1
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Huang T, Du P, Cheng X, Lin YM. Manganese Complexes with Consecutive Mn(IV) → Mn(III) Excitation for Versatile Photoredox Catalysis. J Am Chem Soc 2024; 146:24515-24525. [PMID: 39079011 DOI: 10.1021/jacs.4c07084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/05/2024]
Abstract
Manganese complexes stand out as promising candidates for photocatalyst design, attributed to their eco- and biocompatibility, versatile valence states, and capability for facilitating multiple electronic excitations. However, several intrinsic constraints, such as inadequate visible light response and short excited-state lifetimes, hinder effective photoinduced electron transfer and impede photoredox activation of substrates. To overcome this obstacle, we have developed a class of manganese complexes featuring boron-incorporated N-heterocyclic carbene ligands. These complexes enable prolonged excited-state durations encapsulating both Mn(IV) and Mn(III) oxidation stages, with lifetimes reaching microseconds for Mn(IV) and nanoseconds for Mn(III), concurrently exhibiting robust redox capabilities. They efficiently catalyze direct, site-selective cross-couplings between diverse arenes and aryl bromides, at a low catalyst loading of 0.5 mol %. Their proficiency spans an extensive array of substrates including both highly electron-rich and electron-deficient molecules, which underscore the superior performance of these manganese complexes in tackling intricate transformations. Furthermore, the versatility of these complexes is further highlighted by their successful applications in various photochemical transformations, encompassing reductive cross-couplings for the formation of C-P, C-B, C-S and C-Se bonds, alongside oxidative couplings for creating C-N bonds. This study sheds light on the distinctive photoredox properties and the remarkable catalytic flexibility of manganese complexes, highlighting their immense potential to drive progress in photochemical synthesis and green chemistry applications.
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Affiliation(s)
- Tao Huang
- College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Pangang Du
- College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Xiuliang Cheng
- College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Yu-Mei Lin
- College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
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2
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Trippmacher S, Demeshko S, Prescimone A, Meyer F, Wenger OS, Wang C. Ferromagnetically Coupled Chromium(III) Dimer Shows Luminescence and Sensitizes Photon Upconversion. Chemistry 2024; 30:e202400856. [PMID: 38523568 DOI: 10.1002/chem.202400856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 03/23/2024] [Accepted: 03/25/2024] [Indexed: 03/26/2024]
Abstract
There has been much progress on mononuclear chromium(III) complexes featuring luminescence and photoredox activity, but dinuclear chromium(III) complexes have remained underexplored in these contexts until now. We identified a tridentate chelate ligand able to accommodate both meridional and facial coordination of chromium(III), to either access a mono- or a dinuclear chromium(III) complex depending on reaction conditions. This chelate ligand causes tetragonally distorted primary coordination spheres around chromium(III) in both complexes, entailing comparatively short excited-state lifetimes in the range of 400 to 800 ns in solution at room temperature and making photoluminescence essentially oxygen insensitive. The two chromium(III) ions in the dimer experience ferromagnetic exchange interactions that result in a high spin (S=3) ground state with a coupling constant of +9.3 cm-1. Photoinduced energy transfer from the luminescent ferromagnetically coupled dimer to an anthracene derivative results in sensitized triplet-triplet annihilation upconversion. Based on these proof-of-principle studies, dinuclear chromium(III) complexes seem attractive for the development of fundamentally new types of photophysics and photochemistry enabled by magnetic exchange interactions.
