1
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Ilic A, Strücker BR, Johnson CE, Hainz S, Lomoth R, Wärnmark K. Aminomethylations of electron-deficient compounds-bringing iron photoredox catalysis into play. Chem Sci 2024; 15:12077-12085. [PMID: 39092117 PMCID: PMC11290444 DOI: 10.1039/d4sc02612h] [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: 04/19/2024] [Accepted: 06/26/2024] [Indexed: 08/04/2024] Open
Abstract
The α-functionalisation of N-containing compounds is an area of broad interest in synthetic chemistry due to their presence in biologically active substances among others. Visible light-induced generation of nucleophilic α-aminoalkyl radicals as reactive intermediates that can be trapped by electron-deficient alkenes presents an attractive and mild approach to achieve said functionalisation. In this work, [Fe(iii)(phtmeimb)2]PF6 (phtmeimb = phenyl(tris(3-methylimidazol-2-ylidene))borate), an N-heterocyclic carbene (NHC) complex based on Earth-abundant iron, was used as photoredox catalyst to efficiently drive the formation of α-aminoalkyl radicals from a range of different α-trimethylsilylamines and their subsequent addition to a number of electron-deficient alkenes under green light irradiation. Mechanistic investigations elucidated the different reaction steps of the complete photocatalytic cycle. In terms of yields and substrate scope, we show that [Fe(iii)(phtmeimb)2]PF6 can compete with noble metal photoredox catalysts, for instance outcompeting archetypal [Ru(bpy)3]Cl2 under comparable reaction conditions, illustrating that iron photocatalysts can efficiently facilitate photoredox reactions of synthetic value.
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Affiliation(s)
- Aleksandra Ilic
- Centre for Analysis and Synthesis (CAS), Department of Chemistry, Lund University SE-22100 Lund Sweden
| | - Benjamin R Strücker
- Centre for Analysis and Synthesis (CAS), Department of Chemistry, Lund University SE-22100 Lund Sweden
| | - Catherine E Johnson
- Department of Chemistry-Ångström Laboratory, Uppsala University SE-75120 Uppsala Sweden
| | - Simon Hainz
- Centre for Analysis and Synthesis (CAS), Department of Chemistry, Lund University SE-22100 Lund Sweden
| | - Reiner Lomoth
- Department of Chemistry-Ångström Laboratory, Uppsala University SE-75120 Uppsala Sweden
| | - Kenneth Wärnmark
- Centre for Analysis and Synthesis (CAS), Department of Chemistry, Lund University SE-22100 Lund Sweden
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2
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Reuter T, Zorn D, Naumann R, Klett J, Förster C, Heinze K. A Tetracarbene Iron(II) Complex with a Long-lived Triplet Metal-to-Ligand Charge Transfer State due to a Triplet-Triplet Barrier. Angew Chem Int Ed Engl 2024:e202406438. [PMID: 38946322 DOI: 10.1002/anie.202406438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2024] [Revised: 06/28/2024] [Accepted: 06/28/2024] [Indexed: 07/02/2024]
Abstract
Mixed N-heterocyclic carbene (NHC) / pyridyl iron(II) complexes have attracted a great deal of attention recently because of their potential as photocatalysts and light sensitizers made from Earth-abundant elements. The most decisive challenge for their successful implementation is the lifetime of the lowest triplet metal-to-ligand charge transfer state (3MLCT), which typically decays via a triplet metal-centered (3MC) state back to the ground state. We reveal by variable-temperature ultrafast transient absorption spectroscopy that the tripodal iron(II) bis(pyridine) complex isomers trans- and cis-[Fe(pdmi)2]2+ with four NHC donors show 3MLCT→3MC population transfers with very different barriers and rationalize this by computational means. While trans-[Fe(pdmi)2]2+ possesses an unobservable activation barrier, the cis isomer exhibits a barrier of 492 cm-1, which leads to a nanosecond 3MLCT lifetime at 77 K. The kinetic and quantum chemical data were analyzed in the context of semi-classical Marcus theory revealing a high reorganization energy and small electronic coupling between the two triplet states. This highlights the importance of detailed structural control and kinetic knowledge for the rational design of photosensitizers from first row transition metals such as iron.
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Affiliation(s)
- Thomas Reuter
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128, Mainz, Germany
| | - Dimitri Zorn
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128, Mainz, Germany
| | - Robert Naumann
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128, Mainz, Germany
| | - Jan Klett
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128, Mainz, Germany
| | - Christoph Förster
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128, Mainz, Germany
| | - Katja Heinze
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128, Mainz, Germany
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3
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Jiang Y, Hayes S, Bittmann S, Sarracini A, Liu LC, Müller-Werkmeister HM, Miyawaki A, Hada M, Nakano S, Takahashi R, Banu S, Koshihara SY, Takahashi K, Ishikawa T, Miller RJD. Direct observation of photoinduced sequential spin transition in a halogen-bonded hybrid system by complementary ultrafast optical and electron probes. Nat Commun 2024; 15:4604. [PMID: 38834600 DOI: 10.1038/s41467-024-48529-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Accepted: 05/03/2024] [Indexed: 06/06/2024] Open
Abstract
A detailed understanding of the ultrafast dynamics of halogen-bonded materials is desired for designing supramolecular materials and tuning various electronic properties by external stimuli. Here, a prototypical halogen-bonded multifunctional material containing spin crossover (SCO) cations and paramagnetic radical anions is studied as a model system of photo-switchable SCO hybrid systems using ultrafast electron diffraction and two complementary optical spectroscopic techniques. Our results reveal a sequential dynamics from SCO to radical dimer softening, uncovering a key transient intermediate state. In combination with quantum chemistry calculations, we demonstrate the presence of halogen bonds in the low- and high-temperature phases and propose their role during the photoinduced sequential dynamics, underscoring the significance of exploring ultrafast dynamics. Our research highlights the promising utility of halogen bonds in finely tuning functional properties across diverse photoactive multifunctional materials.
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Affiliation(s)
- Yifeng Jiang
- European XFEL, Holzkoppel 4, 22869, Schenefeld, Germany.
| | - Stuart Hayes
- Departments of Chemistry and Physics, University of Toronto, 80 St. George St., Toronto, M5S 3H6, ON, Canada
| | - Simon Bittmann
- Max Planck Institute for the Structure and Dynamics of Matter, Luruper Chaussee 149, 22761, Hamburg, Germany
| | - Antoine Sarracini
- Departments of Chemistry and Physics, University of Toronto, 80 St. George St., Toronto, M5S 3H6, ON, Canada
- Paul Scherrer Institut, Forschungsstrasse 111, 5232, Villigen PSI, Switzerland
| | - Lai Chung Liu
- Uncharted Software, 600-2 Berkeley St., Toronto, M5A 4J5, ON, Canada
| | | | - Atsuhiro Miyawaki
- Department of Chemistry, Graduate School of Science, Kobe University, 1-1, Rokkodai-cho, Nada-ku, Kobe, Hyogo, 657-8501, Japan
| | - Masaki Hada
- Tsukuba Research Center for Energy Materials Science, University of Tsukuba, 1-1-1, Tennodai, Tsukuba, Ibaraki, 305-8573, Japan
| | - Shinnosuke Nakano
- Department of Chemistry, School of Science, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8551, Japan
| | - Ryoya Takahashi
- Department of Chemistry, School of Science, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8551, Japan
| | - Samiran Banu
- Department of Chemistry, School of Science, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8551, Japan
| | - Shin-Ya Koshihara
- Department of Chemistry, School of Science, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8551, Japan
| | - Kazuyuki Takahashi
- Department of Chemistry, Graduate School of Science, Kobe University, 1-1, Rokkodai-cho, Nada-ku, Kobe, Hyogo, 657-8501, Japan.
| | - Tadahiko Ishikawa
- Department of Chemistry, School of Science, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8551, Japan.
| | - R J Dwayne Miller
- Departments of Chemistry and Physics, University of Toronto, 80 St. George St., Toronto, M5S 3H6, ON, Canada.
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4
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Trippmacher S, Demeshko S, Prescimone A, Meyer F, Wenger OS, Wang C. Ferromagnetically Coupled Chromium(III) Dimer Shows Luminescence and Sensitizes Photon Upconversion. Chemistry 2024; 30:e202400856. [PMID: 38523568 DOI: 10.1002/chem.202400856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 03/23/2024] [Accepted: 03/25/2024] [Indexed: 03/26/2024]
Abstract
There has been much progress on mononuclear chromium(III) complexes featuring luminescence and photoredox activity, but dinuclear chromium(III) complexes have remained underexplored in these contexts until now. We identified a tridentate chelate ligand able to accommodate both meridional and facial coordination of chromium(III), to either access a mono- or a dinuclear chromium(III) complex depending on reaction conditions. This chelate ligand causes tetragonally distorted primary coordination spheres around chromium(III) in both complexes, entailing comparatively short excited-state lifetimes in the range of 400 to 800 ns in solution at room temperature and making photoluminescence essentially oxygen insensitive. The two chromium(III) ions in the dimer experience ferromagnetic exchange interactions that result in a high spin (S=3) ground state with a coupling constant of +9.3 cm-1. Photoinduced energy transfer from the luminescent ferromagnetically coupled dimer to an anthracene derivative results in sensitized triplet-triplet annihilation upconversion. Based on these proof-of-principle studies, dinuclear chromium(III) complexes seem attractive for the development of fundamentally new types of photophysics and photochemistry enabled by magnetic exchange interactions.
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Affiliation(s)
- Simon Trippmacher
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland
| | - Serhiy Demeshko
- Institute of Inorganic Chemistry, University of Göttingen, Tammannstraße 4, 37077, Göttingen, Germany
| | - Alessandro Prescimone
- Department of Chemistry, BPR 1096, University of Basel, Mattenstrasse 24a, 4058, Basel, Switzerland
| | - Franc Meyer
- Institute of Inorganic Chemistry, University of Göttingen, Tammannstraße 4, 37077, Göttingen, Germany
| | - Oliver S Wenger
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland
| | - Cui Wang
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland
- Department of Biology and Chemistry, Osnabrück University, Barbarastraße 7, 49076, Osnabrück, Germany
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5
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Prakash O, Chábera P, Kaul N, Hlynsson VF, Rosemann NW, Losada IB, Hoang Hai YT, Huang P, Bendix J, Ericsson T, Häggström L, Gupta AK, Strand D, Yartsev A, Lomoth R, Persson P, Wärnmark K. How Rigidity and Conjugation of Bidentate Ligands Affect the Geometry and Photophysics of Iron N-Heterocyclic Complexes: A Comparative Study. Inorg Chem 2024; 63:4461-4473. [PMID: 38421802 PMCID: PMC10934811 DOI: 10.1021/acs.inorgchem.3c03972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 02/07/2024] [Accepted: 02/08/2024] [Indexed: 03/02/2024]
Abstract
Two iron complexes featuring the bidentate, nonconjugated N-heterocyclic carbene (NHC) 1,1'-methylenebis(3-methylimidazol-2-ylidene) (mbmi) ligand, where the two NHC moieties are separated by a methylene bridge, have been synthesized to exploit the combined influence of geometric and electronic effects on the ground- and excited-state properties of homoleptic FeIII-hexa-NHC [Fe(mbmi)3](PF6)3 and heteroleptic FeII-tetra-NHC [Fe(mbmi)2(bpy)](PF6)2 (bpy = 2,2'-bipyridine) complexes. They are compared to the reported FeIII-hexa-NHC [Fe(btz)3](PF6)3 and FeII-tetra-NHC [Fe(btz)2(bpy)](PF6)2 complexes containing the conjugated, bidentate mesoionic NHC ligand 3,3'-dimethyl-1,1'-bis(p-tolyl)-4,4'-bis(1,2,3-triazol-5-ylidene) (btz). The observed geometries of [Fe(mbmi)3](PF6)3 and [Fe(mbmi)2(bpy)](PF6)2 are evaluated through L-Fe-L bond angles and ligand planarity and compared to those of [Fe(btz)3](PF6)3 and [Fe(btz)2(bpy)](PF6)2. The FeII/FeIII redox couples of [Fe(mbmi)3](PF6)3 (-0.38 V) and [Fe(mbmi)2(bpy)](PF6)2 (-0.057 V, both vs Fc+/0) are less reducing than [Fe(btz)3](PF6)3 and [Fe(btz)2(bpy)](PF6)2. The two complexes show intense absorption bands in the visible region: [Fe(mbmi)3](PF6)3 at 502 nm (ligand-to-metal charge transfer, 2LMCT) and [Fe(mbmi)2(bpy)](PF6)2 at 410 and 616 nm (metal-to-ligand charge transfer, 3MLCT). Lifetimes of 57.3 ps (2LMCT) for [Fe(mbmi)3](PF6)3 and 7.6 ps (3MLCT) for [Fe(mbmi)2(bpy)](PF6)2 were probed and are somewhat shorter than those for [Fe(btz)3](PF6)3 and [Fe(btz)2(bpy)](PF6)2. [Fe(mbmi)3](PF6)3 exhibits photoluminescence at 686 nm (2LMCT) in acetonitrile at room temperature with a quantum yield of (1.2 ± 0.1) × 10-4, compared to (3 ± 0.5) × 10-4 for [Fe(btz)3](PF6)3.
