1
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Jaros SW, Sokolnicki J, Siczek M, Smoleński P. Strategy for an Effective Eco-Optimized Design of Heteroleptic Cu(I) Coordination Polymers Exhibiting Thermally Activated Delayed Fluorescence. Inorg Chem 2023. [PMID: 38010323 DOI: 10.1021/acs.inorgchem.3c01908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
The new series of copper(I) coordination polymers [Cu(N-N)(μ-PTA)]n[PF6]n {N-N = dmbpy (1), bpy (2), ncup (3), and phen (4)} were generated by straightforward reaction in solution or through a mechanochemical route, of [Cu(MeCN)4][PF6] with 1,3,5-triaza-7-phosphaadamantane (PTA) and the corresponding polypyridines, namely, 5,5'-dimethyl-2,2'-bipyridine (dmbpy), 2,2'-bipyridine (bpy), 2,9-dimethyl-1,10-phenanthroline (ncup), and 1,10-phenanthroline (phen). The compounds were obtained as air-stable solids and fully characterized by IR, NMR spectroscopy, and elemental analyses. The molecular structures were confirmed by single-crystal X-ray diffraction analysis (for 1, 2, and 4), revealing infinite one-dimensional (1D) linear chains driven by μ-PTA N,P-linkers. All tested Cu(I) polymeric compounds show emission at room temperature, which was attributed to thermally activated delayed fluorescence (TADF). Evidence of the involvement of the excited singlet state in the emission process is presented. Comparing the photophysical properties of 1 and 2 as well as 3 and 4, of which 1 and 3 have a stiffened structure, by introducing a methyl group to one of the ligands, we demonstrate how TADF properties depend on molecular rigidity. It is shown that stiffening of the structure reduces the flattening distortion around the Cu(I) center in the 3MLCT state. As a result, the ΔE(S1-T1) energy gap becomes smaller and the fluorescence quantum yield increases without significantly extending the emission lifetime. In particular, the ΔE(S1-T1) values for complexes 1 and 3 are among the shortest reported in the scientific literature, 253 and 337 cm-1, and the TADF lifetimes are τ(300 K) = 5.7 and 4.2 μs, respectively. The fluorescence quantum yields for these complexes are measured to be ΦPL(300 K) = 70 and 80%.
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Affiliation(s)
- Sabina W Jaros
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland
| | - Jerzy Sokolnicki
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland
| | - Miłosz Siczek
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland
| | - Piotr Smoleński
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland
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2
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Wang D, Hu W, Liu C, Huang J, Zhang X. Electronic Tuning of Photoexcited Dynamics in Heteroleptic Cu(I) Complex Photosensitizers. J Phys Chem Lett 2023; 14:10137-10144. [PMID: 37922426 DOI: 10.1021/acs.jpclett.3c02503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2023]
Abstract
Photoexcited dynamics of heteroleptic Cu(I) complexes as noble-metal-free photosensitizers are closely intertwined with the nature of their ligands. By utilizing ultrafast optical and X-ray transient absorption spectroscopies, we characterized a new set of heteroleptic Cu(I) complexes [Cu(PPh3)2(BPyR)]+ (R = CH3, H, Br to COOCH3), with an increase in the electron-withdrawing ability of the functional group (R). We found that after the transient photooxidation of Cu(I) to Cu(II), the increasing electron-withdrawing ability of R barely affects the internal conversion (IC) (e.g., Jahn-taller (JT) distortion) between singlet MLCT states. However, it does accelerate the dynamics of intersystem crossing (ISC) between singlet and triplet MLCT states and the subsequent decay from the triplet MLCT state to the ground state. The associated lifetime constants are reduced by up to 300%. Our understanding of the photoexcited dynamics in heteroleptic Cu(I) complexes through ligand electronic tuning provides valuable insight into the rational design of efficient Cu(I) complex photosensitizers.
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Affiliation(s)
- Denan Wang
- Department of Chemistry, Marquette University, Milwaukee, 53201, United States
| | - Wenhui Hu
- Department of Chemistry, Marquette University, Milwaukee, 53201, United States
| | - Cunming Liu
- X-ray Science Division, Argonne National Laboratory, Argonne, Illinois 60349, United States
| | - Jier Huang
- Department of Chemistry, Marquette University, Milwaukee, 53201, United States
- Department of Chemistry and Schiller Institute for Integrated Science and Society, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Xiaoyi Zhang
- X-ray Science Division, Argonne National Laboratory, Argonne, Illinois 60349, United States
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3
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Wang L, Xie ZL, Phelan BT, Lynch VM, Chen LX, Mulfort KL. Changing Directions: Influence of Ligand Electronics on the Directionality and Kinetics of Photoinduced Charge Transfer in Cu(I)Diimine Complexes. Inorg Chem 2023; 62:14368-14376. [PMID: 37620247 DOI: 10.1021/acs.inorgchem.3c02043] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/26/2023]
Abstract
A key challenge to the effective utilization of solar energy is to promote efficient photoinduced charge transfer, specifically avoiding unproductive, circuitous electron-transfer pathways and optimizing the kinetics of charge separation and recombination. We hypothesize that one way to address this challenge is to develop a fundamental understanding of how to initiate and control directional photoinduced charge transfer, particularly for earth-abundant first-row transition-metal coordination complexes, which typically suffer from relatively short excited-state lifetimes. Here, we report a series of functionalized heteroleptic copper(I)bis(phenanthroline) complexes, which have allowed us to investigate the directionality of intramolecular photoinduced metal-to-ligand charge transfer (MLCT) as a function of the substituent Hammett parameter. Ultrafast transient absorption suggests a complicated interplay of MLCT localization and solvent interaction with the Cu(II) center of the MLCT state. This work provides a set of design principles for directional charge transfer in earth-abundant complexes and can be used to efficiently design pathways for connecting the molecular modules to catalysts or electrodes and integration into systems for light-driven catalysis.
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Affiliation(s)
- Lei Wang
- Division of Chemical Sciences and Engineering, Argonne National Laboratory, Lemont, Illinois 60439, United States
- School of Materials and Chemistry, University of Shanghai for Science and Technology, Shanghai 200093, China
| | - Zhu-Lin Xie
- Division of Chemical Sciences and Engineering, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Brian T Phelan
- Division of Chemical Sciences and Engineering, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Vincent M Lynch
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Lin X Chen
- Division of Chemical Sciences and Engineering, Argonne National Laboratory, Lemont, Illinois 60439, United States
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Karen L Mulfort
- Division of Chemical Sciences and Engineering, Argonne National Laboratory, Lemont, Illinois 60439, United States
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4
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Appleby MV, Cowin RA, Ivalo II, Peralta-Arriaga SL, Robertson CC, Bartlett S, Fitzpatrick A, Dent A, Karras G, Diaz-Moreno S, Chekulaev D, Weinstein JA. Ultrafast electronic, infrared, and X-ray absorption spectroscopy study of Cu(I) phosphine diimine complexes. Faraday Discuss 2023; 244:391-410. [PMID: 37415486 DOI: 10.1039/d3fd00027c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/08/2023]
Abstract
The study aims to understand the role of the transient bonding in the interplay between the structural and electronic changes in heteroleptic Cu(I) diimine diphosphine complexes. This is an emerging class of photosensitisers which absorb in the red region of the spectrum, whilst retaining a sufficiently long excited state lifetime. Here, the dynamics of these complexes are explored by transient absorption (TA) and time-resolved infrared (TRIR) spectroscopy, which reveal ultrafast intersystem crossing and structural distortion occurring. Two potential mechanisms affecting excited state decay in these complexes involve a transient formation of a solvent adduct, made possible by the opening up of the Cu coordination centre in the excited state due to structural distortion, and by a transient coordination of the O-atom of the phosphine ligand to the copper center. X-ray absorption studies of the ground electronic state have been conducted as a prerequisite for the upcoming X-ray spectroscopy studies which will directly determine structural dynamics. The potential for these complexes to be used in bimolecular applications is confirmed by a significant yield of singlet oxygen production.
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Affiliation(s)
- Martin V Appleby
- Department of Chemistry, The University of Sheffield, Sheffield, S3 7HF, UK.
| | - Rory A Cowin
- Department of Chemistry, The University of Sheffield, Sheffield, S3 7HF, UK.
| | - Iona I Ivalo
- Department of Chemistry, The University of Sheffield, Sheffield, S3 7HF, UK.
| | | | - Craig C Robertson
- Department of Chemistry, The University of Sheffield, Sheffield, S3 7HF, UK.
| | - Stuart Bartlett
- Diamond Light Source, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, UK
| | - Ann Fitzpatrick
- Diamond Light Source, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, UK
| | - Andrew Dent
- Diamond Light Source, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, UK
| | - Gabriel Karras
- Diamond Light Source, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, UK
| | - Sofia Diaz-Moreno
- Diamond Light Source, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, UK
| | - Dimitri Chekulaev
- Department of Chemistry, The University of Sheffield, Sheffield, S3 7HF, UK.
| | - Julia A Weinstein
- Department of Chemistry, The University of Sheffield, Sheffield, S3 7HF, UK.
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5
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Yersin H, Czerwieniec R, Monkowius U, Ramazanov R, Valiev R, Shafikov MZ, Kwok WM, Ma C. Intersystem crossing, phosphorescence, and spin-orbit coupling. Two contrasting Cu(I)-TADF dimers investigated by milli- to micro-second phosphorescence, femto-second fluorescence, and theoretical calculations. Coord Chem Rev 2023. [DOI: 10.1016/j.ccr.2022.214975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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6
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Seidler B, Tran JH, Hniopek J, Traber P, Görls H, Gräfe S, Schmitt M, Popp J, Schulz M, Dietzek-Ivanšić B. Photophysics of Anionic Bis(4H-imidazolato)Cu I Complexes. Chemistry 2022; 28:e202202697. [PMID: 36148551 PMCID: PMC10092831 DOI: 10.1002/chem.202202697] [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: 08/29/2022] [Indexed: 12/29/2022]
Abstract
In this paper, the photophysical behavior of four panchromatically absorbing, homoleptic bis(4H-imidazolato)CuI complexes, with a systematic variation in the electron-withdrawing properties of the imidazolate ligand, were studied by wavelength-dependent time-resolved femtosecond transient absorption spectroscopy. Excitation at 400, 480, and 630 nm populates metal-to-ligand charge transfer, intraligand charge transfer, and mixed-character singlet states. The pump wavelength-dependent transient absorption data were analyzed by a recently established 2D correlation approach. Data analysis revealed that all excitation conditions yield similar excited-state dynamics. Key to the excited-state relaxation is fast, sub-picosecond pseudo-Jahn-Teller distortion, which is accompanied by the relocalization of electron density onto a single ligand from the initially delocalized state at Franck-Condon geometry. Subsequent intersystem crossing to the triplet manifold is followed by a sub-100 ps decay to the ground state. The fast, nonradiative decay is rationalized by the low triplet-state energy as found by DFT calculations, which suggest perspective treatment at the strong coupling limit of the energy gap law.
