1
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Wang T, Zhang Z, Yan W, Jiang S, Li S, Zhuang J, Xie H, Li G, Jiang L. Spectroscopic Characterization of Highly Excited Neutral Chromium Tricarbonyl. J Phys Chem A 2024; 128:3321-3328. [PMID: 38634151 DOI: 10.1021/acs.jpca.4c01120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/19/2024]
Abstract
Spectroscopic characterization of highly excited neutral transition-metal complexes is important for understanding the multifaceted reaction mechanisms between metals and ligands. In this work, the reactions of neutral chromium atoms with carbon monoxide were probed by size-specific infrared spectroscopy. Interestingly, Cr(CO)3 was found to have an unprecedented 7A2″ septet excited state rather than the singlet ground state. A combination of experiment and theory shows that the gas-phase formation of this highly excited Cr(CO)3 is facile both thermodynamically and kinetically. Electronic structure and bonding analyses indicate that the valence electrons of Cr atoms in the septet Cr(CO)3 are in a relatively stable configuration, which facilitate the highly excited structure and the planar geometric shape (D3h symmetry). The observed septet Cr(CO)3 affords a paradigm for exploring the structure, properties, and formation mechanism of a large variety of excited neutral compounds.
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Affiliation(s)
- Tiantong Wang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhaoyan Zhang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wenhui Yan
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shuai Jiang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shangdong Li
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jianxing Zhuang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hua Xie
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Gang Li
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Ling Jiang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
- Hefei National Laboratory, Hefei 230088, China
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2
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De Angelis D, Longetti L, Bonano G, Pelli Cresi JS, Foglia L, Pancaldi M, Capotondi F, Pedersoli E, Bencivenga F, Krstulovic M, Menk RH, D'Addato S, Orlando S, de Simone M, Ingle RA, Bleiner D, Coreno M, Principi E, Chergui M, Masciovecchio C, Mincigrucci R. A sub-100 nm thickness flat jet for extreme ultraviolet to soft X-ray absorption spectroscopy. JOURNAL OF SYNCHROTRON RADIATION 2024; 31:605-612. [PMID: 38592969 DOI: 10.1107/s1600577524001875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 02/26/2024] [Indexed: 04/11/2024]
Abstract
Experimental characterization of the structural, electronic and dynamic properties of dilute systems in aqueous solvents, such as nanoparticles, molecules and proteins, are nowadays an open challenge. X-ray absorption spectroscopy (XAS) is probably one of the most established approaches to this aim as it is element-specific. However, typical dilute systems of interest are often composed of light elements that require extreme-ultraviolet to soft X-ray photons. In this spectral regime, water and other solvents are rather opaque, thus demanding radical reduction of the solvent volume and removal of the liquid to minimize background absorption. Here, we present an experimental endstation designed to operate a liquid flat jet of sub-micrometre thickness in a vacuum environment compatible with extreme ultraviolet/soft XAS measurements in transmission geometry. The apparatus developed can be easily connected to synchrotron and free-electron-laser user-facility beamlines dedicated to XAS experiments. The conditions for stable generation and control of the liquid flat jet are analyzed and discussed. Preliminary soft XAS measurements on some test solutions are shown.
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Affiliation(s)
- Dario De Angelis
- CNR - Istituto Officina dei Materiali (IOM), Basovizza, Area Science Park, 34149 Trieste, Italy
| | - Luca Longetti
- Lausanne Centre for Ultrafast Science, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - Gabriele Bonano
- Dipartimento FIM, Università degli Studi di Modena e Reggio Emilia, Via Campi 213/a, 41125 Modena, Italy
| | | | - Laura Foglia
- Elettra-Sincrotrone Trieste, Strada Statale 14-km 163.5, Basovizza, 34149 Trieste, Italy
| | - Matteo Pancaldi
- Elettra-Sincrotrone Trieste, Strada Statale 14-km 163.5, Basovizza, 34149 Trieste, Italy
| | - Flavio Capotondi
- Elettra-Sincrotrone Trieste, Strada Statale 14-km 163.5, Basovizza, 34149 Trieste, Italy
| | - Emanuele Pedersoli
- Elettra-Sincrotrone Trieste, Strada Statale 14-km 163.5, Basovizza, 34149 Trieste, Italy
| | - Filippo Bencivenga
- Elettra-Sincrotrone Trieste, Strada Statale 14-km 163.5, Basovizza, 34149 Trieste, Italy
| | - Marija Krstulovic
- Elettra-Sincrotrone Trieste, Strada Statale 14-km 163.5, Basovizza, 34149 Trieste, Italy
| | - Ralf Hendrik Menk
- Sezione di Trieste, Istituto Nazionale di Fisica Nucleare, Via Valerio 2, 34127 Trieste, Italy
| | - Sergio D'Addato
- Dipartimento FIM, Università degli Studi di Modena e Reggio Emilia, Via Campi 213/a, 41125 Modena, Italy
| | - Stefano Orlando
- ISM-CNR, Trieste Branch, in Basovizza Area Science Park, 34149 Trieste, Italy
| | - Monica de Simone
- CNR - Istituto Officina dei Materiali (IOM), Basovizza, Area Science Park, 34149 Trieste, Italy
| | - Rebecca A Ingle
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
| | - Davide Bleiner
- Laboratory for Advanced Analytical Technologies, EMPA, Uberlandstrasse 129, CH-8600 Dübendorf, Switzerland
| | - Marcello Coreno
- Elettra-Sincrotrone Trieste, Strada Statale 14-km 163.5, Basovizza, 34149 Trieste, Italy
| | - Emiliano Principi
- Elettra-Sincrotrone Trieste, Strada Statale 14-km 163.5, Basovizza, 34149 Trieste, Italy
| | - Majed Chergui
- Elettra-Sincrotrone Trieste, Strada Statale 14-km 163.5, Basovizza, 34149 Trieste, Italy
| | - Claudio Masciovecchio
- Elettra-Sincrotrone Trieste, Strada Statale 14-km 163.5, Basovizza, 34149 Trieste, Italy
| | - Riccardo Mincigrucci
- Elettra-Sincrotrone Trieste, Strada Statale 14-km 163.5, Basovizza, 34149 Trieste, Italy
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3
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Mandal S, Daniel C. Ultrafast Excited-State Nonadiabatic Dynamics in Pt(II) Donor-Bridge-Acceptor Assemblies: A Quantum Approach for Optical Control. J Phys Chem A 2024; 128:3126-3136. [PMID: 38619836 DOI: 10.1021/acs.jpca.4c00646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
The ultrafast nonadiabatic excited state dynamics of (PTZ-N-benzyl-acetylide) (trans-bis-trimethylphosphine) Pt(II) (acetylide-NDI-bis-methyl) 1, representative of a series of Pt(II) donor-bridge-acceptor assemblies experimentally studied by the Weinstein group, University of Sheffield, is investigated by means of wavepacket propagations based on the multiconfiguration time-dependent Hartree (MCTDH) method. On the basis of electronic structure data obtained at the time-dependent density functional theory (TD-DFT) level, the subpicosecond decay is simulated by solving an 11 electronic states multimode problem, up to 18 vibrational normal modes, including both spin-orbit coupling (SOC) and vibronic coupling. A careful analysis of the results, within the diabatic representation, provides the key features of the spin-vibronic mechanism at work in this complex, distinguishing between the spin-orbit and vibronically activated ultrafast processes within the excited states manifold. The knowledge of the key active normal modes that promote selectively the population of specific electronic excited states opens a route toward optical control by selectively exciting these modes in order to drive the associated nonadiabatic processes. Relevant simulations, over 2 ps, are proposed to assess the impact of these selective vibrational excitations on the branching ratio between the primary photoproducts, namely, bridge-acceptor charge-transfer (CT) and donor-acceptor charge-separated (CS) electronic states. Whereas the excitation of the localized acetylide bridge C≡C bond stretching does not modify drastically the population of the low-lying electronic states within the first two ps, vibrational excitation of the out-of-plane twisting motion of the N-benzyl group linked to the donor entity favors the population of the 1,3CS states at the expense of the lowest 1,3CT states. This quantum study opens the route to IR optical control experiments based on the specific alteration of vibrational normal modes that activate vibronic couplings between key electronic excited states. However, the presence of critical crossings along the PES channels associated with these normal modes and the role of concurrent SOC driven ultrafast transfers of population should not be underestimated.
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Affiliation(s)
- Souvik Mandal
- Laboratoire de Chimie Quantique, Institut de Chimie Strasbourg, UMR-7177 CNRS, Université de Strasbourg, 1 Rue Blaise Pascal BP 296/R8, F-67008 Strasbourg, France
| | - Chantal Daniel
- Laboratoire de Chimie Quantique, Institut de Chimie Strasbourg, UMR-7177 CNRS, Université de Strasbourg, 1 Rue Blaise Pascal BP 296/R8, F-67008 Strasbourg, France
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4
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Wellauer J, Ziereisen F, Sinha N, Prescimone A, Velić A, Meyer F, Wenger OS. Iron(III) Carbene Complexes with Tunable Excited State Energies for Photoredox and Upconversion. J Am Chem Soc 2024; 146. [PMID: 38598280 PMCID: PMC11046485 DOI: 10.1021/jacs.4c00605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Revised: 03/13/2024] [Accepted: 03/19/2024] [Indexed: 04/11/2024]
Abstract
Substituting precious elements in luminophores and photocatalysts by abundant first-row transition metals remains a significant challenge, and iron continues to be particularly attractive owing to its high natural abundance and low cost. Most iron complexes known to date face severe limitations due to undesirably efficient deactivation of luminescent and photoredox-active excited states. Two new iron(III) complexes with structurally simple chelate ligands enable straightforward tuning of ground and excited state properties, contrasting recent examples, in which chemical modification had a minor impact. Crude samples feature two luminescence bands strongly reminiscent of a recent iron(III) complex, in which this observation was attributed to dual luminescence, but in our case, there is clear-cut evidence that the higher-energy luminescence stems from an impurity and only the red photoluminescence from a doublet ligand-to-metal charge transfer (2LMCT) excited state is genuine. Photoinduced oxidative and reductive electron transfer reactions with methyl viologen and 10-methylphenothiazine occur with nearly diffusion-limited kinetics. Photocatalytic reactions not previously reported for this compound class, in particular the C-H arylation of diazonium salts and the aerobic hydroxylation of boronic acids, were achieved with low-energy red light excitation. Doublet-triplet energy transfer (DTET) from the luminescent 2LMCT state to an anthracene annihilator permits the proof of principle for triplet-triplet annihilation upconversion based on a molecular iron photosensitizer. These findings are relevant for the development of iron complexes featuring photophysical and photochemical properties competitive with noble-metal-based compounds.
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Affiliation(s)
- Joël Wellauer
- Department
of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
| | - Fabienne Ziereisen
- Department
of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
| | - Narayan Sinha
- Department
of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
| | - Alessandro Prescimone
- Department
of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
| | - Ajdin Velić
- University
of Göttingen, Institute of Inorganic Chemistry, Tammannstraße 4, D-37077 Göttingen, Germany
| | - Franc Meyer
- University
of Göttingen, Institute of Inorganic Chemistry, Tammannstraße 4, D-37077 Göttingen, Germany
| | - Oliver S. Wenger
- Department
of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
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5
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Jin T, Wagner D, Wenger OS. Luminescent and Photoredox-Active Molybdenum(0) Complexes Competitive with Isoelectronic Ruthenium(II) Polypyridines. Angew Chem Int Ed Engl 2024; 63:e202314475. [PMID: 37885363 DOI: 10.1002/anie.202314475] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 10/25/2023] [Accepted: 10/25/2023] [Indexed: 10/28/2023]
Abstract
Ruthenium(II) complexes with chelating polypyridine ligands are among the most frequently investigated compounds in photophysics and photochemistry, owing to their favorable luminescence and photoredox properties. Equally good photoluminescence performance and attractive photocatalytic behavior is now achievable with isoelectronic molybdenum(0) complexes. The zero-valent oxidation state of molybdenum is stabilized by carbonyl or isocyanide ligands, and metal-to-ligand charge transfer (MLCT) excited states analogous to those in ruthenium(II) complexes can be established. Microsecond MLCT excited-state lifetimes and photoluminescence quantum yields up to 0.2 have been achieved in solution at room temperature, and the emission wavelength has become tunable over a large range. The molybdenum(0) complexes are stronger photoreductants than ruthenium(II) polypyridines and can therefore perform more challenging chemical reductions. The triplet nature of their luminescent MLCT states allows sensitization of photon upconversion via triplet-triplet annihilation, to convert low-energy input radiation into higher-energy output fluorescence. This review summarizes the current state of the art concerning luminescent molybdenum(0) complexes and highlights their application potential. Molybdenum is roughly 140 times more abundant and far cheaper than ruthenium, hence this research is relevant in the greater context of finding more sustainable alternatives to using precious and rare transition metals in photophysics and photochemistry.
