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Matsubara Y, Ishitani O. Photochemical formation of hydride using transition metal complexes and its application to photocatalytic reduction of the coenzyme NAD(P)+ and its model compounds. Coord Chem Rev 2023. [DOI: 10.1016/j.ccr.2022.214955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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2
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Mengele A, Rau S. Learning from Nature's Example: Repair Strategies in Light-Driven Catalysis. JACS AU 2023; 3:36-46. [PMID: 36711104 PMCID: PMC9875256 DOI: 10.1021/jacsau.2c00507] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 11/04/2022] [Accepted: 11/10/2022] [Indexed: 06/18/2023]
Abstract
The continuous repair of subunits of the photosynthetic apparatus is a key factor determining the overall efficiency of biological photosynthesis. Recent concepts for repairing artificial photocatalysts and catalytically active materials within the realm of solar fuel formation show great potential in reshaping the research directions within this field. This perspective describes the latest advances, concepts, and mechanisms in the field of catalyst repair and catalyst self-healing and provides an outlook on which additional steps need to be taken to bring artificial photosynthetic systems closer to real-life applications.
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Affiliation(s)
- Alexander
K. Mengele
- Institute
of Inorganic Chemistry I, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Sven Rau
- Institute
of Inorganic Chemistry I, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
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3
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Takahashi M, Asatani T, Morimoto T, Kamakura Y, Fujii K, Yashima M, Hosokawa N, Tamaki Y, Ishitani O. Supramolecular multi-electron redox photosensitisers comprising a ring-shaped Re(i) tetranuclear complex and a polyoxometalate. Chem Sci 2023; 14:691-704. [PMID: 36741525 PMCID: PMC9848162 DOI: 10.1039/d2sc04252e] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Accepted: 11/30/2022] [Indexed: 12/02/2022] Open
Abstract
Redox photosensitisers (PSs) play essential roles in various photocatalytic reactions. Herein, we synthesised new redox PSs of 1 : 1 supramolecules that comprise a ring-shaped Re(i) tetranuclear complex with 4+ charges and a Keggin-type heteropolyoxometalate with 4- charges. These PSs photochemically accumulate multi-electrons in one molecule (three or four electrons) in the presence of an electron donor and can supply electrons with different reduction potentials. PSs were successfully applied in the photocatalytic reduction of CO2 using catalysts (Ru(ii) and Re(i) complexes) and triethanolamine as a reductant. In photocatalytic reactions, these supramolecular PSs supply a different number of electrons to the catalyst depending on the redox potential of the intermediate, which is made from the one-electron-reduced species of the catalyst and CO2. Based on these data, information on the reduction potentials of the intermediates was obtained.
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Affiliation(s)
- Maria Takahashi
- Department of Chemistry, School of Science, Tokyo Institute of TechnologyO-okayama 2-12-1-NE-1Meguro-kuTokyo 152-8550Japan
| | - Tsuyoshi Asatani
- Department of Chemistry, School of Science, Tokyo Institute of TechnologyO-okayama 2-12-1-NE-1Meguro-kuTokyo 152-8550Japan
| | - Tatsuki Morimoto
- School of Engineering, Tokyo University of Technology1404-1 KatakuraHachiojiTokyo 192-0982Japan
| | - Yoshinobu Kamakura
- Department of Chemistry, School of Science, Tokyo Institute of TechnologyO-okayama 2-12-1-NE-1Meguro-kuTokyo 152-8550Japan
| | - Kotaro Fujii
- Department of Chemistry, School of Science, Tokyo Institute of TechnologyO-okayama 2-12-1-NE-1Meguro-kuTokyo 152-8550Japan
| | - Masatomo Yashima
- Department of Chemistry, School of Science, Tokyo Institute of TechnologyO-okayama 2-12-1-NE-1Meguro-kuTokyo 152-8550Japan
| | - Naoki Hosokawa
- Department of Chemistry, School of Science, Tokyo Institute of TechnologyO-okayama 2-12-1-NE-1Meguro-kuTokyo 152-8550Japan
| | - Yusuke Tamaki
- Department of Chemistry, School of Science, Tokyo Institute of TechnologyO-okayama 2-12-1-NE-1Meguro-kuTokyo 152-8550Japan
| | - Osamu Ishitani
- Department of Chemistry, School of Science, Tokyo Institute of TechnologyO-okayama 2-12-1-NE-1Meguro-kuTokyo 152-8550Japan,Department of Chemistry, Graduate School of Advanced Science and Engineering, Hiroshima University1-3-1 KagamiyamaHigashi-HiroshimaHiroshima 739 8526Japan
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4
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Oelschlegel M, Hua SA, Schmid L, Marquetand P, Bäck A, Borter JH, Lücken J, Dechert S, Wenger OS, Siewert I, Schwarzer D, González L, Meyer F. Luminescent Iridium Complexes with a Sulfurated Bipyridine Ligand: PCET Thermochemistry of the Disulfide Unit and Photophysical Properties. Inorg Chem 2022; 61:13944-13955. [PMID: 36001121 DOI: 10.1021/acs.inorgchem.2c01930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Molecular systems combining light harvesting and charge storage are receiving great attention in the context of, for example, artificial photosynthesis and solar fuel generation. As part of ongoing efforts to develop new concepts for photoinduced proton-coupled electron transfer (PCET) reactivities, we report a cyclometallated iridium(III) complex [Ir(ppy)2(S-Sbpy)](PF6) ([1]PF6) equipped with our previously developed sulfurated bipyridine ligand S-Sbpy. A new one-step synthetic protocol for S-Sbpy is developed, starting from commercially available 2,2'-bipyridine, which significantly facilitates the use of this ligand. [1]+ features a two-electron reduction with potential inversion (|E1| > |E2|) at moderate potentials (E1 = -1.12, E2 = -1.11 V versus. Fc+/0 at 253 K), leading to a dithiolate species [1]-. Protonation with weak acids allows for determination of pKa = 23.5 in MeCN for the S-H···S- unit of [1H]. The driving forces for both the H atom and the hydride transfer are calculated to be ∼60 kcal mol-1 and verified experimentally by reaction with a suitable H atom and a hydride acceptor, demonstrating the ability of [1]+ to serve as a versatile PCET reagent, albeit with limited thermal stability. In MeCN solution, an orange emission for [1]PF6 from a triplet-excited state was found. Density functional calculations and ultrafast absorption spectroscopy are used to give insight into the excited-state dynamics of the complex and suggest a significantly stretched S-S bond for the lowest triplet-state T1. The structural responsiveness of the disulfide unit is proposed to open an effective relaxation channel toward the ground state, explaining the unexpectedly short lifetime of [1]+. These insights as well as the quantitative ground-state thermochemistry data provide valuable information for the use of S-Sbpy-functionalized complexes and their disulfide-/dithiol-directed PCET reactivity.