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Affiliation(s)
- Simon Trippmacher
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland
| | - Serhiy Demeshko
- Institute of Inorganic Chemistry, University of Göttingen, Tammannstraße 4, 37077, Göttingen, Germany
| | - Alessandro Prescimone
- Department of Chemistry, BPR 1096, University of Basel, Mattenstrasse 24a, 4058, Basel, Switzerland
| | - Franc Meyer
- Institute of Inorganic Chemistry, University of Göttingen, Tammannstraße 4, 37077, Göttingen, Germany
| | - Oliver S Wenger
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland
| | - Cui Wang
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland
- Department of Biology and Chemistry, Osnabrück University, Barbarastraße 7, 49076, Osnabrück, Germany
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3
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Jones R, Cowin RA, Ivalo II, Chekulaev D, Roseveare TM, Rice CR, Weinstein JA, Elliott PIP, Scattergood PA. A Near-Infrared Luminescent Cr(III) N-Heterocyclic Carbene Complex. Inorg Chem 2024; 63:8526-8530. [PMID: 38696219 PMCID: PMC11094792 DOI: 10.1021/acs.inorgchem.4c01270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 04/23/2024] [Accepted: 04/26/2024] [Indexed: 05/14/2024]
Abstract
Photoluminescent coordination complexes of Cr(III) are of interest as near-infrared spin-flip emitters. Here, we explore the preparation, electrochemistry, and photophysical properties of the first two examples of homoleptic N-heterocyclic carbene complexes of Cr(III), featuring 2,6-bis(imidazolyl)pyridine (ImPyIm) and 2-imidazolylpyridine (ImPy) ligands. The complex [Cr(ImPy)3]3+ displays luminescence at 803 nm on the microsecond time scale (13.7 μs) from a spin-flip doublet excited state, which transient absorption spectroscopy reveals to be populated within several picoseconds following photoexcitation. Conversely, [Cr(ImPyIm)2]3+ is nonemissive and has a ca. 500 ps excited-state lifetime.
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Affiliation(s)
- Robert
W. Jones
- Department
of Chemistry, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K.
| | - Rory A. Cowin
- Department
of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF, U.K.
| | - Iona I. Ivalo
- Department
of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF, U.K.
| | - Dimitri Chekulaev
- Department
of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF, U.K.
| | - Thomas M. Roseveare
- Department
of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF, U.K.
| | - Craig R. Rice
- Department
of Chemistry, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K.
| | - Julia. A. Weinstein
- Department
of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF, U.K.
| | - Paul I. P. Elliott
- Department
of Chemistry, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K.
| | - Paul A. Scattergood
- Department
of Chemistry, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K.
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4
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Payce EN, Knighton RC, Platts JA, Horton PN, Coles SJ, Pope SJA. Luminescent Pt(II) Complexes Using Unsymmetrical Bis(2-pyridylimino)isoindolate Analogues. Inorg Chem 2024; 63:8273-8285. [PMID: 38656154 PMCID: PMC11080048 DOI: 10.1021/acs.inorgchem.4c00558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Revised: 04/09/2024] [Accepted: 04/11/2024] [Indexed: 04/26/2024]
Abstract
A series of ligands based upon a 1,3-diimino-isoindoline framework have been synthesized and investigated as pincer-type (N∧N∧N) chelates for Pt(II). The synthetic route allows different combinations of heterocyclic moieties (including pyridyl, thiazole, and isoquinoline) to yield new unsymmetrical ligands. Pt(L1-6)Cl complexes were obtained and characterized using a range of spectroscopic and analytical techniques: 1H and 13C NMR, IR, UV-vis and luminescence spectroscopies, elemental analyses, high-resolution mass spectrometry, electrochemistry, and one example via X-ray crystallography which showed a distorted square planar environment at Pt(II). Cyclic voltammetry on the complexes showed one irreversible oxidation between +0.75 and +1 V (attributed to Pt2+/3+ couple) and a number of ligand-based reductions; in four complexes, two fully reversible reductions were noted between -1.4 and -1.9 V. Photophysical studies showed that Pt(L1-6)Cl absorbs efficiently in the visible region through a combination of ligand-based bands and metal-to-ligand charge-transfer features at 400-550 nm, with assignments supported by DFT calculations. Excitation at 500 nm led to luminescence (studied in both solutions and solid state) in all cases with different combinations of the heterocyclic donors providing tuning of the emission wavelength around 550-678 nm.
