058
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Hopkinson MN, Sahoo B, Li JL, Glorius F. Dual Catalysis Sees the Light: Combining Photoredox with Organo-, Acid, and Transition-Metal Catalysis. Chemistry 2014; 20:3874-86. [DOI: 10.1002/chem.201304823] [Citation(s) in RCA: 579] [Impact Index Per Article: 57.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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1059
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Chen J, Kuss-Petermann M, Wenger OS. Distance Dependence of Bidirectional Concerted Proton-Electron Transfer in Phenol-Ru(2,2′-bipyridine)32+Dyads. Chemistry 2014; 20:4098-104. [DOI: 10.1002/chem.201304256] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Indexed: 11/08/2022]
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1060
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Li Q, Noffke BW, Wang Y, Menezes B, Peters DG, Raghavachari K, Li LS. Electrocatalytic Oxygen Activation by Carbanion Intermediates of Nitrogen-Doped Graphitic Carbon. J Am Chem Soc 2014; 136:3358-61. [DOI: 10.1021/ja413179n] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Qiqi Li
- Department
of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Benjamin W. Noffke
- Department
of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Yilun Wang
- Department
of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Bruna Menezes
- Department
of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Dennis G. Peters
- Department
of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Krishnan Raghavachari
- Department
of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Liang-shi Li
- Department
of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
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1061
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Lewandowska-Andralojc A, Grills DC, Zhang J, Bullock RM, Miyazawa A, Kawanishi Y, Fujita E. Kinetic and Mechanistic Studies of Carbon-to-Metal Hydrogen Atom Transfer Involving Os-Centered Radicals: Evidence for Tunneling. J Am Chem Soc 2014; 136:3572-8. [DOI: 10.1021/ja4123076] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - David C. Grills
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973-5000, United States
| | - Jie Zhang
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973-5000, United States
| | - R. Morris Bullock
- Physical
Sciences Division, Pacific Northwest National Laboratory, P.O. Box 999, K2-57, Richland, Washington 99352, United States
| | - Akira Miyazawa
- National Institute of Advanced Industrial Science and Technology, 4-2-1 Nigatake,
Miyagino, Sendai, Miyagi 983-8551, Japan
| | - Yuji Kawanishi
- National Institute of Advanced Industrial Science and Technology, Tsukuba Central 5, 1-1-1, Higashi, Tsukuba, Ibaraki, 305-8565, Japan
| | - Etsuko Fujita
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973-5000, United States
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1062
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Burford RJ, Piers WE, Ess DH, Parvez M. Reversible Interconversion Between a Monomeric Iridium Hydroxo and a Dinuclear Iridium μ-Oxo Complex. J Am Chem Soc 2014; 136:3256-63. [DOI: 10.1021/ja412650s] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Richard J. Burford
- Department
of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, Alberta, Canada T2N 1N4,
| | - Warren E. Piers
- Department
of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, Alberta, Canada T2N 1N4,
| | - Daniel H. Ess
- Department
of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, United States
| | - Masood Parvez
- Department
of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, Alberta, Canada T2N 1N4,
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1063
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Li Z, Liu X, Zhao W, Wang S, Zhou W, Wei L, Yu M. Naked-Eye Detection of C1–C4 Alcohols Based on Ground-State Intramolecular Proton Transfer. Anal Chem 2014; 86:2521-5. [DOI: 10.1021/ac403550t] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Zhanxian Li
- The College
of Chemistry
and Molecular Engineering, Zhengzhou University, Zhengzhou 450001, China
| | - Xingjiang Liu
- The College
of Chemistry
and Molecular Engineering, Zhengzhou University, Zhengzhou 450001, China
| | - Wanying Zhao
- The College
of Chemistry
and Molecular Engineering, Zhengzhou University, Zhengzhou 450001, China
| | - Sheng Wang
- The College
of Chemistry
and Molecular Engineering, Zhengzhou University, Zhengzhou 450001, China
| | - Wan Zhou
- The College
of Chemistry
and Molecular Engineering, Zhengzhou University, Zhengzhou 450001, China
| | - Liuhe Wei
- The College
of Chemistry
and Molecular Engineering, Zhengzhou University, Zhengzhou 450001, China
| | - Mingming Yu
- The College
of Chemistry
and Molecular Engineering, Zhengzhou University, Zhengzhou 450001, China
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1064
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Le Goff A, Vénec D, Le Roy C, Pétillon FY, Schollhammer P, Talarmin J. Acid-Base Control of Hemilabile Proton-Responsive Protecting Devices in Dimolybdenum, Thiolate-Bridged Complexes. Inorg Chem 2014; 53:2200-10. [DOI: 10.1021/ic402873c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Alan Le Goff
- UMR CNRS 6521 ≪ Chimie,
Electrochimie Moléculaires et Chimie Analytique ≫ Université de Bretagne Occidentale, UFR Sciences et Techniques, CS 93837, 29238 Brest-Cedex
3, France
| | - David Vénec
- UMR CNRS 6521 ≪ Chimie,
Electrochimie Moléculaires et Chimie Analytique ≫ Université de Bretagne Occidentale, UFR Sciences et Techniques, CS 93837, 29238 Brest-Cedex
3, France
| | - Christine Le Roy
- UMR CNRS 6521 ≪ Chimie,
Electrochimie Moléculaires et Chimie Analytique ≫ Université de Bretagne Occidentale, UFR Sciences et Techniques, CS 93837, 29238 Brest-Cedex
3, France
| | - François Y. Pétillon
- UMR CNRS 6521 ≪ Chimie,
Electrochimie Moléculaires et Chimie Analytique ≫ Université de Bretagne Occidentale, UFR Sciences et Techniques, CS 93837, 29238 Brest-Cedex
3, France
| | - Philippe Schollhammer
- UMR CNRS 6521 ≪ Chimie,