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Affiliation(s)
- Manuel Oelschlegel
- Institute of Inorganic Chemistry, University of Göttingen, Tammannstr. 4, D-37077 Göttingen, Germany
| | - Shao-An Hua
- Institute of Inorganic Chemistry, University of Göttingen, Tammannstr. 4, D-37077 Göttingen, Germany
| | - Lucius Schmid
- Department of Chemistry, University of Basel, CH-4056Basel, Switzerland
| | - Philipp Marquetand
- Institute of Theoretical Chemistry, University of Vienna, Währingerstraße 17, A-1090 Vienna, Austria
| | - Anna Bäck
- Institute of Theoretical Chemistry, University of Vienna, Währingerstraße 17, A-1090 Vienna, Austria
| | - Jan-Hendrik Borter
- Department of Dynamics at Surfaces, Max-Planck-Institute for Multidisciplinary Sciences, Am Faßberg 11, D-37077 Göttingen, Germany
| | - Jana Lücken
- Institute of Inorganic Chemistry, University of Göttingen, Tammannstr. 4, D-37077 Göttingen, Germany
| | - Sebastian Dechert
- Institute of Inorganic Chemistry, University of Göttingen, Tammannstr. 4, D-37077 Göttingen, Germany
| | - Oliver S Wenger
- Department of Chemistry, University of Basel, CH-4056Basel, Switzerland
| | - Inke Siewert
- Institute of Inorganic Chemistry, University of Göttingen, Tammannstr. 4, D-37077 Göttingen, Germany
| | - Dirk Schwarzer
- Department of Dynamics at Surfaces, Max-Planck-Institute for Multidisciplinary Sciences, Am Faßberg 11, D-37077 Göttingen, Germany
| | - Leticia González
- Institute of Theoretical Chemistry, University of Vienna, Währingerstraße 17, A-1090 Vienna, Austria
| | - Franc Meyer
- Institute of Inorganic Chemistry, University of Göttingen, Tammannstr. 4, D-37077 Göttingen, Germany.,International Center for Advanced Studies of Energy Conversion (ICASEC), D-37077 Göttingen, Germany
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Ghosh D, Kumar GR, Subramanian S, Tanaka K. More Than Just a Reagent: The Rise of Renewable Organohydrides for Catalytic Reduction of Carbon Dioxide. CHEMSUSCHEM 2021; 14:824-841. [PMID: 33369102 DOI: 10.1002/cssc.202002660] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 12/06/2020] [Indexed: 06/12/2023]
Abstract
Stoichiometric carbon dioxide reduction to highly reduced C1 molecules, such as formic acid (2e- ), formaldehyde (4e- ), methanol (6e- ) or even most-reduced methane (8e- ), has been successfully achieved by using organosilanes, organoboranes, and frustrated Lewis Pairs (FLPs) in the presence of suitable catalyst. The development of renewable organohydride compounds could be the best alternative in this regard as they have shown promise for the transfer of hydride directly to CO2 . Reduction of CO2 by two electrons and two protons to afford formic acid by using renewable organohydride molecules has recently been investigated by various groups. However, catalytic CO2 reduction to ≥2e- -reduced products by using renewable organohydride-based molecules has rarely been explored. This Minireview summarizes important findings in this regard, encompassing both stoichiometric and catalytic CO2 reduction.
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Affiliation(s)
- Debashis Ghosh
- Department of Chemistry, St. Joseph's College (Autonomous), Bangalore, 560027, Karnataka, India
| | - George Rajendra Kumar
- Department of Applied Chemistry, Karunya Institute of Technology and Sciences, Coimbatore, 641114, Tamil Nadu, India
| | - Saravanan Subramanian
- Inorganic Materials and Catalysis Division, CSIR-Central Salt & Marine Chemicals Research Institute, Bhavnagar, 364002, Gujarat, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Koji Tanaka
- Institute for Integrated Cell-Material Sciences (KUIAS/iCeMS), Kyoto University, Yoshida, Sakyo-ku, Kyoto, 606-8501, Japan
- Department of Applied Chemistry, College of Life Science, Ritsumeikan University, 525-8577 Noji-higashi, 1-1-1, Kusatsu, Shiga, Japan
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Sawaki T, Ishizuka T, Namura N, Hong D, Miyanishi M, Shiota Y, Kotani H, Yoshizawa K, Jung J, Fukuzumi S, Kojima T. Photocatalytic hydrogen evolution using a Ru(ii)-bound heteroaromatic ligand as a reactive site. Dalton Trans 2020; 49:17230-17242. [PMID: 33210674 DOI: 10.1039/d0dt03546g] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A RuII complex, [RuII(tpphz)(bpy)2]2+ (1) (tpphz = tetrapyridophenazine, bpy = 2,2'-bipyridine), whose tpphz ligand has a pyrazine moiety, is converted efficiently to [RuII(tpphz-HH)(bpy)2]2+ (2) having a dihydropyrazine moiety upon photoirradiation of a water-methanol mixed solvent solution of 1 in the presence of an electron donor. In this reaction, the triplet metal-to-ligand charge-transfer excited state (3MLCT*) of 1 is firstly formed upon photoirradiation and the 3MLCT* state is reductively quenched with an electron donor to afford [RuII(tpphz˙-)(bpy)2]+, which is converted to 2 without the observation of detectable reduced intermediates by nano-second laser flash photolysis. The inverse kinetic isotope effect (KIE) was observed to be 0.63 in the N-H bond formation of 2 at the dihydropyrazine moiety. White-light (380-670 nm) irradiation of a solution of 1 in a protic solvent, in the presence of an electron donor under an inert atmosphere, led to photocatalytic H2 evolution and the hydrogenation of organic substrates. In the reactions, complex 2 is required to be excited to form its 3MLCT* state to react with a proton and aldehydes. In photocatalytic H2 evolution, the H-H bond formation between photoexcited 2 and a proton is involved in the rate-determining step with normal KIE being 5.2 on H2 evolving rates. Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations on the reaction mechanism of H2 evolution from the ground and photo-excited states of 2 were performed to have a better understanding of the photocatalytic processes.
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Affiliation(s)
- Takuya Sawaki
- Department of Chemistry, Faculty of Pure and Applied Sciences, University of Tsukuba and CREST (JST), 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8571, Japan.
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7
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Masdeu C, Fuertes M, Martin-Encinas E, Selas A, Rubiales G, Palacios F, Alonso C. Fused 1,5-Naphthyridines: Synthetic Tools and Applications. Molecules 2020; 25:molecules25153508. [PMID: 32752070 PMCID: PMC7436086 DOI: 10.3390/molecules25153508] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 07/28/2020] [Accepted: 07/29/2020] [Indexed: 11/21/2022] Open
Abstract
Heterocyclic nitrogen compounds, including fused 1,5-naphthyridines, have versatile applications in the fields of synthetic organic chemistry and play an important role in the field of medicinal chemistry, as many of them have a wide range of biological activities. In this review, a wide range of synthetic protocols for the construction of this scaffold are presented. For example, Friedländer, Skraup, Semmlere-Wolff, and hetero-Diels-Alder, among others, are well known classical synthetic protocols used for the construction of the main 1,5-naphthyridine scaffold. These syntheses are classified according to the nature of the cycle fused to the 1,5-naphthyridine ring: carbocycles, nitrogen heterocycles, oxygen heterocycles, and sulphur heterocycles. In addition, taking into account the aforementioned versatility of these heterocycles, their reactivity is presented as well as their use as a ligand for metal complexes formation. Finally, those fused 1,5-naphthyridines that present biological activity and optical applications, among others, are indicated.
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Affiliation(s)
| | | | | | | | | | - Francisco Palacios
- Correspondence: (F.P.); (C.A.); Tel.: +34-945-01-3103 (F.P.); +34-945-01-3087 (C.A.)
| | - Concepcion Alonso
- Correspondence: (F.P.); (C.A.); Tel.: +34-945-01-3103 (F.P.); +34-945-01-3087 (C.A.)
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8
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Ohtsu H, Saito T, Tsuge K. A Novel Photo-Driven Hydrogenation Reaction of an NAD+-Type Complex Toward Artificial Photosynthesis. Front Chem 2019; 7:580. [PMID: 31482088 PMCID: PMC6710353 DOI: 10.3389/fchem.2019.00580] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 08/02/2019] [Indexed: 11/16/2022] Open
Abstract
The photocatalytic reduction of carbon dioxide (CO2) to value-added chemicals is an attractive strategy to utilize CO2 as a feedstock for storing renewable energy, such as solar energy, in chemical bonds. Inspired by the biological function of the nicotinamide adenine dinucleotide redox couple (NAD+/NADH), we have been developing transition-metal complexes containing NAD+/NADH-functionalized ligands to create electro- and/or photochemically renewable hydride donors for the conversion of CO2 into value-added chemicals. Our previous findings have provided insights for the development of photocatalytic organic hydride reduction reactions for CO2, however, further examples, as well as investigation, of these photo-driven NAD+/NADH-type hydrogenation and organic hydride transfer reactions are required not only to explore the mechanism in detail but also to develop a highly efficient catalyst for artificial photosynthesis. In this paper, we report the synthesis, characterization, and photo-induced NAD+/NADH conversion properties of a new ruthenium(II) complex, [Ru(bpy)2(Me-pn)](PF6)2 (1), which contains a new NAD+-type ligand, Me-pn (2-methyl-6-(pyridin-2-yl)-1,5-naphthyridine). In addition, we have succeeded in the isolation of the corresponding two-electron reduced ruthenium(II) complex containing the NADH-type ligand Me-pnHH (2-methyl-6-(pyridin-2-yl)-1,4-dihydro-1,5-naphthyridine), i.e., [Ru(bpy)2(Me-pnHH)](PF6)2 (1HH), by the photo-induced hydrogenation reaction of 1. Thus, in this study, a new photo-driven NAD+/NADH-type hydrogenation reaction for possible CO2 reduction using the NAD+/NADH redox function has been constructed.
