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Ferraro V, Bizzarri C, Bräse S. Thermally Activated Delayed Fluorescence (TADF) Materials Based on Earth-Abundant Transition Metal Complexes: Synthesis, Design and Applications. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2404866. [PMID: 38984475 DOI: 10.1002/advs.202404866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2024] [Revised: 06/27/2024] [Indexed: 07/11/2024]
Abstract
Materials exhibiting thermally activated delayed fluorescence (TADF) based on transition metal complexes are currently gathering significant attention due to their technological potential. Their application extends beyond optoelectronics, in particular organic light-emitting diodes (OLEDs) and light-emitting electrochemical cells (LECs), and include also photocatalysis, sensing, and X-ray scintillators. From the perspective of sustainability, earth-abundant metal centers are preferred to rarer second- and third-transition series elements, thus determining a reduction in costs and toxicity but without compromising the overall performances. This review offers an overview of earth-abundant transition metal complexes exhibiting TADF and their application as photoconversion materials. Particular attention is devoted to the types of ligands employed, helping in the design of novel systems with enhanced TADF properties.
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Affiliation(s)
- Valentina Ferraro
- Institute of Organic Chemistry (IOC), Karlsruhe Institute of Technology (KIT), Kaiserstrasse 12, 76131, Karlsruhe, Germany
| | - Claudia Bizzarri
- Institute of Organic Chemistry (IOC), Karlsruhe Institute of Technology (KIT), Kaiserstrasse 12, 76131, Karlsruhe, Germany
| | - Stefan Bräse
- Institute of Organic Chemistry (IOC), Karlsruhe Institute of Technology (KIT), Kaiserstrasse 12, 76131, Karlsruhe, Germany
- Institute of Biological and Chemical Systems-Functional Molecular Systems (IBCS-FMS), Karlsruhe Institute of Technology (KIT), Kaiserstrasse 12, 76131, Karlsruhe, Germany
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2
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Deng H, Wang T, Chen Y, Dou K, Liu X, Zhao C, Zhan H, Yang C, Qin C, Cheng Y. Enhanced Thermally Activated Delayed Fluorescence by Sole Coordination: From an Organic Molecule to Its Zinc Complex. J Phys Chem Lett 2024; 15:7003-7010. [PMID: 38949564 DOI: 10.1021/acs.jpclett.4c01472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
A BPAPTPyC organic molecule containing a sandwich structural chromophore is designed and synthesized to produce blue thermally activated delayed fluorescence (TADF). The chromophore is composed of two di(4-tert-butylphenyl)amino donors and one inserted terpyridyl acceptor hitched at positions 1, 8, and 9 of a single carbazole via the p-phenylene group, in which the multiple space π-π interactions between the donor and acceptor enable the molecule to possess the TADF feature with a high energy emission at 470 nm but a low photoluminescence quantum yield (PLQY) and a small proportion of the delayed component. In contrast, the corresponding Zn(BPAPTPyC)Cl2 complex has a high PLQY and a short lifetime with a red-shifted emission due to the enhanced rigidity and electron accepting ability of the terpyridyl group from coordination. A solution-processed organic light-emitting diode (OLED) based on the complex achieves a maximum external quantum efficiency (EQE) of 17.9% with an emission peak at 585 nm, while an OLED of the organic molecule produces blue emission with a maximum EQE of 2.7%.
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Affiliation(s)
- Hao Deng
- State Key Laboratory of Polymer Physics and Chemistry and Key Laboratory of Polymer Science and Technology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Tao Wang
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, P. R. China
| | - Yuannan Chen
- College of Chemistry, Northeast Normal University, Changchun 130024, P. R. China
| | - Kunkun Dou
- State Key Laboratory of Polymer Physics and Chemistry and Key Laboratory of Polymer Science and Technology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Xuejing Liu
- Key Laboratory on Resources Chemicals and Material of Ministry of Education, Shenyang University of Chemical Technology, Shenyang 110142, P. R. China
| | - Chenyang Zhao
- State Key Laboratory of Polymer Physics and Chemistry and Key Laboratory of Polymer Science and Technology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
| | - Hongmei Zhan
- State Key Laboratory of Polymer Physics and Chemistry and Key Laboratory of Polymer Science and Technology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
| | - Chuluo Yang
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, P. R. China
| | - Chuanjiang Qin
- State Key Laboratory of Polymer Physics and Chemistry and Key Laboratory of Polymer Science and Technology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Yanxiang Cheng
- State Key Laboratory of Polymer Physics and Chemistry and Key Laboratory of Polymer Science and Technology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, P. R. China
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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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Shi Y, Gou H, Wu H, Wan S, Wang K, Yu J, Zhang X, Ye C. Harnessing Heavy-Atom Effects in Multiple Resonance Thermally Activated Delayed Fluorescence (MR-TADF) Sensitizers: Unlocking High-Performance Visible-to-Ultraviolet (Vis-to-UV) Triplet Fusion Upconversion. J Phys Chem Lett 2024; 15:4647-4654. [PMID: 38647524 DOI: 10.1021/acs.jpclett.4c00542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2024]
Abstract
Ultraviolet (UV) light plays a crucial role in various applications, but currently, the efficiency of generating artificial UV light is low. The visible-to-ultraviolet (Vis-to-UV) system based on the triplet-triplet annihilation upconversion (TTA-UC) mechanism can be a viable solution. Metal-free multiple resonance thermally activated delayed fluorescence (MR-TADF) materials are ideal photosensitizers (PSs) apart from the drawback of high photoluminescence quantum yields (PLQYs). Herein, we systematically investigated the impact of the heavy-atom effect (HAE) on the MR-TADF sensitizers. BNCzBr was then synthesized by incorporating a bromine atom into the skeleton of the precursor BNCz. Impressively, the internal HAE (iHAE) leads to a significantly decreased PLQY and a remarkably increased intersystem crossing quantum yield (ΦISC). Consequently, a higher upconversion quantum efficiency of 12.5% was realized. While the external HAE (eHAE) harms the UC performance. This work guides the further development of MR-TADF sensitizers for high-performance Vis-to-UV TTA-UC systems.