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Affiliation(s)
- Om Prakash
- Centre
for Analysis and Synthesis, Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
| | - Pavel Chábera
- Chemical
Physics Division, Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
| | - Nidhi Kaul
- Department
of Chemistry − Ångström Laboratory, Uppsala University, Box
523, SE-751 20 Uppsala, Sweden
| | - Valtýr F. Hlynsson
- Centre
for Analysis and Synthesis, Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
| | - Nils W. Rosemann
- Chemical
Physics Division, Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
| | - Iria Bolaño Losada
- Theoretical
Chemistry Division, Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
| | - Yen Tran Hoang Hai
- Theoretical
Chemistry Division, Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
| | - Ping Huang
- Department
of Chemistry − Ångström Laboratory, Uppsala University, Box
523, SE-751 20 Uppsala, Sweden
| | - Jesper Bendix
- Department
of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
| | - Tore Ericsson
- Department
of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
| | - Lennart Häggström
- Department
of Physics − Ångström Laboratory, Uppsala University, Box 523, SE-751 20 Uppsala, Sweden
| | - Arvind Kumar Gupta
- Centre
for Analysis and Synthesis, Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
| | - Daniel Strand
- Centre
for Analysis and Synthesis, Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
| | - Arkady Yartsev
- Chemical
Physics Division, Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
| | - Reiner Lomoth
- Department
of Chemistry − Ångström Laboratory, Uppsala University, Box
523, SE-751 20 Uppsala, Sweden
| | - Petter Persson
- Theoretical
Chemistry Division, Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
| | - Kenneth Wärnmark
- Centre
for Analysis and Synthesis, Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
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6
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Losada IB, Persson P. Photoredox matching of earth-abundant photosensitizers with hydrogen evolving catalysts by first-principles predictions. J Chem Phys 2024; 160:074302. [PMID: 38375904 DOI: 10.1063/5.0174837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Accepted: 01/09/2024] [Indexed: 02/21/2024] Open
Abstract
Photoredox properties of several earth-abundant light-harvesting transition metal complexes in combination with cobalt-based proton reduction catalysts have been investigated computationally to assess the fundamental viability of different photocatalytic systems of current experimental interest. Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations using several GGA (BP86, BLYP), hybrid-GGA (B3LYP, B3LYP*), hybrid meta-GGA (M06, TPSSh), and range-separated hybrid (ωB97X, CAM-B3LYP) functionals were used to calculate relevant ground and excited state reduction potentials for photosensitizers, catalysts, and sacrificial electron donors. Linear energy correction factors for the DFT/TD-DFT results that provide the best agreement with available experimental reference results were determined in order to provide more accurate predictions. Among the selection of functionals, the B3LYP* and TPSSh sets of correction parameters were determined to give the best redox potentials and excited states energies, ΔEexc, with errors of ∼0.2 eV. Linear corrections for both reduction and oxidation processes significantly improve the predictions for all the redox pairs. In particular, for TPSSh and B3LYP*, the calculated errors decrease by more than 0.5 V against experimental values for catalyst reduction potentials, photosensitizer oxidation potentials, and electron donor oxidation potentials. Energy-corrected TPSSh results were finally used to predict the energetics of complete photocatalytic cycles for the light-driven activation of selected proton reduction cobalt catalysts. These predictions demonstrate the broader usefulness of the adopted approach to systematically predict full photocycle behavior for first-row transition metal photosensitizer-catalyst combinations more broadly.
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Affiliation(s)
- Iria Bolaño Losada
- Division of Computational Chemistry, 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
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7
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Prakash O, Lindh L, Gupta AK, Hoang Hai YT, Kaul N, Chábera P, Lindgren F, Ericsson T, Häggström L, Strand D, Yartsev A, Lomoth R, Persson P, Wärnmark K. Tailoring the Photophysical Properties of a Homoleptic Iron(II) Tetra N-Heterocyclic Carbene Complex by Attaching an Imidazolium Group to the (C ∧N ∧C) Pincer Ligand─A Comparative Study. Inorg Chem 2024; 63:2909-2918. [PMID: 38301278 PMCID: PMC10865346 DOI: 10.1021/acs.inorgchem.3c02890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 01/09/2024] [Accepted: 01/11/2024] [Indexed: 02/03/2024]
Abstract
We here report the synthesis of the homoleptic iron(II) N-heterocyclic carbene (NHC) complex [Fe(miHpbmi)2](PF6)4 (miHpbmi = 4-((3-methyl-1H-imidazolium-1-yl)pyridine-2,6-diyl)bis(3-methylimidazol-2-ylidene)) and its electrochemical and photophysical properties. The introduction of the π-electron-withdrawing 3-methyl-1H-imidazol-3-ium-1-yl group into the NHC ligand framework resulted in stabilization of the metal-to-ligand charge transfer (MLCT) state and destabilization of the metal-centered (MC) states. This resulted in an improved excited-state lifetime of 16 ps compared to the 9 ps for the unsubstituted parent compound [Fe(pbmi)2](PF6)2 (pbmi = (pyridine-2,6-diyl)bis(3-methylimidazol-2-ylidene)) as well as a stronger MLCT absorption band extending more toward the red spectral region. However, compared to the carboxylic acid derivative [Fe(cpbmi)2](PF6)2 (cpbmi = 1,1'-(4-carboxypyridine-2,6-diyl)bis(3-methylimidazol-2-ylidene)), the excited-state lifetime of [Fe(miHpbmi)2](PF6)4 is the same, but both the extinction and the red shift are more pronounced for the former. Hence, this makes [Fe(miHpbmi)2](PF6)4 a promising pH-insensitive analogue of [Fe(cpbmi)2](PF6)2. Finally, the excited-state dynamics of the title compound [Fe(miHpbmi)2](PF6)4 was investigated in solvents with different viscosities, however, showing very little dependency of the depopulation of the excited states on the properties of the solvent used.
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Affiliation(s)
- Om Prakash
- Centre
for Analysis and Synthesis, Department of Chemistry, Lund University, Box 124, Lund SE-22100, Sweden
| | - Linnea Lindh
- Chemical
Physics Division, Department of Chemistry, Lund University, Box 124, Lund SE-22100, Sweden
- Theoretical
Chemistry Division, Department of Chemistry, Lund University, Box 124, Lund SE-22100, Sweden
| | - Arvind Kumar Gupta
- Centre
for Analysis and Synthesis, Department of Chemistry, Lund University, Box 124, Lund SE-22100, Sweden
| | - Yen Tran Hoang Hai
- Theoretical
Chemistry Division, Department of Chemistry, Lund University, Box 124, Lund SE-22100, Sweden
| | - Nidhi Kaul
- Department
of Chemistry—Ångström Laboratory, Uppsala University, Box 523, Uppsala SE-751 20, Sweden
| | - Pavel Chábera
- Chemical
Physics Division, Department of Chemistry, Lund University, Box 124, Lund SE-22100, Sweden
| | - Fredrik Lindgren
- Department
of Chemistry—Ångström Laboratory, Uppsala University, Box 523, Uppsala SE-751 20, Sweden
| | - Tore Ericsson
- Department of Physics—Ångström
Laboratory, Uppsala University, Box 523, Uppsala SE-751
20, Sweden
| | - Lennart Häggström
- Department of Physics—Ångström
Laboratory, Uppsala University, Box 523, Uppsala SE-751
20, Sweden
| | - Daniel Strand
- Centre
for Analysis and Synthesis, Department of Chemistry, Lund University, Box 124, Lund SE-22100, Sweden
| | - Arkady Yartsev
- Chemical
Physics Division, Department of Chemistry, Lund University, Box 124, Lund SE-22100, Sweden
| | - Reiner Lomoth
- Department
of Chemistry—Ångström Laboratory, Uppsala University, Box 523, Uppsala SE-751 20, Sweden
| | - Petter Persson
- Theoretical
Chemistry Division, 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
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8
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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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9
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Shi Y, Li J, Cui C, Wu G, Cheng T. Influence of ligand variation on the deactivation process of metal-to-ligand charge transfer excited states in quadruply bonded dimolybdenum complexes. Phys Chem Chem Phys 2023; 25:32364-32371. [PMID: 37990808 DOI: 10.1039/d3cp03679k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2023]
Abstract
To explore the dynamics of metal-to-ligand charge transfer (MLCT) excited states involving covalently bonded dimetal units, a series of quadruply bonded dimolybdenum (Mo2) complexes, namely, [Mo2]-ph, [Mo2]-naph, and [Mo2]-anth, were synthesized and characterized. Our investigations reveal a non-radiative process associated with the deactivation of the MLCT state into a low-lying dimetal-centered triplet state (3Mo2-δδ*), resulting in the populated MLCT states in these molecular systems exhibiting either extremely weak emission or being non-emissive. The influence of ligand variation on the dynamics of MLCT states was examined using femtosecond transient absorption spectroscopy, with deactivation time constants determined to be 1.9 ps for [Mo2]-ph, 6.5 ps for [Mo2]-naph, and 49 ps for [Mo2]-anth. This electron transfer behaviour follows an inverse energy-gap law, contrary to the general guideline that applies to the decay of the MLCT state back to the electronic ground state. This result offers valuable insights into understanding the photochemical and photophysical properties of covalently bonded dimetal complexes.
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Affiliation(s)
- Yuqing Shi
- School of Chemistry and Chemical Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250353, P. R. China.
| | - Juanjuan Li
- School of Chemistry and Chemical Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250353, P. R. China.
| | - Can Cui
- School of Chemistry and Chemical Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250353, P. R. China.
| | - Guanzhi Wu
- Department of Chemistry, University of Sheffield, Sheffield, S3 7HF, UK
| | - Tao Cheng
- School of Chemistry and Chemical Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250353, P. R. China.
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10
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Johnson CE, Schwarz J, Deegbey M, Prakash O, Sharma K, Huang P, Ericsson T, Häggström L, Bendix J, Gupta AK, Jakubikova E, Wärnmark K, Lomoth R. Ferrous and ferric complexes with cyclometalating N-heterocyclic carbene ligands: a case of dual emission revisited. Chem Sci 2023; 14:10129-10139. [PMID: 37772113 PMCID: PMC10530338 DOI: 10.1039/d3sc02806b] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 08/27/2023] [Indexed: 09/30/2023] Open
Abstract
Iron N-heterocyclic carbene (FeNHC) complexes with long-lived charge transfer states are emerging as a promising class of photoactive materials. We have synthesized [FeII(ImP)2] (ImP = bis(2,6-bis(3-methylimidazol-2-ylidene-1-yl)phenylene)) that combines carbene ligands with cyclometalation for additionally improved ligand field strength. The 9 ps lifetime of its 3MLCT (metal-to-ligand charge transfer) state however reveals no benefit from cyclometalation compared to Fe(ii) complexes with NHC/pyridine or pure NHC ligand sets. In acetonitrile solution, the Fe(ii) complex forms a photoproduct that features emission characteristics (450 nm, 5.1 ns) that were previously attributed to a higher (2MLCT) state of its Fe(iii) analogue [FeIII(ImP)2]+, which led to a claim of dual (MLCT and LMCT) emission. Revisiting the photophysics of [FeIII(ImP)2]+, we confirmed however that higher (2MLCT) states of [FeIII(ImP)2]+ are short-lived (<10 ps) and therefore, in contrast to the previous interpretation, cannot give rise to emission on the nanosecond timescale. Accordingly, pristine [FeIII(ImP)2]+ prepared by us only shows red emission from its lower 2LMCT state (740 nm, 240 ps). The long-lived, higher energy emission previously reported for [FeIII(ImP)2]+ is instead attributed to an impurity, most probably a photoproduct of the Fe(ii) precursor. The previously reported emission quenching on the nanosecond time scale hence does not support any excited state reactivity of [FeIII(ImP)2]+ itself.