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Ilic S, Alherz A, Musgrave CB, Glusac KD. Importance of proton-coupled electron transfer in cathodic regeneration of organic hydrides. Chem Commun (Camb) 2019; 55:5583-5586. [DOI: 10.1039/c9cc00928k] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
This communication reports a combined experimental and computational study of mechanisms by which biomimetic NADH analogs can be electrochemically regenerated.
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Affiliation(s)
- Stefan Ilic
- Department of Chemistry
- University of Illinois at Chicago
- Chicago
- USA
- Chemical Sciences and Engineering Division
| | - Abdulaziz Alherz
- Department of Chemical and Biological Engineering
- University of Colorado
- Boulder
- USA
| | - Charles B. Musgrave
- Department of Chemical and Biological Engineering
- University of Colorado
- Boulder
- USA
- Department of Chemistry
| | - Ksenija D. Glusac
- Department of Chemistry
- University of Illinois at Chicago
- Chicago
- USA
- Chemical Sciences and Engineering Division
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10
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Lymar SV, Ertem MZ, Polyansky DE. Solvent-dependent transition from concerted electron-proton to proton transfer in photoinduced reactions between phenols and polypyridine Ru complexes with proton-accepting sites. Dalton Trans 2018; 47:15917-15928. [PMID: 30375615 DOI: 10.1039/c8dt03858a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The bimolecular rate coefficients (kobsq) for quenching the metal-to-ligand charge transfer excited states of two Ru polypyridine complexes containing H-bond accepting sites by six p-substituted phenols exhibit abrupt deviations from the expected linear correlations of log kobsq with phenol's Hammett σp constant. This pattern is attributed to a transition of the quenching mechanism from a concerted electron-proton transfer (EPT) to a proton transfer (PT); the latter becomes predominant for the most acidic phenols in acetonitrile, but not in dichloromethane. This assertion is supported by a detailed thermochemical analysis, which also excludes the quenching pathways involving electron transfer from phenols with or without deprotonation of phenols to the solvent, either concerted or sequential. The transition from EPT to PT upon the σp increase is consistent/supported by the magnitudes of the measured and computed PhOH/OD kinetic isotope effects and by the observed reduction of the EPT product yields upon replacing the low σp methoxyphenol by the high σp nitrophenol. In addition to modulating the relative contribution of the EPT and PT quenching pathways, the solvent strongly affects the bimolecular rate coefficients for the EPT quenching proper. Unlike with H-atom transfer reactions, this kinetic solvent effect could not be quantitatively accounted for by the phenol-solvent H-bonding alone, which suggests a solvent effect on the H-bonding constants in the phenol-Ru complex precursor exciplexes and/or on the unimolecular EPT rate coefficients within these exciplexes.
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Affiliation(s)
- Sergei V Lymar
- Chemistry Division, Brookhaven National Laboratory, Upton, New York 11973-5000, USA.
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Alherz A, Lim CH, Kuo YC, Lehman P, Cha J, Hynes JT, Musgrave CB. Renewable Hydride Donors for the Catalytic Reduction of CO 2: A Thermodynamic and Kinetic Study. J Phys Chem B 2018; 122:10179-10189. [PMID: 30290115 DOI: 10.1021/acs.jpcb.8b08536] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Increasing atmospheric CO2 concentration and dwindling fossil fuel supply necessitate the search for efficient methods for CO2 conversion to fuels. Assorted studies have shown pyridine and its derivatives capable of (photo)electrochemically reducing CO2 to methanol, and some mechanistic interpretations have been proposed. Here, we analyze the thermodynamic and kinetic aspects of the efficacy of pyridines as hydride-donating catalytic reagents that transfer hydrides via their dihydropyridinic form. We investigate both the effects of functionalizing pyridinic derivatives with electron-donating and electron-withdrawing groups on hydride-transfer catalyst strength, assessed via their hydricity (thermodynamic ability) and nucleophilicity (kinetic ability), and catalyst recyclability, assessed via their reduction potential. We find that pyridines substituted with electron-donating groups have stronger hydride-donating ability (having lower hydricity and larger nucleophilicity values), but are less efficiently recycled (having more negative reduction potentials). In contrast, pyridines substituted with electron-withdrawing groups are more efficiently recycled, but are weaker hydride donors. Functional group modification favorably tunes hydride strength or efficiency, but not both. We attribute this problematic coupling between the strength and recyclability of pyridinic hydrides to their aromatic nature and suggest several avenues for overcoming this difficulty.
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Affiliation(s)
| | | | | | | | | | - James T Hynes
- PASTEUR, Département de Chimie, École Normale Supérieure , PSL University, Sorbonne Université, CNRS , 75005 Paris , France
| | - Charles B Musgrave
- Materials and Chemical Science and Technology Center , National Renewable Energy Laboratory , Golden , Colorado 80401 , United States
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Yamamoto K, Call A, Sakai K. Photocatalytic H2Evolution Using a Ru Chromophore Tethered to Six Viologen Acceptors. Chemistry 2018; 24:16620-16629. [DOI: 10.1002/chem.201803662] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Indexed: 12/29/2022]
Affiliation(s)
- Keiya Yamamoto
- Department of Chemistry; Faculty of Science; Kyushu University; Motooka 744, Nishi-ku Fukuoka 819-0395 Japan
- International Institute for Carbon-Neutral Energy Research; (WPI-I CNER); Kyushu University; Motooka 744, Nishi-ku Fukuoka 819-0395 Japan
| | - Arnau Call
- International Institute for Carbon-Neutral Energy Research; (WPI-I CNER); Kyushu University; Motooka 744, Nishi-ku Fukuoka 819-0395 Japan
| | - Ken Sakai
- Department of Chemistry; Faculty of Science; Kyushu University; Motooka 744, Nishi-ku Fukuoka 819-0395 Japan
- International Institute for Carbon-Neutral Energy Research; (WPI-I CNER); Kyushu University; Motooka 744, Nishi-ku Fukuoka 819-0395 Japan
- Center for Molecular Systems (CMS); Kyushu University; Motooka 744, Nishi-ku Fukuoka 819-0395 Japan
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13
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Kobayashi K, Koizumi TA, Ghosh D, Kajiwara T, Kitagawa S, Tanaka K. Electrochemical behavior of a Rh(pentamethylcyclopentadienyl) complex bearing an NAD +/NADH-functionalized ligand. Dalton Trans 2018. [PMID: 29537007 DOI: 10.1039/c7dt04594h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A RhCp* (Cp* = pentamethylcyclopentadienyl) complex bearing an NAD+/NADH-functionalized ligand, [RhCp*(pbn)Cl]Cl ([1]Cl, pbn = (2-(2-pyridyl)benzo[b]-1,5-naphthyridine)), was synthesized. The cyclic voltammogram of [1]Cl in CH3CN shows two reversible redox waves at E1/2 = -0.58 and -1.53 V (vs. the saturated calomel electrode (SCE)), which correspond to the RhIII/RhI and pbn/pbn˙- redox couples, respectively. The addition of acetic acid to the solution afforded the proton-coupled two-electron reduction of [1]Cl at -0.62 V, from which [RhCp*(pbnHH)Cl]+ was selectively generated, probably via a hydride transfer from a RhIII-hydride intermediate to the pbn ligand. Complex [1]Cl is stable under acidic conditions, whereas a methyl proton of the Cp* moiety dissociates under basic conditions. The resulting anionic methylene group attacks the para carbon of the free pyridine of pbn, accompanied by protonation of the nitrogen atom of the ligand. As a result, treatment of [1]Cl with a base produces selectively the cyclic complex [1CH]Cl, which bears a reduced pbn framework (pbnCH). [1CH]Cl forms 1 : 1 adducts with PhCOO-via hydrogen bonding. A similar adduct, formed by a Ru-pbnHH scaffold and RCOO- (R = CH3, C6H5), has been reported to react with CO2 to produce HCOO- under concomitant regeneration of Ru-pbn. The adduct of [1CH]Cl with PhCOO-, however, lacks such hydride-donor ability, due to a steric barrier in the molecular structure of [1CH]Cl, which hampers the hydride transfer.
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Affiliation(s)
- Katsuaki Kobayashi
- Department of Chemistry, Graduate School of Science, Osaka City University, Sumiyoshi-ku, Osaka 558-8585, Japan.