Electrochimie Moléculaires et Chimie Analytique ≫ Université de Bretagne Occidentale, UFR Sciences et Techniques, CS 93837, 29238 Brest-Cedex
3, France
| | - Jean Talarmin
- UMR CNRS 6521 ≪ Chimie,
Electrochimie Moléculaires et Chimie Analytique ≫ Université de Bretagne Occidentale, UFR Sciences et Techniques, CS 93837, 29238 Brest-Cedex
3, France
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1065
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Photocurrent generation based on a light-driven proton pump in an artificial liquid membrane. Nat Chem 2014; 6:202-7. [DOI: 10.1038/nchem.1858] [Citation(s) in RCA: 124] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Accepted: 12/17/2013] [Indexed: 12/23/2022]
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1066
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Kärkäs MD, Johnston EV, Verho O, Åkermark B. Artificial photosynthesis: from nanosecond electron transfer to catalytic water oxidation. Acc Chem Res 2014; 47:100-11. [PMID: 23957573 DOI: 10.1021/ar400076j] [Citation(s) in RCA: 141] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Human society faces a fundamental challenge as energy consumption is projected to increase due to population and economic growth as fossil fuel resources decrease. Therefore the transition to alternative and sustainable energy sources is of the utmost importance. The conversion of solar energy into chemical energy, by splitting H2O to generate molecular O2 and H2, could contribute to solving the global energy problem. Developing such a system will require the combination of several complicated processes, such as light-harvesting, charge separation, electron transfer, H2O oxidation, and reduction of the generated protons. The primary processes of charge separation and catalysis, which occur in the natural photosynthetic machinery, provide us with an excellent blueprint for the design of such systems. This Account describes our efforts to construct supramolecular assemblies capable of carrying out photoinduced electron transfer and to develop artificial water oxidation catalysts (WOCs). Early work in our group focused on linking a ruthenium chromophore to a manganese-based oxidation catalyst. When we incorporated a tyrosine unit into these supramolecular assemblies, we could observe fast intramolecular electron transfer from the manganese centers, via the tyrosine moiety, to the photooxidized ruthenium center, which clearly resembles the processes occurring in the natural system. Although we demonstrated multi-electron transfer in our artificial systems, the bottleneck proved to be the stability of the WOCs. Researchers have developed a number of WOCs, but the majority can only catalyze H2O oxidation in the presence of strong oxidants such as Ce(IV), which is difficult to generate photochemically. By contrast, illumination of ruthenium(II) photosensitizers in the presence of a sacrificial acceptor generates [Ru(bpy)3](3+)-type oxidants. Their oxidation potentials are significantly lower than that of Ce(IV), but our group recently showed that incorporating negatively charged groups into the ligand backbone could decrease the oxidation potential of the catalysts and, at the same time, decrease the potential for H2O oxidation. This permitted us to develop both ruthenium- and manganese-based WOCs that can operate under neutral conditions, driven by the mild oxidant [Ru(bpy)3](3+). Many hurdles to the development of viable systems for the production of solar fuels remain. However, the combination of important features from the natural photosynthetic machinery and novel artificial components adds insights into the complicated catalytic processes that are involved in splitting H2O.
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Affiliation(s)
- Markus D. Kärkäs
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Eric V. Johnston
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Oscar Verho
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Björn Åkermark
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
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1067
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Inagaki T, Yamamoto T. Critical Role of Deep Hydrogen Tunneling to Accelerate the Antioxidant Reaction of Ubiquinol and Vitamin E. J Phys Chem B 2014; 118:937-50. [DOI: 10.1021/jp410263f] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Taichi Inagaki
- Department of
Chemistry, Graduate School of
Science, Kyoto University, Kyoto 606-8502, Japan
| | - Takeshi Yamamoto
- Department of
Chemistry, Graduate School of
Science, Kyoto University, Kyoto 606-8502, Japan
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1068
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Sumliner JM, Lv H, Fielden J, Geletii YV, Hill CL. Polyoxometalate Multi-Electron-Transfer Catalytic Systems for Water Splitting. Eur J Inorg Chem 2014. [DOI: 10.1002/ejic.201301573] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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1069
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Lamberson CR, Xu L, Muchalski H, Montenegro-Burke JR, Shmanai VV, Bekish AV, McLean JA, Clarke CF, Shchepinov MS, Porter NA. Unusual kinetic isotope effects of deuterium reinforced polyunsaturated fatty acids in tocopherol-mediated free radical chain oxidations. J Am Chem Soc 2014; 136:838-41. [PMID: 24380377 DOI: 10.1021/ja410569g] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Substitution of -CD2- at the reactive centers of linoleic and linolenic acids reduces the rate of abstraction of D by a tocopheryl radical by as much as 36-fold, compared to the abstraction of H from a corresponding -CH2- center. This H atom transfer reaction is the rate-determining step in the tocopherol-mediated peroxidation of lipids in human low-density lipoproteins, a process that has been linked to coronary artery disease. The unanticipated large kinetic isotope effects reported here for the tocopherol-mediated oxidation of linoleic and linolenic acids and esters suggests that tunneling makes this process favorable.