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Affiliation(s)
- Tao Jin
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland
| | - Dorothee Wagner
- 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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6
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Guo M, Braun A, Sokaras D, Kroll T. Iron Kβ X-ray Emission Spectroscopy: The Origin of Spectral Features from Atomic to Molecular Systems Using Multi-configurational Calculations. J Phys Chem A 2024; 128:1260-1273. [PMID: 38329897 DOI: 10.1021/acs.jpca.3c07949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2024]
Abstract
Kβ X-ray emission spectroscopy (XES) is widely used to fingerprint the local spin of transition-metal ions, including in pump-probe experiments, to identify excited states or in chemical and biological reactions to characterize short-lived intermediates. In this study, the spectra of ferrous and ferric complexes for various spin states were measured experimentally and described theoretically through restricted active space (RAS) calculations including dynamic correlations. Through the RAS calculations from simple atomic models to complex molecular systems, spectral effects such as the exchange interactions, crystal-field strength, and covalent orbital mixing were evaluated and discussed. The calculations find that only the spectral features of low-spin cases show a dependence on the crystal-field strength, particularly for ferrous low spin. The effect of the covalent orbital mixing strength on the first moment of the Kβ1,3 main line and the Kβ1,3-Kβ' energy splitting is quantitatively described. Clear relationships are found within a given nominal spin but less between different spin states, which calls for careful selection of reference spectra in future experiments. This study further advances our understanding of the correlation between changes in experimental spectral features and their corresponding electronic structure information.
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Affiliation(s)
- Meiyuan Guo
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Augustin Braun
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Dimosthenis Sokaras
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Thomas Kroll
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
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7
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Zhou L, Feng RR, Zhang W, Gai F. Triple-Bond Vibrations: Emerging Applications in Energy and Biological Sciences. J Phys Chem Lett 2024; 15:187-200. [PMID: 38156972 DOI: 10.1021/acs.jpclett.3c02619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
Triple bonds, such as that formed between two carbon atoms (i.e., C≡C) or that formed between one carbon atom and one nitrogen atom (i.e., C≡N), afford unique chemical bonding and hence vibrational characteristics. As such, they are not only frequently used to construct molecules with tailored chemical and/or physical properties but also employed as vibrational probes to provide site-specific chemical and/or physical information at the molecular level. Herein, we offer our perspective on the emerging applications of various triple-bond vibrations in energy and biological sciences with a focus on C≡C and C≡N triple bonds.
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Affiliation(s)
- Liang Zhou
- Department of Physics and Applied Optics Beijing Area Major Laboratory, Beijing Normal University, Beijing 100875, China
| | - Ran-Ran Feng
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Wenkai Zhang
- Department of Physics and Applied Optics Beijing Area Major Laboratory, Beijing Normal University, Beijing 100875, China
| | - Feng Gai
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
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8
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Kim D, Dang VQ, Teets TS. Improved transition metal photosensitizers to drive advances in photocatalysis. Chem Sci 2023; 15:77-94. [PMID: 38131090 PMCID: PMC10732135 DOI: 10.1039/d3sc04580c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 11/22/2023] [Indexed: 12/23/2023] Open
Abstract
To function effectively in a photocatalytic application, a photosensitizer's light absorption, excited-state lifetime, and redox potentials, both in the ground state and excited state, are critically important. The absorption profile is particularly relevant to applications involving solar harvesting, whereas the redox potentials and excited-state lifetimes determine the thermodynamics, kinetics, and quantum yields of photoinduced redox processes. This perspective article focuses on synthetic inorganic and organometallic approaches to optimize these three characteristics of transition-metal based photosensitizers. We include our own work in these areas, which has focused extensively on exceptionally strong cyclometalated iridium photoreductants that enable challenging reductive photoredox transformations on organic substrates, and more recent work which has led to improved solar harvesting in charge-transfer copper(i) chromophores, an emerging class of earth-abundant compounds particularly relevant to solar-energy applications. We also extensively highlight many other complementary strategies for optimizing these parameters and highlight representative examples from the recent literature. It remains a significant challenge to simultaneously optimize all three of these parameters at once, since improvements in one often come at the detriment of the others. These inherent trade-offs and approaches to obviate or circumvent them are discussed throughout.
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Affiliation(s)
- Dooyoung Kim
- University of Houston, Department of Chemistry 3585 Cullen Blvd. Room 112 Houston TX 77204-5003 USA
| | - Vinh Q Dang
- University of Houston, Department of Chemistry 3585 Cullen Blvd. Room 112 Houston TX 77204-5003 USA
| | - Thomas S Teets
- University of Houston, Department of Chemistry 3585 Cullen Blvd. Room 112 Houston TX 77204-5003 USA
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9
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Buttarazzi E, Perrella F, Rega N, Petrone A. Watching the Interplay between Photoinduced Ultrafast Charge Dynamics and Nuclear Vibrations. J Chem Theory Comput 2023; 19:8751-8766. [PMID: 37991892 PMCID: PMC10720350 DOI: 10.1021/acs.jctc.3c00855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 11/02/2023] [Accepted: 11/03/2023] [Indexed: 11/24/2023]
Abstract
Here is presented the ultrafast hole-electron dynamics of photoinduced metal to ligand charge-transfer (MLCT) states in a Ru(II) complex, [Ru(dcbpy)2(NCS)2]4- (dcbpy = 4,4'-dicarboxy-2,2'-bipyridine), a photoactive molecule employed in dye sensitized solar cells. Via cutting-edge computational techniques, a tailored computational protocol is here presented and developed to provide a detailed analysis of the electronic manifold coupled with nuclear vibrations to better understand the nonradiative pathways and the resulting overall dye performances in light-harvesting processes (electron injection). Thus, the effects of different vibrational modes were investigated on both the electronic levels and charge transfer dynamics through a theoretical-computational approach. First, the linear response time-dependent density functional (LR-TDDFT) formalism was employed to characterize excitation energies and spacing among electronic levels (the electronic layouts). Then, to understand the ultrafast (femtosecond) charge dynamics on the molecular scale, we relied on the nonperturbative mean-field quantum electronic dynamics via real-time (RT-) TDDFT. Three vibrational modes were selected, representative for collective nuclear movements that can have a significant influence on the electronic structure: two involving NCS- ligands and one involving dcbpy ligands. As main results, we observed that such MLCT states, under vibrational distortions, are strongly affected and a faster interligand electron transfer mechanism is observed along with an increasing MLCT character of the adiabatic electronic states approaching closer in energy due to the vibrations. Such findings can help both in providing a molecular picture of multidimensional vibro-electronic spectroscopic techniques, used to characterize ultrafast coherent and noncoherent dynamics of complex systems, and to improve dye performances with particular attention to the study of energy or charge transport processes and vibronic couplings.
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Affiliation(s)
- Edoardo Buttarazzi
- Scuola
Superiore Meridionale, Largo San Marcellino 10, I-80138 Napoli, Italy
- Department
of Chemical Sciences, University of Napoli
Federico II, Complesso Universitario di Monte S. Angelo, Via Cintia 21, I-80126 Napoli, Italy
| | - Fulvio Perrella
- Scuola
Superiore Meridionale, Largo San Marcellino 10, I-80138 Napoli, Italy
| | - Nadia Rega
- Scuola
Superiore Meridionale, Largo San Marcellino 10, I-80138 Napoli, Italy
- Department
of Chemical Sciences, University of Napoli
Federico II, Complesso Universitario di Monte S. Angelo, Via Cintia 21, I-80126 Napoli, Italy
- Istituto
Nazionale Di Fisica Nucleare, sezione di Napoli, Complesso Universitario
di Monte S. Angelo ed. 6, Via Cintia, I-80126 Napoli, Italy
| | - Alessio Petrone
- Scuola
Superiore Meridionale, Largo San Marcellino 10, I-80138 Napoli, Italy
- Department
of Chemical Sciences, University of Napoli
Federico II, Complesso Universitario di Monte S. Angelo, Via Cintia 21, I-80126 Napoli, Italy
- Istituto
Nazionale Di Fisica Nucleare, sezione di Napoli, Complesso Universitario
di Monte S. Angelo ed. 6, Via Cintia, I-80126 Napoli, Italy
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10
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Lindh L, Pascher T, Persson S, Goriya Y, Wärnmark K, Uhlig J, Chábera P, Persson P, Yartsev A. Multifaceted Deactivation Dynamics of Fe(II) N-Heterocyclic Carbene Photosensitizers. J Phys Chem A 2023; 127:10210-10222. [PMID: 38000043 DOI: 10.1021/acs.jpca.3c06983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2023]
Abstract
Excited state dynamics of three iron(II) carbene complexes that serve as prototype Earth-abundant photosensitizers were investigated by ultrafast optical spectroscopy. Significant differences in the dynamics between the investigated complexes down to femtosecond time scales are used to characterize fundamental differences in the depopulation of triplet metal-to-ligand charge-transfer (3MLCT) excited states in the presence of energetically accessible triplet metal-centered (3MC) states. Novel insights into the full deactivation cascades of the investigated complexes include evidence of the need to revise the deactivation model for a prominent iron carbene prototype complex, a refined understanding of complex 3MC dynamics, and a quantitative discrimination between activated and barrierless deactivation steps along the 3MLCT → 3MC → 1GS path. Overall, the study provides an improved understanding of photophysical limitations and opportunities for the use of iron(II)-based photosensitizers in photochemical applications.
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Affiliation(s)
- Linnea Lindh
- Division of Chemical Physics, Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
- Division of Computational Chemistry, Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
| | - Torbjörn Pascher
- Division of Chemical Physics, Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
| | - Samuel Persson
- Center for Analysis and Synthesis (CAS), Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
| | - Yogesh Goriya
- Center for Analysis and Synthesis (CAS), Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
| | - Kenneth Wärnmark
- Center for Analysis and Synthesis (CAS), Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
| | - Jens Uhlig
- Division of Chemical Physics, Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
| | - Pavel Chábera
- Division of Chemical Physics, Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
| | - Petter Persson
- Division of Computational Chemistry, Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
| | - Arkady Yartsev
- Division of Chemical Physics, Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
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11
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Lee A, Son M, Deegbey M, Woodhouse MD, Hart SM, Beissel HF, Cesana PT, Jakubikova E, McCusker JK, Schlau-Cohen GS. Observation of parallel intersystem crossing and charge transfer-state dynamics in [Fe(bpy) 3] 2+ from ultrafast 2D electronic spectroscopy. Chem Sci 2023; 14:13140-13150. [PMID: 38023502 PMCID: PMC10664481 DOI: 10.1039/d3sc02613b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 10/29/2023] [Indexed: 12/01/2023] Open
Abstract
Transition metal-based charge-transfer complexes represent a broad class of inorganic compounds with diverse photochemical applications. Charge-transfer complexes based on earth-abundant elements have been of increasing interest, particularly the canonical [Fe(bpy)3]2+. Photoexcitation into the singlet metal-ligand charge transfer (1MLCT) state is followed by relaxation first to the ligand-field manifold and then to the ground state. While these dynamics have been well-studied, processes within the MLCT manifold that facilitate and/or compete with relaxation have been more elusive. We applied ultrafast two-dimensional electronic spectroscopy (2DES) to disentangle the dynamics immediately following MLCT excitation of this compound. First, dynamics ascribed to relaxation out of the initially formed 1MLCT state was found to correlate with the inertial response time of the solvent. Second, the additional dimension of the 2D spectra revealed a peak consistent with a ∼20 fs 1MLCT → 3MLCT intersystem crossing process. These two observations indicate that the complex simultaneously undergoes intersystem crossing and direct conversion to ligand-field state(s). Resolution of these parallel pathways in this prototypical earth-abundant complex highlights the ability of 2DES to deconvolve the otherwise obscured excited-state dynamics of charge-transfer complexes.