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Grills DC, Polyansky DE, Fujita E. Application of Pulse Radiolysis to Mechanistic Investigations of Catalysis Relevant to Artificial Photosynthesis. CHEMSUSCHEM 2017; 10:4359-4373. [PMID: 28898568 DOI: 10.1002/cssc.201701559] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Indexed: 06/07/2023]
Abstract
Taking inspiration from natural photosystems, the goal of artificial photosynthesis is to harness solar energy to convert abundant materials, such as CO2 and H2 O, into solar fuels. Catalysts are required to ensure that the necessary redox half-reactions proceed in the most energy-efficient manner. It is therefore critical to gain a detailed mechanistic understanding of these catalytic reactions to develop new and improved catalysts. Many of the key catalytic intermediates are short-lived transient species, requiring time-resolved spectroscopic techniques for their observation. The two main methods for rapidly generating such species on the sub-microsecond timescale are laser flash photolysis and pulse radiolysis. These methods complement one another, and both provide important spectroscopic and kinetic information. However, pulse radiolysis proves to be superior in systems with significant spectroscopic overlap between the photosensitizer and other species present during the reaction. Herein, the pulse radiolysis technique and how it has been applied to mechanistic investigations of halfreactions relevant to artificial photosynthesis are reviewed.
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Affiliation(s)
- David C Grills
- Chemistry Division, Brookhaven National Laboratory, Upton, NY, 11973-5000, USA
| | - Dmitry E Polyansky
- Chemistry Division, Brookhaven National Laboratory, Upton, NY, 11973-5000, USA
| | - Etsuko Fujita
- Chemistry Division, Brookhaven National Laboratory, Upton, NY, 11973-5000, USA
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15
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Ghosh D, Kobayashi K, Kajiwara T, Kitagawa S, Tanaka K. Catalytic Hydride Transfer to CO2 Using Ru-NAD-Type Complexes under Electrochemical Conditions. Inorg Chem 2017; 56:11066-11073. [DOI: 10.1021/acs.inorgchem.7b01427] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Debashis Ghosh
- Institute for Integrated
Cell-Material Sciences (KUIAS/iCeMS), Kyoto University, Yoshida, Sakyo-ku,
Kyoto 606-8501, Japan
| | - Katsuaki Kobayashi
- Department of Chemistry, Graduate School of Science, Osaka City University, Sumiyoshi-ku,
Osaka 558-8585, Japan
| | - Takashi Kajiwara
- Institute for Integrated
Cell-Material Sciences (KUIAS/iCeMS), Kyoto University, Yoshida, Sakyo-ku,
Kyoto 606-8501, Japan
| | - Susumu Kitagawa
- Institute for Integrated
Cell-Material Sciences (KUIAS/iCeMS), Kyoto University, Yoshida, Sakyo-ku,
Kyoto 606-8501, Japan
| | - Koji Tanaka
- Institute for Integrated
Cell-Material Sciences (KUIAS/iCeMS), Kyoto University, Yoshida, Sakyo-ku,
Kyoto 606-8501, Japan
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16
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Kuss-Petermann M, Wenger OS. Exceptionally Long-Lived Photodriven Multi-Electron Storage without Sacrificial Reagents. Chemistry 2017; 23:10808-10814. [DOI: 10.1002/chem.201701456] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Indexed: 11/11/2022]
Affiliation(s)
- Martin Kuss-Petermann
- Department of Chemistry; University of Basel; St. Johanns-Ring 19 4056 Basel Switzerland
| | - Oliver S. Wenger
- Department of Chemistry; University of Basel; St. Johanns-Ring 19 4056 Basel Switzerland
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17
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Ghosh D, Fukushima T, Kobayashi K, Sen S, Kitagawa S, kato T, Tanaka K. Base assisted C–C coupling between carbonyl and polypyridyl ligands in a Ru-NADH-type carbonyl complex. Dalton Trans 2017; 46:4373-4381. [DOI: 10.1039/c7dt00312a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Strong organic base assists quantitative conversion of ruthenium(ii)-NADH-type complex to new metallacycle which was further oxidized to Ru-OCO-bridge complex upon reaction with aq. NH4PF6 under air.
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Affiliation(s)
- Debashis Ghosh
- Institute for Cell-Material Sciences
- Kyoto University
- Kyoto 612-8374
- Japan
| | - Takashi Fukushima
- Institute for Cell-Material Sciences
- Kyoto University
- Kyoto 612-8374
- Japan
| | | | - Susan Sen
- Institute for Cell-Material Sciences
- Kyoto University
- Kyoto 615-8530
- Japan
| | - Susumu Kitagawa
- Institute for Cell-Material Sciences
- Kyoto University
- Kyoto 606-8501
- Japan
| | - Tatsuhisa kato
- Institute for Liberal Arts and Sciences
- Kyoto University
- Kyoto 606-8501
- Japan
| | - Koji Tanaka
- Institute for Cell-Material Sciences
- Kyoto University
- Kyoto 612-8374
- Japan
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18
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Wiedner ES, Chambers MB, Pitman CL, Bullock RM, Miller AJM, Appel AM. Thermodynamic Hydricity of Transition Metal Hydrides. Chem Rev 2016; 116:8655-92. [PMID: 27483171 DOI: 10.1021/acs.chemrev.6b00168] [Citation(s) in RCA: 298] [Impact Index Per Article: 37.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Transition metal hydrides play a critical role in stoichiometric and catalytic transformations. Knowledge of free energies for cleaving metal hydride bonds enables the prediction of chemical reactivity, such as for the bond-forming and bond-breaking events that occur in a catalytic reaction. Thermodynamic hydricity is the free energy required to cleave an M-H bond to generate a hydride ion (H(-)). Three primary methods have been developed for hydricity determination: the hydride transfer method establishes hydride transfer equilibrium with a hydride donor/acceptor pair of known hydricity, the H2 heterolysis method involves measuring the equilibrium of heterolytic cleavage of H2 in the presence of a base, and the potential-pKa method considers stepwise transfer of a proton and two electrons to give a net hydride transfer. Using these methods, over 100 thermodynamic hydricity values for transition metal hydrides have been determined in acetonitrile or water. In acetonitrile, the hydricity of metal hydrides spans a range of more than 50 kcal/mol. Methods for using hydricity values to predict chemical reactivity are also discussed, including organic transformations, the reduction of CO2, and the production and oxidation of hydrogen.
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Affiliation(s)
- Eric S Wiedner
- Pacific Northwest National Laboratory , Richland, Washington 99352, United States
| | - Matthew B Chambers
- Department of Chemistry, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599-3290, United States
| | - Catherine L Pitman
- Department of Chemistry, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599-3290, United States
| | - R Morris Bullock
- Pacific Northwest National Laboratory , Richland, Washington 99352, United States
| | - Alexander J M Miller
- Department of Chemistry, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599-3290, United States
| | - Aaron M Appel
- Pacific Northwest National Laboratory , Richland, Washington 99352, United States
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19
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Kitamoto K, Sakai K. Tris(2,2′-bipyridine)ruthenium Derivatives with Multiple Viologen Acceptors: Quadratic Dependence of Photocatalytic H2Evolution Rate on the Local Concentration of the Acceptor Site. Chemistry 2016; 22:12381-90. [DOI: 10.1002/chem.201601554] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Indexed: 11/10/2022]
Affiliation(s)
- Kyoji Kitamoto
- Department of Chemistry; Faculty of Science; Kyushu University; Motooka 744, Nishi-ku Fukuoka 819-0395 Japan
- International Institute for Carbon-Neutral Energy Research (WPI-I2CNER); Kyushu University; Motooka 744, Nishi-ku Fukuoka 819-0395 Japan
| | - Ken Sakai
- Department of Chemistry; Faculty of Science; Kyushu University; Motooka 744, Nishi-ku Fukuoka 819-0395 Japan
- International Institute for Carbon-Neutral Energy Research (WPI-I2CNER); Kyushu University; Motooka 744, Nishi-ku Fukuoka 819-0395 Japan
- Center for Molecular Systems (CMS); Kyushu University; Motooka 744, Nishi-ku Fukuoka 819-0395 Japan
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20
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Orazietti M, Kuss‐Petermann M, Hamm P, Wenger OS. Lichtgetriebene Elektronenakkumulation in einer molekularen Pentade. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201604030] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Margherita Orazietti
- Departement für ChemieUniversität Zürich Winterthurerstrasse 190 8057 Zürich Schweiz
| | | | - Peter Hamm
- Departement für ChemieUniversität Zürich Winterthurerstrasse 190 8057 Zürich Schweiz
| | - Oliver S. Wenger
- Departement für ChemieUniversität Basel St. Johanns-Ring 19 4056 Basel Schweiz
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21
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Orazietti M, Kuss-Petermann M, Hamm P, Wenger OS. Light-Driven Electron Accumulation in a Molecular Pentad. Angew Chem Int Ed Engl 2016; 55:9407-10. [PMID: 27336756 DOI: 10.1002/anie.201604030] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Indexed: 11/10/2022]
Abstract
Accumulation and temporary storage of redox equivalents with visible light as an energy input is of pivotal importance for artificial photosynthesis because key reactions, such as CO2 reduction or water oxidation, require the transfer of multiple redox equivalents. We report on the first purely molecular system, in which a long-lived charge-separated state (τ≈870 ns) with two electrons accumulated on a suitable acceptor unit can be observed after excitation with visible light. Importantly, no sacrificial reagents were employed.