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Affiliation(s)
- Catherine Ellen Johnson
- Department of Chemistry -Ångström Laboratory, Uppsala University Box 523 SE-75120 Uppsala Sweden
| | - Jesper Schwarz
- Centre for Analysis and Synthesis, Department of Chemistry, Lund University Box 124 SE-22100 Lund Sweden
| | - Mawuli Deegbey
- Department of Chemistry, North Carolina State University Raleigh North Carolina 27695 USA
| | - Om Prakash
- Centre for Analysis and Synthesis, Department of Chemistry, Lund University Box 124 SE-22100 Lund Sweden
| | - Kumkum Sharma
- Centre for Analysis and Synthesis, Department of Chemistry, Lund University Box 124 SE-22100 Lund Sweden
| | - Ping Huang
- Department of Chemistry -Ångström Laboratory, Uppsala University Box 523 SE-75120 Uppsala Sweden
| | - Tore Ericsson
- Department of Physics - Ångström Laboratory, Uppsala University Box 523 SE-751 20 Uppsala Sweden
| | - Lennart Häggström
- Department of Physics - Ångström Laboratory, Uppsala University Box 523 SE-751 20 Uppsala Sweden
| | - Jesper Bendix
- Department of Chemistry, University of Copenhagen Universitetsparken 5 DK-2100 Copenhagen Denmark
| | - Arvind Kumar Gupta
- Centre for Analysis and Synthesis, Department of Chemistry, Lund University Box 124 SE-22100 Lund Sweden
| | - Elena Jakubikova
- Department of Chemistry, North Carolina State University Raleigh North Carolina 27695 USA
| | - Kenneth Wärnmark
- Centre for Analysis and Synthesis, Department of Chemistry, Lund University Box 124 SE-22100 Lund Sweden
| | - Reiner Lomoth
- Department of Chemistry -Ångström Laboratory, Uppsala University Box 523 SE-75120 Uppsala Sweden
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11
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Steube J, Kruse A, Bokareva OS, Reuter T, Demeshko S, Schoch R, Argüello Cordero MA, Krishna A, Hohloch S, Meyer F, Heinze K, Kühn O, Lochbrunner S, Bauer M. Janus-type emission from a cyclometalated iron(III) complex. Nat Chem 2023; 15:468-474. [PMID: 36849804 PMCID: PMC10070185 DOI: 10.1038/s41557-023-01137-w] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2021] [Accepted: 01/19/2023] [Indexed: 03/01/2023]
Abstract
Although iron is a dream candidate to substitute noble metals in photoactive complexes, realization of emissive and photoactive iron compounds is demanding due to the fast deactivation of their charge-transfer states. Emissive iron compounds are scarce and dual emission has not been observed before. Here we report the FeIII complex [Fe(ImP)2][PF6] (HImP = 1,1'-(1,3-phenylene)bis(3-methyl-1-imidazol-2-ylidene)), showing a Janus-type dual emission from ligand-to-metal charge transfer (LMCT)- and metal-to-ligand charge transfer (MLCT)-dominated states. This behaviour is achieved by a ligand design that combines four N-heterocyclic carbenes with two cyclometalating aryl units. The low-lying π* levels of the cyclometalating units lead to energetically accessible MLCT states that cannot evolve into LMCT states. With a lifetime of 4.6 ns, the strongly reducing and oxidizing MLCT-dominated state can initiate electron transfer reactions, which could constitute a basis for future applications of iron in photoredox catalysis.
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Affiliation(s)
- Jakob Steube
- Institute of Inorganic Chemistry, Paderborn University, Paderborn, Germany
- Center for Sustainable Systems Design, Paderborn University, Paderborn, Germany
| | - Ayla Kruse
- Department of Life, Light and Matter, University of Rostock, Rostock, Germany
- Institute for Physics, University of Rostock, Rostock, Germany
| | - Olga S Bokareva
- Institute for Physics, University of Rostock, Rostock, Germany
- Institute of Physics, University of Kassel, Kassel, Germany
| | - Thomas Reuter
- Department of Chemistry, Johannes Gutenberg University, Mainz, Germany
| | - Serhiy Demeshko
- Institute of Inorganic Chemistry, University of Göttingen, Göttingen, Germany
| | - Roland Schoch
- Institute of Inorganic Chemistry, Paderborn University, Paderborn, Germany
- Center for Sustainable Systems Design, Paderborn University, Paderborn, Germany
| | - Miguel A Argüello Cordero
- Department of Life, Light and Matter, University of Rostock, Rostock, Germany
- Institute for Physics, University of Rostock, Rostock, Germany
| | - Athul Krishna
- Institute of Inorganic Chemistry, Paderborn University, Paderborn, Germany
- Center for Sustainable Systems Design, Paderborn University, Paderborn, Germany
| | - Stephan Hohloch
- Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innsbruck, Austria
| | - Franc Meyer
- Institute of Inorganic Chemistry, University of Göttingen, Göttingen, Germany
| | - Katja Heinze
- Department of Chemistry, Johannes Gutenberg University, Mainz, Germany
| | - Oliver Kühn
- Department of Life, Light and Matter, University of Rostock, Rostock, Germany
- Institute for Physics, University of Rostock, Rostock, Germany
| | - Stefan Lochbrunner
- Department of Life, Light and Matter, University of Rostock, Rostock, Germany
- Institute for Physics, University of Rostock, Rostock, Germany
| | - Matthias Bauer
- Institute of Inorganic Chemistry, Paderborn University, Paderborn, Germany.
- Center for Sustainable Systems Design, Paderborn University, Paderborn, Germany.
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12
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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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13
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Electronic structures and ligand effect on redox potential of iron and cobalt complexes: a computational insight. Struct Chem 2023. [DOI: 10.1007/s11224-022-02119-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
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14
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Zobel JP, Kruse A, Baig O, Lochbrunner S, Bokarev SI, Kühn O, González L, Bokareva OS. Can range-separated functionals be optimally tuned to predict spectra and excited state dynamics in photoactive iron complexes? Chem Sci 2023; 14:1491-1502. [PMID: 36794199 PMCID: PMC9906774 DOI: 10.1039/d2sc05839a] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 12/27/2022] [Indexed: 01/14/2023] Open
Abstract
Density functional theory is an efficient computational tool to investigate photophysical and photochemical processes in transition metal complexes, giving invaluable assistance in interpreting spectroscopic and catalytic experiments. Optimally tuned range-separated functionals are particularly promising, as they were created to address some of the fundamental deficiencies present in approximate exchange-correlation functionals. In this paper, we scrutinize the selection of optimally tuned parameters and its influence on the excited state dynamics, using the example of the iron complex [Fe(cpmp)2]2+ with push-pull ligands. Various tuning strategies are contemplated based on pure self-consistent DFT protocols, as well as on the comparison with experimental spectra and multireference CASPT2 results. The two most promising sets of optimal parameters are then employed to carry out nonadiabatic surface-hopping dynamics simulations. Intriguingly, we find that the two sets lead to very different relaxation pathways and timescales. While the set of optimal parameters from one of the self-consistent DFT protocols predicts the formation of long-lived metal-to-ligand charge transfer triplet states, the set in better agreement with CASPT2 calculations leads to deactivation in the manifold of metal-centered states, in better agreement with the experimental reference data. These results showcase the complexity of iron-complex excited state landscapes and the difficulty of obtaining an unambiguous parametrization of long-range corrected functionals without experimental input.
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Affiliation(s)
- J. Patrick Zobel
- Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währingerstr. 191090 ViennaAustria
| | - Ayla Kruse
- Institute of Physics, University of Rostock, Albert-Einstein-Straße 23-24 18059 Rostock Germany .,Department of Life, Light and Matter, University of Rostock 18051 Rostock Germany
| | - Omar Baig
- Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währingerstr. 19 1090 Vienna Austria
| | - Stefan Lochbrunner
- Institute of Physics, University of Rostock, Albert-Einstein-Straße 23-24 18059 Rostock Germany .,Department of Life, Light and Matter, University of Rostock 18051 Rostock Germany
| | - Sergey I. Bokarev
- Institute of Physics, University of Rostock, Albert-Einstein-Straße 23-2418059 RostockGermany,Chemistry Department, Technical University of Munich, Lichtenbergstr. 4Garching 85748Germany
| | - Oliver Kühn
- Institute of Physics, University of Rostock, Albert-Einstein-Straße 23-24 18059 Rostock Germany
| | - Leticia González
- Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währingerstr. 19 1090 Vienna Austria
| | - Olga S. Bokareva
- Institute of Physics, University of Rostock, Albert-Einstein-Straße 23-2418059 RostockGermany,Institute of Physics, University of KasselHeinrich-Plett-Straße 4034132 KasselGermany
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15
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Curtin GM, Jakubikova E. Extended π-Conjugated Ligands Tune Excited-State Energies of Iron(II) Polypyridine Dyes. Inorg Chem 2022; 61:18850-18860. [DOI: 10.1021/acs.inorgchem.2c02362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Gregory M. Curtin
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Elena Jakubikova
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
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16
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Moll J, Naumann R, Sorge L, Förster C, Gessner N, Burkhardt L, Ugur N, Nuernberger P, Seidel W, Ramanan C, Bauer M, Heinze K. Pseudo-Octahedral Iron(II) Complexes with Near-Degenerate Charge Transfer and Ligand Field States at the Franck-Condon Geometry. Chemistry 2022; 28:e202201858. [PMID: 35862259 DOI: 10.1002/chem.202201858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Indexed: 01/07/2023]
Abstract
Increasing the metal-to-ligand charge transfer (MLCT) excited state lifetime of polypyridine iron(II) complexes can be achieved by lowering the ligand's π* orbital energy and by increasing the ligand field splitting. In the homo- and heteroleptic complexes [Fe(cpmp)2 ]2+ (12+ ) and [Fe(cpmp)(ddpd)]2+ (22+ ) with the tridentate ligands 6,2''-carboxypyridyl-2,2'-methylamine-pyridyl-pyridine (cpmp) and N,N'-dimethyl-N,N'-di-pyridin-2-ylpyridine-2,6-diamine (ddpd) two or one dipyridyl ketone moieties provide low energy π* acceptor orbitals. A good metal-ligand orbital overlap to increase the ligand field splitting is achieved by optimizing the octahedricity through CO and NMe units between the coordinating pyridines which enable the formation of six-membered chelate rings. The push-pull ligand cpmp provides intra-ligand and ligand-to-ligand charge transfer (ILCT, LL'CT) excited states in addition to MLCT excited states. Ground and excited state properties of 12+ and 22+ were accessed by X-ray diffraction analyses, resonance Raman spectroscopy, (spectro)electrochemistry, EPR spectroscopy, X-ray emission spectroscopy, static and time-resolved IR and UV/Vis/NIR absorption spectroscopy as well as quantum chemical calculations.
