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Zedler L, Kupfer S, Schmidt H, Dietzek-Ivanšić B. Oxidation-state sensitive light-induced dynamics of Ruthenium-4H-Imidazole complexes. Chemistry 2023:e202303079. [PMID: 38131166 DOI: 10.1002/chem.202303079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 12/20/2023] [Accepted: 12/22/2023] [Indexed: 12/23/2023]
Abstract
Oxidized molecular states are key intermediates in photo-induced redox reactions, e. g., intermolecular charge transfer between photosensitizer and catalyst in photoredox catalysis. The stability and longevity of the oxidized photosensitizer is an important factor in optimizing the respective light-driven reaction pathways. In this work the oxidized states of ruthenium(II)-4H-imidazole dyes are studied. The ruthenium complexes constitute benchmark photosensitizers in solar energy interconversion processes with exceptional chemical stability, strong visible light absorption, and favourable redox properties. To rationalize the light-induced reaction in the oxidized ruthenium(III) systems, we combine UV-vis absorption, resonance Raman, and transient absorption spectroelectrochemistry (SEC) with time-dependent density functional theory (TDDFT) calculations. Three complexes are compared, which vary with respect to their coordination environment, i. e., combining an 4H-imidazole with either 2,2'-bipyridine (bpy) or 2,2';6'2"-terpyridine (tpy) coligands, and chloride or isothiocyanate ligands. While all oxidized complexes have similar steady state absorption properties, their excited state kinetics differ significantly; the study thus opens the doorway to study the light-driven reactivity of oxidized molecular intermediates in intermolecular charge transfer cascades.
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Affiliation(s)
- Linda Zedler
- Functional Interfaces, Leibniz Institute of Photonic Technology, Albert-Einstein-Straße 9, 07745, Jena, Germany
| | - Stephan Kupfer
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany
| | - Heiner Schmidt
- Functional Interfaces, Leibniz Institute of Photonic Technology, Albert-Einstein-Straße 9, 07745, Jena, Germany
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany
| | - Benjamin Dietzek-Ivanšić
- Functional Interfaces, Leibniz Institute of Photonic Technology, Albert-Einstein-Straße 9, 07745, Jena, Germany
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany
- Jena Center for Soft Matter, Friedrich Schiller University Jena, Philosophenweg 7, 07743, Jena, Germany
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2
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Kumar K, Wächtler M. Unravelling Dynamics Involving Multiple Charge Carriers in Semiconductor Nanocrystals. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:nano13091579. [PMID: 37177124 PMCID: PMC10181110 DOI: 10.3390/nano13091579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 05/02/2023] [Accepted: 05/04/2023] [Indexed: 05/15/2023]
Abstract
The use of colloidal nanocrystals as part of artificial photosynthetic systems has recently gained significant attention, owing to their strong light absorption and highly reproducible, tunable electronic and optical properties. The complete photocatalytic conversion of water to its components is yet to be achieved in a practically suitable and commercially viable manner. To complete this challenging task, we are required to fully understand the mechanistic aspects of the underlying light-driven processes involving not just single charge carriers but also multiple charge carriers in detail. This review focuses on recent progress in understanding charge carrier dynamics in semiconductor nanocrystals and the influence of various parameters such as dimension, composition, and cocatalysts. Transient absorption spectroscopic studies involving single and multiple charge carriers, and the challenges associated with the need for accumulation of multiple charge carriers to drive the targeted chemical reactions, are discussed.
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Affiliation(s)
- Krishan Kumar
- Department Functional Interfaces, Leibniz Institute of Photonic Technology Jena, Albert-Einstein-Straße 9, 07745 Jena, Germany
| | - Maria Wächtler
- Chemistry Department and State Research Center OPTIMAS, RPTU Kaiserslautern-Landau, Erwin-Schrödinger-Str. 52, 67663 Kaiserslautern, Germany
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3
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Santoro A, Bella G, Cancelliere AM, Serroni S, Lazzaro G, Campagna S. Photoinduced Electron Transfer in Organized Assemblies—Case Studies. Molecules 2022; 27:molecules27092713. [PMID: 35566062 PMCID: PMC9102318 DOI: 10.3390/molecules27092713] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 04/16/2022] [Accepted: 04/19/2022] [Indexed: 12/10/2022] Open
Abstract
In this review, photoinduced electron transfer processes in specifically designed assembled architectures have been discussed in the light of recent results reported from our laboratories. A convenient and useful way to study these systems is described to understand the rules that drive a light-induced charge-separated states and its subsequent decay to the ground state, also with the aim of offering a tutorial for young researchers. Assembled systems of covalent or supramolecular nature have been presented, and some functional multicomponent systems for the conversion of light energy into chemical energy have been discussed.