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Affiliation(s)
- Margherita Orazietti
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Martin Kuss-Petermann
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland
| | - Peter Hamm
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland.
| | - Oliver S Wenger
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland.
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22
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Kobayashi K, Ohtsu H, Nozaki K, Kitagawa S, Tanaka K. Photochemical Properties and Reactivity of a Ru Compound Containing an NAD/NADH-Functionalized 1,10-Phenanthroline Ligand. Inorg Chem 2016; 55:2076-84. [PMID: 26849425 DOI: 10.1021/acs.inorgchem.5b02390] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
An NAD/NADH-functionalized ligand, benzo[b]pyrido[3,2-f][1,7]-phenanthroline (bpp), was newly synthesized. A Ru compound containing the bpp ligand, [Ru(bpp)(bpy)2](2+), underwent 2e(-) and 2H(+) reduction, generating the NADH form of the compound, [Ru(bppHH)(bpy)2](2+), in response to visible light irradiation in CH3CN/TEA/H2O (8/1/1). The UV-vis and fluorescent spectra of both [Ru(bpp)(bpy)2](2+) and [Ru(bppHH)(bpy)2](2+) resembled the spectra of [Ru(bpy)3](2+). Both complexes exhibited strong emission, with quantum yields of 0.086 and 0.031, respectively; values that are much higher than those obtained from the NAD/NADH-functionalized complexes [Ru(pbn)(bpy)2](2+) and [Ru(pbnHH)(bpy)2](2+) (pbn = (2-(2-pyridyl)benzo[b]-1.5-naphthyridine, pbnHH = hydrogenated form of pbn). The reduction potential of the bpp ligand in [Ru(bpp)(bpy)2](2+) (-1.28 V vs SCE) is much more negative than that of the pbn ligand in [Ru(pbn)(bpy)2](2+) (-0.74 V), although the oxidation potentials of bppHH and pbnHH are essentially equal (0.95 V). These results indicate that the electrochemical oxidation of the dihydropyridine moiety in the NADH-type ligand was independent of the π system, including the Ru polypyridyl framework. [Ru(bppHH)(bpy)2](2+) allowed the photoreduction of oxygen, generating H2O2 in 92% yield based on [Ru(bppHH)(bpy)2](2+). H2O2 production took place via singlet oxygen generated by the energy transfer from excited [Ru(bppHH)(bpy)2](2+) to triplet oxygen.
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Affiliation(s)
- Katsuaki Kobayashi
- Institute for Cell-Material Sciences, Kyoto University , ACT-Kyoto #507, Jibucho 105, Fushimi-ku, Kyoto 612-8374, Japan
| | - Hideki Ohtsu
- Graduate School of Science and Engineering, University of Toyama , 3190 Gofuku, Toyama 930-8555, Japan
| | - Koichi Nozaki
- Graduate School of Science and Engineering, University of Toyama , 3190 Gofuku, Toyama 930-8555, Japan
| | - Susumu Kitagawa
- Institute for Cell-Material Sciences, Kyoto University , Yoshida, Sakyo-ku, Kyoto 606-8501, Japan
| | - Koji Tanaka
- Institute for Cell-Material Sciences, Kyoto University , ACT-Kyoto #507, Jibucho 105, Fushimi-ku, Kyoto 612-8374, Japan
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23
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Rogers HM, Arachchige SM, Brewer KJ. Enhancement of Solar Fuel Production Schemes by Using a Ru,Rh,Ru Supramolecular Photocatalyst Containing Hydroxide Labile Ligands. Chemistry 2015; 21:16948-54. [DOI: 10.1002/chem.201502863] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Indexed: 11/06/2022]
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24
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Reynal A, Pastor E, Gross MA, Selim S, Reisner E, Durrant JR. Unravelling the pH-dependence of a molecular photocatalytic system for hydrogen production. Chem Sci 2015; 6:4855-4859. [PMID: 28717491 PMCID: PMC5502398 DOI: 10.1039/c5sc01349f] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 05/27/2015] [Indexed: 11/25/2022] Open
Abstract
The electron-donating ability of the sacrificial agent and the protonation of the catalyst determine the optimum pH for hydrogen production.
Photocatalytic systems for the reduction of aqueous protons are strongly pH-dependent, but the origin of this dependency is still not fully understood. We have studied the effect of different degrees of acidity on the electron transfer dynamics and catalysis taking place in a homogeneous photocatalytic system composed of a phosphonated ruthenium tris(bipyridine) dye (RuP) and a nickel bis(diphosphine) electrocatalyst (NiP) in an aqueous ascorbic acid solution. Our approach is based on transient absorption spectroscopy studies of the efficiency of photo-reduction of RuP and NiP correlated with pH-dependent photocatalytic H2 production and the degree of catalyst protonation. The influence of these factors results in an observed optimum photoactivity at pH 4.5 for the RuP–NiP system. The electron transfer from photo-reduced RuP to NiP is efficient and independent of the pH value of the medium. At pH <4.5, the efficiency of the system is limited by the yield of RuP photo-reduction by the sacrificial electron donor, ascorbic acid. At pH >4.5, the efficiency of the system is limited by the poor protonation of NiP, which inhibits its ability to reduce protons to hydrogen. We have therefore developed a rational strategy utilising transient absorption spectroscopy combined with bulk pH titration, electrocatalytic and photocatalytic experiments to disentangle the complex pH-dependent activity of the homogenous RuP–NiP photocatalytic system, which can be widely applied to other photocatalytic systems.
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Affiliation(s)
- Anna Reynal
- Department of Chemistry , Imperial College London , Exhibition Road , London SW7 2AZ , UK . .,School of Chemistry , Newcastle University , Newcastle Upon Tyne , NE1 7RU , UK .
| | - Ernest Pastor
- Department of Chemistry , Imperial College London , Exhibition Road , London SW7 2AZ , UK .
| | - Manuela A Gross
- Christian Doppler Laboratory for Sustainable SynGas Chemistry , Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge CB2 1EW , UK .
| | - Shababa Selim
- Department of Chemistry , Imperial College London , Exhibition Road , London SW7 2AZ , UK .
| | - Erwin Reisner
- Christian Doppler Laboratory for Sustainable SynGas Chemistry , Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge CB2 1EW , UK .
| | - James R Durrant
- Department of Chemistry , Imperial College London , Exhibition Road , London SW7 2AZ , UK .