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Affiliation(s)
- Bianca Seidler
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany.,Leibniz Institute of Photonic Technology Jena (Leibniz-IPHT), Albert-Einstein-Str. 9, 07745, Jena, Germany
| | - Jens H Tran
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany
| | - Julian Hniopek
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany.,Leibniz Institute of Photonic Technology Jena (Leibniz-IPHT), Albert-Einstein-Str. 9, 07745, Jena, Germany.,Abbe Center of Photonics (ACP), Albert-Einstein-Str. 6, 07745, Jena, Germany
| | - Philipp Traber
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany
| | - Helmar Görls
- Institute of Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, Humboldtstr. 8, 07743, Jena, Germany
| | - Stefanie Gräfe
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany.,Abbe Center of Photonics (ACP), Albert-Einstein-Str. 6, 07745, Jena, Germany
| | - Michael Schmitt
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany.,Abbe Center of Photonics (ACP), Albert-Einstein-Str. 6, 07745, Jena, Germany
| | - Jürgen Popp
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany.,Leibniz Institute of Photonic Technology Jena (Leibniz-IPHT), Albert-Einstein-Str. 9, 07745, Jena, Germany.,Abbe Center of Photonics (ACP), Albert-Einstein-Str. 6, 07745, Jena, Germany
| | - Martin Schulz
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany.,Leibniz Institute of Photonic Technology Jena (Leibniz-IPHT), Albert-Einstein-Str. 9, 07745, Jena, Germany
| | - Benjamin Dietzek-Ivanšić
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany.,Leibniz Institute of Photonic Technology Jena (Leibniz-IPHT), Albert-Einstein-Str. 9, 07745, Jena, Germany.,Abbe Center of Photonics (ACP), Albert-Einstein-Str. 6, 07745, Jena, Germany.,Centre for Energy and Environmental Chemistry Jena (CEEC-Jena), Friedrich Schiller University Jena, Philosophenweg 7a, 07743, Jena, Germany
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7
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Beaudelot J, Oger S, Peruško S, Phan TA, Teunens T, Moucheron C, Evano G. Photoactive Copper Complexes: Properties and Applications. Chem Rev 2022; 122:16365-16609. [PMID: 36350324 DOI: 10.1021/acs.chemrev.2c00033] [Citation(s) in RCA: 50] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Photocatalyzed and photosensitized chemical processes have seen growing interest recently and have become among the most active areas of chemical research, notably due to their applications in fields such as medicine, chemical synthesis, material science or environmental chemistry. Among all homogeneous catalytic systems reported to date, photoactive copper(I) complexes have been shown to be especially attractive, not only as alternative to noble metal complexes, and have been extensively studied and utilized recently. They are at the core of this review article which is divided into two main sections. The first one focuses on an exhaustive and comprehensive overview of the structural, photophysical and electrochemical properties of mononuclear copper(I) complexes, typical examples highlighting the most critical structural parameters and their impact on the properties being presented to enlighten future design of photoactive copper(I) complexes. The second section is devoted to their main areas of application (photoredox catalysis of organic reactions and polymerization, hydrogen production, photoreduction of carbon dioxide and dye-sensitized solar cells), illustrating their progression from early systems to the current state-of-the-art and showcasing how some limitations of photoactive copper(I) complexes can be overcome with their high versatility.
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Affiliation(s)
- Jérôme Beaudelot
- Laboratoire de Chimie Organique, Service de Chimie et PhysicoChimie Organiques, Université libre de Bruxelles (ULB), Avenue F. D. Roosevelt 50 - CP160/06, 1050Brussels, Belgium.,Laboratoire de Chimie Organique et Photochimie, Service de Chimie et PhysicoChimie Organiques, Université libre de Bruxelles (ULB), Avenue F. D. Roosevelt 50 - CP160/08, 1050Brussels, Belgium
| | - Samuel Oger
- Laboratoire de Chimie Organique, Service de Chimie et PhysicoChimie Organiques, Université libre de Bruxelles (ULB), Avenue F. D. Roosevelt 50 - CP160/06, 1050Brussels, Belgium
| | - Stefano Peruško
- Laboratoire de Chimie Organique, Service de Chimie et PhysicoChimie Organiques, Université libre de Bruxelles (ULB), Avenue F. D. Roosevelt 50 - CP160/06, 1050Brussels, Belgium.,Organic Synthesis Division, Department of Chemistry, University of Antwerp, Groenenborgerlaan 171, 2020Antwerp, Belgium
| | - Tuan-Anh Phan
- Laboratoire de Chimie Organique et Photochimie, Service de Chimie et PhysicoChimie Organiques, Université libre de Bruxelles (ULB), Avenue F. D. Roosevelt 50 - CP160/08, 1050Brussels, Belgium
| | - Titouan Teunens
- Laboratoire de Chimie Organique et Photochimie, Service de Chimie et PhysicoChimie Organiques, Université libre de Bruxelles (ULB), Avenue F. D. Roosevelt 50 - CP160/08, 1050Brussels, Belgium.,Laboratoire de Chimie des Matériaux Nouveaux, Université de Mons, Place du Parc 20, 7000Mons, Belgium
| | - Cécile Moucheron
- Laboratoire de Chimie Organique et Photochimie, Service de Chimie et PhysicoChimie Organiques, Université libre de Bruxelles (ULB), Avenue F. D. Roosevelt 50 - CP160/08, 1050Brussels, Belgium
| | - Gwilherm Evano
- Laboratoire de Chimie Organique, Service de Chimie et PhysicoChimie Organiques, Université libre de Bruxelles (ULB), Avenue F. D. Roosevelt 50 - CP160/06, 1050Brussels, Belgium
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8
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Recent developments of photoactive Cu(I) and Ag(I) complexes with diphosphine and related ligands. Coord Chem Rev 2022. [DOI: 10.1016/j.ccr.2022.214700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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9
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Rentschler M, Boden PJ, Argüello Cordero MA, Steiger ST, Schmid MA, Yang Y, Niedner-Schatteburg G, Karnahl M, Lochbrunner S, Tschierlei S. Unexpected Boost in Activity of a Cu(I) Photosensitizer by Stabilizing a Transient Excited State. Inorg Chem 2022; 61:12249-12261. [PMID: 35877171 DOI: 10.1021/acs.inorgchem.2c01468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In this study, we present a slight but surprisingly successful structural modification of the previously reported heteroleptic Cu(I) photosensitizer Cubiipo ([(xantphos)Cu(biipo)]PF6; biipo = 16H-benzo-[4',5']-isoquinolino-[2',1':1,2]-imidazo-[4,5-f]-[1,10]-phenanthrolin-16-one). As a key feature, biipo bears a naphthalimide unit at the back, which is directly fused to a phenanthroline moiety to extend the conjugated π-system. This ligand was now altered to include two additional methyl groups at the 2,9-positions at the phenanthroline scaffold. Comparing the novel Cudmbiipo complex to its predecessor, ultrafast transient absorption spectroscopy reveals the efficient suppression of a major deactivation pathway by stabilization of a transient triplet state. Furthermore, quantitative measurements of singlet oxygen evolution in solution confirmed that a larger fraction of the excited-state population is transferred to the photocatalytically active ligand-centered triplet 3LC state with a much longer lifetime of ∼30 μs compared to Cubiipo (2.6 μs). In addition, Cudmbiipo was compared with the well-established reference complex Cubcp ([(xantphos)Cu(bathocuproine)]PF6) in terms of its photophysical and photocatalytic properties by applying time-resolved femto- and nanosecond absorption, step-scan Fourier transform infrared (FTIR), and emission spectroscopies. Superior light-harvesting properties and a greatly enhanced excited-state lifetime with respect to Cubcp enable Cudmbiipo to be more active in exemplary photocatalytic applications, i.e., in the formation of singlet oxygen and the isomerization of (E)-stilbene.
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Affiliation(s)
- Martin Rentschler
- Department of Energy Conversion, Institute of Physical and Theoretical Chemistry, Technische Universität Braunschweig, Rebenring 31, 38106 Braunschweig, Germany
| | - Pit Jean Boden
- Chemistry Department and State Research Center Optimas, TU Kaiserslautern, Erwin-Schrödinger-Straße 52, 67663 Kaiserslautern, Germany
| | - Miguel A Argüello Cordero
- Institute for Physics and Department of Life, Light and Matter, University of Rostock, Albert-Einstein-Straße 23, 18051 Rostock, Germany
| | - Sophie Theres Steiger
- Chemistry Department and State Research Center Optimas, TU Kaiserslautern, Erwin-Schrödinger-Straße 52, 67663 Kaiserslautern, Germany
| | - Marie-Ann Schmid
- Department of Energy Conversion, Institute of Physical and Theoretical Chemistry, Technische Universität Braunschweig, Rebenring 31, 38106 Braunschweig, Germany
| | - Yingya Yang
- Department of Energy Conversion, Institute of Physical and Theoretical Chemistry, Technische Universität Braunschweig, Rebenring 31, 38106 Braunschweig, Germany
| | - Gereon Niedner-Schatteburg
- Chemistry Department and State Research Center Optimas, TU Kaiserslautern, Erwin-Schrödinger-Straße 52, 67663 Kaiserslautern, Germany
| | - Michael Karnahl
- Department of Energy Conversion, Institute of Physical and Theoretical Chemistry, Technische Universität Braunschweig, Rebenring 31, 38106 Braunschweig, Germany
| | - Stefan Lochbrunner
- Institute for Physics and Department of Life, Light and Matter, University of Rostock, Albert-Einstein-Straße 23, 18051 Rostock, Germany
| | - Stefanie Tschierlei
- Department of Energy Conversion, Institute of Physical and Theoretical Chemistry, Technische Universität Braunschweig, Rebenring 31, 38106 Braunschweig, Germany
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10
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Santander-Nelli M, Sanhueza L, Navas D, Rossin E, Natali M, Dreyse P. Unusual fluorescence behaviour of a heteroleptic Cu( i) complex featuring strong electron donating groups on a diimine ligand. NEW J CHEM 2022. [DOI: 10.1039/d1nj04811b] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Synthesis of a novel bulky diimine ligand and its corresponding heteroleptic Cu(i). Unusual fluorescence behavior of a novel Cu(i) complex due to a strong electron-donor diimine ligand.