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Bürgin T, Wenger OS. Recent Advances and Perspectives in Photodriven Charge Accumulation in Molecular Compounds: A Mini Review. ENERGY & FUELS : AN AMERICAN CHEMICAL SOCIETY JOURNAL 2021; 35:18848-18856. [PMID: 35873109 PMCID: PMC9302442 DOI: 10.1021/acs.energyfuels.1c02073] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The formation of so-called solar fuels from abundant low-energetic compounds, such as carbon dioxide or water, relies on the chemical elementary steps of photoinduced electron transfer and accumulation of multiple redox equivalents. The majority of molecular systems explored to date require sacrificial electron donors to accumulate multiple electrons on a single acceptor unit, but the use of high-energetic sacrificial redox reagents is unsustainable. In recent years, an increasing number of molecular compounds for reversible light-driven accumulation of redox equivalents that do not need sacrificial electron donors has been reported. Those compounds are the focus of this mini review. Different concepts, such as redox potential compression (achieved by proton-coupled electron transfer, Lewis acid-base interactions, or structural rearrangements), hybrids with inorganic nanoparticles, and diffusion-controlled multi-component systems, will be discussed. Newly developed strategies to outcompete unproductive reaction pathways in favor of desired photoproduct formation will be compared, and the importance of identifying reaction intermediates in the course of multiphotonic excitation by different time-resolved spectroscopic techniques will be discussed. The mechanistic insights gained from molecular donor-photosensitizer-acceptor compounds inform the design of next-generation charge accumulation systems for solar energy conversion.
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5
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Gotico P, Tran T, Baron A, Vauzeilles B, Lefumeux C, Ha‐Thi M, Pino T, Halime Z, Quaranta A, Leibl W, Aukauloo A. Tracking Charge Accumulation in a Functional Triazole‐Linked Ruthenium‐Rhenium Dyad Towards Photocatalytic Carbon Dioxide Reduction. CHEMPHOTOCHEM 2021. [DOI: 10.1002/cptc.202100010] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Philipp Gotico
- Université Paris Saclay Institut des Sciences Moléculaires d'Orsay (ISMO) 91405 Orsay France
| | - Thu‐Trang Tran
- Université Paris Saclay Institut des Sciences Moléculaires d'Orsay (ISMO) 91405 Orsay France
| | - Aurelie Baron
- Université Paris-Saclay Institut de Chimie des Substances Naturelles (ICSN) 91191 Gif-sur-Yvette France
| | - Boris Vauzeilles
- Université Paris-Saclay Institut de Chimie des Substances Naturelles (ICSN) 91191 Gif-sur-Yvette France
| | - Christophe Lefumeux
- Université Paris Saclay Institut des Sciences Moléculaires d'Orsay (ISMO) 91405 Orsay France
| | - Minh‐Huong Ha‐Thi
- Université Paris Saclay Institut des Sciences Moléculaires d'Orsay (ISMO) 91405 Orsay France
| | - Thomas Pino
- Université Paris Saclay Institut des Sciences Moléculaires d'Orsay (ISMO) 91405 Orsay France
| | - Zakaria Halime
- Université Paris Saclay Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO) 91405 Orsay France
| | - Annamaria Quaranta
- Université Paris Saclay CEA, CNRS, Institut de Biologie Intégrative de la Cellule (I2BC) 91191 Gif-sur-Yvette France
| | - Winfried Leibl
- Université Paris Saclay CEA, CNRS, Institut de Biologie Intégrative de la Cellule (I2BC) 91191 Gif-sur-Yvette France
| | - Ally Aukauloo
- Université Paris Saclay Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO) 91405 Orsay France
- Université Paris Saclay CEA, CNRS, Institut de Biologie Intégrative de la Cellule (I2BC) 91191 Gif-sur-Yvette France
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6
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Zhang X, Chen X, Zhao J. Electron spin-controlled charge transfer and the resulting long-lived charge transfer state: from transition metal complexes to organic compounds. Dalton Trans 2021; 50:59-67. [PMID: 33338095 DOI: 10.1039/d0dt03737k] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The generation of long-lived charge transfer (CT) states in electron donor/acceptor dyads upon photoexcitation is crucial for artificial photosynthesis, photocatalysis and photovoltaics. Electron spin control is a novel strategy to prolong the CT state lifetime via generation of the 3CT triplet state, instead of the traditional short-lived 1CT state. This method involves a local triplet excited state (3LE) as the precursor of charge separation (CS), and the electron forbidden feature of the charge recombination (CR) of 3CT → S0vs. the electron spin allowed 1CT → S0 prolongs the CT state lifetime. In this article, we summarized the recent developments and challenges in this emerging fascinating area.