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25
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Lewandowska-Andralojc A, Baine T, Zhao X, Muckerman JT, Fujita E, Polyansky DE. Mechanistic Studies of Hydrogen Evolution in Aqueous Solution Catalyzed by a Tertpyridine–Amine Cobalt Complex. Inorg Chem 2015; 54:4310-21. [DOI: 10.1021/ic5031137] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Teera Baine
- Department of Chemistry, University of Memphis, Memphis, Tennessee 38152, United States
| | - Xuan Zhao
- Department of Chemistry, University of Memphis, Memphis, Tennessee 38152, United States
| | - James T. Muckerman
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973-5000, United States
| | - Etsuko Fujita
- 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
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26
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Oyama D, Ukawa N, Hamada T, Takase T. Reversible Intramolecular Cyclization in Ruthenium Complexes Induced by Ligand-centered One-electron Transfer on Bidentate Naphthyridine: An Important Intermediate for Both Metal– and Organo–Hydride Species. CHEM LETT 2015. [DOI: 10.1246/cl.150023] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Dai Oyama
- Cluster of Science and Engineering, Fukushima University
| | - Narumi Ukawa
- Cluster of Science and Engineering, Fukushima University
| | - Takashi Hamada
- Cluster of Science and Engineering, Fukushima University
| | - Tsugiko Takase
- Institute of Environmental Radioactivity, Fukushima University
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27
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Rogers HM, White TA, Stone BN, Arachchige SM, Brewer KJ. Nonchromophoric Halide Ligand Variation in Polyazine-Bridged Ru(II),Rh(III) Bimetallic Supramolecules Offering New Insight into Photocatalytic Hydrogen Production from Water. Inorg Chem 2015; 54:3545-51. [DOI: 10.1021/acs.inorgchem.5b00116] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Travis A. White
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Brittany N. Stone
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
| | | | - Karen J. Brewer
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
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28
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Dassanayake RS, Shelley JT, Cabelli DE, Brasch NE. Pulse Radiolysis and Ultra-High-Performance Liquid Chromatography/High-Resolution Mass Spectrometry Studies on the Reactions of the Carbonate Radical with Vitamin B12Derivatives. Chemistry 2015; 21:6409-19. [DOI: 10.1002/chem.201406269] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Indexed: 12/21/2022]
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29
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Dassanayake RS, Cabelli DE, Brasch NE. Pulse radiolysis studies of the reactions of nitrogen dioxide with the vitamin B12 complexes cob(II)alamin and nitrocobalamin. J Inorg Biochem 2015; 142:54-8. [DOI: 10.1016/j.jinorgbio.2014.09.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Revised: 09/19/2014] [Accepted: 09/21/2014] [Indexed: 12/31/2022]
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30
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Yang Y, Wang M, Xue L, Zhang F, Chen L, Ahlquist MSG, Sun L. Nickel complex with internal bases as efficient molecular catalyst for photochemical H2 production. CHEMSUSCHEM 2014; 7:2889-2897. [PMID: 25179906 DOI: 10.1002/cssc.201402381] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2014] [Revised: 07/11/2014] [Indexed: 06/03/2023]
Abstract
A Ni complex with internal bases that contain bipyridine-derived ligands, [Ni(L)2 (H2 O)2 ](BF4 )2 ([1](BF4 )2 , L=2-(2-pyridyl)-1,8-naphthyridine), and a reference complex that bears analogous bipyridine-derived ligands but without an internal base, [Ni(L')3 ](BF4 )2 ([2](BF4 )2 , L'=2-(2-pyridyl)quinoline), were synthesized and characterized. The electrochemical properties of these complexes were studied in CH3 CN, H2 O, and a mixture of EtOH/H2 O. The fluorescence spectroscopic studies suggest that both dynamic and the sphere-of-action static quenching exist in the fluorescein Fl(2-) /[1](2+) and Fl(2-) /[2](2+) systems. These noble-metal-free molecular systems were studied for photocatalytic H2 generation. Under optimal conditions, the turnover number of H2 evolution reaches 3230 based on [1](2+) , whereas [2](2+) displays only approximately one third of the turnover of [1](2+) . A plausible mechanism for the catalytic H2 generation by [1](2+) is presented based on DFT calculations.
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Affiliation(s)
- Yong Yang
- State Key Laboratory of Fine Chemicals, DUT-KTH Education and Research Centre on Molecular Devices, Dalian University of Technology (DUT), 116024 Dalian (PR China)
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31
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Asatani T, Nakagawa Y, Funada Y, Sawa S, Takeda H, Morimoto T, Koike K, Ishitani O. Ring-Shaped Rhenium(I) Multinuclear Complexes: Improved Synthesis and Photoinduced Multielectron Accumulation. Inorg Chem 2014; 53:7170-80. [DOI: 10.1021/ic501196q] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Tsuyoshi Asatani
- Department of Chemistry,
Graduate School of Science and Engineering, Tokyo Institute of Technology, 2-12-1-NE-1 O-okayama, Meguro-ku, Tokyo 152-8550, Japan
| | - Yuki Nakagawa
- Department of Chemistry,
Graduate School of Science and Engineering, Tokyo Institute of Technology, 2-12-1-NE-1 O-okayama, Meguro-ku, Tokyo 152-8550, Japan
| | - Yusuke Funada
- Department of Chemistry,
Graduate School of Science and Engineering, Tokyo Institute of Technology, 2-12-1-NE-1 O-okayama, Meguro-ku, Tokyo 152-8550, Japan
| | - Shuhei Sawa
- Department of Chemistry,
Graduate School of Science and Engineering, Tokyo Institute of Technology, 2-12-1-NE-1 O-okayama, Meguro-ku, Tokyo 152-8550, Japan
| | - Hiroyuki Takeda
- Department of Chemistry,
Graduate School of Science and Engineering, Tokyo Institute of Technology, 2-12-1-NE-1 O-okayama, Meguro-ku, Tokyo 152-8550, Japan
- CREST, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi-shi, Saitama 322-0012, Japan
| | - Tatsuki Morimoto
- Department of Chemistry,
Graduate School of Science and Engineering, Tokyo Institute of Technology, 2-12-1-NE-1 O-okayama, Meguro-ku, Tokyo 152-8550, Japan
- CREST, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi-shi, Saitama 322-0012, Japan
| | - Kazuhide Koike
- Department of Chemistry,
Graduate School of Science and Engineering, Tokyo Institute of Technology, 2-12-1-NE-1 O-okayama, Meguro-ku, Tokyo 152-8550, Japan
- National Institute of Advanced Industrial Science and Technology, 16-1 Onogawa, Tsukuba 305-8569, Japan
- CREST, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi-shi, Saitama 322-0012, Japan
| | - Osamu Ishitani
- Department of Chemistry,
Graduate School of Science and Engineering, Tokyo Institute of Technology, 2-12-1-NE-1 O-okayama, Meguro-ku, Tokyo 152-8550, Japan
- CREST, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi-shi, Saitama 322-0012, Japan
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32
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Nakamura G, Okamura M, Yoshida M, Suzuki T, Takagi HD, Kondo M, Masaoka S. Electrochemical Behavior of Phosphine-Substituted Ruthenium(II) Polypyridine Complexes with a Single Labile Ligand. Inorg Chem 2014; 53:7214-26. [DOI: 10.1021/ic5003644] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Go Nakamura
- Department of Structural Molecular Science,
School of Physical Sciences, The Graduate University for Advanced Studies (SOKENDAI), Shonan Village, Hayama-cho, Kanagawa 240-0193, Japan
- Institute for Molecular Science (IMS), 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan
| | - Masaya Okamura
- Department of Structural Molecular Science,
School of Physical Sciences, The Graduate University for Advanced Studies (SOKENDAI), Shonan Village, Hayama-cho, Kanagawa 240-0193, Japan
- Institute for Molecular Science (IMS), 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan
| | - Masaki Yoshida
- Institute for Molecular Science (IMS), 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan
| | - Takayoshi Suzuki
- Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan
| | - Hideo D. Takagi
- Graduate School of Science and Research Center
for Material Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8602, Japan
| | - Mio Kondo
- Department of Structural Molecular Science,
School of Physical Sciences, The Graduate University for Advanced Studies (SOKENDAI), Shonan Village, Hayama-cho, Kanagawa 240-0193, Japan
- Institute for Molecular Science (IMS), 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan
- Research Center of Integrative Molecular Systems (CIMoS), 38 Nishigo-naka, Myodaiji, Okazaki, Aichi 444-8585, Japan
- Japan Science and Technology Agency (JST), ACT-C, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Shigeyuki Masaoka
- Department of Structural Molecular Science,
School of Physical Sciences, The Graduate University for Advanced Studies (SOKENDAI), Shonan Village, Hayama-cho, Kanagawa 240-0193, Japan
- Institute for Molecular Science (IMS), 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan
- Research Center of Integrative Molecular Systems (CIMoS), 38 Nishigo-naka, Myodaiji, Okazaki, Aichi 444-8585, Japan
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33
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Wang WH, Himeda Y, Muckerman JT, Fujita E. Interconversion of CO2/H2 and Formic Acid Under Mild Conditions in Water. ADVANCES IN INORGANIC CHEMISTRY 2014. [DOI: 10.1016/b978-0-12-420221-4.00006-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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34
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McSkimming A, Colbran SB. The coordination chemistry of organo-hydride donors: new prospects for efficient multi-electron reduction. Chem Soc Rev 2013; 42:5439-88. [PMID: 23507957 DOI: 10.1039/c3cs35466k] [Citation(s) in RCA: 116] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
In biological reduction processes the dihydronicotinamides NAD(P)H often transfer hydride to an unsaturated substrate bound within an enzyme active site. In many cases, metal ions in the active site bind, polarize and thereby activate the substrate to direct attack by hydride from NAD(P)H cofactor. This review looks more widely at the metal coordination chemistry of organic donors of hydride ion--organo-hydrides--such as dihydronicotinamides, other dihydropyridines including Hantzsch's ester and dihydroacridine derivatives, those derived from five-membered heterocycles including the benzimidazolines and benzoxazolines, and all-aliphatic hydride donors such as hexadiene and hexadienyl anion derivatives. The hydride donor properties--hydricities--of organo-hydrides and how these are affected by metal ions are discussed. The coordination chemistry of organo-hydrides is critically surveyed and the use of metal-organo-hydride systems in electrochemically-, photochemically- and chemically-driven reductions of unsaturated organic and inorganic (e.g. carbon dioxide) substrates is highlighted. The sustainable electrocatalytic, photochemical or chemical regeneration of organo-hydrides such as NAD(P)H, including for driving enzyme-catalysed reactions, is summarised and opportunities for development are indicated. Finally, new prospects are identified for metal-organo-hydride systems as catalysts for organic transformations involving 'hydride-borrowing' and for sustainable multi-electron reductions of unsaturated organic and inorganic substrates directly driven by electricity or light or by renewable reductants such as formate/formic acid.