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Affiliation(s)
- Mireya Santander-Nelli
- Departamento de Química, Universidad Técnica Federico Santa María, Av. España 1680, Casilla 2390123, Valparaíso, Chile
- Centro Integrativo de Biología y Química Aplicada (CIBQA), Universidad Bernardo O'Higgins, General Gana 1702, Santiago 8370854, Chile
| | - Luis Sanhueza
- Departamento de Ciencias Biológicas y Químicas, Facultad de Recursos Naturales, Universidad Católica de Temuco, Casilla 15-D, Temuco, Chile
- Núcleo de Investigación en Bioproductos y Materiales Avanzados (BioMA), Universidad Católica de Temuco, Av. Rudecindo Ortega, 02950 Temuco, Chile
| | - Daniel Navas
- Departamento de Química, Facultad de Ciencias Naturales, Matemática y del Medio Ambiente, Universidad Tecnológica Metropolitana, Las Palmeras 3360, Ñuñoa, Santiago 7800003, Chile
| | - Elena Rossin
- Department of Chemical, Pharmaceutical and Agricultural Sciences (DOCPAS), University of Ferrara, Via L. Borsari 46, 44121 Ferrara, Italy
- Department of Chemical Sciences, University of Padova, Via F. Marzolo 1, 35131, Padova, Italy
| | - Mirco Natali
- Department of Chemical, Pharmaceutical and Agricultural Sciences (DOCPAS), University of Ferrara, Via L. Borsari 46, 44121 Ferrara, Italy
| | - Paulina Dreyse
- Departamento de Química, Universidad Técnica Federico Santa María, Av. España 1680, Casilla 2390123, Valparaíso, Chile
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11
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Argüello Cordero MA, Boden PJ, Rentschler M, Di Martino-Fumo P, Frey W, Yang Y, Gerhards M, Karnahl M, Lochbrunner S, Tschierlei S. Comprehensive Picture of the Excited State Dynamics of Cu(I)- and Ru(II)-Based Photosensitizers with Long-Lived Triplet States. Inorg Chem 2021; 61:214-226. [PMID: 34908410 DOI: 10.1021/acs.inorgchem.1c02771] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Ru(II)- and Cu(I)-based photosensitizers featuring the recently developed biipo ligand (16H-benzo-[4',5']-isoquinolino-[2',1',:1,2]-imidazo-[4,5-f]-[1,10]-phenanthrolin-16-one) were comprehensively investigated by X-ray crystallography, electrochemistry, and especially several time-resolved spectroscopic methods covering all time scales from femto- to milliseconds. The analysis of the experimental results is supported by density functional theory (DFT) calculations. The biipo ligand consists of a coordinating 1,10-phenanthroline moiety fused with a 1,8-naphthalimide unit, which results in an extended π-system with an incorporated electron acceptor moiety. In a previous study, it was shown that this ligand enabled a Ru(II) complex that is an efficient singlet oxygen producer and of potential use for other light-driven applications due to its long emission lifetime. The goal of our here presented research is to provide a full spectroscopic picture of the processes that follow optical excitation. Interestingly, the Ru(II) and Cu(I) complexes differ in their characteristics even though the lowest electronically excited states involve in both cases the biipo ligand. The combined spectroscopic results indicate that an emissive 3MLCT state and a rather dark 3LC state are populated, each to some extent. For the Cu(I) complex, most of the excited population ends up in the 3LC state with an extraordinary lifetime of 439 μs in the solid state at 20 K, while a significant population of the 3MLCT state causes luminescence for the Ru(II) complex. Hence, there is a balance between these two states, which can be tuned by altering the metal center or even by thermal energy, as suggested by the temperature-dependent experiments.
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Affiliation(s)
- Miguel A Argüello Cordero
- Institute for Physics and Department of Life, Light and Matter, University of Rostock, 18051 Rostock, Germany
| | - Pit Jean Boden
- Chemistry Department and Research Center Optimas, TU Kaiserslautern, Erwin-Schrödinger-Straße 52, 67663 Kaiserslautern, Germany
| | - Martin Rentschler
- Institute of Organic Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany.,Department of Energy Conversion, Institute of Physical and Theoretical Chemistry, Technische Universität Braunschweig, Gaußstraße 17, 38106 Braunschweig, Germany
| | - Patrick Di Martino-Fumo
- Chemistry Department and Research Center Optimas, TU Kaiserslautern, Erwin-Schrödinger-Straße 52, 67663 Kaiserslautern, Germany
| | - Wolfgang Frey
- Institute of Organic Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Yingya Yang
- Department of Energy Conversion, Institute of Physical and Theoretical Chemistry, Technische Universität Braunschweig, Gaußstraße 17, 38106 Braunschweig, Germany
| | - Markus Gerhards
- Chemistry Department and Research Center Optimas, TU Kaiserslautern, Erwin-Schrödinger-Straße 52, 67663 Kaiserslautern, Germany
| | - Michael Karnahl
- Institute of Organic Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany.,Department of Energy Conversion, Institute of Physical and Theoretical Chemistry, Technische Universität Braunschweig, Gaußstraße 17, 38106 Braunschweig, Germany
| | - Stefan Lochbrunner
- Institute for Physics and Department of Life, Light and Matter, University of Rostock, 18051 Rostock, Germany
| | - Stefanie Tschierlei
- Department of Energy Conversion, Institute of Physical and Theoretical Chemistry, Technische Universität Braunschweig, Gaußstraße 17, 38106 Braunschweig, Germany
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12
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Grupe M, Boden P, Di Martino‐Fumo P, Gui X, Bruschi C, Israil R, Schmitt M, Nieger M, Gerhards M, Klopper W, Riehn C, Bizzarri C, Diller R. Time-Resolved Spectroscopy and Electronic Structure of Mono-and Dinuclear Pyridyl-Triazole/DPEPhos-Based Cu(I) Complexes. Chemistry 2021; 27:15251-15270. [PMID: 34550622 PMCID: PMC8597052 DOI: 10.1002/chem.202102760] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Indexed: 12/20/2022]
Abstract
Chemical and spectroscopic characterization of the mononuclear photosensitizers [(DPEPhos)Cu(I)(MPyrT)]0/+ (CuL, CuLH) and their dinuclear analogues (Cu2 L', Cu2 L'H2 ), backed by (TD)DFT and high-level GW-Bethe-Salpeter equation calculations, exemplifies the complex influence of charge, nuclearity and structural flexibility on UV-induced photophysical pathways. Ultrafast transient absorption and step-scan FTIR spectroscopy reveal flattening distortion in the triplet state of CuLH as controlled by charge, which also appears to have a large impact on the symmetry of the long-lived triplet states in Cu2 L' and Cu2 L'H2 . Time-resolved luminescence spectroscopy (solid state), supported by transient photodissociation spectroscopy (gas phase), confirm a lifetime of some tens of μs for the respective triplet states, as well as the energetics of thermally activated delayed luminescence, both being essential parameters for application of these materials based on earth-abundant copper in photocatalysis and luminescent devices.
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Affiliation(s)
- Merten Grupe
- Department of PhysicsTU KaiserslauternErwin-Schrödinger-Straße 4667663KaiserslauternGermany
| | - Pit Boden
- Department of ChemistryTU KaiserslauternErwin-Schrödinger-Straße 5267663KaiserslauternGermany
| | - Patrick Di Martino‐Fumo
- Department of ChemistryTU KaiserslauternErwin-Schrödinger-Straße 5267663KaiserslauternGermany
| | - Xin Gui
- Institute of Physical ChemistryKarlsruhe Institute of Technology (KIT)Fritz-Haber-Weg 276131KarlsruheGermany
| | - Cecilia Bruschi
- Institute of Organic Chemistry (IOC)Karlsruhe Institute of Technology (KIT)Fritz-Haber-Weg 676131KarlsruheGermany
| | - Roumany Israil
- Department of ChemistryTU KaiserslauternErwin-Schrödinger-Straße 5267663KaiserslauternGermany
| | - Marcel Schmitt
- Department of ChemistryTU KaiserslauternErwin-Schrödinger-Straße 5267663KaiserslauternGermany
| | - Martin Nieger
- Department of ChemistryUniversity of HelsinkiA.I. Virtasen aukio 100014HelsinkiFinland
| | - Markus Gerhards
- Department of ChemistryTU KaiserslauternErwin-Schrödinger-Straße 5267663KaiserslauternGermany
- Research Center OPTIMASErwin-Schrödinger-Straße 4667663KaiserslauternGermany
| | - Wim Klopper
- Institute of Physical ChemistryKarlsruhe Institute of Technology (KIT)Fritz-Haber-Weg 276131KarlsruheGermany
| | - Christoph Riehn
- Department of ChemistryTU KaiserslauternErwin-Schrödinger-Straße 5267663KaiserslauternGermany
- Research Center OPTIMASErwin-Schrödinger-Straße 4667663KaiserslauternGermany
| | - Claudia Bizzarri
- Institute of Organic Chemistry (IOC)Karlsruhe Institute of Technology (KIT)Fritz-Haber-Weg 676131KarlsruheGermany
| | - Rolf Diller
- Department of PhysicsTU KaiserslauternErwin-Schrödinger-Straße 4667663KaiserslauternGermany
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13
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Seidler B, Sittig M, Zens C, Tran JH, Müller C, Zhang Y, Schneider KRA, Görls H, Schubert A, Gräfe S, Schulz M, Dietzek B. Modulating the Excited-State Decay Pathways of Cu(I) 4 H-Imidazolate Complexes by Excitation Wavelength and Ligand Backbone. J Phys Chem B 2021; 125:11498-11511. [PMID: 34617757 DOI: 10.1021/acs.jpcb.1c06902] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cu(I) 4H-imidazolato complexes are excellent photosensitizers with broad and intense light absorption properties, based on an earth-abundant metal, and hold great promise as photosensitizers in artificial photosynthesis and for accumulation of redox equivalents. In this study, the excited-state relaxation dynamics of three novel heteroleptic Cu(I) 4H-imidazolato complexes with phenyl, tolyl, and mesityl side groups are systematically investigated by femtosecond and nanosecond time-resolved transient absorption spectroscopy and theoretical methods, complemented by steady-state absorption spectroscopy and (spectro)electrochemistry. After photoexcitation into the metal-to-ligand charge transfer (MLCT) and intraligand charge transfer absorption band, fast (0.6-1 ps) intersystem crossing occurs into the triplet MLCT manifold. The triplet-state population relaxes via the geometrical planarization of the N-aryl rings on the Cu(I) 4H-imidazolato complexes. Depending on the initial Franck-Condon state, the remaining small singlet state population relaxes into two geometrically distinct minima geometries with similar energy, S1/2,relax and S3/4,relax. Subsequent ground-state recovery from S1/2,relax and internal conversion from S3/4,relax to S1/2,relax take place on a 100 ps time scale. The internal conversion can be understood as hole transfer from a dyz-orbital to a dxz-orbital, which is accompanied with the structural reorganization of the coordination environment. Generally, the photophysical processes are determined by the steric hindrance of the side groups on the ligands. And the excited singlet-state pathways are dependent on the excitation wavelength.
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Affiliation(s)
- Bianca Seidler
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany.,Department Functional Interfaces, Leibniz Institute of Photonic Technology Jena (Leibniz-IPHT), Albert-Einstein-Str. 9, 07745 Jena, Germany
| | - Maria Sittig
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany.,Department Functional Interfaces, Leibniz Institute of Photonic Technology Jena (Leibniz-IPHT), Albert-Einstein-Str. 9, 07745 Jena, Germany
| | - Clara Zens
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - Jens H Tran
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - Carolin Müller
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany.,Department Functional Interfaces, Leibniz Institute of Photonic Technology Jena (Leibniz-IPHT), Albert-Einstein-Str. 9, 07745 Jena, Germany
| | - Ying Zhang
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - Kilian R A Schneider
- Department Functional Interfaces, Leibniz Institute of Photonic Technology Jena (Leibniz-IPHT), Albert-Einstein-Str. 9, 07745 Jena, Germany
| | - Helmar Görls
- Institute of Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, Humboldtstr. 8, 07743 Jena, Germany
| | - Alexander Schubert
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - Stefanie Gräfe
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany.,Fraunhofer Institute for Applied Optics and Precision Engineering (Fraunhofer IOF), Albert-Einstein-Str.7, 07745 Jena, Germany
| | - Martin Schulz
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany.,Department Functional Interfaces, Leibniz Institute of Photonic Technology Jena (Leibniz-IPHT), Albert-Einstein-Str. 9, 07745 Jena, Germany
| | - Benjamin Dietzek
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany.,Department Functional Interfaces, Leibniz Institute of Photonic Technology Jena (Leibniz-IPHT), Albert-Einstein-Str. 9, 07745 Jena, Germany.,Centre for Energy and Environmental Chemistry Jena (CEEC-Jena), Friedrich Schiller University Jena, Philosophenweg 7a, 07743 Jena, Germany
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14
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P∩N Bridged Cu(I) Dimers Featuring Both TADF and Phosphorescence. From Overview towards Detailed Case Study of the Excited Singlet and Triplet States. Molecules 2021; 26:molecules26113415. [PMID: 34200044 PMCID: PMC8200198 DOI: 10.3390/molecules26113415] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 05/23/2021] [Accepted: 05/25/2021] [Indexed: 11/16/2022] Open
Abstract
We present an overview over eight brightly luminescent Cu(I) dimers of the type Cu2X2(P∩N)3 with X = Cl, Br, I and P∩N = 2-diphenylphosphino-pyridine (Ph2Ppy), 2-diphenylphosphino-pyrimidine (Ph2Ppym), 1-diphenylphosphino-isoquinoline (Ph2Piqn) including three new crystal structures (Cu2Br2(Ph2Ppy)3 1-Br, Cu2I2(Ph2Ppym)3 2-I and Cu2I2(Ph2Piqn)3 3-I). However, we mainly focus on their photo-luminescence properties. All compounds exhibit combined thermally activated delayed fluorescence (TADF) and phosphorescence at ambient temperature. Emission color, decay time and quantum yield vary over large ranges. For deeper characterization, we select Cu2I2(Ph2Ppy)3, 1-I, showing a quantum yield of 81%. DFT and SOC-TDDFT calculations provide insight into the electronic structures of the singlet S1 and triplet T1 states. Both stem from metal+iodide-to-ligand charge transfer transitions. Evaluation of the emission decay dynamics, measured from 1.2 ≤ T ≤ 300 K, gives ∆E(S1-T1) = 380 cm−1 (47 meV), a transition rate of k(S1→S0) = 2.25 × 106 s−1 (445 ns), T1 zero-field splittings, transition rates from the triplet substates and spin-lattice relaxation times. We also discuss the interplay of S1-TADF and T1-phosphorescence. The combined emission paths shorten the overall decay time. For OLED applications, utilization of both singlet and triplet harvesting can be highly favorable for improvement of the device performance.