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Affiliation(s)
- Xue Zhang
- State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, E-208 West Campus, 2 Ling Gong Road, Dalian 116024, P. R. China.
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8
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Skaisgirski M, Larsen CB, Kerzig C, Wenger OS. Stepwise Photoinduced Electron Transfer in a Tetrathiafulvalene‐Phenothiazine‐Ruthenium Triad. Eur J Inorg Chem 2019. [DOI: 10.1002/ejic.201900453] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Michael Skaisgirski
- Department of Chemistry University of Basel St. Johanns‐Ring 19 4056 Basel Switzerland
| | - Christopher B. Larsen
- Department of Chemistry University of Basel St. Johanns‐Ring 19 4056 Basel Switzerland
| | - Christoph Kerzig
- 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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9
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Kerzig C, Wenger OS. Reactivity control of a photocatalytic system by changing the light intensity. Chem Sci 2019; 10:11023-11029. [PMID: 32206254 PMCID: PMC7069242 DOI: 10.1039/c9sc04584h] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 10/08/2019] [Indexed: 12/13/2022] Open
Abstract
By using simple optics such as a lens, switching between one- and two-photon driven reaction mechanisms became feasible, which allows the control over the main products of photochemical reactions.
We report a novel light-intensity dependent reactivity approach allowing us to selectively switch between triplet energy transfer and electron transfer reactions, or to regulate the redox potential available for challenging reductions. Simply by adjusting the light power density with an inexpensive lens while keeping all other parameters constant, we achieved control over one- and two-photon mechanisms, and successfully exploited our approach for lab-scale photoreactions using three substrate classes with excellent selectivities and good product yields. Specifically, our proof-of-concept study demonstrates that the irradiation intensity can be used to control (i) the available photoredox reactivity for reductive dehalogenations to selectively target either bromo- or chloro-substituted arenes, (ii) the photochemical cis–trans isomerization of olefins versus their photoreduction, and (iii) the competition between hydrogen atom abstraction and radical dimerization processes.
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Affiliation(s)
- Christoph Kerzig
- 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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10
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Neumann S, Kerzig C, Wenger OS. Quantitative insights into charge-separated states from one- and two-pulse laser experiments relevant for artificial photosynthesis. Chem Sci 2019; 10:5624-5633. [PMID: 31293747 PMCID: PMC6553010 DOI: 10.1039/c9sc01381d] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 05/01/2019] [Indexed: 01/25/2023] Open
Abstract
Charge-separated states (CSSs) are key intermediates in photosynthesis and solar energy conversion. However, the factors governing the formation efficiencies of CSSs are still poorly understood, and light-induced electron-hole recombinations as deactivation pathways competing with desired charge accumulations are largely unexplored. This greatly limits the possibility to perform efficient multi-electron transfer, which is essential for artificial photosynthesis. We present a systematic investigation of two donor-sensitizer-acceptor triads (with different donor-acceptor distances) capable of storing as much as 2.0 eV in their CSSs upon the absorption of a visible photon. Using quantitative one- and two-pulse laser flash photolysis, we provide deep insights into both the CSS formation quantum yield, which can reach up to 80%, and the fate of the CSS upon further (secondary) excitation with green photons. The triad with shorter intramolecular distances shows a remarkable excitation wavelength dependence of the CSS formation quantum yield, and the CSS of this triad undergoes more efficient light-induced charge recombination than the longer equivalent by about one order of magnitude, whilst thermal charge recombination shows the exact opposite behavior. The unexpected results of our detailed photophysical study can be rationalized by detrimental singlet charge transfer states or structural considerations, and could significantly contribute to the future design of CSS precursors for accumulative multi-electron transfer and artificial photosynthesis.
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Affiliation(s)
- Svenja Neumann
- Department of Chemistry , University of Basel , St. Johanns-Ring 19 , 4056 Basel , Switzerland . ;
| | - Christoph Kerzig
- 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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11
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Pannwitz A, Wenger OS. Proton-coupled multi-electron transfer and its relevance for artificial photosynthesis and photoredox catalysis. Chem Commun (Camb) 2019; 55:4004-4014. [DOI: 10.1039/c9cc00821g] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Photoinduced PCET meets catalysis, and the accumulation of multiple redox equivalents is of key importance.