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Affiliation(s)
- Alex McSkimming
- School of Chemistry, The University of New South Wales, Sydney, NSW 2052, Australia
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35
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Matsubara Y, Hightower SE, Chen J, Grills DC, Polyansky DE, Muckerman JT, Tanaka K, Fujita E. Reactivity of a fac-ReCl(α-diimine)(CO)3 complex with an NAD+ model ligand toward CO2 reduction. Chem Commun (Camb) 2013; 50:728-30. [PMID: 24287872 DOI: 10.1039/c3cc47699e] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The reactivity of a rhenium complex containing an NAD(+) model ligand was examined toward photochemical formation of the corresponding NADH-like dihydro form of the complex and electrochemical CO2 reduction. The hydricity of the NADH-like complex was estimated by a thermodynamic cycle and reaction with Ph3C(+).
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Affiliation(s)
- Yasuo Matsubara
- Brookhaven National Laboratory, Chemistry Department, Upton, New York 11973, USA.
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36
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Zhou R, Sedai B, Manbeck GF, Brewer KJ. New Supramolecular Structural Motif Coupling a Ruthenium(II) Polyazine Light Absorber to a Rhodium(I) Center. Inorg Chem 2013; 52:13314-24. [DOI: 10.1021/ic4006828] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Rongwei Zhou
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24060-0212, United States
| | - Baburam Sedai
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24060-0212, United States
| | - Gerald F. Manbeck
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24060-0212, United States
| | - Karen J. Brewer
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24060-0212, United States
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Zamadar M, Cook AR, Lewandowska-Andralojc A, Holroyd R, Jiang Y, Bikalis J, Miller JR. Electron Transfer by Excited Benzoquinone Anions: Slow Rates for Two-Electron Transitions. J Phys Chem A 2013; 117:8360-7. [DOI: 10.1021/jp403113u] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Matibur Zamadar
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973-5000,
United States
| | - Andrew R. Cook
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973-5000,
United States
| | | | - Richard Holroyd
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973-5000,
United States
| | - Yan Jiang
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973-5000,
United States
| | - Jin Bikalis
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973-5000,
United States
| | - John R. Miller
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973-5000,
United States
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38
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Knoll JD, Higgins SLH, White TA, Brewer KJ. Subunit Variation to Uncover Properties of Polyazine-Bridged Ru(II), Pt(II) Supramolecules with Low Lying Charge Separated States Providing Insight into the Functioning as H2O Reduction Photocatalysts to Produce H2. Inorg Chem 2013; 52:9749-60. [DOI: 10.1021/ic4004406] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jessica D. Knoll
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061-0212, United States
| | | | - Travis A. White
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061-0212, United States
| | - Karen J. Brewer
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061-0212, United States
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39
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Doherty MD, Grills DC, Huang KW, Muckerman JT, Polyansky DE, van Eldik R, Fujita E. Kinetics and Thermodynamics of Small Molecule Binding to Pincer-PCP Rhodium(I) Complexes. Inorg Chem 2013; 52:4160-72. [DOI: 10.1021/ic300672g] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Mark D. Doherty
- Chemistry Department, Brookhaven National Laboratory, P.O. Box 5000, Upton, New York 11973-5000, United States
| | - David C. Grills
- Chemistry Department, Brookhaven National Laboratory, P.O. Box 5000, Upton, New York 11973-5000, United States
| | - Kuo-Wei Huang
- Chemistry Department, Brookhaven National Laboratory, P.O. Box 5000, Upton, New York 11973-5000, United States
| | - James T. Muckerman
- Chemistry Department, Brookhaven National Laboratory, P.O. Box 5000, Upton, New York 11973-5000, United States
| | - Dmitry E. Polyansky
- Chemistry Department, Brookhaven National Laboratory, P.O. Box 5000, Upton, New York 11973-5000, United States
| | - Rudi van Eldik
- Department of Chemistry and Pharmacy, University of Erlangen-Nürnberg, Egerlandstrasse
1, 91058 Erlangen, Germany
| | - Etsuko Fujita
- Chemistry Department, Brookhaven National Laboratory, P.O. Box 5000, Upton, New York 11973-5000, United States
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40
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Kasapbasi EE, Whangbo MH. On the nature of the photochemical reaction of polypyridyl Ru(ii) complexes leading to sunlight-to-chemical energy conversion: density functional analysis. RSC Adv 2013. [DOI: 10.1039/c3ra41195h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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41
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Lewandowska-Andralojc A, Polyansky DE, Zong R, Thummel RP, Fujita E. Enabling light-driven water oxidation via a low-energy RuIVO intermediate. Phys Chem Chem Phys 2013; 15:14058-68. [DOI: 10.1039/c3cp52038b] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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42
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Padhi SK, Fukuda R, Ehara M, Tanaka K. Comparative study of C^N and N^C type cyclometalated ruthenium complexes with a NAD+/NADH function. Inorg Chem 2012; 51:8091-102. [PMID: 22827695 DOI: 10.1021/ic300449q] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Cyclometalated ruthenium complexes having C(^)N and N(^)C type coordinating ligands with NAD(+)/NADH function have been synthesized and characterized by spectroscopic methods. The variation of the coordinating position of σ-donating carbon atom leads to a drastic change in their properties. Both the complex Ru(phbn)(phen)(2)]PF(6) ([1]PF(6)) and [Ru(pad)(phen)(2)]PF(6) ([2]PF(6)) reduced to Ru(phbnHH)(phen)(2)]PF(6) ([1HH]PF(6)) and [Ru(padHH)(phen)(2)]PF(6) ([2HH]PF(6)) by chemical and electrochemical methods. Complex [1]PF(6) photochemically reduced to [1HH]PF(6) in the presence of the sacrificial agent triethylamine (TEA) upon irradiation of visible light (λ ≥ 420 nm), whereas photochemical reduction of [2]PF(6) was not successful. Both experimental results and theoretical calculations reveal that upon protonation the energy level of the π* orbital of either of the ligands phbn or pad is drastically stabilized compared to the nonprotonated forms. In the protonated complex [Ru(padH)(phen)(2)](PF(6))(2) {[2H](PF(6))(2)}, the Ru-C bond exists in a tautomeric equilibrium with Ru═C coordination and behaves as a remote N-heterocyclic carbene (rNHC) compex; on the contrary, this behavior could not be observed in protonated complex [Ru(phbnH)(phen)(2)](PF(6))(2) {[1H](PF(6))(2)}.