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Affiliation(s)
- Yizhong Shi
- School of Materials Science and Engineering, Suzhou University of Science and Technology, 215009 Suzhou, PR China
| | - Haodong Gou
- School of Materials Science and Engineering, Suzhou University of Science and Technology, 215009 Suzhou, PR China
| | - Hao Wu
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, 215123 Suzhou, PR China
| | - Shigang Wan
- School of Materials Science and Engineering, Suzhou University of Science and Technology, 215009 Suzhou, PR China
| | - Kai Wang
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, 215123 Suzhou, PR China
- Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, 215123 Suzhou, PR China
| | - Jia Yu
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, 215123 Suzhou, PR China
| | - Xiaohong Zhang
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, 215123 Suzhou, PR China
- Jiangsu Key Laboratory of Advanced Negative Carbon Technologies, Soochow University, 215123 Suzhou, PR China
| | - Changqing Ye
- School of Materials Science and Engineering, Suzhou University of Science and Technology, 215009 Suzhou, PR China
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Lee J, Cho JB, Li Y, Lee KH, Jang JI, Ok KM. Multifunctional Chiral d 10-Metal Coordination Polymers: Tunable Photoluminescence and Efficient Second-Harmonic Generation with Circular Dichroic Response. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2309323. [PMID: 38085128 DOI: 10.1002/smll.202309323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2023] [Revised: 12/04/2023] [Indexed: 05/25/2024]
Abstract
A series of homochiral coordination polymers (HCPs), [M2(SIAP)2(bpy)2] [M(S)] and [M2(RIAP)2(bpy)2] [M(R)] (M = Zn or Cd, SIAP or RIAP = (S,S)- or (R,R)- 2,2'-(isophthaloylbis(azanediyl))di-propionic acid, bpy = 4,4'-bipyridine), is successfully synthesized through solvothermal reactions, self-assembling d10 metal cations, chiral dicarboxylic ligands, and π-conjugated bipyridyl ligands. The HCPs crystallize in the extremely rare triclinic chiral space group, P1, and present 3D framework structures attributed to the strong intermolecular interactions, such as hydrogen bonds and π-π stacking. Due to the unique crystal structures, the title compounds reveal efficient photoluminescence emission across a broad visible range, with significant brightness and color tuning by varying the excitation wavelength. Moreover, they exhibit efficient phase-matched second-harmonic generation (SHG) with very high laser-induced damage thresholds, essential for high-power nonlinear optical (NLO) applications. Intriguingly, the title compounds exhibit a measurable contrast in the SHG response under right- and left-handed circularly polarized excitation, thereby providing a unique case of SHG circular dichroism from the chiral centers of SIAP2- or RIAP2- ligand packed in the noncentrosymmetric environment. These exceptional attributes position these HCPs as promising candidates for multifunctional materials, with potential applications ranging from NLO devices to tailored luminescent systems with polarization control.
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Affiliation(s)
- Jihyun Lee
- Department of Chemistry, Sogang University, Seoul, 04107, Republic of Korea
| | - Jeong Bin Cho
- Department of Physics, Sogang University, Seoul, 04107, Republic of Korea
| | - Yang Li
- Department of Chemistry, Sogang University, Seoul, 04107, Republic of Korea
| | - Kyeong-Hyeon Lee
- Department of Physics, Sogang University, Seoul, 04107, Republic of Korea
| | - Joon Ik Jang
- Department of Physics, Sogang University, Seoul, 04107, Republic of Korea
| | - Kang Min Ok
- Department of Chemistry, Sogang University, Seoul, 04107, Republic of Korea
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Huang L, Han G. Triplet-triplet annihilation photon upconversion-mediated photochemical reactions. Nat Rev Chem 2024; 8:238-255. [PMID: 38514833 DOI: 10.1038/s41570-024-00585-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/15/2024] [Indexed: 03/23/2024]
Abstract
Photon upconversion is a method for harnessing high-energy excited states from low-energy photons. Such photons, particularly in the red and near-infrared wavelength ranges, can penetrate tissue deeply and undergo less competitive absorption in coloured reaction media, enhancing the efficiency of large-scale reactions and in vivo phototherapy. Among various upconversion methodologies, the organic-based triplet-triplet annihilation upconversion (TTA-UC) stands out - demonstrating high upconversion efficiencies, requiring low excitation power densities and featuring tunable absorption and emission wavelengths. These factors contribute to improved photochemical reactions for fields such as photoredox catalysis, photoactivation, 3D printing and immunotherapy. In this Review, we explore concepts and design principles of organic TTA-UC-mediated photochemical reactions, highlighting notable advancements in the field, as well as identify challenges and propose potential solutions. This Review sheds light on the potential of organic TTA-UC to advance beyond the traditional photochemical reactions and paves the way for research in various fields and clinical applications.
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Affiliation(s)
- Ling Huang
- Tianjin Key Laboratory of Biosensing and Molecular Recognition, Research Center for Analytical Sciences, College of Chemistry, Nankai University, Tianjin, China
- Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Gang Han
- Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Chan Medical School, Worcester, MA, USA.