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Affiliation(s)
- Angela Lee
- Department of Chemistry, Massachusetts Institute of Technology Cambridge MA 02139 USA
| | - Minjung Son
- Department of Chemistry, Massachusetts Institute of Technology Cambridge MA 02139 USA
| | - Mawuli Deegbey
- Department of Chemistry, North Carolina State University Raleigh NC 27695 USA
| | - Matthew D Woodhouse
- Department of Chemistry, Michigan State University East Lansing MI 48824 USA
| | - Stephanie M Hart
- Department of Chemistry, Massachusetts Institute of Technology Cambridge MA 02139 USA
| | - Hayden F Beissel
- Department of Chemistry, Michigan State University East Lansing MI 48824 USA
| | - Paul T Cesana
- Department of Chemistry, Massachusetts Institute of Technology Cambridge MA 02139 USA
| | - Elena Jakubikova
- Department of Chemistry, North Carolina State University Raleigh NC 27695 USA
| | - James K McCusker
- Department of Chemistry, Michigan State University East Lansing MI 48824 USA
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12
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Liu XY, Chen WK, Fang WH, Cui G. Nonadiabatic Dynamics Simulations for Photoinduced Processes in Molecules and Semiconductors: Methodologies and Applications. J Chem Theory Comput 2023. [PMID: 37984502 DOI: 10.1021/acs.jctc.3c00960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Nonadiabatic dynamics (NAMD) simulations have become powerful tools for elucidating complicated photoinduced processes in various systems from molecules to semiconductor materials. In this review, we present an overview of our recent research on photophysics of molecular systems and periodic semiconductor materials with the aid of ab initio NAMD simulation methods implemented in the generalized trajectory surface-hopping (GTSH) package. Both theoretical backgrounds and applications of the developed NAMD methods are presented in detail. For molecular systems, the linear-response time-dependent density functional theory (LR-TDDFT) method is primarily used to model electronic structures in NAMD simulations owing to its balanced efficiency and accuracy. Moreover, the efficient algorithms for calculating nonadiabatic coupling terms (NACTs) and spin-orbit couplings (SOCs) have been coded into the package to increase the simulation efficiency. In combination with various analysis techniques, we can explore the mechanistic details of the photoinduced dynamics of a range of molecular systems, including charge separation and energy transfer processes in organic donor-acceptor structures, ultrafast intersystem crossing (ISC) processes in transition metal complexes (TMCs), and exciton dynamics in molecular aggregates. For semiconductor materials, we developed the NAMD methods for simulating the photoinduced carrier dynamics within the framework of the Kohn-Sham density functional theory (KS-DFT), in which SOC effects are explicitly accounted for using the two-component, noncollinear DFT method. Using this method, we have investigated the photoinduced carrier dynamics at the interface of a variety of van der Waals (vdW) heterojunctions, such as two-dimensional transition metal dichalcogenides (TMDs), carbon nanotubes (CNTs), and perovskites-related systems. Recently, we extended the LR-TDDFT-based NAMD method for semiconductor materials, allowing us to study the excitonic effects in the photoinduced energy transfer process. These results demonstrate that the NAMD simulations are powerful tools for exploring the photodynamics of molecular systems and semiconductor materials. In future studies, the NAMD simulation methods can be employed to elucidate experimental phenomena and reveal microscopic details as well as rationally design novel photofunctional materials with desired properties.
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Affiliation(s)
- Xiang-Yang Liu
- College of Chemistry and Material Science, Sichuan Normal University, Chengdu 610068, P. R. China
| | - Wen-Kai Chen
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Wei-Hai Fang
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
- Hefei National Laboratory, Hefei 230088, P. R. China
| | - Ganglong Cui
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
- Hefei National Laboratory, Hefei 230088, P. R. China
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13
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Ogawa T, Wenger OS. Nickel(II) Analogues of Phosphorescent Platinum(II) Complexes with Picosecond Excited-State Decay. Angew Chem Int Ed Engl 2023; 62:e202312851. [PMID: 37732725 DOI: 10.1002/anie.202312851] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 09/15/2023] [Accepted: 09/18/2023] [Indexed: 09/22/2023]
Abstract
Square-planar NiII complexes are interesting as cheaper and more sustainable alternatives to PtII luminophores widely used in lighting and photocatalysis. We investigated the excited-state behavior of two NiII complexes, which are isostructural with two luminescent PtII complexes. The initially excited singlet metal-to-ligand charge transfer (1 MLCT) excited states in the NiII complexes decay to metal-centered (3 MC) excited states within less than 1 picosecond, followed by non-radiative relaxation of the 3 MC states to the electronic ground state within 9-21 ps. This contrasts with the population of an emissive triplet ligand-centered (3 LC) excited state upon excitation of the PtII analogues. Structural distortions of the NiII complexes are responsible for this discrepant behavior and lead to dark 3 MC states far lower in energy than the luminescent 3 LC states of PtII compounds. Our findings suggest that if these structural distortions could be restricted by more rigid coordination environments and stronger ligand fields, the excited-state relaxation in four-coordinate NiII complexes could be decelerated such that luminescent 3 LC or 3 MLCT excited states become accessible. These insights are relevant to make NiII fit for photophysical and photochemical applications that relied on PtII until now.
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Affiliation(s)
- Tomohiro Ogawa
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland
- Graduate School of Science and Engineering, University of Toyama, Toyama, 930-8555, Japan
| | - 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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Lima FA, Otte F, Vakili M, Ardana-Lamas F, Biednov M, Dall’Antonia F, Frankenberger P, Gawelda W, Gelisio L, Han H, Huang X, Jiang Y, Kloos M, Kluyver T, Knoll M, Kubicek K, Bermudez Macias IJ, Schulz J, Turkot O, Uemura Y, Valerio J, Wang H, Yousef H, Zalden P, Khakhulin D, Bressler C, Milne C. Experimental capabilities for liquid jet samples at sub-MHz rates at the FXE Instrument at European XFEL. JOURNAL OF SYNCHROTRON RADIATION 2023; 30:1168-1182. [PMID: 37860937 PMCID: PMC10624029 DOI: 10.1107/s1600577523008159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 09/18/2023] [Indexed: 10/21/2023]
Abstract
The Femtosecond X-ray Experiments (FXE) instrument at the European X-ray Free-Electron Laser (EuXFEL) provides an optimized platform for investigations of ultrafast physical, chemical and biological processes. It operates in the energy range 4.7-20 keV accommodating flexible and versatile environments for a wide range of samples using diverse ultrafast X-ray spectroscopic, scattering and diffraction techniques. FXE is particularly suitable for experiments taking advantage of the sub-MHz repetition rates provided by the EuXFEL. In this paper a dedicated setup for studies on ultrafast biological and chemical dynamics in solution phase at sub-MHz rates at FXE is presented. Particular emphasis on the different liquid jet sample delivery options and their performance is given. Our portfolio of high-speed jets compatible with sub-MHz experiments includes cylindrical jets, gas dynamic virtual nozzles and flat jets. The capability to perform multi-color X-ray emission spectroscopy (XES) experiments is illustrated by a set of measurements using the dispersive X-ray spectrometer in von Hamos geometry. Static XES data collected using a multi-crystal scanning Johann-type spectrometer are also presented. A few examples of experimental results on ultrafast time-resolved X-ray emission spectroscopy and wide-angle X-ray scattering at sub-MHz pulse repetition rates are given.
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Affiliation(s)
- F. A. Lima
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - F. Otte
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
- Fakultät für Physik, Technical University Dortmund, Dortmund, Germany
| | - M. Vakili
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
- Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
| | | | - M. Biednov
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | | | | | - W. Gawelda
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
- Faculty of Physics, Adam Mickiewicz University, 61-614 Poznań, Poland
| | - L. Gelisio
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - H. Han
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - X. Huang
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Y. Jiang
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - M. Kloos
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - T. Kluyver
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - M. Knoll
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - K. Kubicek
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
- The Hamburg Centre for Ultrafast Imaging, 22761 Hamburg, Germany
- Institut für Experimentalphysik, Universität Hamburg, 22607 Hamburg, Germany
| | | | - J. Schulz
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - O. Turkot
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Y. Uemura
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - J. Valerio
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - H. Wang
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - H. Yousef
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - P. Zalden
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - D. Khakhulin
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - C. Bressler
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
- The Hamburg Centre for Ultrafast Imaging, 22761 Hamburg, Germany
- Institut für Experimentalphysik, Universität Hamburg, 22607 Hamburg, Germany
| | - C. Milne
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
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15
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Sinha N, Wenger OS. Photoactive Metal-to-Ligand Charge Transfer Excited States in 3d 6 Complexes with Cr 0, Mn I, Fe II, and Co III. J Am Chem Soc 2023; 145:4903-4920. [PMID: 36808978 PMCID: PMC9999427 DOI: 10.1021/jacs.2c13432] [Citation(s) in RCA: 40] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
Many coordination complexes and organometallic compounds with the 4d6 and 5d6 valence electron configurations have outstanding photophysical and photochemical properties, which stem from metal-to-ligand charge transfer (MLCT) excited states. This substance class makes extensive use of the most precious and least abundant metal elements, and consequently there has been a long-standing interest in first-row transition metal compounds with photoactive MLCT states. Semiprecious copper(I) with its completely filled 3d subshell is a relatively straightforward and well explored case, but in 3d6 complexes the partially filled d-orbitals lead to energetically low-lying metal-centered (MC) states that can cause undesirably fast MLCT excited state deactivation. Herein, we discuss recent advances made with isoelectronic Cr0, MnI, FeII, and CoIII compounds, for which long-lived MLCT states have become accessible over the past five years. Furthermore, we discuss possible future developments in the search for new first-row transition metal complexes with partially filled 3d subshells and photoactive MLCT states for next-generation applications in photophysics and photochemistry.
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Affiliation(s)
- Narayan Sinha
- 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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Ogawa T, Sinha N, Pfund B, Prescimone A, Wenger OS. Molecular Design Principles to Elongate the Metal-to-Ligand Charge Transfer Excited-State Lifetimes of Square-Planar Nickel(II) Complexes. J Am Chem Soc 2022; 144:21948-21960. [DOI: 10.1021/jacs.2c08838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Tomohiro Ogawa
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
| | - Narayan Sinha
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
| | - Björn Pfund
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
| | - Alessandro Prescimone
- Department of Chemistry, University of Basel, BPR 1096, Mattenstrasse 24a, 4058 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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Kübler J, Pfund B, Wenger OS. Zinc(II) Complexes with Triplet Charge-Transfer Excited States Enabling Energy-Transfer Catalysis, Photoinduced Electron Transfer, and Upconversion. JACS AU 2022; 2:2367-2380. [PMID: 36311829 PMCID: PMC9597861 DOI: 10.1021/jacsau.2c00442] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 09/22/2022] [Accepted: 09/22/2022] [Indexed: 05/28/2023]
Abstract
Many CuI complexes have luminescent triplet charge-transfer excited states with diverse applications in photophysics and photochemistry, but for isoelectronic ZnII compounds, this behavior is much less common, and they typically only show ligand-based fluorescence from singlet π-π* states. We report two closely related tetrahedral ZnII compounds, in which intersystem crossing occurs with appreciable quantum yields and leads to the population of triplet excited states with intraligand charge-transfer (ILCT) character. In addition to showing fluorescence from their initially excited 1ILCT states, these new compounds therefore undergo triplet-triplet energy transfer (TTET) from their 3ILCT states and consequently can act as sensitizers for photo-isomerization reactions and triplet-triplet annihilation upconversion from the blue to the ultraviolet spectral range. The photoactive 3ILCT state furthermore facilitates photoinduced electron transfer. Collectively, our findings demonstrate that mononuclear ZnII compounds with photophysical and photochemical properties reminiscent of well-known CuI complexes are accessible with suitable ligands and that they are potentially amenable to many different applications. Our insights seem relevant in the greater context of obtaining photoactive compounds based on abundant transition metals, complementing well-known precious-metal-based luminophores and photosensitizers.
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18
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Sinha N, Pfund B, Wegeberg C, Prescimone A, Wenger OS. Cobalt(III) Carbene Complex with an Electronic Excited-State Structure Similar to Cyclometalated Iridium(III) Compounds. J Am Chem Soc 2022; 144:9859-9873. [PMID: 35623627 PMCID: PMC9490849 DOI: 10.1021/jacs.2c02592] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
![]()
Many organometallic
iridium(III) complexes have photoactive excited
states with mixed metal-to-ligand and intraligand charge transfer
(MLCT/ILCT) character, which form the basis for numerous applications
in photophysics and photochemistry. Cobalt(III) complexes with analogous
MLCT excited-state properties seem to be unknown yet, despite the
fact that iridium(III) and cobalt(III) can adopt identical low-spin
d6 valence electron configurations due to their close chemical
relationship. Using a rigid tridentate chelate ligand (LCNC), in which a central amido π-donor is flanked by two σ-donating
N-heterocyclic carbene subunits, we obtained a robust homoleptic complex
[Co(LCNC)2](PF6), featuring a photoactive
excited state with substantial MLCT character. Compared to the vast
majority of isoelectronic iron(II) complexes, the MLCT state of [Co(LCNC)2](PF6) is long-lived because it
does not deactivate as efficiently into lower-lying metal-centered
excited states; furthermore, it engages directly in photoinduced electron
transfer reactions. The comparison with [Fe(LCNC)2](PF6), as well as structural, electrochemical, and UV–vis
transient absorption studies, provides insight into new ligand design
principles for first-row transition-metal complexes with photophysical
and photochemical properties reminiscent of those known from the platinum
group metals.
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Affiliation(s)
- Narayan Sinha
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
| | - Björn Pfund
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
| | - Christina Wegeberg
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
| | - Alessandro Prescimone
- Department of Chemistry, University of Basel, BPR 1096, Mattenstrasse 24a, 4058 Basel, Switzerland
| | - Oliver S Wenger
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
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19
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Chiral control of spin-crossover dynamics in Fe(II) complexes. Nat Chem 2022; 14:739-745. [PMID: 35618767 DOI: 10.1038/s41557-022-00933-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 03/14/2022] [Indexed: 11/08/2022]
Abstract
Iron-based spin-crossover complexes hold tremendous promise as multifunctional switches in molecular devices. However, real-world technological applications require the excited high-spin state to be kinetically stable-a feature that has been achieved only at cryogenic temperatures. Here we demonstrate high-spin-state trapping by controlling the chiral configuration of the prototypical iron(II)tris(4,4'-dimethyl-2,2'-bipyridine) in solution, associated for stereocontrol with the enantiopure Δ- or Λ-enantiomer of tris(3,4,5,6-tetrachlorobenzene-1,2-diolato-κ2O1,O2)phosphorus(V) (P(O2C6Cl4)3- or TRISPHAT) anions. We characterize the high-spin-state relaxation using broadband ultrafast circular dichroism spectroscopy in the deep ultraviolet in combination with transient absorption and anisotropy measurements. We find that the high-spin-state decay is accompanied by ultrafast changes of its optical activity, reflecting the coupling to a symmetry-breaking torsional twisting mode, contrary to the commonly assumed picture. The diastereoselective ion pairing suppresses the vibrational population of the identified reaction coordinate, thereby achieving a fourfold increase of the high-spin-state lifetime. More generally, our results motivate the synthetic control of the torsional modes of iron(II) complexes as a complementary route to manipulate their spin-crossover dynamics.
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20
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Herr P, Schwab A, Kupfer S, Wenger OS. Deep‐Red Luminescent Molybdenum(0) Complexes with Bi‐ and Tridentate Isocyanide Chelate Ligands. CHEMPHOTOCHEM 2022. [DOI: 10.1002/cptc.202200052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Patrick Herr
- University of Basel: Universitat Basel Department of Chemistry SWITZERLAND
| | - Alexander Schwab
- Friedrich-Schiller-Universität Jena: Friedrich-Schiller-Universitat Jena Institute of Physical Chemistry GERMANY
| | - Stephan Kupfer
- Friedrich-Schiller-Universität Jena: Friedrich-Schiller-Universitat Jena Institute of Physical Chemistry GERMANY
| | - Oliver S. Wenger
- Universität Basel Departement für Chemie St. Johanns-Ring 19 4056 Basel SWITZERLAND
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21
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Cebrían C, Pastore M, Monari A, Assfeld X, Gros PC, Haacke S. Ultrafast Spectroscopy of Fe(II) Complexes Designed for Solar Energy Conversion: Current Status and Open Questions. Chemphyschem 2022; 23:e202100659. [DOI: 10.1002/cphc.202100659] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 01/22/2022] [Indexed: 11/11/2022]
Affiliation(s)
| | | | | | | | | | - Stefan Haacke
- University of Strasbourg: Universite de Strasbourg IPCMS 23, rue du Loess 67034 Strasbourg FRANCE
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22
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Wegeberg C, Wenger OS. Luminescent First-Row Transition Metal Complexes. JACS AU 2021; 1:1860-1876. [PMID: 34841405 PMCID: PMC8611671 DOI: 10.1021/jacsau.1c00353] [Citation(s) in RCA: 108] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Indexed: 05/25/2023]
Abstract
Precious and rare elements have traditionally dominated inorganic photophysics and photochemistry, but now we are witnessing a paradigm shift toward cheaper and more abundant metals. Even though emissive complexes based on selected first-row transition metals have long been known, recent conceptual breakthroughs revealed that a much broader range of elements in different oxidation states are useable for this purpose. Coordination compounds of V, Cr, Mn, Fe, Co, Ni, and Cu now show electronically excited states with unexpected reactivity and photoluminescence behavior. Aside from providing a compact survey of the recent conceptual key advances in this dynamic field, our Perspective identifies the main design strategies that enabled the discovery of fundamentally new types of 3d-metal-based luminophores and photosensitizers operating in solution at room temperature.
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23
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Longetti L, Barillot TR, Puppin M, Ojeda J, Poletto L, van Mourik F, Arrell CA, Chergui M. Ultrafast photoelectron spectroscopy of photoexcited aqueous ferrioxalate. Phys Chem Chem Phys 2021; 23:25308-25316. [PMID: 34747432 DOI: 10.1039/d1cp02872c] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The photochemistry of metal-organic compounds in solution is determined by both intra- and inter-molecular relaxation processes after photoexcitation. Understanding its prime mechanisms is crucial to optimise the reactive paths and control their outcome. Here we investigate the photoinduced dynamics of aqueous ferrioxalate ([FeIII(C2O4)3]3-) upon 263 nm excitation using ultrafast liquid phase photoelectron spectroscopy (PES). The initial step is found to be a ligand-to-metal electron transfer, occuring on a time scale faster than our time resolution (≲30 fs). Furthermore, we observe that about 25% of the initially formed ferrous species population are lost in ∼2 ps. Cast in the contest of previous ultrafast infrared and X-ray spectroscopic studies, we suggest that upon prompt photoreduction of the metal centre, the excited molecules dissociate in <140 fs into the pair of CO2 and [(CO2)FeII(C2O4)2]3- fragments, with unity quantum yield. About 25% of these pairs geminately recombine in ∼2 ps, due to interaction with the solvent molecules, reforming the ground state of the parent ferric molecule.
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Affiliation(s)
- L Longetti
- Laboratory of Ultrafast Spectroscopy and the Lausanne Centre for Ultrafast Science, ISIC, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
| | - T R Barillot
- Laboratory of Ultrafast Spectroscopy and the Lausanne Centre for Ultrafast Science, ISIC, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
| | - M Puppin
- Laboratory of Ultrafast Spectroscopy and the Lausanne Centre for Ultrafast Science, ISIC, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
| | - J Ojeda
- Laboratory of Ultrafast Spectroscopy and the Lausanne Centre for Ultrafast Science, ISIC, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
| | - L Poletto
- National Research Council of Italy - Institute of Photonics and Nanotechnologies (CNR-IFN), via Trasea 7, 35131 Padova, Italy
| | - F van Mourik
- Laboratory of Ultrafast Spectroscopy and the Lausanne Centre for Ultrafast Science, ISIC, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
| | - C A Arrell
- Laboratory of Ultrafast Spectroscopy and the Lausanne Centre for Ultrafast Science, ISIC, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
| | - M Chergui
- Laboratory of Ultrafast Spectroscopy and the Lausanne Centre for Ultrafast Science, ISIC, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
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24
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Kwon HY, Ashley DC, Jakubikova E. Halogenation affects driving forces, reorganization energies and "rocking" motions in strained [Fe(tpy) 2] 2+ complexes. Dalton Trans 2021; 50:14566-14575. [PMID: 34586133 DOI: 10.1039/d1dt02314d] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Controlling the energetics of spin crossover (SCO) in Fe(II)-polypyridine complexes is critical for designing new multifunctional materials or tuning the excited-state lifetimes of iron-based photosensitizers. It is well established that the Fe-N "breathing" mode is important for intersystem crossing from the singlet to the quintet state, but this does not preclude other, less obvious, structural distortions from affecting SCO. Previous work has shown that halogenation at the 6 and 6'' positions of tpy (tpy = 2,2';6',2''-terpyridine) in [Fe(tpy)2]2+ dramatically increased the lifetime of the excited MLCT state and also had a large impact on the ground state spin-state energetics. To gain insight into the origins of these effects, we used density functional theory calculations to explore how halogenation impacts spin-state energetics and molecular structure in this system. Based on previous work we focused on the ligand "rocking" motion associated with SCO in [Fe(tpy)2]2+ by constructing one-dimensional potential energy surfaces (PESs) along the tpy rocking angle for various spin states. It was found that halogenation has a clear and predictable impact on ligand rocking and spin-state energetics. The rocking is correlated to numerous other geometrical distortions, all of which likely affect the reorganization energies for spin-state changes. We have quantified trends in reorganization energy and also driving force for various spin-state changes and used them to interpret the experimentally measured excited-state lifetimes.
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Affiliation(s)
- Hyuk-Yong Kwon
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Dr., Raleigh, NC 27695, USA.
| | - Daniel C Ashley
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Dr., Raleigh, NC 27695, USA.
| | - Elena Jakubikova
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Dr., Raleigh, NC 27695, USA.
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25
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Capel Berdiell I, Davies DJ, Woodworth J, Kulmaczewski R, Cespedes O, Halcrow MA. Structures and Spin States of Iron(II) Complexes of Isomeric 2,6-Di(1,2,3-triazolyl)pyridine Ligands. Inorg Chem 2021; 60:14988-15000. [PMID: 34547208 DOI: 10.1021/acs.inorgchem.1c02404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Iron(II) complex salts of 2,6-di(1,2,3-triazol-1-yl)pyridine (L1) are unexpectedly unstable in undried solvent. This is explained by the isolation of [Fe(L1)4(H2O)2][ClO4]2 and [Fe(NCS)2(L1)2(H2O)2]·L1, containing L1 bound as a monodentate ligand rather than in the expected tridentate fashion. These complexes associate into 44 grid structures through O-H···N hydrogen bonding; a solvate of a related 44 coordination framework, catena-[Cu(μ-L1)2(H2O)2][BF4]2, is also presented. The isomeric ligands 2,6-di(1,2,3-triazol-2-yl)pyridine (L2) and 2,6-di(1H-1,2,3-triazol-4-yl)pyridine (L3) bind to iron(II) in a more typical tridentate fashion. Solvates of [Fe(L3)2][ClO4]2 are low-spin and diamagnetic in the solid state and in solution, while [Fe(L2)2][ClO4]2 and [Co(L3)2][BF4]2 are fully high-spin. Treatment of L3 with methyl iodide affords 2,6-di(2-methyl-1,2,3-triazol-4-yl)pyridine (L4) and 2-(1-methyl-1,2,3-triazol-4-yl)-6-(2-methyl-1,2,3-triazol-4-yl)pyridine (L5). While salts of [Fe(L5)2]2+ are low-spin in the solid state, [Fe(L4)2][ClO4]2·H2O is high-spin, and [Fe(L4)2][ClO4]2·3MeNO2 exhibits a hysteretic spin transition to 50% completeness at T1/2 = 128 K (ΔT1/2 = 6 K). This transition proceeds via a symmetry-breaking phase transition to an unusual low-temperature phase containing three unique cation sites with high-spin, low-spin, and 1:1 mixed-spin populations. The unusual distribution of the spin states in the low-temperature phase reflects "spin-state frustration" of the mixed-spin cation site by an equal number of high-spin and low-spin nearest neighbors. Gas-phase density functional theory calculations reproduce the spin-state preferences of these and some related complexes. These highlight the interplay between the σ-basicity and π-acidity of the heterocyclic donors in this ligand type, which have opposing influences on the molecular ligand field. The Brønsted basicities of L1-L3 are very sensitive to the linkage isomerism of their triazolyl donors, which explains why their iron complex spin states show more variation than the better-known iron(II)/2,6-dipyrazolylpyridine system.
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Affiliation(s)
- Izar Capel Berdiell
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K
| | - Daniel J Davies
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K
| | - Jack Woodworth
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K
| | - Rafal Kulmaczewski
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K
| | - Oscar Cespedes
- School of Physics and Astronomy, University of Leeds, E. C. Stoner Building, Leeds LS2 9JT, U.K
| | - Malcolm A Halcrow
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K
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26
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Schmid L, Kerzig C, Prescimone A, Wenger OS. Photostable Ruthenium(II) Isocyanoborato Luminophores and Their Use in Energy Transfer and Photoredox Catalysis. JACS AU 2021; 1:819-832. [PMID: 34467335 PMCID: PMC8395604 DOI: 10.1021/jacsau.1c00137] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Indexed: 05/28/2023]
Abstract
Ruthenium(II) polypyridine complexes are among the most popular sensitizers in photocatalysis, but they face some severe limitations concerning accessible excited-state energies and photostability that could hamper future applications. In this study, the borylation of heteroleptic ruthenium(II) cyanide complexes with α-diimine ancillary ligands is identified as a useful concept to elevate the energies of photoactive metal-to-ligand charge-transfer (MLCT) states and to obtain unusually photorobust compounds suitable for thermodynamically challenging energy transfer catalysis as well as oxidative and reductive photoredox catalysis. B(C6F5)3 groups attached to the CN - ligands stabilize the metal-based t2g-like orbitals by ∼0.8 eV, leading to high 3MLCT energies (up to 2.50 eV) that are more typical for cyclometalated iridium(III) complexes. Through variation of their α-diimine ligands, nonradiative excited-state relaxation pathways involving higher-lying metal-centered states can be controlled, and their luminescence quantum yields and MLCT lifetimes can be optimized. These combined properties make the respective isocyanoborato complexes amenable to photochemical reactions for which common ruthenium(II)-based sensitizers are unsuited, due to a lack of sufficient triplet energy or excited-state redox power. Specifically, this includes photoisomerization reactions, sensitization of nickel-catalyzed cross-couplings, pinacol couplings, and oxidative decarboxylative C-C couplings. Our work is relevant in the greater context of tailoring photoactive coordination compounds to current challenges in synthetic photochemistry and solar energy conversion.
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Affiliation(s)
- Lucius Schmid
- Department
of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
| | - Christoph Kerzig
- Department
of Chemistry, Johannes Gutenberg University
Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Alessandro Prescimone
- Department
of Chemistry, University of Basel, BPR 1096, Mattenstrasse 24a, 4058 Basel, Switzerland
| | - Oliver S. Wenger
- Department
of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
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27
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Nair SS, Bysewski OA, Kupfer S, Wächtler M, Winter A, Schubert US, Dietzek B. Excitation Energy-Dependent Branching Dynamics Determines Photostability of Iron(II)-Mesoionic Carbene Complexes. Inorg Chem 2021; 60:9157-9173. [PMID: 34081456 DOI: 10.1021/acs.inorgchem.1c01166] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Photoactive metal complexes containing earth-abundant transition metals recently gained interest as photosensitizers in light-driven chemistry. In contrast to the traditionally employed ruthenium or iridium complexes, iron complexes developed to be promising candidates despite the fact that using iron complexes as photosensitizers poses an inherent challenge associated with the low-lying metal-centered states, which are responsible for ultrafast deactivation of the charge-transfer states. Nonetheless, recent developments of strongly σ-donating carbene ligands yielded highly promising systems, in which destabilized metal-centered states resulted in prolonged lifetimes of charge-transfer excited states. In this context, we introduce a series of novel homoleptic Fe-triazolylidene mesoionic carbene complexes. The excited-state properties of the complexes were investigated by time-resolved femtosecond transient absorption spectroscopy and quantum chemical calculations. Pump wavelength-dependent transient absorption reveals the presence of distinct excited-state relaxation pathways. We relate the excitation-wavelength-dependent branching of the excited-state dynamics into various reaction channels to solvent-dependent photodissociation following the population of dissociative metal centered states upon excitation at 400 nm.
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Affiliation(s)
- Shruthi S Nair
- Department Functional Interfaces, Leibniz Institute of Photonic Technology (Leibniz-IPHT), Albert-Einstein-Strasse 9, 07745 Jena, Germany.,Institute of Physical Chemistry, Friedrich-Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - Oliver A Bysewski
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich-Schiller University Jena, Humboldtstrasse 10, 07743 Jena, Germany.,Center for Energy and Environmental Chemistry Jena (CEEC-Jena), Friedrich-Schiller University Jena, Philosophenweg, 07743 Jena, Germany
| | - Stephan Kupfer
- Institute of Physical Chemistry, Friedrich-Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - Maria Wächtler
- Department Functional Interfaces, Leibniz Institute of Photonic Technology (Leibniz-IPHT), Albert-Einstein-Strasse 9, 07745 Jena, Germany.,Institute of Physical Chemistry, Friedrich-Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany.,Abbe Center of Photonics, Friedrich Schiller University Jena, Philosophenweg, 07745 Jena, Germany
| | - Andreas Winter
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich-Schiller University Jena, Humboldtstrasse 10, 07743 Jena, Germany.,Center for Energy and Environmental Chemistry Jena (CEEC-Jena), Friedrich-Schiller University Jena, Philosophenweg, 07743 Jena, Germany
| | - Ulrich S Schubert
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich-Schiller University Jena, Humboldtstrasse 10, 07743 Jena, Germany.,Center for Energy and Environmental Chemistry Jena (CEEC-Jena), Friedrich-Schiller University Jena, Philosophenweg, 07743 Jena, Germany
| | - Benjamin Dietzek
- Department Functional Interfaces, Leibniz Institute of Photonic Technology (Leibniz-IPHT), Albert-Einstein-Strasse 9, 07745 Jena, Germany.,Institute of Physical Chemistry, Friedrich-Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
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28
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Gaffney KJ. Capturing photochemical and photophysical transformations in iron complexes with ultrafast X-ray spectroscopy and scattering. Chem Sci 2021; 12:8010-8025. [PMID: 34194691 PMCID: PMC8208315 DOI: 10.1039/d1sc01864g] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 05/25/2021] [Indexed: 12/31/2022] Open
Abstract
Light-driven chemical transformations provide a compelling approach to understanding chemical reactivity with the potential to use this understanding to advance solar energy and catalysis applications. Capturing the non-equilibrium trajectories of electronic excited states with precision, particularly for transition metal complexes, would provide a foundation for advancing both of these objectives. Of particular importance for 3d metal compounds is characterizing the population dynamics of charge-transfer (CT) and metal-centered (MC) electronic excited states and understanding how the inner coordination sphere structural dynamics mediate the interaction between these states. Recent advances in ultrafast X-ray laser science has enabled the electronic excited state dynamics in 3d metal complexes to be followed with unprecedented detail. This review will focus on simultaneous X-ray emission spectroscopy (XES) and X-ray solution scattering (XSS) studies of iron coordination and organometallic complexes. These simultaneous XES-XSS studies have provided detailed insight into the mechanism of light-induced spin crossover in iron coordination compounds, the interaction of CT and MC excited states in iron carbene photosensitizers, and the mechanism of Fe-S bond dissociation in cytochrome c.
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Affiliation(s)
- Kelly J Gaffney
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Stanford University Menlo Park California 94025 USA
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29
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Bilger JB, Kerzig C, Larsen CB, Wenger OS. A Photorobust Mo(0) Complex Mimicking [Os(2,2'-bipyridine) 3] 2+ and Its Application in Red-to-Blue Upconversion. J Am Chem Soc 2021; 143:1651-1663. [PMID: 33434435 DOI: 10.1021/jacs.0c12805] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Osmium(II) polypyridines are a well-known class of complexes with luminescent metal-to-ligand charge-transfer (MLCT) excited states that are currently experiencing a revival due to their application potential in organic photoredox catalysis, triplet-triplet annihilation upconversion, and phototherapy. At the same time, there is increased interest in the development of photoactive complexes made from Earth-abundant rather than precious metals. Against this background, we present a homoleptic Mo(0) complex with a new diisocyanide ligand exhibiting different bite angles and a greater extent of π-conjugation than previously reported related chelates. This new design leads to deep red emission, which is unprecedented for homoleptic arylisocyanide complexes of group 6 metals. With a 3MLCT lifetime of 56 ns, an emission band maximum at 720 nm, and a photoluminescence quantum yield of 1.5% in deaerated toluene at room temperature, the photophysical properties are reminiscent of the prototypical [Os(2,2'-bipyridine)3]2+ complex. Under 635 nm irradiation with a cw-laser, the new Mo(0) complex sensitizes triplet-triplet annihilation upconversion of 9,10-diphenylanthracene (DPA), resulting in delayed blue fluorescence with an anti-Stokes shift of 0.93 eV. The photorobustness of the Mo(0) complex and the upconversion quantum yield are high enough to generate a flux of upconverted light that can serve as a sufficiently potent irradiation source for a blue-light-driven photoisomerization reaction. These findings are relevant in the greater contexts of designing new luminophores and photosensitizers for use in red-light-driven photocatalysis, photochemical upconversion, light-harvesting, and phototherapy.
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Affiliation(s)
- Jakob B Bilger
- 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
| | - Christopher B Larsen
- 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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30
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Chábera P, Lindh L, Rosemann NW, Prakash O, Uhlig J, Yartsev A, Wärnmark K, Sundström V, Persson P. Photofunctionality of iron(III) N-heterocyclic carbenes and related d transition metal complexes. Coord Chem Rev 2021. [DOI: 10.1016/j.ccr.2020.213517] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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31
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Aydogan A, Bangle RE, De Kreijger S, Dickenson JC, Singleton ML, Cauët E, Cadranel A, Meyer GJ, Elias B, Sampaio RN, Troian-Gautier L. Mechanistic investigation of a visible light mediated dehalogenation/cyclisation reaction using iron( iii), iridium( iii) and ruthenium( ii) photosensitizers. Catal Sci Technol 2021. [DOI: 10.1039/d1cy01771c] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The identification of reaction mechanisms unique to the iron, ruthenium, and iridium PS represents progress towards the long-sought goal of utilizing earth-abundant, first-row transition metals for emerging energy and environmental applications.
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Affiliation(s)
- Akin Aydogan
- Université catholique de Louvain (UCLouvain), Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), Place Louis Pasteur 1, bte L4.01.02, 1348 Louvain-la-Neuve, Belgium
| | - Rachel E. Bangle
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599-3290, USA
| | - Simon De Kreijger
- Université catholique de Louvain (UCLouvain), Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), Place Louis Pasteur 1, bte L4.01.02, 1348 Louvain-la-Neuve, Belgium
| | - John C. Dickenson
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599-3290, USA
| | - Michael L. Singleton
- Université catholique de Louvain (UCLouvain), Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), Place Louis Pasteur 1, bte L4.01.02, 1348 Louvain-la-Neuve, Belgium
| | - Emilie Cauët
- Spectroscopy, Quantum Chemistry and Atmospheric Remote Sensing (CP 160/09), Université libre de Bruxelles, 50 av. F. D. Roosevelt, B-1050 Brussels, Belgium
| | - Alejandro Cadranel
- Department of Chemistry and Pharmacy, Interdisciplinary Center for Molecular Materials (ICMM), Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstr. 3, 91058 Erlangen, Germany
- 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
| | - Gerald J. Meyer
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599-3290, USA
| | - Benjamin Elias
- Université catholique de Louvain (UCLouvain), Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), Place Louis Pasteur 1, bte L4.01.02, 1348 Louvain-la-Neuve, Belgium
| | - Renato N. Sampaio
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599-3290, USA
- Chemistry Division, Brookhaven National Laboratory, Upton, NY 11973-5000, USA
| | - Ludovic Troian-Gautier
- Université catholique de Louvain (UCLouvain), Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), Place Louis Pasteur 1, bte L4.01.02, 1348 Louvain-la-Neuve, Belgium
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32
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Chergui M. Launching Structural Dynamics. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2020; 7:060401. [PMID: 33415180 PMCID: PMC7771997 DOI: 10.1063/4.0000063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 12/08/2020] [Indexed: 06/12/2023]
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33
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Bacellar C, Kinschel D, Mancini GF, Ingle RA, Rouxel J, Cannelli O, Cirelli C, Knopp G, Szlachetko J, Lima FA, Menzi S, Pamfilidis G, Kubicek K, Khakhulin D, Gawelda W, Rodriguez-Fernandez A, Biednov M, Bressler C, Arrell CA, Johnson PJM, Milne CJ, Chergui M. Spin cascade and doming in ferric hemes: Femtosecond X-ray absorption and X-ray emission studies. Proc Natl Acad Sci U S A 2020; 117:21914-21920. [PMID: 32848065 PMCID: PMC7486745 DOI: 10.1073/pnas.2009490117] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The structure-function relationship is at the heart of biology, and major protein deformations are correlated to specific functions. For ferrous heme proteins, doming is associated with the respiratory function in hemoglobin and myoglobins. Cytochrome c (Cyt c) has evolved to become an important electron-transfer protein in humans. In its ferrous form, it undergoes ligand release and doming upon photoexcitation, but its ferric form does not release the distal ligand, while the return to the ground state has been attributed to thermal relaxation. Here, by combining femtosecond Fe Kα and Kβ X-ray emission spectroscopy (XES) with Fe K-edge X-ray absorption near-edge structure (XANES), we demonstrate that the photocycle of ferric Cyt c is entirely due to a cascade among excited spin states of the iron ion, causing the ferric heme to undergo doming, which we identify. We also argue that this pattern is common to a wide diversity of ferric heme proteins, raising the question of the biological relevance of doming in such proteins.
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Affiliation(s)
- Camila Bacellar
- Laboratoire de Spectroscopie Ultrarapide, Institut des Sciences et Ingéniéries Chimiques and Lausanne Centre for Ultrafast Science, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Dominik Kinschel
- Laboratoire de Spectroscopie Ultrarapide, Institut des Sciences et Ingéniéries Chimiques and Lausanne Centre for Ultrafast Science, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Giulia F Mancini
- Laboratoire de Spectroscopie Ultrarapide, Institut des Sciences et Ingéniéries Chimiques and Lausanne Centre for Ultrafast Science, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Rebecca A Ingle
- Laboratoire de Spectroscopie Ultrarapide, Institut des Sciences et Ingéniéries Chimiques and Lausanne Centre for Ultrafast Science, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Jérémy Rouxel
- Laboratoire de Spectroscopie Ultrarapide, Institut des Sciences et Ingéniéries Chimiques and Lausanne Centre for Ultrafast Science, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Oliviero Cannelli
- Laboratoire de Spectroscopie Ultrarapide, Institut des Sciences et Ingéniéries Chimiques and Lausanne Centre for Ultrafast Science, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Claudio Cirelli
- Swiss Free Electron Laser, Paul-Scherrer-Institut (PSI), 5232 Villigen PSI, Switzerland
| | - Gregor Knopp
- Swiss Free Electron Laser, Paul-Scherrer-Institut (PSI), 5232 Villigen PSI, Switzerland
| | - Jakub Szlachetko
- Institute of Nuclear Physics, Polish Academy of Sciences, 31-342 Kraków, Poland
| | | | - Samuel Menzi
- Swiss Free Electron Laser, Paul-Scherrer-Institut (PSI), 5232 Villigen PSI, Switzerland
| | - Georgios Pamfilidis
- Swiss Free Electron Laser, Paul-Scherrer-Institut (PSI), 5232 Villigen PSI, Switzerland
| | | | | | - Wojciech Gawelda
- European X-ray Free Electron Laser, D-22869 Schenefeld, Germany
- Faculty of Physics, Adam Mickiewicz University, 61-614 Poznan, Poland
| | | | - Mykola Biednov
- European X-ray Free Electron Laser, D-22869 Schenefeld, Germany
| | | | - Christopher A Arrell
- Swiss Free Electron Laser, Paul-Scherrer-Institut (PSI), 5232 Villigen PSI, Switzerland
| | - Philip J M Johnson
- Swiss Free Electron Laser, Paul-Scherrer-Institut (PSI), 5232 Villigen PSI, Switzerland
| | - Christopher J Milne
- Swiss Free Electron Laser, Paul-Scherrer-Institut (PSI), 5232 Villigen PSI, Switzerland
| | - Majed Chergui
- Laboratoire de Spectroscopie Ultrarapide, Institut des Sciences et Ingéniéries Chimiques and Lausanne Centre for Ultrafast Science, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland;
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34
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Naumova MA, Kalinko A, Wong JWL, Alvarez Gutierrez S, Meng J, Liang M, Abdellah M, Geng H, Lin W, Kubicek K, Biednov M, Lima F, Galler A, Zalden P, Checchia S, Mante PA, Zimara J, Schwarzer D, Demeshko S, Murzin V, Gosztola D, Jarenmark M, Zhang J, Bauer M, Lawson Daku ML, Khakhulin D, Gawelda W, Bressler C, Meyer F, Zheng K, Canton SE. Exploring the light-induced dynamics in solvated metallogrid complexes with femtosecond pulses across the electromagnetic spectrum. J Chem Phys 2020; 152:214301. [PMID: 32505143 DOI: 10.1063/1.5138641] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Oligonuclear complexes of d4-d7 transition metal ion centers that undergo spin-switching have long been developed for their practical role in molecular electronics. Recently, they also have appeared as promising photochemical reactants demonstrating improved stability. However, the lack of knowledge about their photophysical properties in the solution phase compared to mononuclear complexes is currently hampering their inclusion into advanced light-driven reactions. In the present study, the ultrafast photoinduced dynamics in a solvated [2 × 2] iron(II) metallogrid complex are characterized by combining measurements with transient optical-infrared absorption and x-ray emission spectroscopy on the femtosecond time scale. The analysis is supported by density functional theory calculations. The photocycle can be described in terms of intra-site transitions, where the FeII centers in the low-spin state are independently photoexcited. The Franck-Condon state decays via the formation of a vibrationally hot high-spin (HS) state that displays coherent behavior within a few picoseconds and thermalizes within tens of picoseconds to yield a metastable HS state living for several hundreds of nanoseconds. Systematic comparison with the closely related mononuclear complex [Fe(terpy)2]2+ reveals that nuclearity has a profound impact on the photoinduced dynamics. More generally, this work provides guidelines for expanding the integration of oligonuclear complexes into new photoconversion schemes that may be triggered by ultrafast spin-switching.
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Affiliation(s)
- Maria A Naumova
- Deutsches Elektronen Synchrotron (DESY), Notkestrasse 85, D-22607 Hamburg, Germany
| | - Aleksandr Kalinko
- Deutsches Elektronen Synchrotron (DESY), Notkestrasse 85, D-22607 Hamburg, Germany
| | - Joanne W L Wong
- Universität Göttingen, Institut für Anorganische Chemie, Tammannstraße 4, 37077 Göttingen, Germany
| | - Sol Alvarez Gutierrez
- Department of Chemistry, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - Jie Meng
- Department of Chemistry, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - Mingli Liang
- Department of Chemistry, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - Mohamed Abdellah
- Chemical Physics and NanoLund, Lund University, Box 124, 22100 Lund, Sweden
| | - Huifang Geng
- ELI-ALPS, ELI-HU Non-Profit Ltd., Dugonics ter 13, Szeged 6720, Hungary
| | - Weihua Lin
- Chemical Physics and NanoLund, Lund University, Box 124, 22100 Lund, Sweden
| | | | | | | | | | - Peter Zalden
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | | | | | - Jennifer Zimara
- Department of Dynamics at Surfaces, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Dirk Schwarzer
- Department of Dynamics at Surfaces, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Serhiy Demeshko
- Universität Göttingen, Institut für Anorganische Chemie, Tammannstraße 4, 37077 Göttingen, Germany
| | - Vadim Murzin
- Deutsches Elektronen Synchrotron (DESY), Notkestrasse 85, D-22607 Hamburg, Germany
| | - David Gosztola
- Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, USA
| | | | - Jianxin Zhang
- State Key Laboratory of Hollow Fiber Membrane Materials and Processes, School of Environmental and Chemical Engineering, Tianjin Polytechnic University, Tianjin 300387, China
| | - Matthias Bauer
- Department Chemie and Center for Sustainable Systems Design (CSSD), University of Paderborn, Warburger Straße 100, D-33098 Paderborn, Germany
| | - Max Latevi Lawson Daku
- Département de Chimie Physique, Université de Genève, Quai E. Ansermet 30, CH-1211 Genève 4, Switzerland
| | | | | | | | - Franc Meyer
- Universität Göttingen, Institut für Anorganische Chemie, Tammannstraße 4, 37077 Göttingen, Germany
| | - Kaibo Zheng
- Department of Chemistry, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - Sophie E Canton
- Deutsches Elektronen Synchrotron (DESY), Notkestrasse 85, D-22607 Hamburg, Germany
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Guo M, Prakash O, Fan H, de Groot LHM, Hlynsson VF, Kaufhold S, Gordivska O, Velásquez N, Chabera P, Glatzel P, Wärnmark K, Persson P, Uhlig J. HERFD-XANES probes of electronic structures of iron II/III carbene complexes. Phys Chem Chem Phys 2020; 22:9067-9073. [PMID: 32297625 DOI: 10.1039/c9cp06309a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Iron centered N-heterocyclic carbene (Fe-NHC) complexes have shown long-lived excited states with charge transfer character useful for light harvesting applications. Understanding the nature of the metal-ligand bond is of fundamental importance to rationally tailor the properties of transition metal complexes. The high-energy-resolution fluorescence detected X-ray absorption near edge structure (HERFD-XANES) has been used to probe the valence orbitals of three carbene complexes, [FeII(bpy)(btz)2](PF6)2 (bpy = 2,2'-bipyridine, btz = 3,3'-dimethyl-1,1'-bis(p-tolyl)-4,4'-bis(1,2,3-triazol-5-ylidene)), [FeIII(btz)3](PF6)3, and [FeIII(phtmeimb)2]PF6 (phtmeimb = [phenyl(tris(3-methylimidazol-2-ylidene))borate]-). The multiconfigurational restrict active space (RAS) approach has been used to simulate the metal K pre-edge X-ray absorption spectroscopy of these carbene complexes, and have reproduced the metal K pre-edge spectral features in terms of relative intensity and peak positions. The evident intensity difference between the FeII and the other two FeIII complexes has been elucidated with different intensity mechanisms in the transition. The smaller splitting between the t2g and eg character peak for [FeIII(btz)3](PF6)3 has been observed in the experimental measurements and been reproduced in the RAS calculations. The results show how the combination of experimental HERFD-XANES measurements and ab initio RAS simulations can give quantitative evaluation of the orbital interactions between metal and ligands for such large and strongly interacting systems and thus allow to understand and predict properties of novel complexes.
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Affiliation(s)
- Meiyuan Guo
- College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, P. R. China
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36
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Kunnus K, Li L, Titus CJ, Lee SJ, Reinhard ME, Koroidov S, Kjær KS, Hong K, Ledbetter K, Doriese WB, O'Neil GC, Swetz DS, Ullom JN, Li D, Irwin K, Nordlund D, Cordones AA, Gaffney KJ. Chemical control of competing electron transfer pathways in iron tetracyano-polypyridyl photosensitizers. Chem Sci 2020; 11:4360-4373. [PMID: 34122894 PMCID: PMC8159445 DOI: 10.1039/c9sc06272f] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 04/15/2020] [Indexed: 12/15/2022] Open
Abstract
Photoinduced intramolecular electron transfer dynamics following metal-to-ligand charge-transfer (MLCT) excitation of [Fe(CN)4(2,2'-bipyridine)]2- (1), [Fe(CN)4(2,3-bis(2-pyridyl)pyrazine)]2- (2) and [Fe(CN)4(2,2'-bipyrimidine)]2- (3) were investigated in various solvents with static and time-resolved UV-Visible absorption spectroscopy and Fe 2p3d resonant inelastic X-ray scattering (RIXS). This series of polypyridyl ligands, combined with the strong solvatochromism of the complexes, enables the 1MLCT vertical energy to be varied from 1.64 eV to 2.64 eV and the 3MLCT lifetime to range from 180 fs to 67 ps. The 3MLCT lifetimes in 1 and 2 decrease exponentially as the MLCT energy increases, consistent with electron transfer to the lowest energy triplet metal-centred (3MC) excited state, as established by the Tanabe-Sugano analysis of the Fe 2p3d RIXS data. In contrast, the 3MLCT lifetime in 3 changes non-monotonically with MLCT energy, exhibiting a maximum. This qualitatively distinct behaviour results from a competing 3MLCT → ground state (GS) electron transfer pathway that exhibits energy gap law behaviour. The 3MLCT → GS pathway involves nuclear tunnelling for the high-frequency polypyridyl breathing mode (hν = 1530 cm-1), which is most displaced for complex 3, making this pathway significantly more efficient. Our study demonstrates that the excited state relaxation mechanism of Fe polypyridyl photosensitizers can be readily tuned by ligand and solvent environment. Furthermore, our study reveals that extending charge transfer lifetimes requires control of the relative energies of the 3MLCT and the 3MC states and suppression of the intramolecular distortion of the acceptor ligand in the 3MLCT excited state.
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Affiliation(s)
- Kristjan Kunnus
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Stanford University Menlo Park California 94025 USA
| | - Lin Li
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Stanford University Menlo Park California 94025 USA
| | - Charles J Titus
- Department of Physics, Stanford University Stanford California 94305 USA
| | - Sang Jun Lee
- SLAC National Accelerator Laboratory Menlo Park California 94025 USA
| | - Marco E Reinhard
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Stanford University Menlo Park California 94025 USA
| | - Sergey Koroidov
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Stanford University Menlo Park California 94025 USA
| | - Kasper S Kjær
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Stanford University Menlo Park California 94025 USA
| | - Kiryong Hong
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Stanford University Menlo Park California 94025 USA
| | - Kathryn Ledbetter
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Stanford University Menlo Park California 94025 USA
- Department of Physics, Stanford University Stanford California 94305 USA
| | | | - Galen C O'Neil
- National Institute of Standards and Technology Boulder CO 80305 USA
| | - Daniel S Swetz
- National Institute of Standards and Technology Boulder CO 80305 USA
| | - Joel N Ullom
- National Institute of Standards and Technology Boulder CO 80305 USA
| | - Dale Li
- SLAC National Accelerator Laboratory Menlo Park California 94025 USA
| | - Kent Irwin
- Department of Physics, Stanford University Stanford California 94305 USA
- SLAC National Accelerator Laboratory Menlo Park California 94025 USA
| | - Dennis Nordlund
- SLAC National Accelerator Laboratory Menlo Park California 94025 USA
| | - Amy A Cordones
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Stanford University Menlo Park California 94025 USA
| | - Kelly J Gaffney
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Stanford University Menlo Park California 94025 USA
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37
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Avila Y, Osiry H, Torres AE, Martínez-dlCruz L, González M. M, Rodríguez-Hernández J, Reguera E. From 2D to 3D solids: stacking of transition metal nitroprusside layers through intermolecular physical interactions. J COORD CHEM 2020. [DOI: 10.1080/00958972.2020.1739272] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Y. Avila
- Instituto Politécnico Nacional, Centro de Investigación en Ciencia Aplicada y tecnología Avanzada, U. Legaria, Ciudad México, México
| | - H. Osiry
- Instituto Politécnico Nacional, Centro de Investigación en Ciencia Aplicada y tecnología Avanzada, U. Legaria, Ciudad México, México
| | - A. E. Torres
- Instituto Politécnico Nacional, Centro de Investigación en Ciencia Aplicada y tecnología Avanzada, U. Legaria, Ciudad México, México
| | - L. Martínez-dlCruz
- CONACyT- Instituto Politécnico Nacional, Centro de Investigación en Ciencia Aplicada y tecnología Avanzada, U. Legaria, Ciudad México, México
| | - M. González M.
- CONACyT- Instituto Politécnico Nacional, Centro de Investigación en Ciencia Aplicada y tecnología Avanzada, U. Legaria, Ciudad México, México
| | | | - E. Reguera
- Instituto Politécnico Nacional, Centro de Investigación en Ciencia Aplicada y tecnología Avanzada, U. Legaria, Ciudad México, México
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38
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Photophysics and Photochemistry of Iron Carbene Complexes for Solar Energy Conversion and Photocatalysis. Catalysts 2020. [DOI: 10.3390/catal10030315] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Earth-abundant first row transition metal complexes are important for the development of large-scale photocatalytic and solar energy conversion applications. Coordination compounds based on iron are especially interesting, as iron is the most common transition metal element in the Earth’s crust. Unfortunately, iron-polypyridyl and related traditional iron-based complexes generally suffer from poor excited state properties, including short excited-state lifetimes, that make them unsuitable for most light-driven applications. Iron carbene complexes have emerged in the last decade as a new class of coordination compounds with significantly improved photophysical and photochemical properties, that make them attractive candidates for a range of light-driven applications. Specific aspects of the photophysics and photochemistry of these iron carbenes discussed here include long-lived excited state lifetimes of charge transfer excited states, capabilities to act as photosensitizers in solar energy conversion applications like dye-sensitized solar cells, as well as recent demonstrations of promising progress towards driving photoredox and photocatalytic processes. Complementary advances towards photofunctional systems with both Fe(II) complexes featuring metal-to-ligand charge transfer excited states, and Fe(III) complexes displaying ligand-to-metal charge transfer excited states are discussed. Finally, we outline emerging opportunities to utilize the improved photochemical properties of iron carbenes and related complexes for photovoltaic, photoelectrochemical and photocatalytic applications.
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Temperton RH, Rosemann NW, Guo M, Johansson N, Fredin LA, Prakash O, Wärnmark K, Handrup K, Uhlig J, Schnadt J, Persson P. Site-Selective Orbital Interactions in an Ultrathin Iron-Carbene Photosensitizer Film. J Phys Chem A 2020; 124:1603-1609. [PMID: 32011141 PMCID: PMC7307919 DOI: 10.1021/acs.jpca.0c00803] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We present the first experimental study of the frontier orbitals in an ultrathin film of the novel hexa-carbene photosensitizer [Fe(btz)3]3+, where btz is 3,3'-dimethyl-1,1'-bis(p-tolyl)-4,4'-bis(1,2,3-triazol-5-ylidene). Resonant photoelectron spectroscopy (RPES) was used to probe the electronic structure of films where the molecular and oxidative integrities had been confirmed with optical and X-ray spectroscopies. In combination with density functional theory calculations, RPES measurements provided direct and site-selective information about localization and interactions of occupied and unoccupied molecular orbitals. Fe 2p, N 1s, and C 1s measurements selectively probed the metal, carbene, and side-group contributions revealing strong metal-ligand orbital mixing of the frontier orbitals. This helps explain the remarkable photophysical properties of iron-carbenes in terms of unconventional electronic structure properties and favorable metal-ligand bonding interactions-important for the continued development of these type of complexes toward light-harvesting and light-emitting applications.
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Affiliation(s)
- Robert H Temperton
- School of Physics and Astronomy , University of Nottingham , Nottingham NG7 2RD , U.K
| | - Nils W Rosemann
- Division of Chemical Physics, Chemical Center , Lund University , Box 124, Lund SE-221 00 , Sweden.,Centre for Analysis and Synthesis, Department of Chemistry , Lund University , Box 124, Lund SE-22100 , Sweden
| | - Meiyuan Guo
- Division of Chemical Physics, Chemical Center , Lund University , Box 124, Lund SE-221 00 , Sweden
| | - Niclas Johansson
- Division of Synchrotron Radiation Research, Department of Physics, MAX IV Laboratory , Lund University , Box 118, Lund SE-22100 , Sweden
| | - Lisa A Fredin
- Theoretical Chemistry Division, Chemical Center , Lund University , Box 124, Lund SE-221 00 , Sweden
| | - Om Prakash
- Centre for Analysis and Synthesis, Department of Chemistry , Lund University , Box 124, Lund SE-22100 , Sweden
| | - Kenneth Wärnmark
- Centre for Analysis and Synthesis, Department of Chemistry , Lund University , Box 124, Lund SE-22100 , Sweden
| | - Karsten Handrup
- Division of Synchrotron Radiation Research, Department of Physics, MAX IV Laboratory , Lund University , Box 118, Lund SE-22100 , Sweden
| | - Jens Uhlig
- Division of Chemical Physics, Chemical Center , Lund University , Box 124, Lund SE-221 00 , Sweden
| | - Joachim Schnadt
- Division of Synchrotron Radiation Research, Department of Physics, MAX IV Laboratory , Lund University , Box 118, Lund SE-22100 , Sweden
| | - Petter Persson
- Theoretical Chemistry Division, Chemical Center , Lund University , Box 124, Lund SE-221 00 , Sweden
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40
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Lykhin AO, Varganov SA. Intersystem crossing in tunneling regime: T 1 → S 0 relaxation in thiophosgene. Phys Chem Chem Phys 2020; 22:5500-5508. [PMID: 32101195 DOI: 10.1039/c9cp06956a] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The T1 excited state relaxation in thiophosgene has attracted much attention as a relatively simple model for the intersystem crossing (ISC) transitions in polyatomic molecules. The very short (20-40 ps) T1 lifetime predicted in several theoretical studies strongly disagrees with the experimental values (∼20 ns) indicating that the kinetics of T1 → S0 ISC is not well understood. We use the nonadiabatic transition state theory (NA-TST) with the Zhu-Nakamura transition probability and the multireference perturbation theory (CASPT2) to show that the T1 → S0 ISC occurs in the quantum tunneling regime. We also introduce a new zero-point vibrational energy correction scheme that improves the accuracy of the predicted ISC rate constants at low internal energies. The predicted lifetimes of the T1 vibrational states are between one and two orders of magnitude larger than the experimental values. This overestimation is attributed to the multidimensional nature of quantum tunneling that facilitates ISC transitions along the non-minimum energy path and is not accounted for in the one-dimensional NA-TST.
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Affiliation(s)
- Aleksandr O Lykhin
- Department of Chemistry, University of Nevada, 1664 N. Virginia Street, Reno, Nevada 89557-0216, USA.
| | - Sergey A Varganov
- Department of Chemistry, University of Nevada, 1664 N. Virginia Street, Reno, Nevada 89557-0216, USA.
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41
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Farcaș AA, Bende A. Improving the Light-Induced Spin Transition Efficiency in Ni(II)-Based Macrocyclic-Ligand Complexes. Molecules 2019; 24:molecules24234249. [PMID: 31766599 PMCID: PMC6930591 DOI: 10.3390/molecules24234249] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 11/15/2019] [Accepted: 11/20/2019] [Indexed: 01/29/2023] Open
Abstract
The structural stability and photoabsorption properties of Ni(II)-based metal-organic complexes with octahedral coordination having different planar ligand ring structures were investigated employing density functional theory (DFT) and its time-dependent extension (TD-DFT) considering the M06 exchange-correlation functional and the Def2-TZVP basis set. The results showed that the molecular composition of different planar cyclic ligand structures had significant influences on the structural stability and photoabsorption properties of metal-organic complexes. Only those planar ligands that contained aromatic rings met the basic criteria (thermal stability, structural reversibility, and appropriate excitation frequency domain) for light-induced excited spin state trapping, but their spin transition efficiencies were very different. While, in all three aromatic cases, the singlet electronic excitations induced charge distribution that could help in the singlet-to-triplet spin transition, and triplet excitations, which could assist in the backward (triplet-to-singlet) spin transition, was found only for one complex.