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15
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Doettinger F, Yang Y, Schmid MA, Frey W, Karnahl M, Tschierlei S. Cross-Coupled Phenyl- and Alkynyl-Based Phenanthrolines and Their Effect on the Photophysical and Electrochemical Properties of Heteroleptic Cu(I) Photosensitizers. Inorg Chem 2021; 60:5391-5401. [PMID: 33764043 DOI: 10.1021/acs.inorgchem.1c00416] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
With the aims of increasing the antenna system and improving the photophysical properties of Cu(I)-based photosensitizers, the backbone of 2,9-dimethyl-1,10-phenanthroline was selectively extended in the 5,6-position. Applying specifically tailored Suzuki-Miyaura and "chemistry-on-the-complex" Sonogashira cross-coupling reactions enabled the development of two sets of structurally related diimine ligands with a broad variety of different phenyl- and alkynyl-based substituents. The resulting 11 novel heteroleptic Cu(I) complexes, including five solid-state structures, were studied with respect to their structure-property relationships. Both sets of substituents are able to red-shift the absorption maxima and to increase the absorptivity. For the alkynyl-based complexes, this is accompanied by a significant anodic shift of the reduction potentials. The phenyl-based substituents strongly influence the emission wavelength and quantum yield of the resulting Cu(I) complexes and lead to an increase in the emission lifetime of up to 504 ns, which clearly indicates competition with the benchmark system [(xantphos)Cu(bathocuproine)]PF6.
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Affiliation(s)
- Florian Doettinger
- Institute of Organic Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany.,Department of Energy Conversion, Institute of Physical and Theoretical Chemistry, Technische Universität Brauschweig, Gaußstraße 17, 38106 Braunschweig, Germany
| | - Yingya Yang
- Department of Energy Conversion, Institute of Physical and Theoretical Chemistry, Technische Universität Brauschweig, Gaußstraße 17, 38106 Braunschweig, Germany
| | - Marie-Ann Schmid
- Department of Energy Conversion, Institute of Physical and Theoretical Chemistry, Technische Universität Brauschweig, Gaußstraße 17, 38106 Braunschweig, Germany
| | - Wolfgang Frey
- Institute of Organic Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Michael Karnahl
- Institute of Organic Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Stefanie Tschierlei
- Department of Energy Conversion, Institute of Physical and Theoretical Chemistry, Technische Universität Brauschweig, Gaußstraße 17, 38106 Braunschweig, Germany
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16
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Rentschler M, Schmid MA, Frey W, Tschierlei S, Karnahl M. Multidentate Phenanthroline Ligands Containing Additional Donor Moieties and Their Resulting Cu(I) and Ru(II) Photosensitizers: A Comparative Study. Inorg Chem 2020; 59:14762-14771. [PMID: 32212646 DOI: 10.1021/acs.inorgchem.9b03687] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
To bind or not to bind: Driven by the motivation to increase the (photo)stability of traditional Cu(I) photosensitizers, multidentate diimine ligands, which contain two additional donor sites, were designed. To this end, a systematic series of four 1,10-phenanthroline ligands with either OR or SR (R = iPr or Ph) donor groups at the 2 and 9 positions and their resulting hetero- and homoleptic Cu(I) complexes were prepared. In addition, the related Ru(II) complexes were also synthesized to study the effect of another metal center. In the following, a combination of NMR spectroscopy and X-ray analysis was used to evaluate the impact of the additional donor moieties on the coordination behavior. Most remarkably, for the homoleptic bis(diimine)copper(I) complexes, a pentacoordinated copper center, corresponding to a (4 + 1)-fold coordination mode, was found in the solid state. This additional binding is the first indication that the extra donor might also occupy a free coordination site in the excited-state complex, modifying the nature of the excited states and their respective deactivation processes. Therefore, the electrochemical and photophysical properties of all novel complexes (in total 13) were studied in detail to assess the potential of these photosensitizers for future applications within solar energy conversion schemes. Finally, the photostabilities and a potential degradation mechanism were analyzed for representative samples.
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Affiliation(s)
- Martin Rentschler
- Institute of Organic Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Marie-Ann Schmid
- Institute of Inorganic Chemistry I, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Wolfgang Frey
- Institute of Organic Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Stefanie Tschierlei
- Institute of Inorganic Chemistry I, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Michael Karnahl
- Institute of Organic Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
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17
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Müller C, Schulz M, Obst M, Zedler L, Gräfe S, Kupfer S, Dietzek B. Role of MLCT States in the Franck-Condon Region of Neutral, Heteroleptic Cu(I)-4 H-imidazolate Complexes: A Spectroscopic and Theoretical Study. J Phys Chem A 2020; 124:6607-6616. [PMID: 32701275 DOI: 10.1021/acs.jpca.0c04351] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The impact of the electronic structure of a series of 4H-imidazolate ligands in neutral, heteroleptic Cu(I) complexes is investigated. Remarkable broad and strong ligand-dependent absorption in the visible range of the electromagnetic spectrum renders the studied complexes promising photosensitizers for photocatalytic applications. The electronic structure of the Cu(I) complexes and the localization of photoexcited states in the Franck-Condon region are unraveled by means of UV-vis absorption and resonance Raman (rR) spectroscopy supported by time-dependent density functional theory (TD-DFT) calculations. The visible absorption bands stem from a superposition of bright metal-to-ligand charge-transfer (MLCT) and π-π* as well as weakly absorbing MLCT states. Additionally, the analysis of involved molecular orbitals and rR spectra upon excitation of MLCT and π-π* states highlights the impact of the electronic structure of the 4H-imidazolate ligands on the properties of the corresponding Cu(I) complexes to avail a toolbox for predictive studies and efficient complex design.
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Affiliation(s)
- Carolin Müller
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany.,Leibniz Institute of Photonic Technology, Albert-Einstein-Straße 9, 07745 Jena, Germany
| | - Martin Schulz
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - Marc Obst
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - Linda Zedler
- Leibniz Institute of Photonic Technology, Albert-Einstein-Straße 9, 07745 Jena, Germany
| | - Stefanie Gräfe
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - Stephan Kupfer
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - Benjamin Dietzek
- Institute of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany.,Leibniz Institute of Photonic Technology, Albert-Einstein-Straße 9, 07745 Jena, Germany.,Center for Energy and Environmental Chemistry Jena (CEEC Jena), Friedrich Schiller University Jena, Lessingstraße 8, 07743 Jena, Germany
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18
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Rentschler M, Iglesias S, Schmid MA, Liu C, Tschierlei S, Frey W, Zhang X, Karnahl M, Moonshiram D. The Coordination Behaviour of Cu I Photosensitizers Bearing Multidentate Ligands Investigated by X-ray Absorption Spectroscopy. Chemistry 2020; 26:9527-9536. [PMID: 32162730 PMCID: PMC7496955 DOI: 10.1002/chem.201905601] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 02/20/2020] [Indexed: 12/05/2022]
Abstract
A systematic series of four novel homo‐ and heteroleptic CuI photosensitizers based on tetradentate 1,10‐phenanthroline ligands of the type X^N^N^X containing two additional donor moieties in the 2,9‐position (X=SMe or OMe) were designed. Their solid‐state structures were assessed by X‐ray diffraction. Cyclic voltammetry, UV‐vis absorption, emission and X‐ray absorption spectroscopy were then used to determine their electrochemical, photophysical and structural features in solution. Following, time‐resolved X‐ray absorption spectroscopy in the picosecond time scale, coupled with time‐dependent density functional theory calculations, provided in‐depth information on the excited state electron configurations. For the first time, a significant shortening of the Cu−X distance and a change in the coordination mode to a pentacoordinated geometry is shown in the excited states of the two homoleptic complexes. These findings are important with respect to a precise understanding of the excited state structures and a further stabilization of this type of photosensitizers.
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Affiliation(s)
- Martin Rentschler
- Institute of Organic Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
| | - Sirma Iglesias
- Instituto Madrileño de Estudios Avanzados en, Nanociencia (IMDEA Nanociencia), Calle Faraday, 9, 28049, Madrid, Spain
| | - Marie-Ann Schmid
- Institute of Inorganic Chemistry I, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Cunming Liu
- X-ray Science Division, Argonne National Laboratory, 9700 S. Cass Avenue, Lemont, IL, 60439, USA
| | - Stefanie Tschierlei
- Institute of Inorganic Chemistry I, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Wolfgang Frey
- Institute of Organic Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
| | - Xiaoyi Zhang
- X-ray Science Division, Argonne National Laboratory, 9700 S. Cass Avenue, Lemont, IL, 60439, USA
| | - Michael Karnahl
- Institute of Organic Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
| | - Dooshaye Moonshiram
- Instituto Madrileño de Estudios Avanzados en, Nanociencia (IMDEA Nanociencia), Calle Faraday, 9, 28049, Madrid, Spain
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19
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Grupe M, Bäppler F, Theiß M, Busch JM, Dietrich F, Volz D, Gerhards M, Bräse S, Diller R. Real-time observation of molecular flattening and intersystem crossing in [(DPEPhos)Cu(i)(PyrTet)] via ultrafast UV/Vis- and mid-IR spectroscopy on solution and solid samples. Phys Chem Chem Phys 2020; 22:14187-14200. [PMID: 32609106 DOI: 10.1039/c9cp05749h] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The primary photo-induced processes in the mononuclear, heteroleptic Cu(i) complex [(DPEPhos)Cu(PyrTet)] (1), relevant for OLED applications, were investigated in various solvents and in solid state samples via femtosecond (fs) time resolved UV/Vis and fs time resolved mid-IR transient absorption spectroscopy (TA) with MLCT excitation around 340 nm. UV/Vis fs-TA on 1 in solution reveals (i) a severe blue-shift of excited state absorption on the time scale of a few picoseconds (τ2) that is not observed in solids, and (ii), on the time scale of several tens of picoseconds (τ3), a process with very similar dynamics in all samples. Mid-IR fs-TA in solution indicates structural changes with τ2. Transient absorption anisotropy experiments temporally resolve a viscosity-dependent change of the excited state transition dipole moment orientation with τ2, as quantitatively predicted for the relaxed S1-state via TD-DFT. The results strongly suggest flattening distortion (FD) and structural rearrangement of the PyrTet-moiety to occur on the time scale of τ2 in liquid phase, and to be suppressed in solid phase. Moreover, intersystem crossing (ISC) is assigned to the process described by τ3, in line with its direct observation via time-resolved luminescence spectroscopy on 1 by Bergmann et al. (Sci. Adv., 2016, 2, e1500889). Overall, the use of structure-sensitive methods and the direct comparison of different preparations of 1 (i.e. solution vs. solid state), are a unique basis for a clear assignment of spectro-temporal characteristics to fundamental deactivation processes such as FD and ISC.