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Affiliation(s)
- Sumanta Kumar Padhi
- Department of Life and Coordination-Complex Molecular Science, Institute for Molecular Science, 5-1, Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan
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Calculation of thermodynamic hydricities and the design of hydride donors for CO2 reduction. Proc Natl Acad Sci U S A 2012; 109:15657-62. [PMID: 22826261 DOI: 10.1073/pnas.1201026109] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We have developed a correlation between experimental and density functional theory-derived results of the hydride-donating power, or "hydricity", of various ruthenium, rhenium, and organic hydride donors. This approach utilizes the correlation between experimental hydricity values and their corresponding calculated free-energy differences between the hydride donors and their conjugate acceptors in acetonitrile, and leads to an extrapolated value of the absolute free energy of the hydride ion without the necessity to calculate it directly. We then use this correlation to predict, from density functional theory-calculated data, hydricity values of ruthenium and rhenium complexes that incorporate the pbnHH ligand-pbnHH = 1,5-dihydro-2-(2-pyridyl)-benzo[b]-1,5-naphthyridine-to model the function of NADPH. These visible light-generated, photocatalytic complexes produced by disproportionation of a protonated-photoreduced dimer of a metal-pbn complex may be valuable for use in reducing CO(2) to fuels such as methanol. The excited-state lifetime of photoexcited [Ru(bpy)(2)(pbnHH)](2+) is found to be about 70 ns, and this excited state can be reductively quenched by triethylamine or 1,4-diazabicyclo[2.2.2]octane to produce the one-electron-reduced [Ru(bpy)(2)(pbnHH)](+) species with half-life exceeding 50 μs, thus opening the door to new opportunities for hydride-transfer reactions leading to CO(2) reduction by producing a species with much increased hydricity.
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Cohen BW, Polyansky DE, Achord P, Cabelli D, Muckerman JT, Tanaka K, Thummel RP, Zong R, Fujita E. Steric effect for proton, hydrogen-atom, and hydride transfer reactions with geometric isomers of NADH-model ruthenium complexes. Faraday Discuss 2012; 155:129-44; discussion 207-22. [PMID: 22470971 DOI: 10.1039/c1fd00094b] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two isomers, [Ru(1)]2+ (Ru = Ru(bpy)2, bpy = 2,2'-bipyridine, 1 = 2-(pyrid-2'-yl)-1-azaacridine) and [Ru(2)]2+ (2 = 3-(pyrid-2'-yl)-4-azaacridine), are bioinspired model compounds containing the nicotinamide functionality and can serve as precursors for the photogeneration of C-H hydrides for studying reactions pertinent to the photochemical reduction of metal-C1 complexes and/or carbon dioxide. While it has been shown that the structural differences between the azaacridine ligands of [Ru(1)]2+ and [Ru(2)]2+ have a significant effect on the mechanism of formation of the hydride donors, [Ru(1HH)]2+ and [Ru(2HH)]2+, in aqueous solution, we describe the steric implications for proton, net-hydrogen-atom and net-hydride transfer reactions in this work. Protonation of [Ru(2*-)] in aprotic and even protic media is slow compared to that of [Ru(1*-)]+. The net hydrogen-atom transfer between *[Ru(1)]2+ and hydroquinone (H2Q) proceeds by one-step EPT, rather than stepwise electron-proton transfer. Such a reaction was not observed for *[Ru(2)]2+ because the non-coordinated N atom is not easily available for an interaction with H2Q. Finally, the rate of the net hydride ion transfer from [Ru(1HH)]2+ to [Ph3C]+ is significantly slower than that of [Ru (2HH)]2+ owing to steric congestion at the donor site.
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Affiliation(s)
- Brian W Cohen
- Chemistry Department, Brookhaven National Laboratory, Upton, New York, 11973-5000, USA
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45
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White TA, Knoll JD, Arachchige SM, Brewer KJ. A Series of Supramolecular Complexes for Solar Energy Conversion via Water Reduction to Produce Hydrogen: An Excited State Kinetic Analysis of Ru(II),Rh(III),Ru(II) Photoinitiated Electron Collectors. MATERIALS 2011; 5:27-46. [PMID: 28817031 PMCID: PMC5448952 DOI: 10.3390/ma5010027] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Revised: 12/12/2011] [Accepted: 12/19/2011] [Indexed: 01/28/2023]
Abstract
Mixed-metal supramolecular complexes have been designed that photochemically absorb solar light, undergo photoinitiated electron collection and reduce water to produce hydrogen fuel using low energy visible light. This manuscript describes these systems with an analysis of the photophysics of a series of six supramolecular complexes, [{(TL)₂Ru(dpp)}₂RhX₂](PF₆)₅ with TL = bpy, phen or Ph₂phen with X = Cl or Br. The process of light conversion to a fuel requires a system to perform a number of complicated steps including the absorption of light, the generation of charge separation on a molecular level, the reduction by one and then two electrons and the interaction with the water substrate to produce hydrogen. The manuscript explores the rate of intramolecular electron transfer, rate of quenching of the supramolecules by the DMA electron donor, rate of reduction of the complex by DMA from the ³MLCT excited state, as well as overall rate of reduction of the complex via visible light excitation. Probing a series of complexes in detail exploring the variation of rates of important reactions as a function of sub-unit modification provides insight into the role of each process in the overall efficiency of water reduction to produce hydrogen. The kinetic analysis shows that the complexes display different rates of excited state reactions that vary with TL and halide. The role of the MLCT excited state is elucidated by this kinetic study which shows that the ³MLCT state and not the ³MMCT is likely that key contributor to the photoreduction of these complexes. The kinetic analysis of the excited state dynamics and reactions of the complexes are important as this class of supramolecules behaves as photoinitiated electron collectors and photocatalysts for the reduction of water to hydrogen.
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Affiliation(s)
- Travis A White
- Department of Chemistry, Virginia Tech, Blacksburg, VA 24061-0212, USA.
| | - Jessica D Knoll
- Department of Chemistry, Virginia Tech, Blacksburg, VA 24061-0212, USA.
| | | | - Karen J Brewer
- Department of Chemistry, Virginia Tech, Blacksburg, VA 24061-0212, USA.
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White TA, Higgins SLH, Arachchige SM, Brewer KJ. Efficient Photocatalytic Hydrogen Production in a Single-Component System Using Ru,Rh,Ru Supramolecules Containing 4,7-Diphenyl-1,10-Phenanthroline. Angew Chem Int Ed Engl 2011; 50:12209-13. [DOI: 10.1002/anie.201105170] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Revised: 09/05/2011] [Indexed: 11/09/2022]
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47
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White TA, Higgins SLH, Arachchige SM, Brewer KJ. Efficient Photocatalytic Hydrogen Production in a Single-Component System Using Ru,Rh,Ru Supramolecules Containing 4,7-Diphenyl-1,10-Phenanthroline. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201105170] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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48
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Padhi SK, Tanaka K. Photo- and Electrochemical Redox Behavior of Cyclometalated Ru(II) Complexes Having a 3-Phenylbenzo[b][1,6]naphthyridine Ligand. Inorg Chem 2011; 50:10718-23. [DOI: 10.1021/ic201207x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sumanta Kumar Padhi
- Department of Life and Coordination-Complex Molecular Science, Institute for Molecular Science, 5-1, Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan
| | - Koji Tanaka
- Department of Life and Coordination-Complex Molecular Science, Institute for Molecular Science, 5-1, Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan
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49
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White TA, Whitaker BN, Brewer KJ. Discovering the Balance of Steric and Electronic Factors Needed To Provide a New Structural Motif for Photocatalytic Hydrogen Production from Water. J Am Chem Soc 2011; 133:15332-4. [DOI: 10.1021/ja206782k] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Travis A. White
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061-0212, United States
| | - Brittany N. Whitaker
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061-0212, United States
| | - Karen J. Brewer
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061-0212, United States
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50
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Padhi SK, Kobayashi K, Masuno S, Tanaka K. Proton-induced dynamic equilibrium between cyclometalated ruthenium rNHC (remote N-heterocyclic carbene) tautomers with an NAD+/NADH function. Inorg Chem 2011; 50:5321-3. [PMID: 21615114 DOI: 10.1021/ic200315f] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cyclometalated ruthenium(II) complexes having acridine moieties have been synthesized and characterized by spectroscopic methods. Protonation of the acridine nitrogen of the ruthenium(II) complexes not only causes dynamic equilibrium with remote N-heterocyclic carbene Ru═C complexes but also generates the NAD(+)/NADH redox function driven by a proton-coupled two-electron transfer accompanying a reversible C-H bond formation in the pyridinium ring.
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Affiliation(s)
- Sumanta Kumar Padhi
- Department of Life and Coordination-Complex Molecular Science, Institute for Molecular Science, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan
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