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Affiliation(s)
- Andrea Pannwitz
- Department of Chemistry
- University of Basel
- 4056 Basel
- Switzerland
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12
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Ha-Thi MH, Pham VT, Pino T, Maslova V, Quaranta A, Lefumeux C, Leibl W, Aukauloo A. Photoinduced electron transfer in a molecular dyad by nanosecond pump-pump-probe spectroscopy. Photochem Photobiol Sci 2018; 17:903-909. [PMID: 29855023 DOI: 10.1039/c8pp00048d] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The design of robust and inexpensive molecular photocatalysts for the conversion of abundant stable molecules like H2O and CO2 into an energetic carrier is one of the major fundamental questions for scientists nowadays. The outstanding challenge is to couple single photoinduced charge separation events with the sequential accumulation of redox equivalents at the catalytic unit for performing multielectronic catalytic reactions. Herein, double excitation by nanosecond pump-pump-probe experiments was used to interrogate the photoinduced charge transfer and charge accumulation on a molecular dyad composed of a porphyrin chromophore and a ruthenium-based catalyst in the presence of a reversible electron acceptor. An accumulative charge transfer state is unattainable because of rapid reverse electron transfer to the photosensitizer upon the second excitation and the low driving force of the forward photodriven electron transfer reaction. Such a method allows the fundamental understanding of the relaxation mechanism after two sequential photon absorptions, deciphering the undesired electron transfer reactions that limit the charge accumulation efficiency. This study is a step toward the improvement of synthetic strategies of molecular photocatalysts for light-induced charge accumulation and more generally, for solar energy conversion.
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Affiliation(s)
- M-H Ha-Thi
- Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS, Univ. Paris-Sud, Université Paris-Saclay, F-91405 Orsay, France.
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13
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Nomrowski J, Wenger OS. Exploiting Potential Inversion for Photoinduced Multielectron Transfer and Accumulation of Redox Equivalents in a Molecular Heptad. J Am Chem Soc 2018; 140:5343-5346. [PMID: 29652485 DOI: 10.1021/jacs.8b02443] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Photoinduced multielectron transfer and reversible accumulation of redox equivalents is accomplished in a fully integrated molecular heptad composed of four donors, two photosensitizers, and one acceptor. The second reduction of the dibenzo[1,2]dithiin acceptor occurs more easily than the first by 1.3 V, and this potential inversion facilitates the light-driven formation of a two-electron reduced state with a lifetime of 66 ns in deaerated CH3CN. The quantum yield for formation of this doubly charge-separated photoproduct is 0.5%. In acidic oxygen-free solution, the reduction product is a stable dithiol. Under steady-state photoirradiation, our heptad catalyzes the two-electron reduction of an aliphatic disulfide via thiolate-disulfide interchange. Exploitation of potential inversion for the reversible light-driven accumulation of redox equivalents in artificial systems is unprecedented and the use of such a charge-accumulated state for multielectron photoredox catalysis represents an important proof-of-concept.
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Affiliation(s)
- Julia Nomrowski
- 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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14
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Tran TT, Ha-Thi MH, Pino T, Quaranta A, Lefumeux C, Leibl W, Aukauloo A. Snapshots of Light Induced Accumulation of Two Charges on Methylviologen using a Sequential Nanosecond Pump-Pump Photoexcitation. J Phys Chem Lett 2018; 9:1086-1091. [PMID: 29442519 DOI: 10.1021/acs.jpclett.8b00169] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Methylviologen (MV2+) is perhaps the most used component as a reversible electron acceptor in photophysical studies. While MV2+ is most commonly implicated as a reversible one-electron mediator, its electrochemical properties clearly evidence two successive one-electron reduction processes. In this report, we have investigated on the light driven two-charge accumulation on MV2+ using a multicomponent system composed of the prototypical molecular photosensitizer [Ru(bpy)3]2+ and MV2+ in the presence of ascorbate as reversible electron donor. The sequential addition of two electrons on the methylviologen was tracked upon sequential excitation of the [Ru(bpy)3]2+ at optimized concentration of the electron acceptor. The charge accumulated state carries an energy of 0.9 eV above the ground state and has a lifetime of ca. 50 μs. We have reached a fairly good global yield of approximately 9% for the two-charge accumulation. This result clearly demonstrates the potential of this simple approach for applications in artificial photosynthesis.