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Affiliation(s)
- Johannes Moll
- Department of Chemistry, Johannes Gutenberg University of Mainz, Duesbergweg 10-14, 55128, Mainz, Germany
| | - Robert Naumann
- Department of Chemistry, Johannes Gutenberg University of Mainz, Duesbergweg 10-14, 55128, Mainz, Germany
| | - Lukas Sorge
- Department of Chemistry, Johannes Gutenberg University of Mainz, Duesbergweg 10-14, 55128, Mainz, Germany
| | - Christoph Förster
- Department of Chemistry, Johannes Gutenberg University of Mainz, Duesbergweg 10-14, 55128, Mainz, Germany
| | - Niklas Gessner
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Lukas Burkhardt
- Department of Chemistry, University of Paderborn, Warburger Str. 100, 33098, Paderborn, Germany
| | - Naz Ugur
- Max-Planck-Institute for Polymer Research, Mainz, Germany
| | - Patrick Nuernberger
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Wolfram Seidel
- Institute of Chemistry, University of Rostock, Albert-Einstein-Straße 3a, 18059, Rostock, Germany
| | - Charusheela Ramanan
- Max-Planck-Institute for Polymer Research, Mainz, Germany
- Department of Physics and Astronomy, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Matthias Bauer
- Department of Chemistry, University of Paderborn, Warburger Str. 100, 33098, Paderborn, Germany
| | - Katja Heinze
- Department of Chemistry, Johannes Gutenberg University of Mainz, Duesbergweg 10-14, 55128, Mainz, Germany
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17
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Schmid L, Chábera P, Rüter I, Prescimone A, Meyer F, Yartsev A, Persson P, Wenger OS. Borylation in the Second Coordination Sphere of Fe II Cyanido Complexes and Its Impact on Their Electronic Structures and Excited-State Dynamics. Inorg Chem 2022; 61:15853-15863. [PMID: 36167335 PMCID: PMC9554916 DOI: 10.1021/acs.inorgchem.2c01667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
![]()
Second coordination sphere interactions
of cyanido complexes with hydrogen-bonding solvents and Lewis acids
are known to influence their electronic structures, whereby the non-labile
attachment of B(C6F5)3 resulted in
several particularly interesting new compounds lately. Here, we investigate
the effects of borylation on the properties of two FeII cyanido complexes in a systematic manner by comparing five different
compounds and using a range of experimental techniques. Electrochemical
measurements indicate that borylation entails a stabilization of the
FeII-based t2g-like orbitals by up to 1.65 eV,
and this finding was confirmed by Mössbauer spectroscopy. This
change in the electronic structure has a profound impact on the UV–vis
absorption properties of the borylated complexes compared to the non-borylated
ones, shifting their metal-to-ligand charge transfer (MLCT) absorption
bands over a wide range. Ultrafast UV–vis transient absorption
spectroscopy provides insight into how borylation affects the excited-state
dynamics. The lowest metal-centered (MC) excited states become shorter-lived
in the borylated complexes compared to their cyanido analogues by
a factor of ∼10, possibly due to changes in outer-sphere reorganization
energies associated with their decay to the electronic ground state
as a result of B(C6F5)3 attachment
at the cyanido N lone pair. Borylation
in the second coordination sphere of two well-known
FeII cyanido complexes leads to isocyanoborato complexes.
The effects of borylation on their electronic structure and photophysical
properties are thoroughly investigated with a range of experimental
techniques.
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Affiliation(s)
- Lucius Schmid
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
| | - Pavel Chábera
- Department of Chemical Physics, Lund University, P.O. Box 12 4, 22100 Lund, Sweden
| | - Isabelle Rüter
- Institute of Inorganic Chemistry, University of Göttingen, Tammannstrasse 4, D-37077 Göttingen, Germany
| | - Alessandro Prescimone
- Department of Chemistry, University of Basel, BPR 1096, Mattenstrasse 24a, 4058 Basel, Switzerland
| | - Franc Meyer
- Institute of Inorganic Chemistry, University of Göttingen, Tammannstrasse 4, D-37077 Göttingen, Germany
| | - Arkady Yartsev
- Department of Chemical Physics, Lund University, P.O. Box 12 4, 22100 Lund, Sweden
| | - Petter Persson
- Theoretical Chemistry Division, Lund University, P.O. Box 124, 22100 Lund, Sweden
| | - Oliver S Wenger
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
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18
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Ossinger S, Prescimone A, Häussinger D, Wenger OS. Manganese(I) Complex with Monodentate Arylisocyanide Ligands Shows Photodissociation Instead of Luminescence. Inorg Chem 2022; 61:10533-10547. [PMID: 35768069 PMCID: PMC9377510 DOI: 10.1021/acs.inorgchem.2c01438] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Recently reported manganese(I) complexes with chelating arylisocyanide ligands exhibit luminescent metal-to-ligand charge-transfer (MLCT) excited states, similar to ruthenium(II) polypyridine complexes with the same d6 valence electron configuration used for many different applications in photophysics and photochemistry. However, chelating arylisocyanide ligands require substantial synthetic effort, and therefore it seemed attractive to explore the possibility of using more readily accessible monodentate arylisocyanides instead. Here, we synthesized the new Mn(I) complex [Mn(CNdippPhOMe2)6]PF6 with the known ligand CNdippPhOMe2 = 4-(3,5-dimethoxyphenyl)-2,6-diisopropylphenylisocyanide. This complex was investigated by NMR spectroscopy, single-crystal structure analysis, high-resolution electrospray ionization mass spectrometry (HR-ESI-MS) measurements, IR spectroscopy supported by density functional theory (DFT) calculations, cyclic voltammetry, and time-resolved as well as steady-state UV-vis absorption spectroscopy. The key finding is that the new Mn(I) complex is nonluminescent and instead undergoes arylisocyanide ligand loss during continuous visible laser irradiation into ligand-centered and charge-transfer absorption bands, presumably owed to the population of dissociative d-d excited states. Thus, it seems that chelating bi- or tridentate binding motifs are essential for obtaining emissive MLCT excited states in manganese(I) arylisocyanides. Our work contributes to understanding the basic properties of photoactive first-row transition metal complexes and could help advance the search for alternatives to precious metal-based luminophores, photocatalysts, and sensors.
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Affiliation(s)
- Sascha Ossinger
- Department
of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
| | - Alessandro Prescimone
- Department
of Chemistry, University of Basel, Mattenstrasse 24a, 4058 Basel, Switzerland
| | - Daniel Häussinger
- 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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19
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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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20
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Moll J, Förster C, König A, Carrella LM, Wagner M, Panthöfer M, Möller A, Rentschler E, Heinze K. Panchromatic Absorption and Oxidation of an Iron(II) Spin Crossover Complex. Inorg Chem 2022; 61:1659-1671. [PMID: 35020386 DOI: 10.1021/acs.inorgchem.1c03511] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In order to expand and exploit the useful properties of d6-iron(II) and d5-iron(III) complexes in potential magnetic, photophysical, or magnetooptical applications, crucial ligand-controlled parameters are the ligand field strength in a given coordination mode and the availability of suitable metal and ligand frontier orbitals for charge-transfer processes. The push-pull ligand 2,6-diguanidylpyridine (dgpy) features low-energy π* orbitals at the pyridine site and strongly electron-donating guanidinyl donors combined with the ability to form six-membered chelate rings for optimal metal-ligand orbital overlap. The electronic ground states of the pseudo-octahedral d6- and d5-complexes mer-[Fe(dgpy)2]2+, cis-fac-[Fe(dgpy)2]2+, and mer-[Fe(dgpy)2]3+ as well as their charge-transfer (CT) and metal-centered (MC) excited states are probed by variable temperature UV/vis absorption, NMR, EPR, and Mössbauer spectroscopy, magnetic susceptibility measurements at variable temperature as well as quantum chemical calculations.
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Affiliation(s)
- Johannes Moll
- Department of Chemistry, Johannes Gutenberg University, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Christoph Förster
- Department of Chemistry, Johannes Gutenberg University, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Alexandra König
- Department of Chemistry, Johannes Gutenberg University, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Luca M Carrella
- Department of Chemistry, Johannes Gutenberg University, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Manfred Wagner
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Martin Panthöfer
- Department of Chemistry, Johannes Gutenberg University, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Angela Möller
- Department of Chemistry, Johannes Gutenberg University, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Eva Rentschler
- Department of Chemistry, Johannes Gutenberg University, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Katja Heinze
- Department of Chemistry, Johannes Gutenberg University, Duesbergweg 10-14, 55128 Mainz, Germany
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21
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Kunnus K, Guo M, Biasin E, Larsen CB, Titus CJ, Lee SJ, Nordlund D, Cordones AA, Uhlig J, Gaffney KJ. Quantifying the Steric Effect on Metal-Ligand Bonding in Fe Carbene Photosensitizers with Fe 2p3d Resonant Inelastic X-ray Scattering. Inorg Chem 2022; 61:1961-1972. [PMID: 35029978 DOI: 10.1021/acs.inorgchem.1c03124] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Understanding the electronic structure and chemical bonding of transition metal complexes is important for improving the function of molecular photosensitizers and catalysts. We have utilized X-ray absorption spectroscopy (XAS) and resonant inelastic X-ray scattering (RIXS) at the Fe L3 edge to investigate the electronic structure of two Fe N-heterocyclic carbene complexes with similar chemical structures but different steric effects and contrasting excited-state dynamics: [Fe(bmip)2]2+ and [Fe(btbip)2]2+, bmip = 2,6-bis(3-methyl-imidazole-1-ylidine)pyridine and btbip = 2,6-bis(3-tert-butyl-imidazole-1-ylidene)pyridine. In combination with charge transfer multiplet and ab initio calculations, we quantified how changes in Fe-carbene bond length due to steric effects modify the metal-ligand bonding, including σ/π donation and π back-donation. We find that σ donation is significantly stronger in [Fe(bmip)2]2+, whereas the π back-donation is similar in both complexes. The resulting stronger ligand field and nephelauxetic effect in [Fe(bmip)2]2+ lead to approximately 1 eV destabilization of the quintet metal-centered 5T2g excited state compared to [Fe(btbip)2]2+, providing an explanation for the absence of a photoinduced 5T2g population and a longer metal-to-ligand charge-transfer excited-state lifetime in [Fe(bmip)2]2+. This work demonstrates how combined modeling of XAS and RIXS spectra can be utilized to understand the electronic structure of transition metal complexes governed by correlated electrons and donation/back-donation interactions.
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Affiliation(s)
- Kristjan Kunnus
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, United States.,Institute of Physics, University of Tartu, W. Ostwaldi 1, Tartu EE-50411, Estonia
| | - Meiyuan Guo
- Department of Chemistry, Lund University, Lund SE-22100, Sweden
| | - Elisa Biasin
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, United States
| | - Christopher B Larsen
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, United States
| | - Charles J Titus
- Department of Physics, Stanford University, Stanford, California 94305, United States
| | - Sang Jun Lee
- SSRL, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Dennis Nordlund
- SSRL, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Amy A Cordones
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, United States
| | - Jens Uhlig
- Department of Chemistry, Lund University, Lund SE-22100, Sweden
| | - Kelly J Gaffney
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, United States
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22
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Dierks P, Vukadinovic Y, Bauer M. Photoactive iron complexes: more sustainable, but still a challenge. Inorg Chem Front 2022. [DOI: 10.1039/d1qi01112j] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
With the “Criticality Score” used as a benchmark for sustainability – potentials, strategies and challenges are discussed to replace noble metal compounds in photosensitizers by the sustainable alternative iron.