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7
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Shillito GE, Preston D, Crowley JD, Wagner P, Harris SJ, Gordon KC, Kupfer S. Controlling Excited State Localization in Bichromophoric Photosensitizers via the Bridging Group. Inorg Chem 2024; 63:4947-4956. [PMID: 38437618 PMCID: PMC10951951 DOI: 10.1021/acs.inorgchem.3c04110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 01/18/2024] [Accepted: 01/30/2024] [Indexed: 03/06/2024]
Abstract
A series of photosensitizers comprised of both an inorganic and an organic chromophore are investigated in a joint synthetic, spectroscopic, and theoretical study. This bichromophoric design strategy provides a means by which to significantly increase the excited state lifetime by isolating the excited state away from the metal center following intersystem crossing. A variable bridging group is incorporated between the donor and acceptor units of the organic chromophore, and its influence on the excited state properties is explored. The Franck-Condon (FC) photophysics and subsequent excited state relaxation pathways are investigated with a suite of steady-state and time-resolved spectroscopic techniques in combination with scalar-relativistic quantum chemical calculations. It is demonstrated that the presence of an electronically conducting bridge that facilitates donor-acceptor communication is vital to generate long-lived (32 to 45 μs), charge-separated states with organic character. In contrast, when an insulating 1,2,3-triazole bridge is used, the excited state properties are dominated by the inorganic chromophore, with a notably shorter lifetime of 60 ns. This method of extending the lifetime of a molecular photosensitizer is, therefore, of interest for a range of molecular electronic devices and photophysical applications.
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Affiliation(s)
- Georgina E. Shillito
- Institute
of Physical Chemistry, Friedrich Schiller
University Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - Dan Preston
- Research
School of Chemistry, Australian National
University, Canberra, ACT 2600, Australia
| | - James D. Crowley
- Department
of Chemistry, University of Otago, 362 Leith Street, Dunedin 9016, New Zealand
- MacDiarmid
Institute for Advanced Materials and Nanotechnology, Wellington, 6012, New Zealand
| | - Pawel Wagner
- University
of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia
| | - Samuel J. Harris
- Department
of Chemistry, University of Otago, 362 Leith Street, Dunedin 9016, New Zealand
- MacDiarmid
Institute for Advanced Materials and Nanotechnology, Wellington, 6012, New Zealand
| | - Keith C. Gordon
- Department
of Chemistry, University of Otago, 362 Leith Street, Dunedin 9016, New Zealand
- MacDiarmid
Institute for Advanced Materials and Nanotechnology, Wellington, 6012, New Zealand
| | - Stephan Kupfer
- Institute
of Physical Chemistry, Friedrich Schiller
University Jena, Helmholtzweg 4, 07743 Jena, Germany
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Mitra M, Mrózek O, Putscher M, Guhl J, Hupp B, Belyaev A, Marian CM, Steffen A. Structural Control of Highly Efficient Thermally Activated Delayed Fluorescence in Carbene Zinc(II) Dithiolates. Angew Chem Int Ed Engl 2024; 63:e202316300. [PMID: 38063260 DOI: 10.1002/anie.202316300] [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: 10/27/2023] [Indexed: 01/16/2024]
Abstract
Luminescent metal complexes based on earth abundant elements are a valuable target to substitute 4d/5d transition metal complexes as triplet emitters in advanced photonic applications. Whereas CuI complexes have been thoroughly investigated in the last two decades for this purpose, no structure-property-relationships for efficient luminescence involving triplet excited states from ZnII complexes are established. Herein, we report on the design of monomeric carbene zinc(II) dithiolates (CZT) featuring a donor-acceptor-motif that leads to highly efficient thermally activated delayed fluorescence (TADF) with for ZnII compounds unprecedented radiative rate constants kTADF =1.2×106 s-1 at 297 K. Our high-level DFT/MRCI calculations revealed that the relative orientation of the ligands involved in the ligand-to-ligand charge transfer (1/3 LLCT) states is paramount to control the TADF process. Specifically, a dihedral angle of 36-40° leads to very efficient reverse intersystem-crossing (rISC) on the order of 109 s-1 due to spin-orbit coupling (SOC) mediated by the sulfur atoms in combination with a small ΔES1-T1 of ca. 56 meV.
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Affiliation(s)
- Mousree Mitra
- Faculty of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Str. 6, 44227, Dortmund, Germany
| | - Ondřej Mrózek
- Faculty of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Str. 6, 44227, Dortmund, Germany
| | - Markus Putscher
- Institute of Theoretical and Computational Chemistry, Faculty of Mathematics and Natural Sciences, Heinrich Heine University Düsseldorf, Universitätsstr. 1, 40225, Düsseldorf, Germany
| | - Jasper Guhl
- Institute of Theoretical and Computational Chemistry, Faculty of Mathematics and Natural Sciences, Heinrich Heine University Düsseldorf, Universitätsstr. 1, 40225, Düsseldorf, Germany
| | - Benjamin Hupp
- Faculty of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Str. 6, 44227, Dortmund, Germany
| | - Andrey Belyaev
- Faculty of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Str. 6, 44227, Dortmund, Germany
| | - Christel M Marian
- Institute of Theoretical and Computational Chemistry, Faculty of Mathematics and Natural Sciences, Heinrich Heine University Düsseldorf, Universitätsstr. 1, 40225, Düsseldorf, Germany
| | - Andreas Steffen
- Faculty of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Str. 6, 44227, Dortmund, Germany
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Koop S, Mrózek O, Janiak L, Belyaev A, Putscher M, Marian CM, Steffen A. Synthesis, Structural Characterization, and Phosphorescence Properties of Trigonal Zn(II) Carbene Complexes. Inorg Chem 2024; 63:891-901. [PMID: 38118184 DOI: 10.1021/acs.inorgchem.3c03915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2023]
Abstract
The sterically demanding N-heterocyclic carbene ITr (N,N'-bis(triphenylmethyl)imidazolylidene) was employed for the preparation of novel trigonal zinc(II) complexes of the type [ZnX2(ITr)] [X = Cl (1), Br (2), and I (3)], for which the low coordination mode was confirmed in both solution and solid state. Because of the atypical coordination geometry, the reactivity of 1-3 was studied in detail using partial or exhaustive halide exchange and halide abstraction reactions to access [ZnLCl(ITr)] [L = carbazolate (4), 3,6-di-tert-butyl-carbazolate (5), phenoxazine (6), and phenothiazine (7)], [Zn(bdt)(ITr)] (bdt = benzene-1,2-dithiolate) (8), and cationic [Zn(μ2-X)(ITr)]2[B(C6F5)4]2 [X = Cl (9), Br (10), and I (11)], all of which were isolated and structurally characterized. Importantly, for all complexes 4-11, the trigonal coordination environment of the ZnII ion is maintained, demonstrating a highly stabilizing effect due to the steric demand of the ITr ligand, which protects the metal center from further ligand association. In addition, complexes 1-3 and 8-11 show long-lived luminescence from triplet excited states in the solid state at room temperature, according to our photophysical studies. Our quantum chemical density functional theory/multireference configuration interaction (DFT/MRCI) calculations reveal that the phosphorescence of 8 originates from a locally excited triplet state on the bdt ligand. They further suggest that the phenyl substituents of ITr are photochemically not innocent but can coordinate to the electron-deficient metal center of this trigonal complex in the excited state.
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Affiliation(s)
- Stefan Koop
- Department of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Straße 6, Dortmund 44227, Germany
| | - Ondřej Mrózek
- Department of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Straße 6, Dortmund 44227, Germany
| | - Lars Janiak
- Department of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Straße 6, Dortmund 44227, Germany
| | - Andrey Belyaev
- Department of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Straße 6, Dortmund 44227, Germany
| | - Markus Putscher
- Institute of Theoretical and Computational Chemistry, Heinrich Heine University Düsseldorf, Universitätsstraße 1, Düsseldorf 40225, Germany
| | - Christel M Marian
- Institute of Theoretical and Computational Chemistry, Heinrich Heine University Düsseldorf, Universitätsstraße 1, Düsseldorf 40225, Germany
| | - Andreas Steffen
- Department of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Straße 6, Dortmund 44227, Germany
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Body N, Bevernaegie R, Lefebvre C, Jabin I, Hermans S, Riant O, Troian-Gautier L. Photo-Catalyzed α-Arylation of Enol Acetate Using Recyclable Silica-Supported Heteroleptic and Homoleptic Copper(I) Photosensitizers. Chemistry 2023; 29:e202301212. [PMID: 37582678 DOI: 10.1002/chem.202301212] [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: 04/18/2023] [Revised: 07/14/2023] [Accepted: 08/15/2023] [Indexed: 08/17/2023]
Abstract
Earth-abundant photosensitizers are highly sought after for light-mediated applications, such as photoredox catalysis, depollution and energy conversion schemes. Homoleptic and heteroleptic copper(I) complexes are promising candidates in this field, as copper is abundant and the corresponding complexes are easily obtained in smooth conditions. However, some heteroleptic copper(I) complexes suffer from low (photo)stability that leads to the gradual formation of the corresponding homoleptic complex. Such degradation pathways are detrimental, especially when recyclability is desired. This study reports a novel approach for the heterogenization of homoleptic and heteroleptic Cu complexes on silica nanoparticles. In both cases, the photophysical properties upon surface immobilization were only slightly affected. Excited-state quenching with aryl diazonium derivatives occurred efficiently (108 -1010 M-1 s-1 ) with heterogeneous and homogeneous photosensitizers. Moderate but almost identical yields were obtained for the α-arylation of enol acetate using the homoleptic complex in homogeneous or heterogeneous conditions. Importantly, the silica-supported photocatalysts were recycled with moderate loss in photoactivity over multiple experiments. Transient absorption spectroscopy confirmed that excited-state electron transfer occurred from the homogeneous and heterogeneous homoleptic copper(I) complexes to aryl diazonium derivatives, generating the corresponding copper(II) center that persisted for several hundreds of microseconds, compatible with photoredox catalysis applications.
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Affiliation(s)
- Nathalie Body
- Université catholique de Louvain (UCLouvain), Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), Place Louis Pasteur 1, bte L4.01.02, 1348, Louvain-la-Neuve, Belgium
| | - Robin Bevernaegie
- Université libre de Bruxelles (ULB), Service de Chimie et PhysicoChimie Organiques (CPCO), Laboratoire de Chimie Organique (LCO), Avenue F. D. Roosevelt 50, 1050, Bruxelles, Belgium
| | - Corentin Lefebvre
- Université catholique de Louvain (UCLouvain), Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), Place Louis Pasteur 1, bte L4.01.02, 1348, Louvain-la-Neuve, Belgium
| | - Ivan Jabin
- Université libre de Bruxelles (ULB), Service de Chimie et PhysicoChimie Organiques (CPCO), Laboratoire de Chimie Organique (LCO), Avenue F. D. Roosevelt 50, 1050, Bruxelles, Belgium
| | - Sophie Hermans
- Université catholique de Louvain (UCLouvain), Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), Place Louis Pasteur 1, bte L4.01.02, 1348, Louvain-la-Neuve, Belgium
| | - Olivier Riant
- Université catholique de Louvain (UCLouvain), Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), Place Louis Pasteur 1, bte L4.01.02, 1348, Louvain-la-Neuve, Belgium
| | - Ludovic Troian-Gautier
- Université catholique de Louvain (UCLouvain), Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), Place Louis Pasteur 1, bte L4.01.02, 1348, Louvain-la-Neuve, Belgium
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11
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Ogawa T, Wenger OS. Nickel(II) Analogues of Phosphorescent Platinum(II) Complexes with Picosecond Excited-State Decay. Angew Chem Int Ed Engl 2023; 62:e202312851. [PMID: 37732725 DOI: 10.1002/anie.202312851] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 09/15/2023] [Accepted: 09/18/2023] [Indexed: 09/22/2023]
Abstract
Square-planar NiII complexes are interesting as cheaper and more sustainable alternatives to PtII luminophores widely used in lighting and photocatalysis. We investigated the excited-state behavior of two NiII complexes, which are isostructural with two luminescent PtII complexes. The initially excited singlet metal-to-ligand charge transfer (1 MLCT) excited states in the NiII complexes decay to metal-centered (3 MC) excited states within less than 1 picosecond, followed by non-radiative relaxation of the 3 MC states to the electronic ground state within 9-21 ps. This contrasts with the population of an emissive triplet ligand-centered (3 LC) excited state upon excitation of the PtII analogues. Structural distortions of the NiII complexes are responsible for this discrepant behavior and lead to dark 3 MC states far lower in energy than the luminescent 3 LC states of PtII compounds. Our findings suggest that if these structural distortions could be restricted by more rigid coordination environments and stronger ligand fields, the excited-state relaxation in four-coordinate NiII complexes could be decelerated such that luminescent 3 LC or 3 MLCT excited states become accessible. These insights are relevant to make NiII fit for photophysical and photochemical applications that relied on PtII until now.
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Affiliation(s)
- Tomohiro Ogawa
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland
- Graduate School of Science and Engineering, University of Toyama, Toyama, 930-8555, Japan
| | - Oliver S Wenger
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland
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12
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Wang C, Wegeberg C, Wenger OS. First-Row d 6 Metal Complex Enables Photon Upconversion and Initiates Blue Light-Dependent Polymerization with Red Light. Angew Chem Int Ed Engl 2023; 62:e202311470. [PMID: 37681516 DOI: 10.1002/anie.202311470] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 09/07/2023] [Accepted: 09/08/2023] [Indexed: 09/09/2023]
Abstract
Photosensitizers for sensitized triplet-triplet annihilation upconversion (sTTA-UC) often rely on precious heavy metals, whereas coordination complexes based on abundant first-row transition metals are less common. This is mainly because long-lived triplet excited states are more difficult to obtain for 3d metals, particularly when the d-subshell is only partially filled. Here, we report the first example of sTTA-UC based on a 3d6 metal photosensitizer yielding an upconversion performance competitive with precious metal-based analogues. Using a newly developed Cr0 photosensitizer featuring equally good photophysical properties as an OsII benchmark complex in combination with an acetylene-decorated anthracene annihilator, red-to-blue upconversion is achievable. The upconversion efficiency under optimized conditions is 1.8 %, and the excitation power density threshold to reach the strong annihilation limit is 5.9 W/cm2 . These performance factors, along with high photostability, permit the initiation of acrylamide polymerization by red light, based on radiative energy transfer between delayed annihilator fluorescence and a blue light absorbing photo-initiator. Our study provides the proof-of-concept for photon upconversion with elusive first-row analogues of widely employed precious d6 metal photosensitizers, and for their application in photochemical reactions triggered by excitation wavelengths close to near-infrared.
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Affiliation(s)
- Cui Wang
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland
- Current address: Department of Biology and Chemistry, Osnabrück University, Barbarastraße 7, 49076, Osnabrück, Germany
| | - Christina Wegeberg
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland
- Current address: Division of Chemical Physics, Department of Chemistry, Lund University 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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13
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Pfund B, Hutskalova V, Sparr C, Wenger OS. Isoacridone dyes with parallel reactivity from both singlet and triplet excited states for biphotonic catalysis and upconversion. Chem Sci 2023; 14:11180-11191. [PMID: 37860649 PMCID: PMC10583676 DOI: 10.1039/d3sc02768f] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 09/23/2023] [Indexed: 10/21/2023] Open
Abstract
Metal-based photosensitizers commonly undergo quantitative intersystem crossing into photoactive triplet excited states. In contrast, organic photosensitizers often feature weak spin-orbit coupling and low intersystem crossing efficiencies, leading to photoactive singlet excited states. By modifying the well-known acridinium dyes, we obtained a new family of organic photocatalysts, the isoacridones, in which both singlet- and triplet-excited states are simultaneously photoactive. These new isoacridone dyes are synthetically readily accessible and show intersystem crossing efficiencies of up to 52%, forming microsecond-lived triplet excited states (T1), storing approximately 1.9 eV of energy. Their photoactive singlet excited states (S1) populated in parallel have only nanosecond lifetimes, but store ∼0.4 eV more energy and act as strong oxidants. Consequently, the new isoacridone dyes are well suited for applications requiring parallel triplet-triplet energy transfer and photoinduced electron transfer elementary steps, which have become increasingly important in modern photocatalysis. In proof-of-principle experiments, the isoacridone dyes were employed for Birch-type arene reductions and C-C couplings via sensitization-initiated electron transfer, substituting the commonly used iridium or ruthenium based photocatalysts. Further, in combination with a pyrene-based annihilator, sensitized triplet-triplet annihilation upconversion was achieved in an all-organic system, where the upconversion quantum yield correlated with the intersystem crossing quantum yield of the photosensitizer. This work seems relevant in the greater contexts of developing new applications that utilize biphotonic photophysical and photochemical behavior within metal-free systems.
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Affiliation(s)
- Björn Pfund
- Department of Chemistry, University of Basel St. Johanns-Ring 19 4056 Basel Switzerland
| | - Valeriia Hutskalova
- Department of Chemistry, University of Basel St. Johanns-Ring 19 4056 Basel Switzerland
| | - Christof Sparr
- Department of Chemistry, University of Basel St. Johanns-Ring 19 4056 Basel Switzerland
| | - Oliver S Wenger
- Department of Chemistry, University of Basel St. Johanns-Ring 19 4056 Basel Switzerland
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14
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Kim D, Rosko MC, Dang VQ, Castellano FN, Teets TS. Sterically Encumbered Heteroleptic Copper(I) β-Diketiminate Complexes with Extended Excited-State Lifetimes. Inorg Chem 2023; 62:16759-16769. [PMID: 37782937 DOI: 10.1021/acs.inorgchem.3c02042] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
One of the main challenges in developing effective copper(I) photosensitizers is their short excited-state lifetimes, usually attributed to structural distortion upon light excitation. We have previously introduced copper(I) charge-transfer chromophores of the general formula Cu(N^N)(ArNacNac), where N^N is a conjugated diimine ligand and ArNacNac is a substituted β-diketiminate ligand. These chromophores were promising regarding their tunable redox potentials and intense visible absorption but were ineffective as photosensitizers, presumably due to short excited-state lifetimes. Here, we introduce sterically crowded analogues of these heteroleptic chromophores with bulky alkyl substituents on the N^N and/or ArNacNac ligand. Structural analysis was combined with electrochemical and photophysical characterization, including ultrafast transient absorption (UFTA) spectroscopy to investigate the effects of the alkyl groups on the excited-state lifetimes of the complexes. The molecular structures determined by single-crystal X-ray diffraction display more distortion in the ground state as alkyl substituents are introduced into the phenanthroline or the NacNac ligand, showing smaller τ4 values due to the steric hindrance. UFTA measurements were carried out to determine the excited-state dynamics. Sterically encumbered Cu5 and Cu6 display excited-state lifetimes 15-20 times longer than unsubstituted complex Cu1, likely indicating that the incorporation of bulky alkyl substituents inhibits the pseudo-Jahn-Teller (PJT) flattening distortion in the excited state. This work suggests that the steric properties of these heteroleptic copper(I) charge-transfer chromophores can be readily modified and that the excited-state dynamics are strongly responsive to these modifications.
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Affiliation(s)
- Dooyoung Kim
- Department of Chemistry, University of Houston, Houston, Texas 77204-5003, United States
| | - Michael C Rosko
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
| | - Vinh Q Dang
- Department of Chemistry, University of Houston, Houston, Texas 77204-5003, United States
| | - Felix N Castellano
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
| | - Thomas S Teets
- Department of Chemistry, University of Houston, Houston, Texas 77204-5003, United States
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15
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Olesund A, Ghasemi S, Moth-Poulsen K, Albinsson B. Bulky Substituents Promote Triplet-Triplet Annihilation Over Triplet Excimer Formation in Naphthalene Derivatives. J Am Chem Soc 2023; 145:22168-22175. [PMID: 37766514 PMCID: PMC10571077 DOI: 10.1021/jacs.3c08115] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Indexed: 09/29/2023]
Abstract
Visible-to-ultraviolet (UV) triplet-triplet annihilation photochemical upconversion (TTA-UC) has gained a lot of attention recently due to its potential for driving demanding high-energy photoreactions using low-intensity visible light. The efficiency of this process has rapidly improved in the past few years, in part thanks to the recently discovered annihilator compound 1,4-bis((triisopropylsilyl)ethynyl)naphthalene (N-2TIPS). Despite its beneficial TTA-UC characteristics, the success of N-2TIPS in this context is not yet fully understood. In this work, we seek to elucidate what role the specific type and number of substituents in naphthalene annihilator compounds play to achieve the characteristics sought after for TTA-UC. We show that the type of substituent attached to the naphthalene core is crucial for its performance as an annihilator. More specifically, we argue that the choice of substituent dictates to what degree the sensitized triplets form excimer complexes with ground state annihilators of the same type, which is a process competing with that of TTA. The addition of more bulky substituents positively impacts the upconverting ability by impeding excimer formation on the triplet surface, an effect that is enhanced with the number of substituents. The presence of triplet excimers is confirmed from transient absorption measurements, and the excimer formation rate is quantified, showing several orders of magnitude differences between different derivatives. These insights will aid in the further development of annihilator compounds for solar energy applications for which the behavior at low incident powers is of particular significance.
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Affiliation(s)
- Axel Olesund
- Department
of Chemistry and Chemical Engineering, Chalmers
University of Technology, Gothenburg 412 96, Sweden
| | - Shima Ghasemi
- Department
of Chemistry and Chemical Engineering, Chalmers
University of Technology, Gothenburg 412 96, Sweden
| | - Kasper Moth-Poulsen
- Department
of Chemistry and Chemical Engineering, Chalmers
University of Technology, Gothenburg 412 96, Sweden
- Institute
of Materials Science of Barcelona, ICMAB-CSIC, Bellaterra, Barcelona 08193, Spain
- Catalan
Institution for Research and Advanced Studies ICREA, Pg. Lluís Companys 23, Barcelona 08010, Spain
- Department
of Chemical Engineering, Universitat Politècnica
de Catalunya, EEBE, Eduard
Maristany 10−14, Barcelona 08019, Spain
| | - Bo Albinsson
- Department
of Chemistry and Chemical Engineering, Chalmers
University of Technology, Gothenburg 412 96, Sweden
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16
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Shin C, Kim J, Huh S. Fluorescent and Catalytic Properties of a 2D Lamellar Zn Metal-Organic Framework with sql Network Structure. Molecules 2023; 28:6357. [PMID: 37687188 PMCID: PMC10488886 DOI: 10.3390/molecules28176357] [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: 08/07/2023] [Revised: 08/23/2023] [Accepted: 08/29/2023] [Indexed: 09/10/2023] Open
Abstract
A two-dimensional (2D) lamellar Zn metal-organic framework (Zn-MOF, 1) with a fluorescent 1,6-di(pyridin-3-yl)pyrene (3-DPPy) and 1,4-benzenedicarboxylate (BDC2-) bridging linkers was prepared and structurally characterized. The chemical formula of 1 is [Zn(μ-3-DPPy)(μ-BDC)]n. The mononuclear Zn(II) ion, acting as a node, is tetrahedrally coordinated with two 3-DPPy and two BDC linkers. The coordination environment of Zn(II) is a distorted tetrahedral geometry. The Zn-MOF is the sql network structure based on topology analysis. The undulated 2D sheets of 1 tightly pack together to form a lamellar structure. The pyrene moieties are parallelly oriented to each other. The Zn-MOF is not porous, possibly because the mononuclear Zn(II) node did not form cluster-based secondary building units due to the less symmetric 3-DPPy. The steady-state fluorescence measurements indicate that the fluorescence signal of the 1 is slightly blue-shifted compared to the free 3-DPPy in the solid state. The excimer emission band at 463 nm for crystalline 3-DPPy is shifted to 447 nm for 1. The value of 447 nm is also a blue-shift value compared to nonsubstituted pyrene crystals (470 nm). Despite its nonporosity, the surface Lewis acidic sites of 1 could catalyze the transesterification of esters. Surface defect sites are responsible for this catalytic activity.