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Affiliation(s)
- Merten Grupe
- Physics Department, TU Kaiserslautern, Erwin-Schrödinger-Straße 46, 67663 Kaiserslautern, Germany.
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20
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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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21
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Giereth R, Mengele AK, Frey W, Kloß M, Steffen A, Karnahl M, Tschierlei S. Copper(I) Phosphinooxazoline Complexes: Impact of the Ligand Substitution and Steric Demand on the Electrochemical and Photophysical Properties. Chemistry 2020; 26:2675-2684. [PMID: 31747089 PMCID: PMC7065177 DOI: 10.1002/chem.201904379] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Indexed: 12/29/2022]
Abstract
A series of seven homoleptic CuI complexes based on hetero-bidentate P^N ligands was synthesized and comprehensively characterized. In order to study structure-property relationships, the type, size, number and configuration of substituents at the phosphinooxazoline (phox) ligands were systematically varied. To this end, a combination of X-ray diffraction, NMR spectroscopy, steady-state absorption and emission spectroscopy, time-resolved emission spectroscopy, quenching experiments and cyclic voltammetry was used to assess the photophysical and electrochemical properties. Furthermore, time-dependent density functional theory calculations were applied to also analyze the excited state structures and characteristics. Surprisingly, a strong dependency on the chirality of the respective P^N ligand was found, whereas the specific kind and size of the different substituents has only a minor impact on the properties in solution. Most importantly, all complexes except C3 are photostable in solution and show fully reversible redox processes. Sacrificial reductants were applied to demonstrate a successful electron transfer upon light irradiation. These properties render this class of photosensitizers as potential candidates for solar energy conversion issues.
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Affiliation(s)
- Robin Giereth
- Institute of Inorganic Chemistry I, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Alexander K Mengele
- Institute of Inorganic Chemistry I, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Wolfgang Frey
- Institute of Organic Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
| | - Marvin Kloß
- Faculty of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Strasse 6, 44227, Dortmund, Germany
| | - Andreas Steffen
- Faculty of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Strasse 6, 44227, Dortmund, Germany
| | - Michael Karnahl
- Institute of Organic Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
| | - Stefanie Tschierlei
- Institute of Inorganic Chemistry I, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
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22
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Levi G, Biasin E, Dohn AO, Jónsson H. On the interplay of solvent and conformational effects in simulated excited-state dynamics of a copper phenanthroline photosensitizer. Phys Chem Chem Phys 2020; 22:748-757. [DOI: 10.1039/c9cp06086c] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
QM/MM direct dynamics simulations in acetonitrile reveal the interplay between solvent and conformational effects in the photoinduced ultrafast flattening of a copper photosensitizer.
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Affiliation(s)
- Gianluca Levi
- Science Institute and Faculty of Physical Sciences
- University of Iceland
- Iceland
| | - Elisa Biasin
- PULSE Institute
- SLAC National Accelerator Laboratory
- Menlo Park
- California 94025
- USA
| | - Asmus O. Dohn
- Science Institute and Faculty of Physical Sciences
- University of Iceland
- Iceland
| | - Hannes Jónsson
- Science Institute and Faculty of Physical Sciences
- University of Iceland
- Iceland
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23
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Yanagida S, Yoshida M, Sameera WMC, Kobayashi A, Kato M. Insight into the Origin of Competitive Emission of Copper(I) Complexes Bearing Diimine and Diphosphine Ligands. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2019. [DOI: 10.1246/bcsj.20190128] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Sae Yanagida
- Department of Chemistry, Faculty of Science, Hokkaido University, North-10 West-8, Kita-ku, Sapporo, Hokkaido 060-0810, Japan
| | - Masaki Yoshida
- Department of Chemistry, Faculty of Science, Hokkaido University, North-10 West-8, Kita-ku, Sapporo, Hokkaido 060-0810, Japan
| | - W. M. C. Sameera
- Department of Chemistry, Faculty of Science, Hokkaido University, North-10 West-8, Kita-ku, Sapporo, Hokkaido 060-0810, Japan
| | - Atsushi Kobayashi
- Department of Chemistry, Faculty of Science, Hokkaido University, North-10 West-8, Kita-ku, Sapporo, Hokkaido 060-0810, Japan
| | - Masako Kato
- Department of Chemistry, Faculty of Science, Hokkaido University, North-10 West-8, Kita-ku, Sapporo, Hokkaido 060-0810, Japan
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24
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Takeda H, Monma Y, Sugiyama H, Uekusa H, Ishitani O. Development of Visible-Light Driven Cu(I) Complex Photosensitizers for Photocatalytic CO 2 Reduction. Front Chem 2019; 7:418. [PMID: 31245355 PMCID: PMC6562897 DOI: 10.3389/fchem.2019.00418] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 05/21/2019] [Indexed: 11/13/2022] Open
Abstract
The visible-light responsive Cu(I)-complex photosensitizers were developed by introducing various aromatic substituents at the 4,7-positions of a 2,9-dimethyl-1,10-phenanthroline (dmp) ligand in a heteroleptic CuI(dmp)(DPEphos)+-type complexes (DPEphos = [2-(diphenylphosphino)phenyl]ether) for photocatalytic CO2 reduction. Introducing biphenyl groups (Bp-) on the dmp ligand enhanced the molar extinction coefficient (ε) of the metal-to-ligand charge transfer (MLCT) band in the visible region (ε = 7,500 M-1cm-1) compared to that of the phenyl (Ph-)-containing analog (ε = 5,700 M-1cm-1 at λmax = 388 nm). However, introducing 4-R-Ph- groups (R = the electron-withdrawing groups NC-, or NO2-) led to a red shift in the band to λmax = 390, 400, and 401 nm, respectively. Single-crystal X-ray analysis showed the Ph- groups were twisted because of the steric repulsion between the 2,6-protons of the Ph- groups and 5,6-protons of the dmp ligand. The result strongly indicated that the π-conjugation effect of the 4-R-Ph- groups is so weak that the lowering of the energy of the dmp π* orbitals is small. However, when 4-R-ph- was substituted by a 5-membered heterorings, there was a larger red shift, leading to an increase in the ε value of the MLCT absorption band. Thus, the substitution to 2-benzofuranyl- groups resulted in visible-light absorption up to 500 nm and a shoulder peak at around 420 nm (ε = 12,300 M-1cm-1) due to the expansion of π-conjugation over the substituted dmp ligand. The photocatalytic reaction for CO2 reduction was tested using the obtained CuI complexes as photosensitizers in the presence of a Fe(dmp)2(NCS)2 catalyst and 1,3-dimethyl-2-phenyl-2,3-dihydro-1H-benzo[d]imidazole as a sacrificial reductant, which showed improved CO generation.
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Affiliation(s)
- Hiroyuki Takeda
- Department of Chemistry, School of Science, Tokyo Institute of Technology, Tokyo, Japan
| | - Yu Monma
- Department of Chemistry, School of Science, Tokyo Institute of Technology, Tokyo, Japan
| | - Haruki Sugiyama
- Department of Chemistry, School of Science, Tokyo Institute of Technology, Tokyo, Japan
| | - Hidehiro Uekusa
- Department of Chemistry, School of Science, Tokyo Institute of Technology, Tokyo, Japan
| | - Osamu Ishitani
- Department of Chemistry, School of Science, Tokyo Institute of Technology, Tokyo, Japan
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25
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Holler M, Delavaux‐Nicot B, Nierengarten J. Topological and Steric Constraints to Stabilize Heteroleptic Copper(I) Complexes Combining Phenanthroline Ligands and Phosphines. Chemistry 2019; 25:4543-4550. [DOI: 10.1002/chem.201805671] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Indexed: 11/05/2022]
Affiliation(s)
- Michel Holler
- Laboratoire de Chimie des Matériaux MoléculairesUniversité de Strasbourg et CNRS (LIMA-UMR 7042), École Européenne de Chimie, Polymères et Matériaux (ECPM) 25 rue Becquerel 67087 Strasbourg Cedex 2 France
| | - Béatrice Delavaux‐Nicot
- Laboratoire de Chimie de Coordination du CNRS (UPR 8241)Université de Toulouse (UPS, INPT) 205 Route de Narbonne 31077 Toulouse Cedex 04 France
| | - Jean‐François Nierengarten
- Laboratoire de Chimie des Matériaux MoléculairesUniversité de Strasbourg et CNRS (LIMA-UMR 7042), École Européenne de Chimie, Polymères et Matériaux (ECPM) 25 rue Becquerel 67087 Strasbourg Cedex 2 France
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26
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Zhang Y, Zedler L, Karnahl M, Dietzek B. Excited-state dynamics of heteroleptic copper(i) photosensitizers and their electrochemically reduced forms containing a dipyridophenazine moiety – a spectroelectrochemical transient absorption study. Phys Chem Chem Phys 2019; 21:10716-10725. [DOI: 10.1039/c9cp00412b] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Heteroleptic copper(i) dipyridophenazine complexes were investigated by transient absorption spectroelectrochemistry to examine their multi-electron photoaccumulation properties.
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Affiliation(s)
- Ying Zhang
- Institute of Physical Chemistry and Abbe Center of Photonics
- Friedrich Schiller University Jena
- 07743 Jena
- Germany
- Department Functional Interfaces
| | - Linda Zedler
- Department Functional Interfaces
- Leibniz Institute of Photonic Technology Jena (IPHT)
- 07745 Jena
- Germany
| | - Michael Karnahl
- Institute of Organic Chemistry
- University of Stuttgart
- 70569 Stuttgart
- Germany
| | - Benjamin Dietzek
- Institute of Physical Chemistry and Abbe Center of Photonics
- Friedrich Schiller University Jena
- 07743 Jena
- Germany
- Department Functional Interfaces
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27
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Imidazo-Phenanthroline Ligands as a Convenient Modular Platform for the Preparation of Heteroleptic Cu(I) Photosensitizers. INORGANICS 2018. [DOI: 10.3390/inorganics6040134] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The capture and storage of solar energy is a promising option to overcome current energy issues. To put such systems into practice, molecular photosensitizers should be based on abundant metals and possess a strong absorption capability for visible light. Therefore, a systematic series of four novel heteroleptic Cu(I) complexes of the type [(P^P)Cu(N^N)]+ (with P^P = xantphos and N^N = different diimine ligands) has been prepared. As an essential feature, these copper photosensitizers contain an imidazole moiety at the backbone of the diimine ligand, which increases the aromatic π-system compared to phenanthroline type ligands. Moreover, 2-(4-bromophenyl)-1-phenyl-1H-imidazo-[4,5-f][1,10]phenanthroline was used as a starting point and modular platform for gradually extended diimine ligands. Suzuki cross-coupling was applied to introduce different kind of substituents in the back of this ligand. Afterwards, a combination of NMR spectroscopy, mass spectrometry, X-ray analysis, cyclic voltammetry, UV/vis and emission spectroscopy was used to investigate the structural, electrochemical and photophysical properties of these compounds. As a result, a reversible reduction, strongly increased extinction coefficients and significantly redshifted absorption maxima (>20 nm) were found compared to traditional Cu(I) photosensitizers without an imidazo moiety. Moreover, these compounds show a bright emission in the solid state.
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28
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Leoni E, Mohanraj J, Holler M, Mohankumar M, Nierengarten I, Monti F, Sournia-Saquet A, Delavaux-Nicot B, Jean-Franco Is Nierengarten, Armaroli N. Heteroleptic Copper(I) Complexes Prepared from Phenanthroline and Bis-Phosphine Ligands: Rationalization of the Photophysical and Electrochemical Properties. Inorg Chem 2018; 57:15537-15549. [PMID: 30481016 DOI: 10.1021/acs.inorgchem.8b02879] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The electronic and structural properties of ten heteroleptic [Cu(NN)(PP)]+ complexes have been investigated. NN indicates 1,10-phenanthroline (phen) or 4,7-diphenyl-1,10-phenanthroline (Bphen); each of these ligands is combined with five PP bis-phosphine chelators, i.e., bis(diphenylphosphino)methane (dppm), 1,2-bis(diphenylphosphino)ethane (dppe), 1,3-bis(diphenylphosphino)propane (dppp), 1,2-bis(diphenylphosphino)benzene (dppb), and bis[(2-diphenylphosphino)phenyl] ether (POP). All complexes are mononuclear, apart from those based on dppm, which are dinuclear. Experimental data-also taken from the literature and including electrochemical properties, X-ray crystal structures, UV-vis absorption spectra in CH2Cl2, luminescence spectra and lifetimes in solution, in PMMA, and as powders-have been rationalized with the support of density functional theory calculations. Temperature dependent studies (78-358 K) have been performed for selected complexes to assess thermally activated delayed fluorescence. The main findings are (i) dependence of the ground-state geometry on the crystallization conditions, with the same complex often yielding different crystal structures; (ii) simple model compounds with imposed C2 v symmetry ([Cu(phen)(PX3)2]+; X = H or CH3) are capable of modeling structural parameters as a function of the P-Cu-P bite angle, which plays a key role in dictating the overall structure of [Cu(NN)(PP)]+ complexes; (iii) as the P-Cu-P angle increases, the energy of the metal-to-ligand charge transfer absorption bands linearly increases; (iv) the former correlation does not hold for emission spectra, which are red-shifted for the weaker luminophores; (v) the larger the number of intramolecular π-interactions within the complex in the ground state, the higher the luminescence quantum yield, underpinning a geometry locking effect that limits the structural flattening of the excited state. This work provides a general framework to rationalize the structure-property relationships of [Cu(NN)(PP)]+, a class of compounds of increasing relevance for electroluminescent devices, photoredox catalysis, and solar-to-fuels conversion, which so far have been investigated in an unsystematic fashion, eluding a comprehensive understanding.
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Affiliation(s)
- Enrico Leoni
- Istituto per la Sintesi Organica e la Fotoreattività, Consiglio Nazionale delle Ricerche , Via Gobetti 101 , 40129 Bologna , Italy.,Laboratorio Tecnologie dei Materiali Faenza , ENEA , Via Ravegnana 186 , 48018 Faenza (RA) , Italy
| | - John Mohanraj
- Istituto per la Sintesi Organica e la Fotoreattività, Consiglio Nazionale delle Ricerche , Via Gobetti 101 , 40129 Bologna , Italy
| | - Michel Holler
- Laboratoire de Chimie des Matériaux Moléculaires , Université de Strasbourg et CNRS (LIMA - UMR 7042) , 25 rue Becquerel , 67087 Strasbourg Cedex 2 , France
| | - Meera Mohankumar
- Laboratoire de Chimie des Matériaux Moléculaires , Université de Strasbourg et CNRS (LIMA - UMR 7042) , 25 rue Becquerel , 67087 Strasbourg Cedex 2 , France
| | - Iwona Nierengarten
- Laboratoire de Chimie des Matériaux Moléculaires , Université de Strasbourg et CNRS (LIMA - UMR 7042) , 25 rue Becquerel , 67087 Strasbourg Cedex 2 , France
| | - Filippo Monti
- Istituto per la Sintesi Organica e la Fotoreattività, Consiglio Nazionale delle Ricerche , Via Gobetti 101 , 40129 Bologna , Italy
| | - Alix Sournia-Saquet
- Laboratoire de Chimie de Coordination du CNRS (UPR 8241) , Université de Toulouse (UPS, INPT) , 205 Route de Narbonne , 31077 Toulouse Cedex 4 , France
| | - Béatrice Delavaux-Nicot
- Laboratoire de Chimie de Coordination du CNRS (UPR 8241) , Université de Toulouse (UPS, INPT) , 205 Route de Narbonne , 31077 Toulouse Cedex 4 , France
| | - Jean-Franco Is Nierengarten
- Laboratoire de Chimie des Matériaux Moléculaires , Université de Strasbourg et CNRS (LIMA - UMR 7042) , 25 rue Becquerel , 67087 Strasbourg Cedex 2 , France
| | - Nicola Armaroli
- Istituto per la Sintesi Organica e la Fotoreattività, Consiglio Nazionale delle Ricerche , Via Gobetti 101 , 40129 Bologna , Italy
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29
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Friedrich A, Bokareva OS, Luo SP, Junge H, Beller M, Kühn O, Lochbrunner S. Effective quenching and excited-state relaxation of a Cu(I) photosensitizer addressed by time-resolved spectroscopy and TDDFT calculations. Chem Phys 2018. [DOI: 10.1016/j.chemphys.2018.08.048] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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30
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Eckenhoff WT. Molecular catalysts of Co, Ni, Fe, and Mo for hydrogen generation in artificial photosynthetic systems. Coord Chem Rev 2018. [DOI: 10.1016/j.ccr.2017.11.002] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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31
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Moonshiram D, Garrido‐Barros P, Gimbert‐Suriñach C, Picón A, Liu C, Zhang X, Karnahl M, Llobet A. Elucidating the Nature of the Excited State of a Heteroleptic Copper Photosensitizer by using Time‐Resolved X‐ray Absorption Spectroscopy. Chemistry 2018; 24:6464-6472. [DOI: 10.1002/chem.201800330] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Indexed: 11/06/2022]
Affiliation(s)
- Dooshaye Moonshiram
- Max Planck Institute for Chemical Energy Conversion Stiftstrasse 34–36 Mülheim an der Ruhr 45470 Germany
- Institute of Chemical Research of Catalonia (ICIQ) Avinguda Països Catalans 16 43007 Tarragona Spain
| | - Pablo Garrido‐Barros
- Institute of Chemical Research of Catalonia (ICIQ) Avinguda Països Catalans 16 43007 Tarragona Spain
- Departament de Química Física i Inorganica Universitat Rovira i Virgili Campus Sescelades, C/Marcellí Domingo, s/n 43007 Tarragona Spain
| | - Carolina Gimbert‐Suriñach
- Institute of Chemical Research of Catalonia (ICIQ) Avinguda Països Catalans 16 43007 Tarragona Spain
| | - Antonio Picón
- Grupo de Investigacion en Aplicaciones del Laser y Fotonica Universidad de Salamanca 37008 Salamanca Spain
- Departamento de Química, Modulo 13 Universidad Autónoma de Madrid Cantoblanco 28049 Madrid Spain
| | - Cunming Liu
- X-ray Science Division Argonne National Laboratory 9700 S. Cass Avenue Lemont IL 60439 USA
| | - Xiaoyi Zhang
- X-ray Science Division Argonne National Laboratory 9700 S. Cass Avenue Lemont IL 60439 USA
| | - Michael Karnahl
- University of Stuttgart Institute of Organic Chemistry Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Antoni Llobet
- Institute of Chemical Research of Catalonia (ICIQ) Avinguda Països Catalans 16 43007 Tarragona Spain
- Departament de Química Universitat Autonoma de Barcelona 08193 Cerdanyola del Valles Barcelona Spain
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32
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Reim I, Wriedt B, Tastan Ü, Ziegenbalg D, Karnahl M. Impact of the Type of Reactor and the Catalytic Conditions on the Photocatalytic Production of Hydrogen Using a Fully Noble-Metal-Free System. ChemistrySelect 2018. [DOI: 10.1002/slct.201800289] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Immanuel Reim
- Institute of Organic Chemistry; University of Stuttgart; Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Benjamin Wriedt
- Institute of Chemical Technology; University of Stuttgart; Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Ümit Tastan
- Institute of Chemical Technology; University of Stuttgart; Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Dirk Ziegenbalg
- Institute of Chemical Technology; University of Stuttgart; Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Michael Karnahl
- Institute of Organic Chemistry; University of Stuttgart; Pfaffenwaldring 55 70569 Stuttgart Germany
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33
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Schulz M, Reichardt C, Müller C, Schneider KRA, Holste J, Dietzek B. Excited State Properties of Heteroleptic Cu(I) 4H-Imidazolate Complexes. Inorg Chem 2018; 56:12978-12986. [PMID: 29064681 DOI: 10.1021/acs.inorgchem.7b01680] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The excited state properties of three heteroleptic copper(I) xantphos 4H-imidazolate complexes are investigated by means of femtosecond and nanosecond time-resolved transient absorption spectroscopy in dichloromethane solution. The subpicosecond spectral changes observed after excitation into the MLCT absorption band are interpreted as intersystem crossing from the singlet to the triplet manifold. This interpretation is corroborated by DFT and TD-DFT results, indicating a comparable molecular geometry in the ground state (and hence the nonrelaxed singlet state) and the excited triplet state. Population of the triplet state is followed by planarization of the N-aryl rings of the 4H-imidazolate ligand on a 10 ps time scale. The planarization strongly depends on the substitution pattern of the N-aryls and correlates with the reduced moment of inertia for the planarization motion. The triplet state subsequently decays to the ground state in about 100 ns. These results demonstrate that the excited state processes of copper(I) complexes depend on the specific ligand(s) and their substitution pattern. Thus, the work presented points to a possibility to design copper(I) complexes with specific photophysical properties.
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Affiliation(s)
- Martin Schulz
- Institute of Physical Chemistry, Friedrich Schiller University Jena , Helmholtzweg 4, 07743 Jena, Germany.,Leibniz Institute of Photonic Technology (IPHT) , Department Functional Interfaces, Albert-Einstein-Straße 9, 07745 Jena, Germany
| | - Christian Reichardt
- Institute of Physical Chemistry, Friedrich Schiller University Jena , Helmholtzweg 4, 07743 Jena, Germany.,Leibniz Institute of Photonic Technology (IPHT) , Department Functional Interfaces, Albert-Einstein-Straße 9, 07745 Jena, Germany
| | - Carolin Müller
- Institute of Physical Chemistry, Friedrich Schiller University Jena , Helmholtzweg 4, 07743 Jena, Germany
| | - Kilian R A Schneider
- Leibniz Institute of Photonic Technology (IPHT) , Department Functional Interfaces, Albert-Einstein-Straße 9, 07745 Jena, Germany
| | - Jonas Holste
- Institute of Physical Chemistry, Friedrich Schiller University Jena , Helmholtzweg 4, 07743 Jena, Germany
| | - Benjamin Dietzek
- Institute of Physical Chemistry, Friedrich Schiller University Jena , Helmholtzweg 4, 07743 Jena, Germany.,Leibniz Institute of Photonic Technology (IPHT) , Department Functional Interfaces, Albert-Einstein-Straße 9, 07745 Jena, Germany.,Center für Energy and Environmental Chemistry (CEEC), Friedrich Schiller University Jena , Philosophenweg 7a, 07743 Jena, Germany
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34
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McCullough BJ, Neyhouse BJ, Schrage BR, Reed DT, Osinski AJ, Ziegler CJ, White TA. Visible-Light-Driven Photosystems Using Heteroleptic Cu(I) Photosensitizers and Rh(III) Catalysts To Produce H 2. Inorg Chem 2018; 57:2865-2875. [PMID: 29446925 DOI: 10.1021/acs.inorgchem.7b03273] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The synthesis of two new heteroleptic Cu(I) photosensitizers (PS), [Cu(Xantphos)(NN)]PF6 (NN = biq = 2,2'-biquinoline, dmebiq = 2,2'-biquinoline-4,4'-dimethyl ester; Xantphos = 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene), along with the associated structural, photophysical, and electrochemical properties, are described. The biquinoline diimine ligand extends the PS light absorbing properties into the visible with a maximum absorption at 455 and 505 nm for NN = biq and dmebiq, respectively, in CH2Cl2 solvent. Following photoexcitation, both Cu(I) PS are emissive at low energy, albeit displaying stark differences in their excited state lifetimes (τMLCT = 410 ± 5 (biq) and 44 ± 4 ns (dmebiq)). Cyclic voltammetry indicates a Cu-based HOMO and NN-based LUMO for both complexes, whereby the methyl ester substituents stabilize the LUMO within [Cu(Xantphos)(dmebiq)]+ by ∼0.37 V compared to the unsubstituted analogue. When combined with H2O, N,N-dimethylaniline (DMA) electron donor, and cis-[Rh(NN)2Cl2]PF6 (NN = Me2bpy = 4,4'-dimethyl-2,2'-bipyridine, bpy = 2,2'-bipyridine, dmebpy = 2,2'-bipyridine-4,4'-dimethyl ester) water reduction catalysts (WRC), photocatalytic H2 evolution is only observed using the [Cu(Xantphos)(biq)]+ PS. Furthermore, the choice of cis-[Rh(NN)2Cl2]+ WRC strongly affects the catalytic activity with turnover numbers (TONRh = mol H2 per mol Rh catalyst) of 25 ± 3, 22 ± 1, and 43 ± 3 for NN = Me2bpy, bpy, and dmebpy, respectively. This work illustrates how ligand modification to carefully tune the PS light absorbing, excited state, and redox-active properties, along with the WRC redox potentials, can have a profound impact on the photoinduced intermolecular electron transfer between components and the subsequent catalytic activity.
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Affiliation(s)
- Bradley J McCullough
- Department of Chemistry and Biochemistry, Clippinger Laboratories , Ohio University , Athens , Ohio 45701 , United States
| | - Bertrand J Neyhouse
- Department of Chemistry and Biochemistry, Clippinger Laboratories , Ohio University , Athens , Ohio 45701 , United States
| | - Briana R Schrage
- Department of Chemistry, Knight Chemical Laboratory , University of Akron , Akron , Ohio 44325 , United States
| | - Demi T Reed
- Department of Chemistry and Biochemistry, Clippinger Laboratories , Ohio University , Athens , Ohio 45701 , United States
| | - Allen J Osinski
- Department of Chemistry, Knight Chemical Laboratory , University of Akron , Akron , Ohio 44325 , United States
| | - Christopher J Ziegler
- Department of Chemistry, Knight Chemical Laboratory , University of Akron , Akron , Ohio 44325 , United States
| | - Travis A White
- Department of Chemistry and Biochemistry, Clippinger Laboratories , Ohio University , Athens , Ohio 45701 , United States
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35
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Zhang Y, Schulz M, Wächtler M, Karnahl M, Dietzek B. Heteroleptic diimine–diphosphine Cu(I) complexes as an alternative towards noble-metal based photosensitizers: Design strategies, photophysical properties and perspective applications. Coord Chem Rev 2018. [DOI: 10.1016/j.ccr.2017.10.016] [Citation(s) in RCA: 130] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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36
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Yersin H, Czerwieniec R, Shafikov MZ, Suleymanova AF. TADF Material Design: Photophysical Background and Case Studies Focusing on Cu I and Ag I Complexes. Chemphyschem 2017; 18:3508-3535. [PMID: 29083512 DOI: 10.1002/cphc.201700872] [Citation(s) in RCA: 134] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2017] [Revised: 10/24/2017] [Indexed: 12/21/2022]
Abstract
The development of organic light emitting diodes (OLEDs) and the use of emitting molecules have strongly stimulated scientific research of emitting compounds. In particular, for OLEDs it is required to harvest all singlet and triplet excitons that are generated in the emission layer. This can be achieved using the so-called triplet harvesting mechanism. However, the materials to be applied are based on high-cost rare metals and therefore, it has been proposed already more than one decade ago by our group to use the effect of thermally activated delayed fluorescence (TADF) to harvest all generated excitons in the lowest excited singlet state S1 . In this situation, the resulting emission is an S1 →S0 fluorescence, though a delayed one. Hence, this mechanism represents the singlet harvesting mechanism. Using this effect, high-cost and strong SOC-carrying rare metals are not required. This mechanism can very effectively be realized by use of CuI or AgI complexes and even by purely organic molecules. In this investigation, we focus on photoluminescence properties and on crucial requirements for designing CuI and AgI materials that exhibit short TADF decay times at high emission quantum yields. The decay times should be as short as possible to minimize non-radiative quenching and, in particular, chemical reactions that frequently occur in the excited state. Thus, a short TADF decay time can strongly increase the material's long-term stability. Here, we study crucial parameters and analyze their impact on the TADF decay time. For example, the energy separation ΔE(S1 -T1 ) between the lowest excited singlet state S1 and the triplet state T1 should be small. Accordingly, we present detailed photophysical properties of two case-study materials designed to exhibit a large ΔE(S1 -T1 ) value of 1000 cm-1 (120 meV) and, for comparison, a small one of 370 cm-1 (46 meV). From these studies-extended by investigations of many other CuI TADF compounds-we can conclude that just small ΔE(S1 -T1 ) is not a sufficient requirement for short TADF decay times. High allowedness of the transition from the emitting S1 state to the electronic ground state S0 , expressed by the radiative rate kr (S1 →S0 ) or the oscillator strength f(S1 →S0 ), is also very important. However, mostly small ΔE(S1 -T1 ) is related to small kr (S1 →S0 ). This relation results from an experimental investigation of a large number of CuI complexes and basic quantum mechanical considerations. As a consequence, a reduction of τ(TADF) to below a few μs might be problematic. However, new materials can be designed for which this disadvantage is not prevailing. A new TADF compound, Ag(dbp)(P2 -nCB) (with dbp=2,9-di-n-butyl-1,10-phenanthroline and P2 -nCB=bis-(diphenylphosphine)-nido-carborane) seems to represent such an example. Accordingly, this material shows TADF record properties, such as short TADF decay time at high emission quantum yield. These properties are based (i) on geometry optimizations of the AgI complex for a fast radiative S1 →S0 rate and (ii) on restricting the extent of geometry reorganizations after excitation for reducing non-radiative relaxation and emission quenching. Indeed, we could design a TADF material with breakthrough properties showing τ(TADF)=1.4 μs at 100 % emission quantum yield.
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Affiliation(s)
- Hartmut Yersin
- University of Regensburg, Institute of Physical Chemistry, Universitätsstr. 31, 93053, Regensburg, Germany
| | - Rafal Czerwieniec
- University of Regensburg, Institute of Physical Chemistry, Universitätsstr. 31, 93053, Regensburg, Germany
| | - Marsel Z Shafikov
- University of Regensburg, Institute of Physical Chemistry, Universitätsstr. 31, 93053, Regensburg, Germany.,Ural Federal University, Mira 19, Ekaterinburg, 620002, Russia
| | - Alfiya F Suleymanova
- University of Regensburg, Institute of Physical Chemistry, Universitätsstr. 31, 93053, Regensburg, Germany.,I. Postovsky Institute of Organic Synthesis, Ekaterinburg, 620990, Russia
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Giereth R, Frey W, Junge H, Tschierlei S, Karnahl M. Copper Photosensitizers Containing P^N Ligands and Their Influence on Photoactivity and Stability. Chemistry 2017; 23:17432-17437. [PMID: 29024115 DOI: 10.1002/chem.201703672] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2017] [Indexed: 11/09/2022]
Abstract
Driven by the intention to improve classic heteroleptic copper photosensitizers two novel Cu(I) complexes applying a hetero-bidentate P^N ligand were prepared. A combined photophysical, electrochemical, and theoretical study gives insights into structure-activity relationships and revealed an increased absorptivity. Both complexes were tested for the light-driven production of H2 .
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Affiliation(s)
- Robin Giereth
- Institute of Organic Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
| | - Wolfgang Frey
- Institute of Organic Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
| | - Henrik Junge
- Leibniz-Institute for Catalysis at the University of Rostock (LIKAT), Albert-Einstein-Str. 29a, 18059, Rostock, Germany
| | - Stefanie Tschierlei
- Institute of Inorganic Chemistry I, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Michael Karnahl
- Institute of Organic Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
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38
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Light to Hydrogen: Photocatalytic Hydrogen Generation from Water with Molecularly-Defined Iron Complexes. INORGANICS 2017. [DOI: 10.3390/inorganics5010014] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
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Kubiček K, Thekku Veedu S, Storozhuk D, Kia R, Techert S. Geometric and electronic properties in a series of phosphorescent heteroleptic Cu(I) complexes: Crystallographic and computational studies. Polyhedron 2017. [DOI: 10.1016/j.poly.2016.12.035] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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40
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Tschierlei S, Neubauer A, Rockstroh N, Karnahl M, Schwarzbach P, Junge H, Beller M, Lochbrunner S. Ultrafast excited state dynamics of iridium(III) complexes and their changes upon immobilisation onto titanium dioxide layers. Phys Chem Chem Phys 2017; 18:10682-7. [PMID: 27006105 DOI: 10.1039/c6cp00343e] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Time-resolved spectroscopy was applied to investigate the excited state dynamics of two heteroleptic Ir(III) complexes with the general formula [Ir(C^N)2(N^N)](+), where C^N and N^N represent different cyclometalating and diimine ligands, respectively. The excited state relaxation is influenced by the ligand substitution as well as the light polarisation. Vibrational relaxation occurs in the sub-ps timescale and interligand charge transfer results in polarisation dependent signal dynamics with a time constant of about 30 ps. Electron injection from the iridium dye to TiO2 is analysed with respect to potential applications in solar energy conversion.