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Affiliation(s)
- Ellie N Payce
- School of Chemistry, Main Building, Cardiff University, Cardiff CF10 3AT, Cymru/Wales, U.K
| | - Richard C Knighton
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, England, U.K
| | - James A Platts
- School of Chemistry, Main Building, Cardiff University, Cardiff CF10 3AT, Cymru/Wales, U.K
| | - Peter N Horton
- UK National Crystallographic Service, Chemistry, Faculty of Natural and Environmental Sciences, University of Southampton, Highfield, Southampton SO17 1BJ, England, U.K
| | - Simon J Coles
- UK National Crystallographic Service, Chemistry, Faculty of Natural and Environmental Sciences, University of Southampton, Highfield, Southampton SO17 1BJ, England, U.K
| | - Simon J A Pope
- School of Chemistry, Main Building, Cardiff University, Cardiff CF10 3AT, Cymru/Wales, U.K
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5
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Sinha N, Wellauer J, Maisuradze T, Prescimone A, Kupfer S, Wenger OS. Reversible Photoinduced Ligand Substitution in a Luminescent Chromium(0) Complex. J Am Chem Soc 2024; 146:10418-10431. [PMID: 38588581 PMCID: PMC11027151 DOI: 10.1021/jacs.3c13925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Revised: 03/13/2024] [Accepted: 03/19/2024] [Indexed: 04/10/2024]
Abstract
Light-triggered dissociation of ligands forms the basis for many compounds of interest for photoactivated chemotherapy (PACT), in which medicinally active substances are released or "uncaged" from metal complexes upon illumination. Photoinduced ligand dissociation is usually irreversible, and many recent studies performed in the context of PACT focused on ruthenium(II) polypyridines and related heavy metal complexes. Herein, we report a first-row transition metal complex, in which photoinduced dissociation and spontaneous recoordination of a ligand unit occurs. Two scorpionate-type tridentate chelates provide an overall six-coordinate arylisocyanide environment for chromium(0). Photoexcitation causes decoordination of one of these six ligating units and coordination of a solvent molecule, at least in tetrahydrofuran and 1,4-dioxane solvents, but far less in toluene, and below detection limit in cyclohexane. Transient UV-vis absorption spectroscopy and quantum chemical simulations point to photoinduced ligand dissociation directly from an excited metal-to-ligand charge-transfer state. Owing to the tridentate chelate design and the substitution lability of the first-row transition metal, recoordination of the photodissociated arylisocyanide ligand unit can occur spontaneously on a millisecond time scale. This work provides insight into possible self-healing mechanisms counteracting unwanted photodegradation processes and seems furthermore relevant in the contexts of photoswitching and (photo)chemical information storage.
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Affiliation(s)
- Narayan Sinha
- Department
of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
- School
of Chemical Sciences, Indian Institute of
Technology Mandi, Mandi 175075, Himachal Pradesh, India
| | - Joël Wellauer
- Department
of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
| | - Tamar Maisuradze
- Institute
of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - Alessandro Prescimone
- Department
of Chemistry, University of Basel, BPR 1096, Mattenstrasse 24a, 4058 Basel, Switzerland
| | - Stephan Kupfer
- Institute
of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - Oliver S. Wenger
- Department
of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
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6
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Wellauer J, Ziereisen F, Sinha N, Prescimone A, Velić A, Meyer F, Wenger OS. Iron(III) Carbene Complexes with Tunable Excited State Energies for Photoredox and Upconversion. J Am Chem Soc 2024; 146. [PMID: 38598280 PMCID: PMC11046485 DOI: 10.1021/jacs.4c00605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Revised: 03/13/2024] [Accepted: 03/19/2024] [Indexed: 04/11/2024]
Abstract