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Affiliation(s)
- Thu-Trang Tran
- Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS, Univ Paris Sud, Université Paris-Saclay , F-91405 Orsay, France
| | - Minh-Huong Ha-Thi
- Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS, Univ Paris Sud, Université Paris-Saclay , F-91405 Orsay, France
| | - Thomas Pino
- Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS, Univ Paris Sud, Université Paris-Saclay , F-91405 Orsay, France
| | - Annamaria Quaranta
- Institute for integrative Biology of the Cell (I2BC), CEA, CNRS, UMR 9198 , F-91191, Gif-sur-Yvette, France
| | - Christophe Lefumeux
- Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS, Univ Paris Sud, Université Paris-Saclay , F-91405 Orsay, France
| | - Winfried Leibl
- Institute for integrative Biology of the Cell (I2BC), CEA, CNRS, UMR 9198 , F-91191, Gif-sur-Yvette, France
| | - Ally Aukauloo
- Institute for integrative Biology of the Cell (I2BC), CEA, CNRS, UMR 9198 , F-91191, Gif-sur-Yvette, France
- Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), Univ Paris Sud, CNRS , F-91405 Orsay Cedex, France
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15
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Pannwitz A, Wenger OS. Photoinduced Electron Transfer Coupled to Donor Deprotonation and Acceptor Protonation in a Molecular Triad Mimicking Photosystem II. J Am Chem Soc 2017; 139:13308-13311. [PMID: 28906113 DOI: 10.1021/jacs.7b08761] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The first artificial donor-sensitizer-acceptor compound in which photoinduced long-range electron transfer is coupled to donor deprotonation and acceptor protonation is reported. The long-lived photoproduct stores energy in the form of a radical pair state in which the charges of the donor and the acceptor remain unchanged, much in contrast to previously investigated systems that exhibit charge-separated states comprised of electron-hole pairs. This finding is relevant for light-driven accumulation of redox equivalents, because it exemplifies how the buildup of charge can be avoided yet light energy can be stored. Proton-coupled electron transfer (PCET) reactions at a phenol donor and a monoquat acceptor triggered by excitation of a Ru(II) sensitizer enable this form of photochemical energy storage. Our triad emulates photosystem II more closely than previously investigated systems, because tyrosine Z is oxidized and deprotonated, whereas plastoquinone B is reduced and protonated.
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Affiliation(s)
- Andrea Pannwitz
- 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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16
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Solvent-control of photoinduced electron transfer via hydrogen bonding in a molecular triad made of a dinuclear chromophore subunit. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2017.02.035] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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17
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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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18
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Kuss-Petermann M, Orazietti M, Neuburger M, Hamm P, Wenger OS. Intramolecular Light-Driven Accumulation of Reduction Equivalents by Proton-Coupled Electron Transfer. J Am Chem Soc 2017; 139:5225-5232. [PMID: 28362497 DOI: 10.1021/jacs.7b01605] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The photochemistry of a molecular pentad composed of a central anthraquinone (AQ) acceptor flanked by two Ru(bpy)32+ photosensitizers and two peripheral triarylamine (TAA) donors was investigated by transient IR and UV-vis spectroscopies in the presence of 0.2 M p-toluenesulfonic acid (TsOH) in deaerated acetonitrile. In ∼15% of all excited pentad molecules, AQ is converted to its hydroquinone form (AQH2) via reversible intramolecular electron transfer from the two TAA units (τ = 65 ps), followed by intermolecular proton transfer from TsOH (τ ≈ 3 ns for the first step). Although the light-driven accumulation of reduction equivalents occurs through a sequence of electron and proton transfer steps, the resulting photoproduct decays via concerted PCET (τ = 4.7 μs) with an H/D kinetic isotope effect of 1.4 ± 0.2. Moreover, the reoxidation of AQH2 seems to take place via a double electron transfer step involving both TAA+ units rather than sequential single electron transfer events. Thus, the overall charge-recombination reaction seems to involve a concerted proton-coupled two-electron oxidation of AQH2. The comparison of experimental data obtained in neat acetonitrile with data from acidic solutions suggests that the inverted driving-force effect can play a crucial role for obtaining long-lived photoproducts resulting from multiphoton, multielectron processes. Our pentad provides the first example of light-driven accumulation of reduction equivalents stabilized by PCET in artificial molecular systems without sacrificial reagents. Our study provides fundamental insight into how light-driven multielectron redox chemistry, for example the reduction of CO2 or the oxidation of H2O, can potentially be performed without sacrificial reagents.
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Affiliation(s)
- Martin Kuss-Petermann
- Department of Chemistry, University of Basel , St. Johanns-Ring 19, 4056 Basel, Switzerland
| | - Margherita Orazietti
- Department of Chemistry, University of Zurich , Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Markus Neuburger
- 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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Skaisgirski M, Guo X, Wenger OS. Electron Accumulation on Naphthalene Diimide Photosensitized by [Ru(2,2′-Bipyridine)3]2+. Inorg Chem 2017; 56:2432-2439. [DOI: 10.1021/acs.inorgchem.6b02446] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Michael Skaisgirski
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
| | - Xingwei Guo
- 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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