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Affiliation(s)
- Philipp Dierks
- Faculty of Science, Chemistry Department and Center for Sustainable Systems Design, Paderborn University, 33098 Paderborn, Germany
| | - Yannik Vukadinovic
- Faculty of Science, Chemistry Department and Center for Sustainable Systems Design, Paderborn University, 33098 Paderborn, Germany
| | - Matthias Bauer
- Faculty of Science, Chemistry Department and Center for Sustainable Systems Design, Paderborn University, 33098 Paderborn, Germany
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23
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Magra K, Francés‐Monerris A, Cebrián C, Monari A, Haacke S, Gros PC. Bidentate Pyridyl‐NHC Ligands: Synthesis, Ground and Excited State Properties of Their Iron(II) Complexes and the Role of the fac/mer Isomerism. Eur J Inorg Chem 2021. [DOI: 10.1002/ejic.202100818] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Kévin Magra
- Université de Lorraine, CNRS, L2CM 57000 Metz France
| | | | | | - Antonio Monari
- Université de Lorraine, CNRS, LPCT 54000 Nancy France
- Université de de Paris and CNRS, Itodys 75006 Paris France
| | - Stefan Haacke
- Université de Strasbourg, CNRS, IPCMS 67000 Strasbourg France
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24
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Lindh L, Gordivska O, Persson S, Michaels H, Fan H, Chábera P, Rosemann NW, Gupta AK, Benesperi I, Uhlig J, Prakash O, Sheibani E, Kjaer KS, Boschloo G, Yartsev A, Freitag M, Lomoth R, Persson P, Wärnmark K. Dye-sensitized solar cells based on Fe N-heterocyclic carbene photosensitizers with improved rod-like push-pull functionality. Chem Sci 2021; 12:16035-16053. [PMID: 35024126 PMCID: PMC8672732 DOI: 10.1039/d1sc02963k] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 11/11/2021] [Indexed: 11/21/2022] Open
Abstract
A new generation of octahedral iron(ii)–N-heterocyclic carbene (NHC) complexes, employing different tridentate C^N^C ligands, has been designed and synthesized as earth-abundant photosensitizers for dye sensitized solar cells (DSSCs) and related solar energy conversion applications. This work introduces a linearly aligned push–pull design principle that reaches from the ligand having nitrogen-based electron donors, over the Fe(ii) centre, to the ligand having an electron withdrawing carboxylic acid anchor group. A combination of spectroscopy, electrochemistry, and quantum chemical calculations demonstrate the improved molecular excited state properties in terms of a broader absorption spectrum compared to the reference complex, as well as directional charge-transfer displacement of the lowest excited state towards the semiconductor substrate in accordance with the push–pull design. Prototype DSSCs based on one of the new Fe NHC photosensitizers demonstrate a power conversion efficiency exceeding 1% already for a basic DSSC set-up using only the I−/I3− redox mediator and standard operating conditions, outcompeting the corresponding DSSC based on the homoleptic reference complex. Transient photovoltage measurements confirmed that adding the co-sensitizer chenodeoxycholic acid helped in improving the efficiency by increasing the electron lifetime in TiO2. Time-resolved spectroscopy revealed spectral signatures for successful ultrafast (<100 fs) interfacial electron injection from the heteroleptic dyes to TiO2. However, an ultrafast recombination process results in undesirable fast charge recombination from TiO2 back to the oxidized dye, leaving only 5–10% of the initially excited dyes available to contribute to a current in the DSSC. On slower timescales, time-resolved spectroscopy also found that the recombination dynamics (longer than 40 μs) were significantly slower than the regeneration of the oxidized dye by the redox mediator (6–8 μs). Therefore it is the ultrafast recombination down to fs-timescales, between the oxidized dye and the injected electron, that remains as one of the main bottlenecks to be targeted for achieving further improved solar energy conversion efficiencies in future work. Iron-based photosensitizers for dye-sensitized solar cells with a rod-like push–pull design. Solar cell performance was limited by ultrafast (sub-ps) recombination, but yielded better performance than the homoleptic parent photosensitizer.![]()
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Affiliation(s)
- Linnea Lindh
- Chemical Physics Division, Department of Chemistry, Lund University Box 124 SE-22100 Lund Sweden.,Theoretical Chemistry Division, Department of Chemistry, Lund University Box 124 SE-22100 Lund Sweden
| | - Olga Gordivska
- Centre for Analysis and Synthesis, Department of Chemistry, Lund University Box 124 SE-22100 Lund Sweden
| | - Samuel Persson
- Centre for Analysis and Synthesis, Department of Chemistry, Lund University Box 124 SE-22100 Lund Sweden
| | - Hannes Michaels
- Department of Chemistry - Angstrom Laboratory, Uppsala University Box 523 SE-75120 Uppsala Sweden .,School of Natural and Environmental Science, Newcastle University Bedson Building NE1 7RU Newcastle upon Tyne UK
| | - Hao Fan
- Centre for Analysis and Synthesis, Department of Chemistry, Lund University Box 124 SE-22100 Lund Sweden
| | - Pavel Chábera
- Chemical Physics Division, Department of Chemistry, Lund University Box 124 SE-22100 Lund Sweden
| | - Nils W Rosemann
- Chemical Physics Division, Department of Chemistry, Lund University Box 124 SE-22100 Lund Sweden.,Centre for Analysis and Synthesis, Department of Chemistry, Lund University Box 124 SE-22100 Lund Sweden
| | - Arvind Kumar Gupta
- Centre for Analysis and Synthesis, Department of Chemistry, Lund University Box 124 SE-22100 Lund Sweden
| | - Iacopo Benesperi
- Centre for Analysis and Synthesis, Department of Chemistry, Lund University Box 124 SE-22100 Lund Sweden .,School of Natural and Environmental Science, Newcastle University Bedson Building NE1 7RU Newcastle upon Tyne UK
| | - Jens Uhlig
- Chemical Physics Division, Department of Chemistry, Lund University Box 124 SE-22100 Lund Sweden
| | - Om Prakash
- Centre for Analysis and Synthesis, Department of Chemistry, Lund University Box 124 SE-22100 Lund Sweden
| | - Esmaeil Sheibani
- Centre for Analysis and Synthesis, Department of Chemistry, Lund University Box 124 SE-22100 Lund Sweden
| | - Kasper S Kjaer
- Chemical Physics Division, Department of Chemistry, Lund University Box 124 SE-22100 Lund Sweden
| | - Gerrit Boschloo
- Department of Chemistry - Angstrom Laboratory, Uppsala University Box 523 SE-75120 Uppsala Sweden
| | - Arkady Yartsev
- Chemical Physics Division, Department of Chemistry, Lund University Box 124 SE-22100 Lund Sweden
| | - Marina Freitag
- Department of Chemistry - Angstrom Laboratory, Uppsala University Box 523 SE-75120 Uppsala Sweden .,School of Natural and Environmental Science, Newcastle University Bedson Building NE1 7RU Newcastle upon Tyne UK
| | - Reiner Lomoth
- Department of Chemistry - Angstrom Laboratory, Uppsala University Box 523 SE-75120 Uppsala Sweden
| | - Petter Persson
- Theoretical Chemistry Division, Department of Chemistry, Lund University Box 124 SE-22100 Lund Sweden
| | - Kenneth Wärnmark
- Centre for Analysis and Synthesis, Department of Chemistry, Lund University Box 124 SE-22100 Lund Sweden
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25
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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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26
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Wegeberg C, Häussinger D, Wenger OS. Pyrene-Decoration of a Chromium(0) Tris(diisocyanide) Enhances Excited State Delocalization: A Strategy to Improve the Photoluminescence of 3d 6 Metal Complexes. J Am Chem Soc 2021; 143:15800-15811. [PMID: 34516734 DOI: 10.1021/jacs.1c07345] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
There is a long-standing interest in iron(II) complexes that emit from metal-to-ligand charge transfer (MLCT) excited states, analogous to ruthenium(II) polypyridines. The 3d6 electrons of iron(II) are exposed to a relatively weak ligand field, rendering nonradiative relaxation of MLCT states via metal-centered excited states undesirably efficient. For isoelectronic chromium(0), chelating diisocyanide ligands recently provided access to very weak MLCT emission in solution at room temperature. Here, we present a concept that boosts the luminescence quantum yield of a chromium(0) isocyanide complex by nearly 2 orders of magnitude, accompanied by a significant increase of the MLCT lifetime. Pyrene units in the diisocyanide ligand backbone lead to an enlarged π-conjugation system and to a strongly delocalized MLCT state, from which nonradiative relaxation is less dominant despite a sizable redshift of the emission. While the pyrene moiety is electronically coupled to the core of the chromium(0) complex in the excited state, UV-vis absorption and 2D NMR spectroscopy show that this is not the case in the ground state. Luminescence lifetimes and quantum yields for our pyrenyl-decorated chromium(0) complex exhibit an unusual bell-shaped dependence on solvent polarity, indicative of two counteracting effects governing the MLCT deactivation. These two effects are identified as predominant deactivation either through an energetically nearby lying metal-centered state in the most apolar solvents, or alternatively via direct nonradiative relaxation to the ground state following the energy gap law in more polar solvents. This is the first example of a 3d6 MLCT emitter to benefit from an increased π-conjugation network.
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Affiliation(s)
- Christina Wegeberg
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
| | - Daniel Häussinger
- 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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27
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Reuter T, Kruse A, Schoch R, Lochbrunner S, Bauer M, Heinze K. Higher MLCT lifetime of carbene iron(II) complexes by chelate ring expansion. Chem Commun (Camb) 2021; 57:7541-7544. [PMID: 34240092 DOI: 10.1039/d1cc02173g] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Combining strong σ-donating N-heterocyclic carbene ligands and π-accepting pyridine ligands with a high octahedricity in rigid iron(ii) complexes increases the 3MLCT lifetime from 0.15 ps in the prototypical [Fe(tpy)2]2+ complex to 9.2 ps in [Fe(dpmi)2]2+12+. The tripodal CNN ligand dpmi (di(pyridine-2-yl)(3-methylimidazol-2-yl)methane) forms six-membered chelate rings with the iron(ii) centre leading to close to 90° bite angles and enhanced iron-ligand orbital overlap.
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Affiliation(s)
- Thomas Reuter
- Department of Chemistry, Johannes Gutenberg University of Mainz, Duesbergweg 10-14, Mainz 55128, Germany.
| | - Ayla Kruse
- Institute for Physics and Department of Life, Light and Matter, University of Rostock, Rostock 18051, Germany
| | - Roland Schoch
- Faculty of Science, Chemistry Department and Centre for Sustainable Systems Design, Paderborn University, Paderborn 33098, Germany
| | - Stefan Lochbrunner
- Institute for Physics and Department of Life, Light and Matter, University of Rostock, Rostock 18051, Germany
| | - Matthias Bauer
- Faculty of Science, Chemistry Department and Centre for Sustainable Systems Design, Paderborn University, Paderborn 33098, Germany
| | - Katja Heinze
- Department of Chemistry, Johannes Gutenberg University of Mainz, Duesbergweg 10-14, Mainz 55128, Germany.
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28
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Dierks P, Kruse A, Bokareva OS, Al-Marri MJ, Kalmbach J, Baltrun M, Neuba A, Schoch R, Hohloch S, Heinze K, Seitz M, Kühn O, Lochbrunner S, Bauer M. Distinct photodynamics of κ-N and κ-C pseudoisomeric iron(II) complexes. Chem Commun (Camb) 2021; 57:6640-6643. [PMID: 34126627 DOI: 10.1039/d1cc01716k] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Two closely related FeII complexes with 2,6-bis(1-ethyl-1H-1,2,3-triazol-4yl)pyridine and 2,6-bis(1,2,3-triazol-5-ylidene)pyridine ligands are presented to gain new insights into the photophysics of bis(tridentate) iron(ii) complexes. The [Fe(N^N^N)2]2+ pseudoisomer sensitizes singlet oxygen through a MC state with nanosecond lifetime after MLCT excitation, while the bis(tridentate) [Fe(C^N^C)2]2+ pseudoisomer possesses a similar 3MLCT lifetime as the tris(bidentate) [Fe(C^C)2(N^N)]2+ complexes with four mesoionic carbenes.
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Affiliation(s)
- Philipp Dierks
- Faculty of Science, Chemistry Department and Centre for Sustainable Systems Design, Paderborn University, 33098 Paderborn, Germany.
| | - Ayla Kruse
- Institute of Physics and Department of Life, Light and Matter, University of Rostock, 18051 Rostock, Germany
| | - Olga S Bokareva
- Institute of Physics and Department of Life, Light and Matter, University of Rostock, 18051 Rostock, Germany and Department of Physical Chemistry, Kazan Federal University, 420008 Kazan, Russia
| | - Mohammed J Al-Marri
- Institute of Physics and Department of Life, Light and Matter, University of Rostock, 18051 Rostock, Germany and College of Engineering, Qatar University, P.O. Box 2713, Doha, Qatar
| | - Jens Kalmbach
- Institute of Inorganic Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
| | - Marc Baltrun
- Faculty of Science, Chemistry Department and Centre for Sustainable Systems Design, Paderborn University, 33098 Paderborn, Germany.
| | - Adam Neuba
- Faculty of Science, Chemistry Department and Centre for Sustainable Systems Design, Paderborn University, 33098 Paderborn, Germany.
| | - Roland Schoch
- Faculty of Science, Chemistry Department and Centre for Sustainable Systems Design, Paderborn University, 33098 Paderborn, Germany.
| | - Stephan Hohloch
- University of Innsbruck, Faculty of Chemistry and Pharmacy, Institute for General, Inorganic and Theoretical Chemistry, Innrain 80-82, Innsbruck 6020, Austria
| | - Katja Heinze
- Department of Chemistry, Johannes Gutenberg, University of Mainz, 55128 Mainz, Germany
| | - Michael Seitz
- Institute of Inorganic Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
| | - Oliver Kühn
- Institute of Physics and Department of Life, Light and Matter, University of Rostock, 18051 Rostock, Germany
| | - Stefan Lochbrunner
- Institute of Physics and Department of Life, Light and Matter, University of Rostock, 18051 Rostock, Germany
| | - Matthias Bauer
- Faculty of Science, Chemistry Department and Centre for Sustainable Systems Design, Paderborn University, 33098 Paderborn, Germany.
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29
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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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30
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Darari M, Francés-Monerris A, Marekha B, Doudouh A, Wenger E, Monari A, Haacke S, Gros PC. Towards Iron(II) Complexes with Octahedral Geometry: Synthesis, Structure and Photophysical Properties. Molecules 2020; 25:E5991. [PMID: 33348914 PMCID: PMC7767130 DOI: 10.3390/molecules25245991] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 12/11/2020] [Accepted: 12/14/2020] [Indexed: 12/13/2022] Open
Abstract
The control of ligand-field splitting in iron (II) complexes is critical to slow down the metal-to-ligand charge transfer (MLCT)-excited states deactivation pathways. The gap between the metal-centered states is maximal when the coordination sphere of the complex approaches an ideal octahedral geometry. Two new iron(II) complexes (C1 and C2), prepared from pyridylNHC and pyridylquinoline type ligands, respectively, have a near-perfect octahedral coordination of the metal. The photophysics of the complexes have been further investigated by means of ultrafast spectroscopy and TD-DFT modeling. For C1, it is shown that-despite the geometrical improvement-the excited state deactivation is faster than for the parent pseudo-octahedral C0 complex. This unexpected result is due to the increased ligand flexibility in C1 that lowers the energetic barrier for the relaxation of 3MLCT into the 3MC state. For C2, the effect of the increased ligand field is not strong enough to close the prominent deactivation channel into the metal-centered quintet state, as for other Fe-polypyridine complexes.
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Affiliation(s)
- Mohamed Darari
- Université de Lorraine, CNRS, L2CM, F-54000 Nancy, France;
| | - Antonio Francés-Monerris
- Université de Lorraine, CNRS, LPCT, F-54000 Nancy, France; (A.F.-M.); (A.M.)
- Departament de Química Física, Universitat de València, 46100 Burjassot, Spain
| | - Bogdan Marekha
- Max-Planck-Institute for Medical Research, 69120 Heidelberg, Germany;
| | - Abdelatif Doudouh
- Université de Lorraine, CNRS, CRM2, F-54000 Nancy, France; (A.D.); (E.W.)
| | - Emmanuel Wenger
- Université de Lorraine, CNRS, CRM2, F-54000 Nancy, France; (A.D.); (E.W.)
| | - Antonio Monari
- Université de Lorraine, CNRS, LPCT, F-54000 Nancy, France; (A.F.-M.); (A.M.)
| | - Stefan Haacke
- Université de Strasbourg, CNRS, IPCMS, F-67034 Strasbourg, France;
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31
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Sárosiné Szemes D, Keszthelyi T, Papp M, Varga L, Vankó G. Quantum-chemistry-aided ligand engineering for potential molecular switches: changing barriers to tune excited state lifetimes. Chem Commun (Camb) 2020; 56:11831-11834. [PMID: 33021253 DOI: 10.1039/d0cc04467a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Substitution of terpyridine at the 4' position with electron withdrawing and donating groups is used to tune the quintet lifetime of its iron(ii) complex. DFT calculations suggest that the energy barrier between the quintet and singlet states can be altered significantly upon substitution, inducing a large variation of the lifetime of the photoexcited quintet state. This prediction was experimentally verified by transient optical absorption spectroscopy and good agreement with the trend expected from the calculations was found. This demonstrates that the potential energy landscape can indeed be rationally tailored by relevant modifications based on DFT predictions. This result should pave the way to advancing efficient theory-based ligand engineering of functional molecules to a wide range of applications.
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32
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Dierks P, Päpcke A, Bokareva OS, Altenburger B, Reuter T, Heinze K, Kühn O, Lochbrunner S, Bauer M. Ground- and Excited-State Properties of Iron(II) Complexes Linked to Organic Chromophores. Inorg Chem 2020; 59:14746-14761. [PMID: 32935979 DOI: 10.1021/acs.inorgchem.0c02039] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Two new bichromophoric complexes, [Fe(bim-ant)2]2+ and [Fe(bim-pyr)2]2+ ([H2-bim]2+ = 1,1'-(pyridine-2,6-diyl)bis(3-methyl-1H-imidazol-3-ium); ant = 9-anthracenyl; pyr = 1-pyrenyl), are investigated to explore the possibility of tuning the excited-state behavior in photoactive iron(II) complexes to design substitutes for noble-metal compounds. The ground-state properties of both complexes are characterized thoroughly by electrochemical methods and optical absorption spectroscopy, complemented by time-dependent density functional theory calculations. The excited states are investigated by static and time-resolved luminescence and femtosecond transient absorption spectroscopy. Both complexes exhibit room temperature luminescence, which originates from singlet states dominated by the chromophore (1Chrom). In the cationic pro-ligands and in the iron(II) complexes, the emission is shifted to red by up to 110 nm (5780 cm-1). This offers the possibility of tuning the organic chromophore emission by metal-ion coordination. The fluorescence lifetimes of the complexes are in the nanosecond range, while triplet metal-to-ligand charge-transfer (3MLCT) lifetimes are around 14 ps. An antenna effect as in ruthenium(II) polypyridine complexes connected to an organic chromophore is found in the form of an internal conversion within 3.4 ns from the 1Chrom to the 1MLCT states. Because no singlet oxygen forms from triplet oxygen in the presence of the iron(II) complexes and light, efficient intersystem crossing to the triplet state of the organic chromophore (3Chrom) is not promoted in the iron(II) complexes.
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Affiliation(s)
- Philipp Dierks
- Faculty of Science, Chemistry Department and Center for Sustainable Systems Design, Paderborn University, Warburger Strasse 100, 33098 Paderborn, Germany
| | - Ayla Päpcke
- Institute of Physics, University of Rostock, Albert-Einstein-Strasse 23-24, 18059 Rostock, Germany.,Department of Life, Light and Matter, University of Rostock, 18051 Rostock, Germany
| | - Olga S Bokareva
- Institute of Physics, University of Rostock, Albert-Einstein-Strasse 23-24, 18059 Rostock, Germany.,Department of Physical Chemistry, Kazan Federal University, Kremlevskaya Strasse 18, 420008, Kazan, Russia
| | - Björn Altenburger
- Institute of Physics, University of Rostock, Albert-Einstein-Strasse 23-24, 18059 Rostock, Germany.,Department of Physics, Chalmers University of Technology, Fysikgränd 3, SE-412 96 Göteborg, Sweden
| | - Thomas Reuter
- Department of Chemistry, Johannes Gutenberg University of Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Katja Heinze
- Department of Chemistry, Johannes Gutenberg University of Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Oliver Kühn
- Institute of Physics, University of Rostock, Albert-Einstein-Strasse 23-24, 18059 Rostock, Germany.,Department of Life, Light and Matter, University of Rostock, 18051 Rostock, Germany
| | - Stefan Lochbrunner
- Institute of Physics, University of Rostock, Albert-Einstein-Strasse 23-24, 18059 Rostock, Germany.,Department of Life, Light and Matter, University of Rostock, 18051 Rostock, Germany
| | - Matthias Bauer
- Faculty of Science, Chemistry Department and Center for Sustainable Systems Design, Paderborn University, Warburger Strasse 100, 33098 Paderborn, Germany
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33
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Electronic structure and photophysics of a supermolecular iron complex having a long MLCT-state lifetime and panchromatic absorption. Proc Natl Acad Sci U S A 2020; 117:20430-20437. [PMID: 32788361 PMCID: PMC7456135 DOI: 10.1073/pnas.2009996117] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The main hurdle that prevents earth-abundant iron-based complexes from replacing environmentally unfriendly and expensive heavy metal [e.g., Ru(II), Os(II), Ir(III)] complexes in solar-energy conversion applications is the typical ultrashort (femtosecond timescale) charge-transfer state lifetime of Fe(II) chromophores. We provide a design roadmap to a generation of efficient iron-based photosensitizers and present an Fe(II) complex archetype, FeNHCPZn, which features a profoundly extended metal-to-ligand charge-transfer (3MLCT) lifetime and a large transition-dipole moment difference between its ground and metal-to-ligand charge-transfer states. This supermolecular design promotes superior visible photon harvesting over classic metal complexes while assuring a triplet excited-state oxidation potential appropriate for charge injection into the conduction bands of common semiconductor electrode materials, highlighting its photosensitizing utility in dye-sensitized solar-cell architectures. Exploiting earth-abundant iron-based metal complexes as high-performance photosensitizers demands long-lived electronically excited metal-to-ligand charge-transfer (MLCT) states, but these species suffer typically from femtosecond timescale charge-transfer (CT)-state quenching by low-lying nonreactive metal-centered (MC) states. Here, we engineer supermolecular Fe(II) chromophores based on the bis(tridentate-ligand)metal(II)-ethyne-(porphinato)zinc(II) conjugated framework, previously shown to give rise to highly delocalized low-lying 3MLCT states for other Group VIII metal (Ru, Os) complexes. Electronic spectral, potentiometric, and ultrafast pump–probe transient dynamical data demonstrate that a combination of a strong σ-donating tridentate ligand and a (porphinato)zinc(II) moiety with low-lying π*-energy levels, sufficiently destabilize MC states and stabilize supermolecular MLCT states to realize Fe(II) complexes that express 3MLCT state photophysics reminiscent of their heavy-metal analogs. The resulting Fe(II) chromophore archetype, FeNHCPZn, features a highly polarized CT state having a profoundly extended 3MLCT lifetime (160 ps), 3MLCT phosphorescence, and ambient environment stability. Density functional and domain-based local pair natural orbital coupled cluster [DLPNO-CCSD(T)] theory reveal triplet-state wavefunction spatial distributions consistent with electronic spectroscopic and excited-state dynamical data, further underscoring the dramatic Fe metal-to-extended ligand CT character of electronically excited FeNHCPZn. This design further prompts intense panchromatic absorptivity via redistributing high-energy absorptive oscillator strength throughout the visible spectral domain, while maintaining a substantial excited-state oxidation potential for wide-ranging photochemistry––highlighted by the ability of FeNHCPZn to photoinject charges into a SnO2/FTO electrode in a dye-sensitized solar cell (DSSC) architecture. Concepts enumerated herein afford opportunities for replacing traditional rare-metal–based emitters for solar-energy conversion and photoluminescence applications.