Substituting precious elements in luminophores and photocatalysts by abundant first-row transition metals remains a significant challenge, and iron continues to be particularly attractive owing to its high natural abundance and low cost. Most iron complexes known to date face severe limitations due to undesirably efficient deactivation of luminescent and photoredox-active excited states. Two new iron(III) complexes with structurally simple chelate ligands enable straightforward tuning of ground and excited state properties, contrasting recent examples, in which chemical modification had a minor impact. Crude samples feature two luminescence bands strongly reminiscent of a recent iron(III) complex, in which this observation was attributed to dual luminescence, but in our case, there is clear-cut evidence that the higher-energy luminescence stems from an impurity and only the red photoluminescence from a doublet ligand-to-metal charge transfer (2LMCT) excited state is genuine. Photoinduced oxidative and reductive electron transfer reactions with methyl viologen and 10-methylphenothiazine occur with nearly diffusion-limited kinetics. Photocatalytic reactions not previously reported for this compound class, in particular the C-H arylation of diazonium salts and the aerobic hydroxylation of boronic acids, were achieved with low-energy red light excitation. Doublet-triplet energy transfer (DTET) from the luminescent 2LMCT state to an anthracene annihilator permits the proof of principle for triplet-triplet annihilation upconversion based on a molecular iron photosensitizer. These findings are relevant for the development of iron complexes featuring photophysical and photochemical properties competitive with noble-metal-based compounds.
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Affiliation(s)
- Joël Wellauer
- Department
of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
| | - Fabienne Ziereisen
- Department
of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
| | - Narayan Sinha
- Department
of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
| | - Alessandro Prescimone
- Department
of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
| | - Ajdin Velić
- University
of Göttingen, Institute of Inorganic Chemistry, Tammannstraße 4, D-37077 Göttingen, Germany
| | - Franc Meyer
- University
of Göttingen, Institute of Inorganic Chemistry, Tammannstraße 4, D-37077 Göttingen, Germany
| | - Oliver S. Wenger
- Department
of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
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7
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Benchohra A, Chong J, Cruz CM, Besnard C, Guénée L, Rosspeintner A, Piguet C. Additional Insights into the Design of Cr(III) Phosphorescent Emitters Using 6-Membered Chelate Ring Bis(imidazolyl) Didentate Ligands. Inorg Chem 2024; 63:3617-3629. [PMID: 38206181 DOI: 10.1021/acs.inorgchem.3c03422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2024]
Abstract
The interest in Cr(III) complexes has been renewed over the past decades for building practical guidelines in the design of efficient earth-abundant phosphorescent near-infrared emitters. In that context, we report the first family of homoleptic tri(didentate) Cr(III) complexes [CrL3]3+ based on polyaromatic ligands inducing 6-membered chelate rings, namely, the bis(1-methylimidazol-2-yl)ketone (L = bik), bis(1-methylimidazol-2-yl)methane (L = bim), and bis(1-methylimidazol-2-yl)ethane (L = bie) ligands. The programmed close-to-perfect octahedral microsymmetry of {CrIIIN6} chromophores found in [Cr(bik)3](OTf)3 (1), [Cr(bim)3](OTf)3 (2), and [Cr(bie)3](BF4)3 (3) ensures a ligand-field strength large enough to induce intense and long-lived Cr-based phosphorescence. Impressive excited-state lifetimes (5.0-8.2 ms) were obtained at low temperatures for the [Cr(L)3]3+ series. Additionally, the photoluminescent quantum yield climbs to 0.8% for compound 1 in deaerated solutions. Moreover, the photophysical features of the three homoleptic complexes are barely influenced by the presence of dioxygen presumably because of the poor overlap between the Cr-based phosphorescence spectra (ca. 14100 cm-1) and the 1Σg+ ← 3Σg- transition in the absorption spectrum of dioxygen (13100 cm-1). The multiredox electrochemical pattern of 1 is evidenced by cyclic voltammetry as well as its strong photooxidant behavior. The pH sensitivity of 2 and 3 luminescence is discussed, along with the reactivity of their β-diketiminate derivatives.
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Affiliation(s)
- Amina Benchohra
- