1
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Stamoulis A, Mato M, Bruzzese PC, Leutzsch M, Cadranel A, Gil-Sepulcre M, Neese F, Cornella J. Red-Light-Active N,C,N-Pincer Bismuthinidene: Excited State Dynamics and Mechanism of Oxidative Addition into Aryl Iodides. J Am Chem Soc 2025; 147:6037-6048. [PMID: 39924910 PMCID: PMC11848931 DOI: 10.1021/jacs.4c16815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2024] [Revised: 01/29/2025] [Accepted: 01/31/2025] [Indexed: 02/11/2025]
Abstract
Despite the progress made in the field of synthetic organic photocatalysis over the past decade, the use of higher wavelengths, especially those in the deep-red portion of the electromagnetic spectrum, remains comparatively rare. We have previously disclosed that a well-defined N,C,N-pincer bismuthinidene (1a) can undergo formal oxidative addition into a wide range of aryl electrophiles upon absorption of low-energy red light. In this study, we map out the photophysical dynamics of 1a and glean insights into the nature of the excited state responsible for the activation of aryl electrophiles. Transient absorption and emission techniques reveal that, upon irradiation with red light, the complex undergoes a direct S0 → S1 metal-to-ligand charge transfer (MLCT) transition, followed by rapid intersystem crossing (ISC) to a highly reducing emissive triplet state (-2.61 V vs Fc+/0 in MeCN). The low dissipative losses incurred during ISC (∼6% of the incident light energy) help rationalize the ability of the bismuthinidene to convert low-energy light into useful chemical energy. Spectroelectrochemical and computational data support a charge-separated excited-state structure with radical-anion character on the ligand and radical-cation character on bismuth. Kinetic studies and competition experiments afford insights into the mechanism of oxidative addition into aryl iodides; concerted and inner-sphere processes from the triplet excited state are ruled out, with the data strongly supporting a pathway that proceeds via outer-sphere dissociative electron transfer.
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Affiliation(s)
- Alexios Stamoulis
- Max-Planck-Institut
für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an
der Ruhr 45470, Germany
| | - Mauro Mato
- Max-Planck-Institut
für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an
der Ruhr 45470, Germany
| | - Paolo Cleto Bruzzese
- Max-Planck-Institut
für Chemische Energiekonversion, Stiftstrasse 34–36, Mülheim an der Ruhr 45470, Germany
| | - Markus Leutzsch
- Max-Planck-Institut
für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an
der Ruhr 45470, Germany
| | - Alejandro Cadranel
- Universidad
de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Inorgánica, Analítica
y Química Física, Pabellón 2, Ciudad Universitaria, C1428EHA Buenos
Aires, Argentina
- CONICET—Universidad
de Buenos Aires, Instituto de Química Física de Materiales,
Medio Ambiente y Energía (INQUIMAE), Pabellón 2, Ciudad
Universitaria, C1428EHA Buenos Aires, Argentina
- Department
Chemie und Pharmazie, Physikalische Chemie I, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen 91058, Germany
- Interdisciplinary
Center for Molecular Materials, Friedrich-Alexander-Universität
Erlangen-Nürnberg (FAU), Erlangen 91058, Germany
| | - Marcos Gil-Sepulcre
- Max-Planck-Institut
für Chemische Energiekonversion, Stiftstrasse 34–36, Mülheim an der Ruhr 45470, Germany
| | - Frank Neese
- Max-Planck-Institut
für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an
der Ruhr 45470, Germany
| | - Josep Cornella
- Max-Planck-Institut
für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an
der Ruhr 45470, Germany
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2
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Shee M, Schleisiek J, Maity N, Das G, Montesdeoca N, Ha-Thi MH, Gore KR, Karges J, Singh NDP. Exploring Excited-State Intramolecular Proton-Coupled Electron Transfer in Dinuclear Ir(III)-Complex via Covalently Tagged Hydroquinone: Phototherapy Through Futile Redox Cycling. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2025; 21:e2408437. [PMID: 39711252 DOI: 10.1002/smll.202408437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2024] [Revised: 11/01/2024] [Indexed: 12/24/2024]
Abstract
Anticipating intramolecular excited-state proton-coupled electron transfer (PCET) process within dinuclear Ir2-photocatalytic system via the covalent linkage is seminal, yet challenging. Indeed, the development of various dinuclear complexes is also promising for studying integral photophysics and facilitating applications in catalysis or biology. Herein, this study reports dinuclear [Ir2(bis{imidazo-phenanthrolin-2-yl}-hydroquinone)(ppy)4]2+ (12+) complex by leveraging both ligand-centered redox property and intramolecular H-bonding for exploring dual excited-state proton-transfer assisted PCET process. The vital role of covalently placed hydroquinone in bridged ligand is investigated as electron-proton transfer (ET-PT) mediator in intramolecular PCET and validated from triplet spin density plot. Moreover, bimolecular photoinduced ET reaction is studied in acetonitrile/water medium, forging the lowest energy triplet charge separated (3CSPhen-Im) state of 12+ with methyl viologen via favorably concerted-PCET pathway. The result indicates strong donor-acceptors coupling, which limits charge recombination and enhances catalytic efficiency. To showcase the potential application, this bioinspired PCET-based photocatalytic platform is studied for phototherapeutics, indicating significant mitochondrial localization and leading to programmed cell death (apoptosis) through futile redox cycling. Indeed, the consequences of effective internalization (via energy-dependent endocytosis), better safety profile, and higher photoinduced antiproliferative activity of 12+ compared to Cisplatin, as explored in 3D tumor spheroids, this study anticipates it to be a potential lead compound.
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Affiliation(s)
- Maniklal Shee
- Department of Chemistry, Indian Institute of Technology, Kharagpur, West Bengal, 721302, India
| | - Julia Schleisiek
- Faculty of Chemistry and Biochemistry, Ruhr-University Bochum, Universitätsstrasse 150, 44780, Bochum, Germany
| | - Nishith Maity
- Université Paris-Saclay, CNRS, Institut des Sciences Molécu-laires d'Orsay, Orsay, 91405, France
| | - Gourav Das
- Department of Chemistry, Indian Institute of Technology, Kharagpur, West Bengal, 721302, India
| | - Nicolás Montesdeoca
- Faculty of Chemistry and Biochemistry, Ruhr-University Bochum, Universitätsstrasse 150, 44780, Bochum, Germany
| | - Minh-Huong Ha-Thi
- Université Paris-Saclay, CNRS, Institut des Sciences Molécu-laires d'Orsay, Orsay, 91405, France
| | - Kiran R Gore
- Department of Chemistry, Indian Institute of Technology, Kharagpur, West Bengal, 721302, India
| | - Johannes Karges
- Faculty of Chemistry and Biochemistry, Ruhr-University Bochum, Universitätsstrasse 150, 44780, Bochum, Germany
| | - N D Pradeep Singh
- Department of Chemistry, Indian Institute of Technology, Kharagpur, West Bengal, 721302, India
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3
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Liu Z, Brian D, Sun X. PyCTRAMER: A Python package for charge transfer rate constant of condensed-phase systems from Marcus theory to Fermi's golden rule. J Chem Phys 2024; 161:064101. [PMID: 39120028 DOI: 10.1063/5.0224524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2024] [Accepted: 07/24/2024] [Indexed: 08/10/2024] Open
Abstract
In this work, we introduce PyCTRAMER, a comprehensive Python package designed for calculating charge transfer (CT) rate constants in disordered condensed-phase systems at finite temperatures, such as organic photovoltaic (OPV) materials. PyCTRAMER is a restructured and enriched version of the CTRAMER (Charge-Transfer RAtes from Molecular dynamics, Electronic structure, and Rate theory) package [Tinnin et al. J. Chem. Phys. 154, 214108 (2021)], enabling the computation of the Marcus CT rate constant and the six levels of the linearized semiclassical approximations of Fermi's golden rule (FGR) rate constant. It supports various types of intramolecular and intermolecular CT transitions from the excitonic states to CT state. Integrating quantum chemistry calculations, all-atom molecular dynamics (MD) simulations, spin-boson model construction, and rate constant calculations, PyCTRAMER offers an automatic workflow for handling photoinduced CT processes in explicit solvent environments and interfacial CT in amorphous donor/acceptor blends. The package also provides versatile tools for individual workflow steps, including electronic state analysis, state-specific force field construction, MD simulations, and spin-boson model construction from energy trajectories. We demonstrate the software's capabilities through two examples, highlighting both intramolecular and intermolecular CT processes in prototypical OPV systems.
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Affiliation(s)
- Zengkui Liu
- Shanghai Frontiers Science Center of Artificial Intelligence and Deep Learning, NYU Shanghai, 567 West Yangsi Road, Shanghai 200124, China
- Division of Arts and Sciences, NYU Shanghai, 567 West Yangsi Road, Shanghai 200124, China
- NYU-ECNU Center for Computational Chemistry at NYU Shanghai, 3663 Zhongshan Road North, Shanghai 200062, China
- Department of Chemistry, New York University, New York, New York 10003, USA
| | - Dominikus Brian
- Division of Arts and Sciences, NYU Shanghai, 567 West Yangsi Road, Shanghai 200124, China
- NYU-ECNU Center for Computational Chemistry at NYU Shanghai, 3663 Zhongshan Road North, Shanghai 200062, China
- Department of Chemistry, New York University, New York, New York 10003, USA
| | - Xiang Sun
- Shanghai Frontiers Science Center of Artificial Intelligence and Deep Learning, NYU Shanghai, 567 West Yangsi Road, Shanghai 200124, China
- Division of Arts and Sciences, NYU Shanghai, 567 West Yangsi Road, Shanghai 200124, China
- NYU-ECNU Center for Computational Chemistry at NYU Shanghai, 3663 Zhongshan Road North, Shanghai 200062, China
- Department of Chemistry, New York University, New York, New York 10003, USA
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4
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Cotic A, Heinemann FW, Slep LD, Cadranel A. Influence of Donor-Acceptor Interactions on MLCT Hole Reconfiguration in {Ru(bpy)} Chromophores. Chemphyschem 2024; 25:e202400246. [PMID: 38656666 DOI: 10.1002/cphc.202400246] [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: 03/05/2024] [Revised: 04/16/2024] [Accepted: 04/23/2024] [Indexed: 04/26/2024]
Abstract
In MLCT chromophores, internal conversion (IC) in the form of hole reconfiguration pathways (HR) is a major source of dissipation of the absorbed photon energy. Therefore, it is desirable to minimize their impact in energy conversion schemes by slowing them down. According to previous findings on {Ru(bpy)} chromophores, donor-acceptor interactions between the Ru ion and the ligand scaffold might allow to control HR/IC rates. Here, a series of [Ru(tpm)(bpy)(R-py)]2+ chromophores, where tpm is tris(1-pyrazolyl)methane, bpy is 2,2'-bipyridine and R-py is a 4-substituted pyridine, were prepared and fully characterized employing electrochemistry, spectroelectrochemistry, steady-state absorption/emission spectroscopy and electronic structure computations based on DFT/TD-DFT. Their excited-state decay was monitored using nanosecond and femtosecond transient absorption spectroscopy. HR/IC lifetimes as slow as 568 ps were obtained in DMSO at room temperature, twice as slow as in the reference species [Ru(tpm)(bpy)(NCS)]+.
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Affiliation(s)
- Agustina Cotic
- Departamento de Química Inorgánica, Analítica y Química Física, Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Pabellón 2, Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina
- CONICET - Universidad de Buenos Aires, Instituto de Química Física de Materiales, Medio Ambiente y Energía (INQUIMAE), Pabellón 2, Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina
| | - Frank W Heinemann
- Department Chemie und Pharmazie, Anorganische Chemie II, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 1, 91058, Erlangen, Germany
| | - Leonardo D Slep
- Departamento de Química Inorgánica, Analítica y Química Física, Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Pabellón 2, Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina
- CONICET - Universidad de Buenos Aires, Instituto de Química Física de Materiales, Medio Ambiente y Energía (INQUIMAE), Pabellón 2, Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina
| | - Alejandro Cadranel
- Departamento de Química Inorgánica, Analítica y Química Física, Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Pabellón 2, Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina
- CONICET - Universidad de Buenos Aires, Instituto de Química Física de Materiales, Medio Ambiente y Energía (INQUIMAE), Pabellón 2, Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina
- Department Chemie und Pharmazie, Physikalische Chemie I, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 3, 91058, Erlangen, Germany
- Interdisciplinary Center for Molecular Materials, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 3, 91058, Erlangen, Germany
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5
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Liu Z, Song Z, Sun X. All-Atom Photoinduced Charge Transfer Dynamics in Condensed Phase via Multistate Nonlinear-Response Instantaneous Marcus Theory. J Chem Theory Comput 2024; 20:3993-4006. [PMID: 38657208 PMCID: PMC11099976 DOI: 10.1021/acs.jctc.4c00010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 03/30/2024] [Accepted: 04/08/2024] [Indexed: 04/26/2024]
Abstract
Photoinduced charge transfer (CT) in the condensed phase is an essential component in solar energy conversion, but it is challenging to simulate such a process on the all-atom level. The traditional Marcus theory has been utilized for obtaining CT rate constants between pairs of electronic states but cannot account for the nonequilibrium effects due to the initial nuclear preparation. The recently proposed instantaneous Marcus theory (IMT) and its nonlinear-response formulation allow for incorporating the nonequilibrium nuclear relaxation to electronic transition between two states after the photoexcitation from the equilibrium ground state and provide the time-dependent rate coefficient. In this work, we extend the nonlinear-response IMT method for treating photoinduced CT among general multiple electronic states and demonstrate it in the organic photovoltaic carotenoid-porphyrin-fullerene triad dissolved in explicit tetrahydrofuran solvent. All-atom molecular dynamics simulations were employed to obtain the time correlation functions of energy gaps, which were used to generate the IMT-required time-dependent averages and variances of the relevant energy gaps. Our calculations show that the multistate IMT could capture the significant nonequilibrium effects due to the initial nuclear state preparation, and this is corroborated by the substantial differences between the population dynamics predicted by the multistate IMT and the Marcus theory, where the Marcus theory underestimates the population transfer. The population dynamics by multistate IMT is also shown to have a better agreement with the all-atom nonadiabatic mapping dynamics than the Marcus theory does. Because the multistate nonlinear-response IMT is straightforward and cost-effective in implementation and accounts for the nonequilibrium nuclear effects, we believe this method offers a practical strategy for studying charge transfer dynamics in complex condensed-phase systems.
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Affiliation(s)
- Zengkui Liu
- Division
of Arts and Sciences, NYU Shanghai, 567 West Yangsi Road, Shanghai 200124, China
- NYU-ECNU
Center for Computational Chemistry at NYU Shanghai, 3663 Zhongshan Road North, Shanghai 200062, China
- Department
of Chemistry, New York University, New York, New York 10003, United States
| | - Zailing Song
- Division
of Arts and Sciences, NYU Shanghai, 567 West Yangsi Road, Shanghai 200124, China
| | - Xiang Sun
- Division
of Arts and Sciences, NYU Shanghai, 567 West Yangsi Road, Shanghai 200124, China
- NYU-ECNU
Center for Computational Chemistry at NYU Shanghai, 3663 Zhongshan Road North, Shanghai 200062, China
- Department
of Chemistry, New York University, New York, New York 10003, United States
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6
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East NR, Naumann R, Förster C, Ramanan C, Diezemann G, Heinze K. Oxidative two-state photoreactivity of a manganese(IV) complex using near-infrared light. Nat Chem 2024; 16:827-834. [PMID: 38332331 DOI: 10.1038/s41557-024-01446-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 01/11/2024] [Indexed: 02/10/2024]
Abstract
Highly reducing or oxidizing photocatalysts are a fundamental challenge in photochemistry. Only a few transition metal complexes with Earth-abundant metal ions have so far advanced to excited state oxidants. All these photocatalysts require high-energy light for excitation, and their oxidizing power has not been fully exploited due to energy dissipation before reaching the photoactive state. Here we demonstrate that the complex [Mn(dgpy)2]4+, based on Earth-abundant manganese and the tridentate 2,6-diguanidylpyridine ligand (dgpy), evolves to a luminescent doublet ligand-to-metal charge transfer (2LMCT) excited state (1,435 nm, 0.86 eV) with a lifetime of 1.6 ns after excitation with low-energy near-infrared light. This 2LMCT state oxidizes naphthalene to its radical cation. Substrates with extremely high oxidation potentials up to 2.4 V enable the [Mn(dgpy)2]4+ photoreduction via a high-energy quartet 4LMCT excited state with a lifetime of 0.78 ps, proceeding via static quenching by the solvent. This process minimizes free energy losses and harnesses the full photooxidizing power, and thus allows oxidation of nitriles and benzene using Earth-abundant elements and low-energy light.
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Affiliation(s)
- Nathan R East
- Department of Chemistry, Johannes Gutenberg University, Mainz, Germany
| | - Robert Naumann
- Department of Chemistry, Johannes Gutenberg University, Mainz, Germany
| | - Christoph Förster
- Department of Chemistry, Johannes Gutenberg University, Mainz, Germany
| | - Charusheela Ramanan
- Department of Physics and Astronomy, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
- Max-Planck-Institute for Polymer Research, Mainz, Germany
| | - Gregor Diezemann
- Department of Chemistry, Johannes Gutenberg University, Mainz, Germany
| | - Katja Heinze
- Department of Chemistry, Johannes Gutenberg University, Mainz, Germany.
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7
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De Kreijger S, Ripak A, Elias B, Troian-Gautier L. Investigation of the Excited-State Electron Transfer and Cage Escape Yields Between Halides and a Fe(III) Photosensitizer. J Am Chem Soc 2024; 146:10286-10292. [PMID: 38569088 DOI: 10.1021/jacs.4c02808] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2024]
Abstract
Excited-state quenching and reduction of [Fe(phtmeimb)2]+, where phtmeimb is phenyl[tris(3-methyl-imidazolin-2-ylidene)]borate, with iodide, bromide, and chloride were studied in dichloromethane, acetonitrile, and acetonitrile/water 1:1 mixture by means of steady-state and time-resolved spectroscopic techniques. Quenching rate constants were almost diffusion-limited in dichloromethane and acetonitrile and followed the expected periodic trend, i.e., I- > Br- > Cl-. Confirmation of excited-state reductive electron transfer was only unambiguously obtained when iodide was used as a quencher. The cage escape yields, i.e., the separation of the geminate radical pair formed upon bimolecular excited-state electron transfer, were determined. These yields were larger in dichloromethane (0.079) than in acetonitrile (0.017), and no photoproduct could be observed in acetonitrile/water 1:1. This study further emphasizes that solvents with low dielectric constant are more suited for productive excited-state electron transfer using Fe(III) photosensitizers with 2LMCT excited state.
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Affiliation(s)
- Simon De Kreijger
- UCLouvain, Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), Place Louis Pasteur 1/L4.01.02, B-1348 Louvain-la-Neuve, Belgium
| | - Alexia Ripak
- UCLouvain, Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), Place Louis Pasteur 1/L4.01.02, B-1348 Louvain-la-Neuve, Belgium
| | - Benjamin Elias
- UCLouvain, Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), Place Louis Pasteur 1/L4.01.02, B-1348 Louvain-la-Neuve, Belgium
| | - Ludovic Troian-Gautier
- UCLouvain, Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), Place Louis Pasteur 1/L4.01.02, B-1348 Louvain-la-Neuve, Belgium
- Wel Research Institute, Avenue Pasteur 6, 1300 Wavre, Belgium
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8
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Franz J, Oelschlegel M, Zobel JP, Hua SA, Borter JH, Schmid L, Morselli G, Wenger OS, Schwarzer D, Meyer F, González L. Bifurcation of Excited-State Population Leads to Anti-Kasha Luminescence in a Disulfide-Decorated Organometallic Rhenium Photosensitizer. J Am Chem Soc 2024; 146. [PMID: 38598687 PMCID: PMC11046484 DOI: 10.1021/jacs.4c00548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 03/07/2024] [Accepted: 03/12/2024] [Indexed: 04/12/2024]
Abstract
We report a rhenium diimine photosensitizer equipped with a peripheral disulfide unit on one of the bipyridine ligands, [Re(CO)3(bpy)(S-Sbpy4,4)]+ (1+, bpy = 2,2'-bipyridine, S-Sbpy4,4 = [1,2]dithiino[3,4-c:6,5-c']dipyridine), showing anti-Kasha luminescence. Steady-state and ultrafast time-resolved spectroscopies complemented by nonadiabatic dynamics simulations are used to disclose its excited-state dynamics. The calculations show that after intersystem crossing the complex evolves to two different triplet minima: a (S-Sbpy4,4)-ligand-centered excited state (3LC) lying at lower energy and a metal-to-(bpy)-ligand charge transfer (3MLCT) state at higher energy, with relative yields of 90% and 10%, respectively. The 3LC state involves local excitation of the disulfide group into the antibonding σ* orbital, leading to significant elongation of the S-S bond. Intriguingly, it is the higher-lying 3MLCT state, which is assigned to display luminescence with a lifetime of 270 ns: a signature of anti-Kasha behavior. This assignment is consistent with an energy barrier ≥ 0.6 eV or negligible electronic coupling, preventing reaction toward the 3LC state after the population is trapped in the 3MLCT state. This study represents a striking example on how elusive excited-state dynamics of transition-metal photosensitizers can be deciphered by synergistic experiments and state-of-the-art calculations. Disulfide functionalization lays the foundation of a new design strategy toward harnessing excess energy in a system for possible bimolecular electron or energy transfer reactivity.
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Affiliation(s)
- Julia Franz
- Institute
of Theoretical Chemistry, University of
Vienna, Währinger Straße 17, A-1090 Vienna, Austria
| | - Manuel Oelschlegel
- Institute
of Inorganic Chemistry, University of Göttingen, Tammannstraße 4, D-37077 Göttingen, Germany
| | - J. Patrick Zobel
- Institute
of Theoretical Chemistry, University of
Vienna, Währinger Straße 17, A-1090 Vienna, Austria
| | - Shao-An Hua
- Institute
of Inorganic Chemistry, University of Göttingen, Tammannstraße 4, D-37077 Göttingen, Germany
| | - Jan-Hendrik Borter
- Department
of Dynamics at Surfaces, Max-Planck-Institute
for Multidisciplinary Sciences, Am Faßberg 11, D-37077 Göttingen, Germany
| | - Lucius Schmid
- Department
of Chemistry, University of Basel, St.-Johanns-Ring 19, CH-4056 Basel, Switzerland
| | - Giacomo Morselli
- Department
of Chemistry, University of Basel, St.-Johanns-Ring 19, CH-4056 Basel, Switzerland
| | - Oliver S. Wenger
- Department
of Chemistry, University of Basel, St.-Johanns-Ring 19, CH-4056 Basel, Switzerland
| | - Dirk Schwarzer
- Department
of Dynamics at Surfaces, Max-Planck-Institute
for Multidisciplinary Sciences, Am Faßberg 11, D-37077 Göttingen, Germany
| | - Franc Meyer
- Institute
of Inorganic Chemistry, University of Göttingen, Tammannstraße 4, D-37077 Göttingen, Germany
- International
Center for Advanced Studies of Energy Conversion (ICASEC), D-37077 Göttingen, Germany
| | - Leticia González
- Institute
of Theoretical Chemistry, University of
Vienna, Währinger Straße 17, A-1090 Vienna, Austria
- Vienna Research
Platform for Accelerating Photoreaction Discovery, University of Vienna, Währinger Straße 17, A-1090 Vienna, Austria
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9
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De Kreijger S, Elias B, Troian-Gautier L. Chloride, Bromide, and Iodide Photooxidation in Acetonitrile/Water Mixtures Using Binuclear Iridium(III) Photosensitizers. Inorg Chem 2023; 62:16196-16202. [PMID: 37734153 DOI: 10.1021/acs.inorgchem.3c02648] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/23/2023]
Abstract
Two iridium(III) binuclear photosensitizers, [Ir(dFCF3ppy)2(N-N)Ir(dFCF3ppy)2]2+, where N-N is tetrapyrido[3,2-a:2',3'-c:3″,2″-h:2‴,3‴-j]phenazine (Ir-TPPHZ) and 1,4,5,8-tetraazaphenanthrene[9,10-b]-1,4,5,8,9,12-hexaazatriphenylene (Ir-TAPHAT) are reported for iodide, bromide, and chloride photooxidation in acetonitrile and acetonitrile/water mixtures using blue-light irradiation. Excited-state reduction potentials Ered* of +2.02 and +2.09 V vs NHE were determined for Ir-TPPHZ and Ir-TAPHAT, respectively. Both photosensitizers' excited states were efficiently quenched by iodide, bromide, and chloride with quenching rate constants in the (3.5-9.2) × 1010 and (0.0036-2.9) × 1010 M-1 s-1 ranges in neat acetonitrile and acetonitrile/water mixtures, respectively. Nanosecond transient absorption spectroscopy provided unambiguous evidence of reductive excited-state electron transfer, with all halides in the solvent mixtures containing up to 50% water. Cage-escape yields were large (55-96%) in acetonitrile and dropped below 32% in 50:50 acetonitrile/water mixtures.
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Affiliation(s)
- Simon De Kreijger
- Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), UCLouvain, Place Louis Pasteur 1, Box L4.01.02, B-1348 Louvain-la-Neuve, Belgium
| | - Benjamin Elias
- Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), UCLouvain, Place Louis Pasteur 1, Box L4.01.02, B-1348 Louvain-la-Neuve, Belgium
| | - Ludovic Troian-Gautier
- Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), UCLouvain, Place Louis Pasteur 1, Box L4.01.02, B-1348 Louvain-la-Neuve, Belgium
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