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Affiliation(s)
| | | | - Seong Huh
- Department of Chemistry and Protein Research Center for Bio-Industry, Hankuk University of Foreign Studies, Yongin 17035, Republic of Korea
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17
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Kitzmann WR, Bertrams MS, Boden P, Fischer AC, Klauer R, Sutter J, Naumann R, Förster C, Niedner-Schatteburg G, Bings NH, Hunger J, Kerzig C, Heinze K. Stable Molybdenum(0) Carbonyl Complex for Upconversion and Photoredox Catalysis. J Am Chem Soc 2023. [PMID: 37478053 DOI: 10.1021/jacs.3c03832] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/23/2023]
Abstract
Photoactive complexes with earth-abundant metals have attracted increasing interest in the recent years fueled by the promise of sustainable photochemistry. However, sophisticated ligands with complicated syntheses are oftentimes required to enable photoactivity with nonprecious metals. Here, we combine a cheap metal with simple ligands to easily access a photoactive complex. Specifically, we synthesize the molybdenum(0) carbonyl complex Mo(CO)3(tpe) featuring the tripodal ligand 1,1,1-tris(pyrid-2-yl)ethane (tpe) in two steps with a high overall yield. The complex shows intense deep-red phosphorescence with excited state lifetimes of several hundred nanoseconds. Time-resolved infrared spectroscopy and laser flash photolysis reveal a triplet metal-to-ligand charge-transfer (3MLCT) state as the lowest excited state. Temperature-dependent luminescence complemented by density functional theory (DFT) calculations suggest thermal deactivation of the 3MLCT state via higher lying metal-centered states in analogy to the well-known photophysics of [Ru(bpy)3]2+. Importantly, we found that the title compound is very photostable due to the lack of labilized Mo-CO bonds (as caused by trans-coordinated CO) in the facial configuration of the ligands. Finally, we show the versatility of the molybdenum(0) complex in two applications: (1) green-to-blue photon upconversion via a triplet-triplet annihilation mechanism and (2) photoredox catalysis for a green-light-driven dehalogenation reaction. Overall, our results establish tripodal carbonyl complexes as a promising design strategy to access stable photoactive complexes of nonprecious metals avoiding tedious multistep syntheses.
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Affiliation(s)
- Winald R Kitzmann
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Maria-Sophie Bertrams
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Pit Boden
- Department of Chemistry and State Research Center OPTIMAS, RPTU Kaiserslautern, Erwin-Schrödinger-Straße 52, 67663 Kaiserslautern-Landau, Germany
| | - Alexander C Fischer
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - René Klauer
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Johannes Sutter
- Max-Planck-Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Robert Naumann
- 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
| | - Gereon Niedner-Schatteburg
- Department of Chemistry and State Research Center OPTIMAS, RPTU Kaiserslautern, Erwin-Schrödinger-Straße 52, 67663 Kaiserslautern-Landau, Germany
| | - Nicolas H Bings
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Johannes Hunger
- Max-Planck-Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Christoph Kerzig
- 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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18
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Li H, Wang C, Glaser F, Sinha N, Wenger OS. Metal-Organic Bichromophore Lowers the Upconversion Excitation Power Threshold and Promotes UV Photoreactions. J Am Chem Soc 2023; 145:11402-11414. [PMID: 37186558 PMCID: PMC10214436 DOI: 10.1021/jacs.3c02609] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Indexed: 05/17/2023]
Abstract
Sensitized triplet-triplet annihilation upconversion is a promising strategy to use visible light for chemical reactions requiring the energy input of UV photons. This strategy avoids unsafe ultraviolet light sources and can mitigate photo-damage and provide access to reactions, for which filter effects hamper direct UV excitation. Here, we report a new approach to make blue-to-UV upconversion more amenable to photochemical applications. The tethering of a naphthalene unit to a cyclometalated iridium(III) complex yields a bichromophore with a high triplet energy (2.68 eV) and a naphthalene-based triplet reservoir featuring a lifetime of 72.1 μs, roughly a factor of 20 longer than the photoactive excited state of the parent iridium(III) complex. In combination with three different annihilators, consistently lower thresholds for the blue-to-UV upconversion to crossover from a quadratic into a linear excitation power dependence regime were observed with the bichromophore compared to the parent iridium(III) complex. The upconversion system composed of the bichromophore and the 2,5-diphenyloxazole annihilator is sufficiently robust under long-term blue irradiation to continuously provide a high-energy singlet-excited state that can drive chemical reactions normally requiring UV light. Both photoredox and energy transfer catalyses were feasible using this concept, including the reductive N-O bond cleavage of Weinreb amides, a C-C coupling reaction based on reductive aryl debromination, and two Paternò-Büchi [2 + 2] cycloaddition reactions. Our work seems relevant in the context of developing new strategies for driving energetically demanding photochemistry with low-energy input light.
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Affiliation(s)
- Han Li
- Department of Chemistry, University
of Basel, St. Johanns-Ring 19, Basel 4056, Switzerland
| | - Cui Wang
- Department of Chemistry, University
of Basel, St. Johanns-Ring 19, Basel 4056, Switzerland
| | - Felix Glaser
- Department of Chemistry, University
of Basel, St. Johanns-Ring 19, Basel 4056, Switzerland
| | - Narayan Sinha
- Department of Chemistry, University
of Basel, St. Johanns-Ring 19, Basel 4056, Switzerland
| | - Oliver S. Wenger
- Department of Chemistry, University
of Basel, St. Johanns-Ring 19, Basel 4056, Switzerland
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19
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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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20
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Schloemer T, Narayanan P, Zhou Q, Belliveau E, Seitz M, Congreve DN. Nanoengineering Triplet-Triplet Annihilation Upconversion: From Materials to Real-World Applications. ACS NANO 2023; 17:3259-3288. [PMID: 36800310 DOI: 10.1021/acsnano.3c00543] [Citation(s) in RCA: 23] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Using light to control matter has captured the imagination of scientists for generations, as there is an abundance of photons at our disposal. Yet delivering photons beyond the surface to many photoresponsive systems has proven challenging, particularly at scale, due to light attenuation via absorption and scattering losses. Triplet-triplet annihilation upconversion (TTA-UC), a process which allows for low energy photons to be converted to high energy photons, is poised to overcome these challenges by allowing for precise spatial generation of high energy photons due to its nonlinear nature. With a wide range of sensitizer and annihilator motifs available for TTA-UC, many researchers seek to integrate these materials in solution or solid-state applications. In this Review, we discuss nanoengineering deployment strategies and highlight their uses in recent state-of-the-art examples of TTA-UC integrated in both solution and solid-state applications. Considering both implementation tactics and application-specific requirements, we identify critical needs to push TTA-UC-based applications from an academic curiosity to a scalable technology.
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Affiliation(s)
- Tracy Schloemer
- Department of Electrical Engineering, Stanford University, Stanford, California 94305, United States
| | - Pournima Narayanan
- Department of Electrical Engineering, Stanford University, Stanford, California 94305, United States
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Qi Zhou
- Department of Electrical Engineering, Stanford University, Stanford, California 94305, United States
| | - Emma Belliveau
- Department of Electrical Engineering, Stanford University, Stanford, California 94305, United States
| | - Michael Seitz
- Department of Electrical Engineering, Stanford University, Stanford, California 94305, United States
| | - Daniel N Congreve
- Department of Electrical Engineering, Stanford University, Stanford, California 94305, United States
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21
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Zähringer TJB, Moghtader JA, Bertrams MS, Roy B, Uji M, Yanai N, Kerzig C. Blue-to-UVB Upconversion, Solvent Sensitization and Challenging Bond Activation Enabled by a Benzene-Based Annihilator. Angew Chem Int Ed Engl 2023; 62:e202215340. [PMID: 36398891 PMCID: PMC10108172 DOI: 10.1002/anie.202215340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 11/18/2022] [Accepted: 11/18/2022] [Indexed: 11/19/2022]
Abstract
Several energy-demanding photoreactions require harsh UV light from inefficient light sources. The conversion of low-energy visible light to high-energy singlet states via triplet-triplet annihilation upconversion (TTA-UC) could offer a solution for driving such reactions under mild conditions. We present the first annihilator with an emission maximum in the UVB region that, combined with an organic sensitizer, is suitable for blue-to-UVB upconversion. The annihilator singlet was successfully employed as an energy donor in subsequent FRET activations of aliphatic carbonyls. This hitherto unreported UC-FRET reaction sequence was directly monitored using laser spectroscopy and applied to mechanistic irradiation experiments demonstrating the feasibility of Norrish chemistry. Our results provide clear evidence for a novel blue light-driven substrate or solvent activation strategy, which is important in the context of developing more sustainable light-to-chemical energy conversion systems.
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Affiliation(s)
- Till J B Zähringer
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128, Mainz, Germany
| | - Julian A Moghtader
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128, Mainz, Germany
| | - Maria-Sophie Bertrams
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128, Mainz, Germany
| | - Bibhisan Roy
- Department of Applied Chemistry, Graduate School of Engineering, Center for Molecular Systems (CMS), Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Masanori Uji
- Department of Applied Chemistry, Graduate School of Engineering, Center for Molecular Systems (CMS), Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Nobuhiro Yanai
- Department of Applied Chemistry, Graduate School of Engineering, Center for Molecular Systems (CMS), Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Christoph Kerzig
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128, Mainz, Germany
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22
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Mrózek O, Mitra M, Hupp B, Belyaev A, Lüdtke N, Wagner D, Wang C, Wenger OS, Marian CM, Steffen A. An Air- and Moisture-stable Zinc(II) Carbene Dithiolate Dimer Showing Fast Thermally Activated Delayed Fluorescence and Dexter Energy Transfer Catalysis. Chemistry 2023; 29:e202203980. [PMID: 36637038 DOI: 10.1002/chem.202203980] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 01/06/2023] [Accepted: 01/09/2023] [Indexed: 01/14/2023]
Abstract
A dimeric ZnII carbene complex featuring bridging and chelating benzene-1,2-dithiolate ligands is highly stable towards air and water. The donor-Zn-acceptor structure leads to visible light emission in the solid state, solution and polymer matrices with λmax between 577-657 nm and, for zinc(II) complexes, unusually high radiative rate constants for triplet exciton decay of up to kr =1.5×105 s-1 at room temperature. Variable temperature and DFT/MRCI studies show that a small energy gap between the 1/3 LL/LMCT states of only 79 meV is responsible for efficient thermally activated delayed fluorescence (TADF). Time-resolved luminescence and transient absorption studies confirm the occurrence of long-lived, dominantly ligand-to-ligand charge transfer excited states in solution, allowing for application in Dexter energy transfer photocatalysis.
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Affiliation(s)
- Ondřej Mrózek
- Department of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Str. 6, 44227, Dortmund, Germany
| | - Mousree Mitra
- Department of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Str. 6, 44227, Dortmund, Germany
| | - Bejamin Hupp
- Department of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Str. 6, 44227, Dortmund, Germany
| | - Andrey Belyaev
- Department of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Str. 6, 44227, Dortmund, Germany
| | - Nora Lüdtke
- Institute of Theoretical and Computational Chemistry, Heinrich Heine University Düsseldorf, 40225, Düsseldorf, Germany
| | - Dorothee Wagner
- Department of Chemistry, University of Basel, 4056, Basel, Switzerland
| | - Cui Wang
- Department of Chemistry, University of Basel, 4056, Basel, Switzerland
| | - Oliver S Wenger
- Department of Chemistry, University of Basel, 4056, Basel, Switzerland
| | - Christel M Marian
- Institute of Theoretical and Computational Chemistry, Heinrich Heine University Düsseldorf, 40225, Düsseldorf, Germany
| | - Andreas Steffen
- Department of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Str. 6, 44227, Dortmund, Germany
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