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Affiliation(s)
- Stefanie Tschierlei
- Institute of Physics, University of Rostock, Albert-Einstein-Straße 23, 18059 Rostock, Germany. and Institute of Organic Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany.
| | - Antje Neubauer
- Institute of Physics, University of Rostock, Albert-Einstein-Straße 23, 18059 Rostock, Germany. and Becker & Hickl GmbH, Nahmitzer Damm 30, 12277 Berlin, Germany
| | - Nils Rockstroh
- Leibniz-Institute for Catalysis at the University of Rostock (LIKAT), Albert-Einstein-Str. 29a, 18059 Rostock, Germany
| | - Michael Karnahl
- Institute of Organic Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany. and Leibniz-Institute for Catalysis at the University of Rostock (LIKAT), Albert-Einstein-Str. 29a, 18059 Rostock, Germany
| | - Patrick Schwarzbach
- Institute of Physics, University of Rostock, Albert-Einstein-Straße 23, 18059 Rostock, Germany.
| | - Henrik Junge
- Leibniz-Institute for Catalysis at the University of Rostock (LIKAT), Albert-Einstein-Str. 29a, 18059 Rostock, Germany
| | - Matthias Beller
- Leibniz-Institute for Catalysis at the University of Rostock (LIKAT), Albert-Einstein-Str. 29a, 18059 Rostock, Germany
| | - Stefan Lochbrunner
- Institute of Physics, University of Rostock, Albert-Einstein-Straße 23, 18059 Rostock, Germany.
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41
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Heberle M, Tschierlei S, Rockstroh N, Ringenberg M, Frey W, Junge H, Beller M, Lochbrunner S, Karnahl M. Heteroleptic Copper Photosensitizers: Why an Extended π-System Does Not Automatically Lead to Enhanced Hydrogen Production. Chemistry 2016; 23:312-319. [DOI: 10.1002/chem.201604005] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Indexed: 11/10/2022]
Affiliation(s)
- Martin Heberle
- Institute of Organic Chemistry; University of Stuttgart; Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Stefanie Tschierlei
- Institute of Organic Chemistry; University of Stuttgart; Pfaffenwaldring 55 70569 Stuttgart Germany
- Institute of Physics; University of Rostock; Albert-Einstein-Str. 23 18059 Rostock Germany
| | - Nils Rockstroh
- Leibniz-Institute for Catalysis at the; University of Rostock (LIKAT); Albert-Einstein-Str. 29a 18059 Rostock Germany
| | - Mark Ringenberg
- Institute of Inorganic Chemistry; University of Stuttgart; Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Wolfgang Frey
- Institute of Organic Chemistry; University of Stuttgart; Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Henrik Junge
- Leibniz-Institute for Catalysis at the; University of Rostock (LIKAT); Albert-Einstein-Str. 29a 18059 Rostock Germany
| | - Matthias Beller
- Leibniz-Institute for Catalysis at the; University of Rostock (LIKAT); Albert-Einstein-Str. 29a 18059 Rostock Germany
| | - Stefan Lochbrunner
- Institute of Physics; University of Rostock; Albert-Einstein-Str. 23 18059 Rostock Germany
| | - Michael Karnahl
- Institute of Organic Chemistry; University of Stuttgart; Pfaffenwaldring 55 70569 Stuttgart Germany
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Takeda H, Cometto C, Ishitani O, Robert M. Electrons, Photons, Protons and Earth-Abundant Metal Complexes for Molecular Catalysis of CO2 Reduction. ACS Catal 2016. [DOI: 10.1021/acscatal.6b02181] [Citation(s) in RCA: 455] [Impact Index Per Article: 56.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Hiroyuki Takeda
- Department
of Chemistry, Faculty of Science, Tokyo Institute of Technology, 2-12-1, NE-1 O-okayama, Meguro-ku, Tokyo, 152-8550, Japan
| | - Claudio Cometto
- Université
Paris Diderot, Sorbonne Paris Cité, Laboratoire d’Electrochimie
Moléculaire, Unité Mixte de Recherche Université−CNRS
no. 7591, Bâtiment Lavoisier,
15 rue Jean de Baïf, 75205 CEDEX
13 Paris, France
| | - Osamu Ishitani
- Department
of Chemistry, Faculty of Science, Tokyo Institute of Technology, 2-12-1, NE-1 O-okayama, Meguro-ku, Tokyo, 152-8550, Japan
| | - Marc Robert
- Université
Paris Diderot, Sorbonne Paris Cité, Laboratoire d’Electrochimie
Moléculaire, Unité Mixte de Recherche Université−CNRS
no. 7591, Bâtiment Lavoisier,
15 rue Jean de Baïf, 75205 CEDEX
13 Paris, France
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Leitl MJ, Zink DM, Schinabeck A, Baumann T, Volz D, Yersin H. Copper(I) Complexes for Thermally Activated Delayed Fluorescence: From Photophysical to Device Properties. Top Curr Chem (Cham) 2016; 374:25. [PMID: 27573265 DOI: 10.1007/s41061-016-0019-1] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Accepted: 03/07/2016] [Indexed: 11/27/2022]
Abstract
Molecules that exhibit thermally activated delayed fluorescence (TADF) represent a very promising emitter class for application in electroluminescent devices since all electrically generated excitons can be transferred into light according to the singlet harvesting mechanism. Cu(I) compounds are an important class of TADF emitters. In this contribution, we want to give a deeper insight into the photophysical properties of this material class and demonstrate how the emission properties depend on molecular and host rigidity. Moreover, we show that with molecular optimization a significant improvement of selected emission properties can be achieved. From the discussed materials, we select one specific dinuclear complex, for which the two Cu(I) centers are four-fold bridged to fabricate an organic light emitting diode (OLED). This device shows the highest efficiency (of 23 % external quantum efficiency) reported so far for OLEDs based on Cu(I) emitters.
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Affiliation(s)
- Markus J Leitl
- Institut für Physikalische Chemie, Universität Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany
| | - Daniel M Zink
- Cynora GmbH, Werner-von-Siemensstraße 2-6, Building 5110, 76646, Bruchsal, Germany
| | - Alexander Schinabeck
- Institut für Physikalische Chemie, Universität Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany
| | - Thomas Baumann
- Cynora GmbH, Werner-von-Siemensstraße 2-6, Building 5110, 76646, Bruchsal, Germany
| | - Daniel Volz
- Cynora GmbH, Werner-von-Siemensstraße 2-6, Building 5110, 76646, Bruchsal, Germany.
| | - Hartmut Yersin
- Institut für Physikalische Chemie, Universität Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany.
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Zhang Y, Heberle M, Wächtler M, Karnahl M, Dietzek B. Determination of side products in the photocatalytic generation of hydrogen with copper photosensitizers by resonance Raman spectroelectrochemistry. RSC Adv 2016. [DOI: 10.1039/c6ra21469j] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
A combination of UV-Vis, resonance Raman spectroscopy and electrochemistry is employed to reveal the nature of a side product when using heteroleptic Cu(i)-photosensitizers for photocatalytic hydrogen production.
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Affiliation(s)
- Ying Zhang
- Institute of Physical Chemistry
- Friedrich Schiller University Jena
- 07743 Jena
- Germany
- Leibniz Institute of Photonic Technology Jena (IPHT)
| | - Martin Heberle
- University of Stuttgart
- Institute of Organic Chemistry
- 70569 Stuttgart
- Germany
| | - Maria Wächtler
- Leibniz Institute of Photonic Technology Jena (IPHT)
- 07745 Jena
- Germany
| | - Michael Karnahl
- University of Stuttgart
- Institute of Organic Chemistry
- 70569 Stuttgart
- Germany
| | - Benjamin Dietzek
- Institute of Physical Chemistry
- Friedrich Schiller University Jena
- 07743 Jena
- Germany
- Leibniz Institute of Photonic Technology Jena (IPHT)
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Lennox AJJ, Fischer S, Jurrat M, Luo SP, Rockstroh N, Junge H, Ludwig R, Beller M. Copper-Based Photosensitisers in Water Reduction: A More Efficient In Situ Formed System and Improved Mechanistic Understanding. Chemistry 2015; 22:1233-8. [DOI: 10.1002/chem.201503812] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Indexed: 11/05/2022]
Affiliation(s)
- Alastair J. J. Lennox
- Leibniz Institute for Catalysis at the; University of Rostock; Albert Einstein-Straße 29a 18059 Rostock Germany
| | - Steffen Fischer
- Institute of Chemistry; Department Physical Chemistry; University of Rostock; Dr. Lorenz-Weg 1 18059 Rostock Germany
| | - Mark Jurrat
- Leibniz Institute for Catalysis at the; University of Rostock; Albert Einstein-Straße 29a 18059 Rostock Germany
| | - Shu-Ping Luo
- State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology; Zhejiang University of Technology; 310014 Hangzhou P.R. China
| | - Nils Rockstroh
- Leibniz Institute for Catalysis at the; University of Rostock; Albert Einstein-Straße 29a 18059 Rostock Germany
| | - Henrik Junge
- Leibniz Institute for Catalysis at the; University of Rostock; Albert Einstein-Straße 29a 18059 Rostock Germany
| | - Ralf Ludwig
- Institute of Chemistry; Department Physical Chemistry; University of Rostock; Dr. Lorenz-Weg 1 18059 Rostock Germany
| | - Matthias Beller
- Leibniz Institute for Catalysis at the; University of Rostock; Albert Einstein-Straße 29a 18059 Rostock Germany
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Knorn M, Rawner T, Czerwieniec R, Reiser O. [Copper(phenanthroline)(bisisonitrile)]+-Complexes for the Visible-Light-Mediated Atom Transfer Radical Addition and Allylation Reactions. ACS Catal 2015. [DOI: 10.1021/acscatal.5b01071] [Citation(s) in RCA: 145] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Matthias Knorn
- Institut
für Organische Chemie, Universität Regensburg, Universitätsstraße
31, 93053 Regensburg, Germany
| | - Thomas Rawner
- Institut
für Organische Chemie, Universität Regensburg, Universitätsstraße
31, 93053 Regensburg, Germany
| | - Rafał Czerwieniec
- Institut
für Physikalische Chemie, Universität Regensburg, Universitätsstraße
31, 93053 Regensburg, Germany
| | - Oliver Reiser
- Institut
für Organische Chemie, Universität Regensburg, Universitätsstraße
31, 93053 Regensburg, Germany
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Czerwieniec R, Yersin H. Diversity of copper(I) complexes showing thermally activated delayed fluorescence: basic photophysical analysis. Inorg Chem 2015; 54:4322-7. [PMID: 25894718 DOI: 10.1021/ic503072u] [Citation(s) in RCA: 127] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
A comparison of three copper(I) compounds [1, Cu(dppb)(pz2Bph2); 2, Cu(pop)(pz2Bph2); 3, Cu(dmp)(phanephos)(+)] that show pronounced thermally activated delayed fluorescence (TADF) at ambient temperature demonstrates a wide diversity of emission behavior. In this study, we focus on compound 1. A computational density functional theory (DFT)/time-dependent DFT approach allows us to predict detailed photophysical properties, while experimental emission studies over a wide temperature range down to T = 1.5 K lead to better insight into the electronic structures even with respect to spin-orbit coupling efficiencies, radiative rates, and zero-field splitting of the triplet state. All three compounds, with emission quantum yields higher than ϕPL = 70%, are potentially well suited as emitters for organic light-emitting diodes (OLEDs) based on the singlet-harvesting mechanism. Interestingly, compound 1 is by far the most attractive one because of a very small energy separation between the lowest excited singlet S1 and triplet T1 state of ΔE(S1-T1) = 370 cm(-1) (46 meV). Such a small value has not been reported so far. It is responsible for the very short decay time of τ(TADF, 300 K) = 3.3 μs. Hence, if focused on the requirements of a short TADF decay time for reduction of the saturation effects in OLEDs, copper(I) complexes are well comparable or even slightly better than the best purely organic TADF emitters.
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Affiliation(s)
- Rafał Czerwieniec
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, 93053 Regensburg, Germany
| | - Hartmut Yersin
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, 93053 Regensburg, Germany
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