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Affiliation(s)
- Connor R Lamberson
- Department of Chemistry and Vanderbilt Institute of Chemical Biology, Vanderbilt University , Nashville, Tennessee 37235, United States
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1070
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Sousa SF, Sampaio RN, Barbosa Neto NM, Machado AEH, Patrocinio AOT. The photophysics of fac-[Re(CO)3(NN)(bpa)]+ complexes: a theoretical/experimental study. Photochem Photobiol Sci 2014; 13:1213-24. [DOI: 10.1039/c4pp00074a] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The influence of the polypyridyl ligand on the photophysics of Re(i) tricarbonyl complexes was investigated by steady-state and time resolved spectroscopy as well as by theoretical calculations.
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Affiliation(s)
- S. F. Sousa
- Laboratory of Photochemistry and Materials Science
- Instituto de Química – Universidade Federal de Uberlandia
- Uberlandia, Brazil
| | - R. N. Sampaio
- Instituto de Física – Universidade Federal de Uberlandia
- Uberlandia, Brazil
| | - N. M. Barbosa Neto
- Instituto de Física – Universidade Federal de Uberlandia
- Uberlandia, Brazil
| | - A. E. H. Machado
- Laboratory of Photochemistry and Materials Science
- Instituto de Química – Universidade Federal de Uberlandia
- Uberlandia, Brazil
| | - A. O. T. Patrocinio
- Laboratory of Photochemistry and Materials Science
- Instituto de Química – Universidade Federal de Uberlandia
- Uberlandia, Brazil
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1071
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Linke K, Ho FM. Water in Photosystem II: Structural, functional and mechanistic considerations. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:14-32. [DOI: 10.1016/j.bbabio.2013.08.003] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Revised: 08/08/2013] [Accepted: 08/13/2013] [Indexed: 12/30/2022]
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1072
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Xie X, Bakker E. Creating electrochemical gradients by light: from bio-inspired concepts to photoelectric conversion. Phys Chem Chem Phys 2014; 16:19781-9. [DOI: 10.1039/c4cp02566k] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Artificial light harvesting systems can be used to convert light into electrochemical gradients and photocurrents.
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Affiliation(s)
- Xiaojiang Xie
- Department of Inorganic and Analytical Chemistry
- University of Geneva
- Geneva, Switzerland
| | - Eric Bakker
- Department of Inorganic and Analytical Chemistry
- University of Geneva
- Geneva, Switzerland
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1073
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Krah T, Amor NB, Robert V. Switching magnetic interactions in the NiFe Prussian Blue Analogue: an ab initio inspection. Phys Chem Chem Phys 2014; 16:9509-14. [DOI: 10.1039/c4cp00662c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Wave function embedded cluster calculations are performed to stress a cation-coupled electron transfer process in the NiFe Prussian Blue Analogue.
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Affiliation(s)
- Tim Krah
- Laboratoire de Chimie Quantique
- Université de Strasbourg
- 67000 Strasbourg, France
| | - Nadia Ben Amor
- Laboratoire de Chimie et Physique Quantiques
- 31062 Toulouse Cedex 09, France
| | - Vincent Robert
- Laboratoire de Chimie Quantique
- Université de Strasbourg
- 67000 Strasbourg, France
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1074
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Matson EM, Gordon Z, Lin B, Nilges MJ, Fout AR. Meridional vs. facial coordination geometries of a dipodal ligand framework featuring a secondary coordination sphere. Dalton Trans 2014; 43:16992-5. [DOI: 10.1039/c4dt02327g] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ligation of bipyridine invokes a conformational change in iron and copper complexes.
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Affiliation(s)
- Ellen M. Matson
- School of Chemical Sciences
- University of Illinois at Urbana-Champaign
- Urbana, USA
| | - Zachary Gordon
- School of Chemical Sciences
- University of Illinois at Urbana-Champaign
- Urbana, USA
| | - Benjamin Lin
- Department of Chemistry and Chemical Biology
- Harvard University
- Cambridge, USA
| | - Mark J. Nilges
- School of Chemical Sciences
- University of Illinois at Urbana-Champaign
- Urbana, USA
| | - Alison R. Fout
- School of Chemical Sciences
- University of Illinois at Urbana-Champaign
- Urbana, USA
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1075
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Jia HP, Quadrelli EA. Mechanistic aspects of dinitrogen cleavage and hydrogenation to produce ammonia in catalysis and organometallic chemistry: relevance of metal hydride bonds and dihydrogen. Chem Soc Rev 2014; 43:547-64. [DOI: 10.1039/c3cs60206k] [Citation(s) in RCA: 516] [Impact Index Per Article: 51.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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1076
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Bullock RM, Appel AM, Helm ML. Production of hydrogen by electrocatalysis: making the H–H bond by combining protons and hydrides. Chem Commun (Camb) 2014; 50:3125-43. [DOI: 10.1039/c3cc46135a] [Citation(s) in RCA: 213] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Electrocatalytic production of hydrogen by nickel complexes is reviewed, with an emphasis on heterocoupling of protons and hydrides.