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Tang Z, Chang XY, Wan Q, Wang J, Ma C, Law KC, Liu Y, Che CM. Bis(tridentate) Iron(II) Complexes with a Cyclometalating Unit: Photophysical Property Enhancement with Combinatorial Strong Ligand Field Effect. Organometallics 2020. [DOI: 10.1021/acs.organomet.0c00149] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Zhou Tang
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, Guangdong 518055, People’s Republic of China
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, People’s Republic of China
| | - Xiao-Yong Chang
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, Guangdong 518055, People’s Republic of China
| | - Qingyun Wan
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, People’s Republic of China
| | - Jian Wang
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, Guangdong 518055, People’s Republic of China
| | - Chensheng Ma
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, Guangdong 518055, People’s Republic of China
| | - Kwok-Chung Law
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, People’s Republic of China
| | - Yungen Liu
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, Guangdong 518055, People’s Republic of China
| | - Chi-Ming Che
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, Guangdong 518055, People’s Republic of China
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, People’s Republic of China
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Moll J, Wang C, Päpcke A, Förster C, Resch‐Genger U, Lochbrunner S, Heinze K. Green-Light Activation of Push-Pull Ruthenium(II) Complexes. Chemistry 2020; 26:6820-6832. [PMID: 32162414 PMCID: PMC7318647 DOI: 10.1002/chem.202000871] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 03/09/2020] [Indexed: 11/07/2022]
Abstract
Synthesis, characterization, electrochemistry, and photophysics of homo- and heteroleptic ruthenium(II) complexes [Ru(cpmp)2 ]2+ (22+ ) and [Ru(cpmp)(ddpd)]2+ (32+ ) bearing the tridentate ligands 6,2''-carboxypyridyl-2,2'-methylamine-pyridyl-pyridine (cpmp) and N,N'-dimethyl-N,N'-dipyridin-2-ylpyridine-2,6-diamine (ddpd) are reported. The complexes possess one (32+ ) or two (22+ ) electron-deficient dipyridyl ketone fragments as electron-accepting sites enabling intraligand charge transfer (ILCT), ligand-to-ligand charge transfer (LL'CT) and low-energy metal-to-ligand charge transfer (MLCT) absorptions. The latter peak around 544 nm (green light). Complex 22+ shows 3 MLCT phosphorescence in the red to near-infrared spectral region at room temperature in deaerated acetonitrile solution with an emission quantum yield of 1.3 % and a 3 MLCT lifetime of 477 ns, whereas 32+ is much less luminescent. This different behavior is ascribed to the energy gap law and the shape of the parasitic excited 3 MC state potential energy surface. This study highlights the importance of the excited-state energies and geometries for the actual excited-state dynamics. Aromatic and aliphatic amines reductively quench the excited state of 22+ paving the way to photocatalytic applications using low-energy green light as exemplified with the green-light-sensitized thiol-ene click reaction.
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Affiliation(s)
- Johannnes Moll
- Department of ChemistryJohannes Gutenberg University of MainzDuesbergweg 10–1455128MainzGermany
| | - Cui Wang
- Division 1.2 BiophotonicsFederal Institute for Materials Research and Testing (BAM)Richard Willstätter-Straße 1112489BerlinGermany
- Institut für Chemie und BiochemieFreie Universität BerlinArnimallee 2214195BerlinGermany
| | - Ayla Päpcke
- Institute for Physics and Department of Life, Light and MatterUniversity of Rostock18051RostockGermany
| | - Christoph Förster
- Department of ChemistryJohannes Gutenberg University of MainzDuesbergweg 10–1455128MainzGermany
| | - Ute Resch‐Genger
- Division 1.2 BiophotonicsFederal Institute for Materials Research and Testing (BAM)Richard Willstätter-Straße 1112489BerlinGermany
| | - Stefan Lochbrunner
- Institute for Physics and Department of Life, Light and MatterUniversity of Rostock18051RostockGermany
| | - Katja Heinze
- Department of ChemistryJohannes Gutenberg University of MainzDuesbergweg 10–1455128MainzGermany
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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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Päpcke A, Friedrich A, Lochbrunner S. Revealing the initial steps in homogeneous photocatalysis by time-resolved spectroscopy. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:153001. [PMID: 31801126 DOI: 10.1088/1361-648x/ab5ed1] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Photocatalysis attracts currently intense research since it can provide efficient routes for generating solar fuels and allows to apply sunlight for an environmentally friendly synthesis of valuable chemical compounds. Accordingly, in future photocatalysis may contribute significantly to a sustainable economy. However, up to now photocatalysis has made it only into some niche applications. The reasons are manifold including too low yields, insufficient stability, and scarce availability of the precious metals and rare earths used in most cases. The design of better systems is the goal of many research activities. They call for a detailed knowledge of the individual steps and the microscopic mechanisms. Time-resolved spectroscopy is a powerful tool to improve our understanding of the individual steps of a photocatalytic process and of the efficiencies and losses associated with them. This allows to address specific weaknesses of the components of a photocatalytic system and to pursue a rational design of the corresponding compounds. In this review an overview is given about what insights can be gained by time-resolved spectroscopy referring mostly to our own results while it has to be stressed that many other groups are also highly successfully working in this area. We restrict ourselves to homogeneous systems which are often easier to analyze and focus on the primary steps occurring after optical excitation. This includes intramolecular relaxation and intersystem crossing in the photosensitizer as well as the first electron transfer step resulting from the interaction of the sensitizer with other components of the system. Ultrafast pump-probe spectroscopy turns out to be particularly helpful in analyzing new photosensitizers based on abundant metals, i.e. copper and iron. These sensitizers can suffer from short lifetimes of the metal-to-ligand charge transfer states which are typically involved in the intermolecular charge transfer processes. The latter are investigated on the pico- to microsecond timescale by quenching experiments making use of a streak camera and by pump-probe spectroscopy applying a YAG-laser system for excitation. The experiments with the streak camera allow to discriminate between oxidative and reductive pathways and to determine the corresponding bimolecular quenching rates which are compared to their diffusion limit to obtain a measure for the quenching efficiency. By applying transient absorption spectroscopy, it is furthermore possible to observe appearing charge transfer products and to determine their concentrations. In this way the efficiency of the electron transfer itself can be deduced and the relevance of lossy quenching events can be estimated.
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Affiliation(s)
- Ayla Päpcke
- Institute for Physics and Department of Life, Light and Matter, University of Rostock, 18051 Rostock, Germany
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Abstract
The use of iron in photoactive metal complexes has been investigated for decades. In this respect, the charge transfer (CT) states are of particular interest, since they are usually responsible for the photofunctionality of such compounds. However, only recently breakthroughs have been made in extending CT excited state lifetimes that are notoriously short-lived in classical polypyridine iron coordination compounds. This success is in large parts owed to the use of strongly σ-donating N-heterocyclic carbene (NHC) ligands that help manipulating the photophysical and photochemical properties of iron complexes. In this review we aim to map out the basic design principles for the generation of photofunctional iron NHC complexes, summarize the progress made so far and recapitulate on the synthetic methods used. Further, we want to highlight the challenges still existing and give inspiration for future generations of photoactive iron complexes.
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Hsu LY, Liang Q, Wang Z, Kuo HH, Tai WS, Su SJ, Zhou X, Yuan Y, Chi Y. Bis-tridentate Ir III Phosphors Bearing Two Fused Five-Six-Membered Metallacycles: A Strategy to Improved Photostability of Blue Emitters. Chemistry 2019; 25:15375-15386. [PMID: 31573110 DOI: 10.1002/chem.201903707] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 09/30/2019] [Indexed: 12/19/2022]
Abstract
Iridium complexes bearing chelating cyclometalates are popular choices as dopant emitters in the fabrication of organic light-emitting diodes (OLEDs). In this contribution, we report a series of blue-emitting, bis-tridentate IrIII complexes bearing chelates with two fused five-six-membered metallacycles, which are in sharp contrast to the traditional designs of tridentate chelates that form the alternative, fused five-five metallacycles. Five IrIII complexes, Px-21-23, Cz-4, and Cz-5, have been synthesized that contain a coordinated dicarbene pincer chelate incorporating a methylene spacer and a dianionic chromophoric chelate possessing either a phenoxy or carbazolyl appendage to tune the coordination arrangement. All these tridentate chelates afford peripheral ligand-metal-ligand bite angles of 166-170°, which are larger than the typical bite angle of 153-155° observed for their five-five-coordinated tridentate counterparts, thereby leading to reduced geometrical distortion in the octahedral frameworks. Photophysical measurements and TD-DFT studies verified the inherent transition characteristics that give rise to high emission efficiency, and photodegradation experiments confirmed the improved stability in comparison with the benchmark fac-[Ir(ppy)3 ] in degassed toluene at room temperature. Phosphorescent OLED devices were also fabricated, among which the carbazolyl-functionalized emitter Cz-5 exhibited the best performance among all the studied bis-tridentate phosphors, showing a maximum external quantum efficiency (EQEmax ) of 18.7 % and CIEx,y coordinates of (0.145, 0.218), with a slightly reduced EQE of 13.7 % at 100 cd m-2 due to efficiency roll-off.
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Affiliation(s)
- Ling-Yang Hsu
- Department of Chemistry and Frontier Research Center on, Fundamental and Applied Sciences of Matter, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Qiumin Liang
- State Key Laboratory of Luminescent Materials and Devices, and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou, 510640, P.R. China
| | - Zhiheng Wang
- State Key Laboratory of Luminescent Materials and Devices, and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou, 510640, P.R. China
| | - Hsin-Hung Kuo
- Department of Chemistry and Frontier Research Center on, Fundamental and Applied Sciences of Matter, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Wun-Shan Tai
- Department of Chemistry and Frontier Research Center on, Fundamental and Applied Sciences of Matter, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Shi-Jian Su
- State Key Laboratory of Luminescent Materials and Devices, and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou, 510640, P.R. China
| | - Xiuwen Zhou
- School of Mathematics and Physics, The University of Queensland, Brisbane, Queensland, 4072, Australia
| | - Yi Yuan
- Department of Materials Science and Engineering, and Department of Chemistry, City University of Hong Kong, Hong Kong, SAR
| | - Yun Chi
- Department of Chemistry and Frontier Research Center on, Fundamental and Applied Sciences of Matter, National Tsing Hua University, Hsinchu, 30013, Taiwan.,Department of Materials Science and Engineering, and Department of Chemistry, City University of Hong Kong, Hong Kong, SAR
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Tu MF, Doumy G, Al Haddad A, March AM, Southworth SH, Assoufid L, Kumagai Y, Walko DA, DiChiara AD, Liu Z, Shi B, Young L, Bostedt C. Micro-focused MHz pink beam for time-resolved X-ray emission spectroscopy. JOURNAL OF SYNCHROTRON RADIATION 2019; 26:1956-1966. [PMID: 31721741 DOI: 10.1107/s1600577519012268] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 09/03/2019] [Indexed: 06/10/2023]
Abstract
The full radiation from the first harmonic of a synchrotron undulator (between 5 and 12 keV) at the Advanced Photon Source is microfocused using a stack of beryllium compound refractive lenses onto a fast-moving liquid jet and overlapped with a high-repetition-rate optical laser. This micro-focused geometry is used to perform efficient nonresonant X-ray emission spectroscopy on transient species using a dispersive spectrometer geometry. The overall usable flux achieved on target is above 1015 photons s-1 at 8 keV, enabling photoexcited systems in the liquid phase to be tracked with time resolutions from tens of picoseconds to microseconds, and using the full emission spectrum, including the weak valence-to-core signal that is sensitive to chemically relevant electronic properties.
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Affiliation(s)
- Ming Feng Tu
- Chemical Sciences and Engineering Division, Argonne National Laboratory, USA
| | - Gilles Doumy
- Chemical Sciences and Engineering Division, Argonne National Laboratory, USA
| | - Andre Al Haddad
- Chemical Sciences and Engineering Division, Argonne National Laboratory, USA
| | - Anne Marie March
- Chemical Sciences and Engineering Division, Argonne National Laboratory, USA
| | | | | | - Yoshiaki Kumagai
- Chemical Sciences and Engineering Division, Argonne National Laboratory, USA
| | - Donald A Walko
- Advanced Photon Source, Argonne National Laboratory, USA
| | | | - Zunping Liu
- Advanced Photon Source, Argonne National Laboratory, USA
| | - Bing Shi
- Advanced Photon Source, Argonne National Laboratory, USA
| | - Linda Young
- Chemical Sciences and Engineering Division, Argonne National Laboratory, USA
| | - Christoph Bostedt
- Chemical Sciences and Engineering Division, Argonne National Laboratory, USA
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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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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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Megow S, Fitschen HL, Tuczek F, Temps F. Ultrafast Photodynamics of an Azopyridine-Functionalized Iron(II) Complex: Implications for the Concept of Ligand-Driven Light-Induced Spin Change. J Phys Chem Lett 2019; 10:6048-6054. [PMID: 31549841 DOI: 10.1021/acs.jpclett.9b02083] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We report on the ultrafast photodynamics of an iron(II) complex with a photoisomerizable pentadentate azo-tetrapyridylamino ligand after irradiation with ultraviolet light. The results of femtosecond transient electronic absorption spectroscopy performed on the low-spin (LS) form of the title complex show that initial excitation of the ππ* state of the azopyridine unit in the ligand at λpump = 312 nm is followed by an ultrafast intersystem crossing (ISC) that leads to the formation of a metal-centered (MC) 5T state, in competition with the intended photoswitching of the azopyridine unit. Additional measurements carried out upon excitation of the singlet metal-to-ligand charge-transfer (1MLCT) transition at λpump = 455 nm suggest that this energy transfer occurs via an MLCT state. The resulting high-spin (HS) 5T state of the complex is metastable and recovers to the LS ground state with a time constant of ∼3 ns. The implications of these observations on the ligand-driven light-induced spin change concept are discussed.
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Affiliation(s)
- Sebastian Megow
- Institut für Physikalische Chemie , Christian-Albrechts-Universität , Olshausenstrasse 40 , 24098 Kiel , Germany
| | - Henrike-Leonie Fitschen
- Institut für Anorganische Chemie , Christian-Albrechts-Universität , Olshausenstrasse 40 , 24098 Kiel , Germany
| | - Felix Tuczek
- Institut für Anorganische Chemie , Christian-Albrechts-Universität , Olshausenstrasse 40 , 24098 Kiel , Germany
| | - Friedrich Temps
- Institut für Physikalische Chemie , Christian-Albrechts-Universität , Olshausenstrasse 40 , 24098 Kiel , Germany
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Zhang K, Ash R, Girolami GS, Vura-Weis J. Tracking the Metal-Centered Triplet in Photoinduced Spin Crossover of Fe(phen) 32+ with Tabletop Femtosecond M-Edge X-ray Absorption Near-Edge Structure Spectroscopy. J Am Chem Soc 2019; 141:17180-17188. [PMID: 31587557 DOI: 10.1021/jacs.9b07332] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Fe(II) coordination complexes are promising alternatives to Ru(II) and Ir(III) chromophores for photoredox chemistry and solar energy conversion, but rapid deactivation of the initial metal-to-ligand charge transfer (MLCT) state to low-lying (d,d) states limits their performance. Relaxation to a long-lived quintet state is postulated to occur via a metal-centered triplet state, but this mechanism remains controversial. We use femtosecond extreme ultraviolet (XUV) transient absorption spectroscopy to measure the excited-state relaxation of Fe(phen)32+ and conclusively identify a 3T intermediate that forms in 170 fs and decays to a vibrationally hot 5T2g state in 39 fs. A coherent vibrational wavepacket with a period of 249 fs and damping time of 0.63 ps is observed on the 5T2g surface, and the spectrum of this oscillation serves as a fingerprint for the Fe-N symmetric stretch. The results show that the shape of the M2,3-edge X-ray absorption near-edge structure (XANES) spectrum is sensitive to the electronic structure of the metal center, and the high-spin sensitivity, fast time resolution, and tabletop convenience of XUV transient absorption make it a powerful tool for studying the complex photophysics of transition metal complexes.
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Affiliation(s)
- Kaili Zhang
- Department of Chemistry , University of Illinois at Urbana-Champaign , Urbana , Illinois 61801 , United States
| | - Ryan Ash
- Department of Chemistry , University of Illinois at Urbana-Champaign , Urbana , Illinois 61801 , United States
| | - Gregory S Girolami
- Department of Chemistry , University of Illinois at Urbana-Champaign , Urbana , Illinois 61801 , United States
| | - Josh Vura-Weis
- Department of Chemistry , University of Illinois at Urbana-Champaign , Urbana , Illinois 61801 , United States
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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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46
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Jiménez JR, Doistau B, Cruz CM, Besnard C, Cuerva JM, Campaña AG, Piguet C. Chiral Molecular Ruby [Cr(dqp)2]3+ with Long-Lived Circularly Polarized Luminescence. J Am Chem Soc 2019; 141:13244-13252. [DOI: 10.1021/jacs.9b06524] [Citation(s) in RCA: 89] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Juan-Ramón Jiménez
- Department of Inorganic and Analytical Chemistry, University of Geneva, 30 Quai E. Ansermet, CH-1211 Geneva 4, Switzerland
| | - Benjamin Doistau
- Department of Inorganic and Analytical Chemistry, University of Geneva, 30 Quai E. Ansermet, CH-1211 Geneva 4, Switzerland
| | - Carlos M. Cruz
- Departamento de Quı́mica Orgánica, Unidad de Excelencia de Quı́mica Aplicada a Biomedicina y Medioambiente, Universidad de Granada, Avda. Fuentenueva, E-18071 Granada, España
| | - Céline Besnard
- Laboratory of Crystallography, University of Geneva, 24 Quai E. Ansermet, CH-1211 Geneva 4, Switzerland
| | - Juan M. Cuerva
- Departamento de Quı́mica Orgánica, Unidad de Excelencia de Quı́mica Aplicada a Biomedicina y Medioambiente, Universidad de Granada, Avda. Fuentenueva, E-18071 Granada, España
| | - Araceli G. Campaña
- Departamento de Quı́mica Orgánica, Unidad de Excelencia de Quı́mica Aplicada a Biomedicina y Medioambiente, Universidad de Granada, Avda. Fuentenueva, E-18071 Granada, España
| | - Claude Piguet
- Department of Inorganic and Analytical Chemistry, University of Geneva, 30 Quai E. Ansermet, CH-1211 Geneva 4, Switzerland
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47
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Britz A, Gawelda W, Assefa TA, Jamula LL, Yarranton JT, Galler A, Khakhulin D, Diez M, Harder M, Doumy G, March AM, Bajnóczi É, Németh Z, Pápai M, Rozsályi E, Sárosiné Szemes D, Cho H, Mukherjee S, Liu C, Kim TK, Schoenlein RW, Southworth SH, Young L, Jakubikova E, Huse N, Vankó G, Bressler C, McCusker JK. Using Ultrafast X-ray Spectroscopy To Address Questions in Ligand-Field Theory: The Excited State Spin and Structure of [Fe(dcpp)2]2+. Inorg Chem 2019; 58:9341-9350. [DOI: 10.1021/acs.inorgchem.9b01063] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Alexander Britz
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
- The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Wojciech Gawelda
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
- Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań, Poland
| | - Tadesse A. Assefa
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
- Institute of Laser Physics, University of Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Lindsey L. Jamula
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
| | - Jonathan T. Yarranton
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
| | | | - Dmitry Khakhulin
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
- The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Michael Diez
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
- The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Manuel Harder
- Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany
| | - Gilles Doumy
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Anne Marie March
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Éva Bajnóczi
- Wigner Research Centre for Physics, Hungarian Academy Sciences, H-1525 Budapest, Hungary
| | - Zoltán Németh
- Wigner Research Centre for Physics, Hungarian Academy Sciences, H-1525 Budapest, Hungary
| | - Mátyás Pápai
- Wigner Research Centre for Physics, Hungarian Academy Sciences, H-1525 Budapest, Hungary
- Department of Chemistry, Technical University of Denmark, DK-2800, Kongens Lyngby, Denmark
| | - Emese Rozsályi
- Wigner Research Centre for Physics, Hungarian Academy Sciences, H-1525 Budapest, Hungary
| | | | - Hana Cho
- Center for Analytical Chemistry, Division of Chemical and Medical Metrology, Korea Research Institute of Standards and Science, Daejeon 34113, Republic of Korea
| | - Sriparna Mukherjee
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Chang Liu
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Tae Kyu Kim
- Department of Chemistry and Chemistry Institute of Functional Materials, Pusan National University, Busan 46241, Republic of Korea
| | - Robert W. Schoenlein
- Ultrafast X-ray Science Laboratory, Lawrence Berkeley National Laboratory, Berkeley, United States
| | - Stephen H. Southworth
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Linda Young
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
- Department of Physics and The James Franck Institute, The University of Chicago, Chicago, Illinois 60637, United States
| | - Elena Jakubikova
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Nils Huse
- Center for Free-Electron Laser Science, University of Hamburg, 22607 Hamburg, Germany
- Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany
| | - György Vankó
- Wigner Research Centre for Physics, Hungarian Academy Sciences, H-1525 Budapest, Hungary
| | - Christian Bressler
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
- The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - James K. McCusker
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
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48
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Steube J, Burkhardt L, Päpcke A, Moll J, Zimmer P, Schoch R, Wölper C, Heinze K, Lochbrunner S, Bauer M. Excited‐State Kinetics of an Air‐Stable Cyclometalated Iron(II) Complex. Chemistry 2019; 25:11826-11830. [DOI: 10.1002/chem.201902488] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Indexed: 11/07/2022]
Affiliation(s)
- Jakob Steube
- Institute of Inorganic Chemistry and Center for Sustainable, Systems Design (CSSD)University of Paderborn Warburger Straße 100 33098 Paderborn Germany
| | - Lukas Burkhardt
- Institute of Inorganic Chemistry and Center for Sustainable, Systems Design (CSSD)University of Paderborn Warburger Straße 100 33098 Paderborn Germany
| | - Ayla Päpcke
- Institute of Physics and Department of Life, Light and MatterUniversity of Rostock 18051 Rostock Germany
| | - Johannes Moll
- Institute of Inorganic Chemistry and Analytical ChemistryJohannes Gutenberg University Duesbergweg 10–14 55128 Mainz Germany
| | - Peter Zimmer
- Institute of Inorganic Chemistry and Center for Sustainable, Systems Design (CSSD)University of Paderborn Warburger Straße 100 33098 Paderborn Germany
| | - Roland Schoch
- Institute of Inorganic Chemistry and Center for Sustainable, Systems Design (CSSD)University of Paderborn Warburger Straße 100 33098 Paderborn Germany
| | - Christoph Wölper
- Institute for Inorganic Chemistry and Center for Nanointegration, Duisburg-Essen (Cenide)University of Duisburg-Essen Universitätsstraße 5-7 45117 Essen Germany
| | - Katja Heinze
- Institute of Inorganic Chemistry and Analytical ChemistryJohannes Gutenberg University Duesbergweg 10–14 55128 Mainz Germany
| | - Stefan Lochbrunner
- Institute of Physics and Department of Life, Light and MatterUniversity of Rostock 18051 Rostock Germany
| | - Matthias Bauer
- Institute of Inorganic Chemistry and Center for Sustainable, Systems Design (CSSD)University of Paderborn Warburger Straße 100 33098 Paderborn Germany
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49
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Francés‐Monerris A, Gros PC, Assfeld X, Monari A, Pastore M. Toward Luminescent Iron Complexes: Unravelling the Photophysics by Computing Potential Energy Surfaces. CHEMPHOTOCHEM 2019. [DOI: 10.1002/cptc.201900100] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Antonio Francés‐Monerris
- Laboratoire de Physique et Chimie Théoriques (LPCT)Université de Lorraine, CNRS 54000 Nancy France
| | - Philippe C. Gros
- Laboratoire Lorrain de Chimie Moléculaire (L2CM)Université de Lorraine, CNRS 54000 Nancy France
| | - Xavier Assfeld
- Laboratoire de Physique et Chimie Théoriques (LPCT)Université de Lorraine, CNRS 54000 Nancy France
| | - Antonio Monari
- Laboratoire de Physique et Chimie Théoriques (LPCT)Université de Lorraine, CNRS 54000 Nancy France
| | - Mariachiara Pastore
- Laboratoire de Physique et Chimie Théoriques (LPCT)Université de Lorraine, CNRS 54000 Nancy France
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50
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Predicting the electrochemical behavior of Fe(II) complexes from ligand orbital energies. J Photochem Photobiol A Chem 2019. [DOI: 10.1016/j.jphotochem.2019.01.026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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