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Affiliation(s)
- Alex-Adrian Farcaș
- National Institute for Research and Development of Isotopic and Molecular Technologies, Donat Street, No. 67-103, Ro-400293 Cluj-Napoca, Romania;
- Faculty of Physics, “Babeş-Bolyai” University, Mihail Kogalniceanu Street No. 1, Ro-400084 Cluj-Napoca, Romania
| | - Attila Bende
- National Institute for Research and Development of Isotopic and Molecular Technologies, Donat Street, No. 67-103, Ro-400293 Cluj-Napoca, Romania;
- Correspondence:
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42
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Tatsuno H, Kjær KS, Kunnus K, Harlang TCB, Timm C, Guo M, Chàbera P, Fredin LA, Hartsock RW, Reinhard ME, Koroidov S, Li L, Cordones AA, Gordivska O, Prakash O, Liu Y, Laursen MG, Biasin E, Hansen FB, Vester P, Christensen M, Haldrup K, Németh Z, Sárosiné Szemes D, Bajnóczi É, Vankó G, Van Driel TB, Alonso‐Mori R, Glownia JM, Nelson S, Sikorski M, Lemke HT, Sokaras D, Canton SE, Dohn AO, Møller KB, Nielsen MM, Gaffney KJ, Wärnmark K, Sundström V, Persson P, Uhlig J. Hot Branching Dynamics in a Light‐Harvesting Iron Carbene Complex Revealed by Ultrafast X‐ray Emission Spectroscopy. Angew Chem Int Ed Engl 2019; 59:364-372. [DOI: 10.1002/anie.201908065] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 09/17/2019] [Indexed: 12/13/2022]
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43
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Tatsuno H, Kjær KS, Kunnus K, Harlang TCB, Timm C, Guo M, Chàbera P, Fredin LA, Hartsock RW, Reinhard ME, Koroidov S, Li L, Cordones AA, Gordivska O, Prakash O, Liu Y, Laursen MG, Biasin E, Hansen FB, Vester P, Christensen M, Haldrup K, Németh Z, Sárosiné Szemes D, Bajnóczi É, Vankó G, Van Driel TB, Alonso‐Mori R, Glownia JM, Nelson S, Sikorski M, Lemke HT, Sokaras D, Canton SE, Dohn AO, Møller KB, Nielsen MM, Gaffney KJ, Wärnmark K, Sundström V, Persson P, Uhlig J. Hot Branching Dynamics in a Light‐Harvesting Iron Carbene Complex Revealed by Ultrafast X‐ray Emission Spectroscopy. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201908065] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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44
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Avila Y, Plasencia Y, Osiry H, Martínez‐dlCruz L, González Montiel M, Reguera E. Thermally Induced Spin Transition in a 2D Ferrous Nitroprusside. Eur J Inorg Chem 2019. [DOI: 10.1002/ejic.201900837] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Yosuan Avila
- Instituto Politécnico Nacional Centro de Investigación en Ciencia Aplicada y tecnología Avanzada Unidad Legaria 11500 Ciudad México México
| | - Yosdel Plasencia
- Instituto Politécnico Nacional Centro de Investigación en Ciencia Aplicada y tecnología Avanzada Unidad Legaria 11500 Ciudad México México
| | - Hernandez Osiry
- Instituto Politécnico Nacional Centro de Investigación en Ciencia Aplicada y tecnología Avanzada Unidad Legaria 11500 Ciudad México México
| | - Lorena Martínez‐dlCruz
- CONACyT ‐ Instituto Politécnico Nacional Centro de Investigación en Ciencia Aplicada y tecnología Avanzada U. Legaria 11500 Ciudad México México
| | - Marlene González Montiel
- CONACyT ‐ Instituto Politécnico Nacional Centro de Investigación en Ciencia Aplicada y tecnología Avanzada U. Legaria 11500 Ciudad México México
| | - Edilso Reguera
- Instituto Politécnico Nacional Centro de Investigación en Ciencia Aplicada y tecnología Avanzada Unidad Legaria 11500 Ciudad México México
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45
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Galler A, Gawelda W, Biednov M, Bomer C, Britz A, Brockhauser S, Choi TK, Diez M, Frankenberger P, French M, Görries D, Hart M, Hauf S, Khakhulin D, Knoll M, Korsch T, Kubicek K, Kuster M, Lang P, Alves Lima F, Otte F, Schulz S, Zalden P, Bressler C. Scientific instrument Femtosecond X-ray Experiments (FXE): instrumentation and baseline experimental capabilities. JOURNAL OF SYNCHROTRON RADIATION 2019; 26:1432-1447. [PMID: 31490131 PMCID: PMC6730617 DOI: 10.1107/s1600577519006647] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 05/08/2019] [Indexed: 05/15/2023]
Abstract
The European X-ray Free-Electron Laser (EuXFEL) delivers extremely intense (>1012 photons pulse-1 and up to 27000 pulses s-1), ultrashort (<100 fs) and transversely coherent X-ray radiation, at a repetition rate of up to 4.5 MHz. Its unique X-ray beam parameters enable novel and groundbreaking experiments in ultrafast photochemistry and material sciences at the Femtosecond X-ray Experiments (FXE) scientific instrument. This paper provides an overview of the currently implemented experimental baseline instrumentation and its performance during the commissioning phase, and a preview of planned improvements. FXE's versatile instrumentation combines the simultaneous application of forward X-ray scattering and X-ray spectroscopy techniques with femtosecond time resolution. These methods will eventually permit exploitation of wide-angle X-ray scattering studies and X-ray emission spectroscopy, along with X-ray absorption spectroscopy, including resonant inelastic X-ray scattering and X-ray Raman scattering. A suite of ultrafast optical lasers throughout the UV-visible and near-IR ranges (extending up to mid-IR in the near future) with pulse length down to 15 fs, synchronized to the X-ray source, serve to initiate dynamic changes in the sample. Time-delayed hard X-ray pulses in the 5-20 keV range are used to probe the ensuing dynamic processes using the suite of X-ray probe tools. FXE is equipped with a primary monochromator, a primary and secondary single-shot spectrometer, and a timing tool to correct the residual timing jitter between laser and X-ray pulses.
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Affiliation(s)
- Andreas Galler
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Wojciech Gawelda
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
- Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań, Poland
| | - Mykola Biednov
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Christina Bomer
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
- The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, 22607 Hamburg, Germany
| | - Alexander Britz
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Sandor Brockhauser
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
- Biological Research Centre (BRC), Hungarian Academy of Sciences, Temesvári krt 62, H-6726 Szeged, Hungary
| | - Tae-Kyu Choi
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Michael Diez
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
- The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, 22607 Hamburg, Germany
| | - Paul Frankenberger
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Marcus French
- STFC Technology, Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0QX, UK
| | - Dennis Görries
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Matthiew Hart
- STFC Technology, Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0QX, UK
| | - Steffen Hauf
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Dmitry Khakhulin
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Martin Knoll
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Timo Korsch
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Katharina Kubicek
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Markus Kuster
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Philipp Lang
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Frederico Alves Lima
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Florian Otte
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
- The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, 22607 Hamburg, Germany
- Fakultät Physik, Technische Universität Dortmund, 44227 Dortmund, Germany
| | - Sebastian Schulz
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Peter Zalden
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Christian Bressler
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
- The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, 22607 Hamburg, Germany
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Herr P, Glaser F, Büldt LA, Larsen CB, Wenger OS. Long-Lived, Strongly Emissive, and Highly Reducing Excited States in Mo(0) Complexes with Chelating Isocyanides. J Am Chem Soc 2019; 141:14394-14402. [PMID: 31464429 DOI: 10.1021/jacs.9b07373] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Newly discovered tris(diisocyanide)molybdenum(0) complexes are Earth-abundant isoelectronic analogues of the well-known class of [Ru(α-diimine)3]2+ compounds with long-lived 3MLCT (metal-to-ligand charge transfer) excited states that lead to rich photophysics and photochemistry. Depending on ligand design, luminescence quantum yields up to 0.20 and microsecond excited state lifetimes are achieved in solution at room temperature, both significantly better than those for [Ru(2,2'-bipyridine)3]2+. The excited Mo(0) complexes can induce chemical reactions that are thermodynamically too demanding for common precious metal-based photosensitizers, including the widely employed fac-[Ir(2-phenylpyridine)3] complex, as demonstrated on a series of light-driven aryl-aryl coupling reactions. The most robust Mo(0) complex exhibits stable photoluminescence and remains photoactive after continuous irradiation exceeding 2 months. Our comprehensive optical spectroscopic and photochemical study shows that Mo(0) complexes with diisocyanide chelate ligands constitute a new family of luminophores and photosensitizers, which is complementary to precious metal-based 4d6 and 5d6 complexes and represents an alternative to nonemissive Fe(II) compounds. This is relevant in the greater context of sustainable photophysics and photochemistry, as well as for possible applications in lighting, sensing, and catalysis.
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Affiliation(s)
- Patrick Herr
- Department of Chemistry , University of Basel , St. Johanns-Ring 19 , 4056 Basel , Switzerland
| | - Felix Glaser
- Department of Chemistry , University of Basel , St. Johanns-Ring 19 , 4056 Basel , Switzerland
| | - Laura A Büldt
- 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
| | - Oliver S Wenger
- Department of Chemistry , University of Basel , St. Johanns-Ring 19 , 4056 Basel , Switzerland
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Wernet P. Chemical interactions and dynamics with femtosecond X-ray spectroscopy and the role of X-ray free-electron lasers. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2019; 377:20170464. [PMID: 30929622 PMCID: PMC6452048 DOI: 10.1098/rsta.2017.0464] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
X-ray free-electron lasers with intense, tuneable and short-pulse X-ray radiation are transformative tools for the investigation of transition-metal complexes and metalloproteins. This becomes apparent in particular when combining the experimental observables from X-ray spectroscopy with modern theoretical tools for calculations of electronic structures and X-ray spectra from first principles. The combination gives new insights into how charge and spin densities change in chemical reactions and how they determine reactivity. This is demonstrated for the investigations of structural dynamics with metal K-edge absorption spectroscopy, spin states in excited-state dynamics with metal 3p-3d exchange interactions, the frontier-orbital interactions in dissociation and substitution reactions with metal-specific X-ray spectroscopy, and studies of metal oxidation states with femtosecond pulses for 'probe-before-destroy' spectroscopy. The role of X-ray free-electron lasers is addressed with thoughts about how they enable 'bringing back together' different aspects of the same problem and this is thought to go beyond a conventional review paper where these aspects are formulated in italic font type in a prequel, an interlude and in a sequel. This article is part of the theme issue 'Measurement of ultrafast electronic and structural dynamics with X-rays'.
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Affiliation(s)
- Majed Chergui
- Laboratoire de Spectroscopie Ultrarapide (LSU) and Lausanne Centre for Ultrafast Science (LACUS), Ecole Polytechnique Fédérale de Lausanne, ISIC, FSB, Station 6, CH-1015 Lausanne, Switzerland
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McCusker JK. Electronic structure in the transition metal block and its implications for light harvesting. Science 2019; 363:484-488. [PMID: 30705184 DOI: 10.1126/science.aav9104] [Citation(s) in RCA: 171] [Impact Index Per Article: 34.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Transition metal-based chromophores play a central role in a variety of light-enabled chemical processes ranging from artificial solar energy conversion to photoredox catalysis. The most commonly used compounds include elements from the second and third transition series (e.g., ruthenium and iridium), but their Earth-abundant first-row analogs fail to engage in photoinduced electron transfer chemistry despite having virtually identical absorptive properties. This disparate behavior stems from fundamental differences in the nature of 3d versus 4d and 5d orbitals, resulting in an inversion in the compounds' excited-state electronic structure and undermining the ability of compounds with first-row elements to engage in photoinduced electron transfer. This Review will survey the key experimental observations establishing this difference in behavior, discuss the underlying reasons for this phenomenon, and briefly summarize efforts that are currently under way to alter this paradigm and open the door to new opportunities for using Earth-abundant materials for photoinduced electron transfer chemistries.
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Affiliation(s)
- James K McCusker
- Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA
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