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Affiliation(s)
- R. Morris Bullock
- Center for Molecular Electrocatalysis (efrc.pnnl.gov)
- Physical Sciences Division
- Pacific Northwest National Laboratory
- , USA
| | - Aaron M. Appel
- Center for Molecular Electrocatalysis (efrc.pnnl.gov)
- Physical Sciences Division
- Pacific Northwest National Laboratory
- , USA
| | - Monte L. Helm
- Center for Molecular Electrocatalysis (efrc.pnnl.gov)
- Physical Sciences Division
- Pacific Northwest National Laboratory
- , USA
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1077
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Bronner C, Wenger OS. Long-range proton-coupled electron transfer in phenol–Ru(2,2′-bipyrazine)32+ dyads. Phys Chem Chem Phys 2014; 16:3617-22. [DOI: 10.1039/c3cp55071k] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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1078
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Saouma CT, Mayer JM. Do Spin State and Spin Density Affect Hydrogen Atom Transfer Reactivity? Chem Sci 2014; 5. [PMID: 24416504 DOI: 10.1039/c3sc52664j] [Citation(s) in RCA: 117] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The prevalence of hydrogen atom transfer (HAT) reactions in chemical and biological systems has prompted much interest in establishing and understanding the underlying factors that enable this reactivity. Arguments have been advanced that the electronic spin state of the abstractor and/or the spin-density at the abstracting atom are critical for HAT reactivity. This is consistent with the intuition derived from introductory organic chemistry courses. Herein we present an alternative view on the role of spin state and spin-density in HAT reactions. After a brief introduction, the second section introduces a new and simple fundamental kinetic analysis, which shows that unpaired spin cannot be the dominant effect. The third section examines published computational studies of HAT reactions, which indicates that the spin state affects these reactions indirectly, primarily via changes in driving force. The essay concludes with a broader view of HAT reactivity, including indirect effects of spin and other properties on reactivity. It is suggested that some of the controversy in this area may arise from the diversity of HAT reactions and their overlap with proton-coupled electron transfer (PCET) reactions.
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Affiliation(s)
- Caroline T Saouma
- Department of Chemistry, University of Washington, Campus Box 351700, Seattle, WA, USA
| | - James M Mayer
- Department of Chemistry, University of Washington, Campus Box 351700, Seattle, WA, USA
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1079
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Savarese M, Netti PA, Rega N, Adamo C, Ciofini I. Intermolecular proton shuttling in excited state proton transfer reactions: insights from theory. Phys Chem Chem Phys 2014; 16:8661-6. [DOI: 10.1039/c4cp00068d] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The mechanism of intermolecular proton shuttling involved in a prototypical excited state proton transfer reaction is disclosed using DFT and TD-DFT.
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Affiliation(s)
- Marika Savarese
- Dipartimento di Chimica ‘Paolo Corradini’
- Università di Napoli Federico II
- Complesso Universitario di M.S.Angelo
- 80126 Napoli, Italy
- Center for Advanced Biomaterials for Health Care@CRIB
| | - Paolo A. Netti
- Dipartimento di Chimica ‘Paolo Corradini’
- Università di Napoli Federico II
- Complesso Universitario di M.S.Angelo
- 80126 Napoli, Italy
- Center for Advanced Biomaterials for Health Care@CRIB
| | - Nadia Rega
- Dipartimento di Chimica ‘Paolo Corradini’
- Università di Napoli Federico II
- Complesso Universitario di M.S.Angelo
- 80126 Napoli, Italy
- Center for Advanced Biomaterials for Health Care@CRIB
| | - Carlo Adamo
- LECIME
- Laboratoire d'Electrochimie
- Chimie des Interfaces et Modélisation pour l'Energie
- UMR
- France
| | - Ilaria Ciofini
- LECIME
- Laboratoire d'Electrochimie
- Chimie des Interfaces et Modélisation pour l'Energie
- UMR
- France
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1080
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Amić A, Marković Z, Dimitrić Marković JM, Stepanić V, Lučić B, Amić D. Towards an improved prediction of the free radical scavenging potency of flavonoids: the significance of double PCET mechanisms. Food Chem 2013; 152:578-85. [PMID: 24444978 DOI: 10.1016/j.foodchem.2013.12.025] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Revised: 11/07/2013] [Accepted: 12/04/2013] [Indexed: 02/08/2023]
Abstract
The 1H(+)/1e(-) and 2H(+)/2e(-) proton-coupled electron transfer (PCET) processes of free radical scavenging by flavonoids were theoretically studied for aqueous and lipid environments using the PM6 and PM7 methods. The results reported here indicate that the significant contribution of the second PCET mechanism, resulting in the formation of a quinone/quinone methide, effectively discriminates the active from inactive flavonoids. The predictive potency of descriptors related to the energetics of second PCET mechanisms (the second O-H bond dissociation enthalpy (BDE2) related to hydrogen atom transfer (HAT) mechanism, and the second electron transfer enthalpy (ETE2) related to sequential proton loss electron transfer (SPLET) mechanism) are superior to the currently used indices, which are related to the first 1H(+)/1e(-) processes, and could serve as primary descriptors in development of the QSAR (quantitative structure-activity relationships) of flavonoids.
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Affiliation(s)
- Ana Amić
- Department of Biology, The Josip Juraj Strossmayer University, Cara Hadrijana 8a, HR-31000 Osijek, Croatia
| | - Zoran Marković
- Department of Chemical-Technological Sciences, State University of Novi Pazar, Vuka Karadžića bb, 36300 Novi Pazar, Serbia
| | | | - Višnja Stepanić
- Division of Molecular Medicine, Rudjer Bošković Institute, P.O. Box 180, HR-10002 Zagreb, Croatia
| | - Bono Lučić
- NMR Center, Rudjer Bošković Institute, P.O. Box 180, HR-10002 Zagreb, Croatia
| | - Dragan Amić
- Faculty of Agriculture, The Josip Juraj Strossmayer University, Kralja Petra Svačića 1d, HR-31000 Osijek, Croatia.
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1081
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Clare LA, Pham AT, Magdaleno F, Acosta J, Woods JE, Cooksy AL, Smith DK. Electrochemical evidence for intermolecular proton-coupled electron transfer through a hydrogen bond complex in a p-phenylenediamine-based urea. Introduction of the "wedge scheme" as a useful means to describe reactions of this type. J Am Chem Soc 2013; 135:18930-41. [PMID: 24283378 DOI: 10.1021/ja410061x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The electrochemistry of several p-phenylenediamine derivatives, in which one of the amino groups is part of an urea functional group, has been investigated in methylene chloride and acetonitrile. The ureas are abbreviated U(R)R', where R' indicates the substituent on the N that is part of the phenylenediamine redox couple and R indicates the substituent on the other urea N. Cyclic voltammetry and UV-vis spectroelectrochemical studies indicate that U(Me)H and U(H)H undergo an apparent 1e(-) oxidation that actually corresponds to 2e(-) oxidation of half the ureas to a quinoidal-diimine cation, U(R)(+). This is accompanied by proton transfer to the other half of the ureas to make the electroinactive cation HU(R)H(+). This explains the observed irreversibility of the oxidation of U(Me)H in both solvents and U(H)H in acetonitrile. However, the oxidation of U(H)H in methylene chloride is reversible at higher concentrations and slower scan rates. Several lines of evidence suggest that the most likely reason for this is the accessibility of a H-bond complex between U(H)(+) and HU(H)H(+) in methylene chloride. Reduction of the H-bond complex occurs at a less negative potential than that of U(H)(+), leading to reversible behavior. This conclusion is strongly supported by the appearance of a more negative reduction peak at lower concentrations and faster scan rates, conditions in which the H-bond complex is less favored. The overall reaction mechanism is conveniently described by a "wedge scheme", which is a more general version of the square scheme typically used to describe redox processes in which proton transfer accompanies electron transfer.
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Affiliation(s)
- Laurie A Clare
- Department of Chemistry and Biochemistry, San Diego State University , San Diego, California 92182-1030, United States
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1082
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Long R, English NJ, Prezhdo OV. Defects Are Needed for Fast Photo-Induced Electron Transfer from a Nanocrystal to a Molecule: Time-Domain Ab Initio Analysis. J Am Chem Soc 2013; 135:18892-900. [DOI: 10.1021/ja408936j] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Run Long
- Department
of Chemistry, University of Rochester, Rochester, New York 14627, United States
| | | | - Oleg V. Prezhdo
- Department
of Chemistry, University of Rochester, Rochester, New York 14627, United States
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1083
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Savarese M, Netti PA, Adamo C, Rega N, Ciofini I. Exploring the Metric of Excited State Proton Transfer Reactions. J Phys Chem B 2013; 117:16165-73. [DOI: 10.1021/jp406301p] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Marika Savarese
- Dipartimento
di Chimica ‘Paolo Corradini’, Università di Napoli Federico II, Complesso Universitario di M.S. Angelo, via Cintia, 80126 Napoli, Italy
- Center
for Advanced Biomaterials for Health Care@CRIB, Istituto Italiano di Tecnologia, Largo Barsanti e Matteucci n, 53 80125 Napoli, Italy
| | - Paolo A. Netti
- Center
for Advanced Biomaterials for Health Care@CRIB, Istituto Italiano di Tecnologia, Largo Barsanti e Matteucci n, 53 80125 Napoli, Italy
| | - Carlo Adamo
- Laboratoire
d’Electrochimie, Chimie des Interfaces et Modelisation pour
l’Energie, CNRS UMR-7575, Ecole Nationale Supérieure de Chimie de Paris, Chimie ParisTech, 11 rue P. et M. Curie, F-75231 Paris Cedex 05, France
- Institut Universitaire de France, 103 Bd Saint-Michel, F-75005 Paris, France
| | - Nadia Rega
- Dipartimento
di Chimica ‘Paolo Corradini’, Università di Napoli Federico II, Complesso Universitario di M.S. Angelo, via Cintia, 80126 Napoli, Italy
- Center
for Advanced Biomaterials for Health Care@CRIB, Istituto Italiano di Tecnologia, Largo Barsanti e Matteucci n, 53 80125 Napoli, Italy
| | - Ilaria Ciofini
- Laboratoire
d’Electrochimie, Chimie des Interfaces et Modelisation pour
l’Energie, CNRS UMR-7575, Ecole Nationale Supérieure de Chimie de Paris, Chimie ParisTech, 11 rue P. et M. Curie, F-75231 Paris Cedex 05, France
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1084
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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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1085
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Molčanov K, Stare J, Vener MV, Kojić-Prodić B, Mali G, Grdadolnik J, Mohaček-Grošev V. Nitranilic acid hexahydrate, a novel benchmark system of the Zundel cation in an intrinsically asymmetric environment: spectroscopic features and hydrogen bond dynamics characterised by experimental and theoretical methods. Phys Chem Chem Phys 2013; 16:998-1007. [PMID: 24281720 DOI: 10.1039/c3cp54026j] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Nitranilic acid (2,5-dihydroxy-3,6-dinitro-2,5-cyclohexadiene-1,4-dione) as a strong dibasic acid in acidic aqueous media creates the Zundel cation, H5O2(+). The structural unit in a crystal comprises (H5O2)2(+) (2,5-dihydroxy-3,6-dinitro-1,4-benzoquinonate)(2-) dihydrate where the Zundel cation reveals no symmetry, being an ideal case for studying proton dynamics and its stability. The Zundel cation and proton transfer dynamics are studied by variable-temperature X-ray diffraction, IR and solid-state NMR spectroscopy, and various quantum chemical methods, including periodic DFT calculations, ab initio molecular dynamics simulation, and quantization of nuclear motion along three fully coupled internal coordinates. The Zundel cation features a short H-bond with the O···O distance of 2.433(2) Å with an asymmetric placement of hydrogen. The proton potential is of a single well type and, due to the non-symmetric surroundings, of asymmetric shape. The formation of the Zundel cation is facilitated by the electronegative NO2 groups. The employed spectroscopic techniques supported by calculations confirm the presence of a short H-bond with a complex proton dynamics.
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1086
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Usharani D, Lacy DC, Borovik AS, Shaik S. Dichotomous hydrogen atom transfer vs proton-coupled electron transfer during activation of X-H bonds (X = C, N, O) by nonheme iron-oxo complexes of variable basicity. J Am Chem Soc 2013; 135:17090-104. [PMID: 24124906 PMCID: PMC3876471 DOI: 10.1021/ja408073m] [Citation(s) in RCA: 191] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
We describe herein the hydrogen-atom transfer (HAT)/proton-coupled electron-transfer (PCET) reactivity for Fe(IV)-oxo and Fe(III)-oxo complexes (1-4) that activate C-H, N-H, and O-H bonds in 9,10-dihydroanthracene (S1), dimethylformamide (S2), 1,2-diphenylhydrazine (S3), p-methoxyphenol (S4), and 1,4-cyclohexadiene (S5). In 1-3, the iron is pentacoordinated by tris[N'-tert-butylureaylato)-N-ethylene]aminato ([H3buea](3-)) or its derivatives. These complexes are basic, in the order 3 ≫ 1 > 2. Oxidant 4, [Fe(IV)N4Py(O)](2+) (N4Py: N,N-bis(2-pyridylmethyl)bis(2-pyridyl)methylamine), is the least basic oxidant. The DFT results match experimental trends and exhibit a mechanistic spectrum ranging from concerted HAT and PCET reactions to concerted-asynchronous proton transfer (PT)/electron transfer (ET) mechanisms, all the way to PT. The singly occupied orbital along the O···H···X (X = C, N, O) moiety in the TS shows clearly that in the PCET cases, the electron is transferred separately from the proton. The Bell-Evans-Polanyi principle does not account for the observed reactivity pattern, as evidenced by the scatter in the plot of calculated barrier vs reactions driving forces. However, a plot of the deformation energy in the TS vs the respective barrier provides a clear signature of the HAT/PCET dichotomy. Thus, in all C-H bond activations, the barrier derives from the deformation energy required to create the TS, whereas in N-H/O-H bond activations, the deformation energy is much larger than the corresponding barrier, indicating the presence of a stabilizing interaction between the TS fragments. A valence bond model is used to link the observed results with the basicity/acidity of the reactants.
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Affiliation(s)
- Dandamudi Usharani
- Institute of Chemistry and the Lise-Meitner-Minerva Center for Computational Quantum Chemistry, The Hebrew University of Jerusalem, 91904 Jerusalem, Israel
| | - David C. Lacy
- Department of Chemistry, University of California-Irvine, 1102 Natural Sciences II, Irvine, California 92697, United States
| | - A. S. Borovik
- Department of Chemistry, University of California-Irvine, 1102 Natural Sciences II, Irvine, California 92697, United States
| | - Sason Shaik
- Institute of Chemistry and the Lise-Meitner-Minerva Center for Computational Quantum Chemistry, The Hebrew University of Jerusalem, 91904 Jerusalem, Israel
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1087
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Rono LJ, Yayla HG, Wang DY, Armstrong MF, Knowles RR. Enantioselective Photoredox Catalysis Enabled by Proton-Coupled Electron Transfer: Development of an Asymmetric Aza-Pinacol Cyclization. J Am Chem Soc 2013; 135:17735-8. [DOI: 10.1021/ja4100595] [Citation(s) in RCA: 340] [Impact Index Per Article: 30.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Lydia J. Rono
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Hatice G. Yayla
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - David Y. Wang
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Michael F. Armstrong
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Robert R. Knowles
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
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1088
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Concerted Electron/Proton Transfer Mechanism in the Oxidation of Phenols by Laccase. Chembiochem 2013; 14:2500-5. [DOI: 10.1002/cbic.201300531] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Indexed: 11/07/2022]
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1089
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Liu Y, Guo SX, Bond AM, Zhang J, Geletii YV, Hill CL. Voltammetric Determination of the Reversible Potentials for [{Ru4O4(OH)2(H2O)4}(γ-SiW10O36)2]10– over the pH Range of 2–12: Electrolyte Dependence and Implications for Water Oxidation Catalysis. Inorg Chem 2013; 52:11986-96. [DOI: 10.1021/ic401748y] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Yuping Liu
- School of Chemistry, Monash University, Clayton, Victoria 3800 Australia
| | - Si-Xuan Guo
- School of Chemistry, Monash University, Clayton, Victoria 3800 Australia
| | - Alan M. Bond
- School of Chemistry, Monash University, Clayton, Victoria 3800 Australia
| | - Jie Zhang
- School of Chemistry, Monash University, Clayton, Victoria 3800 Australia
| | - Yurii V. Geletii
- Department of Chemistry, Emory University, 1525 Dickey Drive, Atlanta, Georgia 30322, United States
| | - Craig L. Hill
- Department of Chemistry, Emory University, 1525 Dickey Drive, Atlanta, Georgia 30322, United States
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1090
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Molčanov K, Stilinović V. Die chemische Kristallographie vor der Röntgenbeugung. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201301319] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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1091
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Molčanov K, Stilinović V. Chemical Crystallography before X-ray Diffraction. Angew Chem Int Ed Engl 2013; 53:638-52. [DOI: 10.1002/anie.201301319] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Indexed: 11/11/2022]
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1092
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Efficient water oxidation catalyzed by homogeneous cationic cobalt porphyrins with critical roles for the buffer base. Proc Natl Acad Sci U S A 2013; 110:15579-84. [PMID: 24019473 DOI: 10.1073/pnas.1315383110] [Citation(s) in RCA: 258] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
A series of cationic cobalt porphyrins was found to catalyze electrochemical water oxidation to O2 efficiently at room temperature in neutral aqueous solution. Co-5,10,15,20-tetrakis-(1,3-dimethylimidazolium-2-yl)porphyrin, with a highly electron-deficient meso-dimethylimidazolium porphyrin, was the most effective catalyst. The O2 formation rate was 170 nmol · cm(-2) · min(-1) (k(obs) = 1.4 × 10(3) s(-1)) with a Faradaic efficiency near 90%. Mechanistic investigations indicate the generation of a Co(IV)-O porphyrin cation radical as the reactive oxidant, which has accumulated two oxidizing equivalents above the Co(III) resting state of the catalyst. The buffer base in solution was shown to play several critical roles during the catalysis by facilitating both redox-coupled proton transfer processes leading to the reactive oxidant and subsequent O-O bond formation. More basic buffer anions led to lower catalytic onset potentials, extending below 1 V. This homogeneous cobalt-porphyrin system was shown to be robust under active catalytic conditions, showing negligible decomposition over hours of operation. Added EDTA or ion exchange resin caused no catalyst poisoning, indicating that cobalt ions were not released from the porphyrin macrocycle during catalysis. Likewise, surface analysis by energy dispersive X-ray spectroscopy of the working electrodes showed no deposition of heterogeneous cobalt films. Taken together, the results indicate that Co-5,10,15,20-tetrakis-(1,3-dimethylimidazolium-2-yl)porphyrin is an efficient, homogeneous, single-site water oxidation catalyst.
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1093
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Neidlinger A, Ksenofontov V, Heinze K. Proton-Coupled Electron Transfer in Ferrocenium–Phenolate Radicals. Organometallics 2013. [DOI: 10.1021/om400498h] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Andreas Neidlinger
- Institute of Inorganic
and Analytical Chemistry, Johannes Gutenberg-University of Mainz, Duesbergweg
10-14, 55128 Mainz, Germany
| | - Vadim Ksenofontov
- Institute of Inorganic
and Analytical Chemistry, Johannes Gutenberg-University of Mainz, Staudinger
Weg 9, 55128 Mainz, Germany
| | - Katja Heinze
- Institute of Inorganic
and Analytical Chemistry, Johannes Gutenberg-University of Mainz, Duesbergweg
10-14, 55128 Mainz, Germany
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1094
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Zhang HX, Abe M, Zhang Y, Li G, Ye S, Osawa M, Sasaki Y. Proton-coupled electron transfer and Lewis acid recognition at self-assembled monolayers of an oxo-bridged diruthenium(III) complex functionalized with two disulfide anchors. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:10110-10119. [PMID: 23829546 DOI: 10.1021/la401736f] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
A new μ-oxo-bis(μ-acetato)diruthenium(III) complex bearing two pyridyl disulfide ligands {[Ru2(μ-O)(μ-OAc)2(bpy)2(L(py-SS))2](PF6)2 (OAc = CH3CO2(-), bpy = 2,2'-bipyridine, L(py-SS) = (C5H4N)CH2NHC(O)(CH2)4CH(CH2)2SS) (1)} has been synthesized to prepare self-assembled monolayers (SAMs) on the Au(111) electrode surface. The SAMs have been characterized by contact-angle measurements, reflection-absorption surface infrared spectroscopy, cyclic voltammetry, and reductive desorption experiments. The SAMs exhibited proton-coupled electron transfer (PCET) reactions when the electrochemistry was studied in aqueous electrolyte solution (0.1 M NaClO4 with Britton-Robinson buffer to adjust the solution pH). The potential-pH plot (Pourbaix diagram) in the pH range from 1 to 12 has established that the dinuclear ruthenium moiety was involved in the interfacial PCET processes with four distinct redox states: Ru(III)Ru(III)(μ-O), Ru(II)Ru(III)(μ-OH), Ru(II)Ru(II)(μ-OH), and Ru(II)Ru(II)(μ-OH2). We also demonstrated that the interfacial redox processes were modulated by the addition of Lewis acids such as BF3 or Al(3+) to the electrolyte media, in which the externally added Lewis acids interacted with μ-O of the dinuclear moiety within the SAMs.
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Affiliation(s)
- Hua-Xin Zhang
- Catalysis Research Center, Hokkaido University, Kita-ku, Sapporo 001-0021, Japan
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1095
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Sheng H, Ji H, Ma W, Chen C, Zhao J. Direct Four-Electron Reduction of O2to H2O on TiO2Surfaces by Pendant Proton Relay. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201304481] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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1096
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Savini A, Bucci A, Bellachioma G, Rocchigiani L, Zuccaccia C, Llobet A, Macchioni A. Mechanistic Aspects of Water Oxidation Catalyzed by Organometallic Iridium Complexes. Eur J Inorg Chem 2013. [DOI: 10.1002/ejic.201300530] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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1097
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Sheng H, Ji H, Ma W, Chen C, Zhao J. Direct four-electron reduction of O2 to H2O on TiO2 surfaces by pendant proton relay. Angew Chem Int Ed Engl 2013; 52:9686-90. [PMID: 23873729 DOI: 10.1002/anie.201304481] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Indexed: 11/06/2022]
Affiliation(s)
- Hua Sheng
- Key Laboratory of Photochemistry, Institute of Chemistry, The Chinese Academy of Sciences, Beijing, 100190, China
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1098
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Abstract
Proton-coupled electron transfer (PCET) plays a crucial role in many enzymatic reactions and is relevant for a variety of processes including water oxidation, nitrogen fixation, and carbon dioxide reduction. Much of the research on PCET has focused on transfers between molecules in their electronic ground states, but increasingly researchers are investigating PCET between photoexcited reactants. This Account describes recent studies of excited-state PCET with d(6) metal complexes emphasizing work performed in my laboratory. Upon photoexcitation, some complexes release an electron and a proton to benzoquinone reaction partners. Others act as combined electron-proton acceptors in the presence of phenols. As a result, we can investigate photoinduced PCET involving electron and proton transfer in a given direction, a process that resembles hydrogen-atom transfer (HAT). In other studies, the photoexcited metal complexes merely serve as electron donors or electron acceptors because the proton donating and accepting sites are located on other parts of the molecular PCET ensemble. We and others have used this multisite design to explore so-called bidirectional PCET which occurs in many enzymes. A central question in all of these studies is whether concerted proton-electron transfer (CPET) can compete kinetically with sequential electron and proton transfer steps. Short laser pulses can trigger excited-state PCET, making it possible to investigate rapid reactions. Luminescence spectroscopy is a convenient tool for monitoring PCET, but unambiguous identification of reaction products can require a combination of luminescence spectroscopy and transient absorption spectroscopy. Nevertheless, in some cases, distinguishing between PCET photoproducts and reaction products formed by simple photoinduced electron transfer (ET) (reactions that don't include proton transfer) is tricky. Some of the studies presented here deal directly with this important problem. In one case study we employed a cyclometalated iridium(III) complex. Our other studies with ruthenium(II) complexes and phenols focused on systematic variations of the reaction free energies for the CPET, ET, and proton transfer (PT) steps to explore their influence on the overall PCET reaction. Still other work with rhenium(I) complexes concentrated on the question of how the electronic structure of the metal-to-ligand charge transfer (MLCT) excited states affects PCET. We used covalent rhenium(I)-phenol dyads to explore the influence of the electron donor-electron acceptor distance on bidirectional PCET. In covalent triarylamine-Ru(bpy)₃²⁺/Os(bpy)₃²⁺-anthraquinone triads (bpy = 2,2'-bipyridine), hydrogen-bond donating solvents significantly lengthened the lifetimes of photogenerated electron/hole pairs because of hydrogen-bonding to the quinone radical anion. Until now, comparatively few researchers have investigated this variation of PCET: the strengthening of H-bonds upon photoreduction.
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Affiliation(s)
- Oliver S. Wenger
- Departement Chemie, Universität Basel, Spitalstrasse 51, CH-4056 Basel, Switzerland
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1099
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Badiei YM, Polyansky DE, Muckerman JT, Szalda DJ, Haberdar R, Zong R, Thummel RP, Fujita E. Water Oxidation with Mononuclear Ruthenium(II) Polypyridine Complexes Involving a Direct RuIV═O Pathway in Neutral and Alkaline Media. Inorg Chem 2013; 52:8845-50. [DOI: 10.1021/ic401023w] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Yosra M. Badiei
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973-5000, United States
| | - Dmitry E. Polyansky
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973-5000, United States
| | - James T. Muckerman
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973-5000, United States
| | - David J. Szalda
- Department of Natural Science, Baruch College, CUNY, New York, New York 10010, United States
| | - Rubabe Haberdar
- Department of Chemistry, University of Houston, Houston, Texas 77204-5003, United
States
| | - Ruifa Zong
- Department of Chemistry, University of Houston, Houston, Texas 77204-5003, United
States
| | - Randolph P. Thummel
- Department of Chemistry, University of Houston, Houston, Texas 77204-5003, United
States
| | - Etsuko Fujita
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973-5000, United States
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1100
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Messina F, Prémont-Schwarz M, Braem O, Xiao D, Batista VS, Nibbering ETJ, Chergui M. Ultrafast Solvent-Assisted Electronic Level Crossing in 1-Naphthol. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201301931] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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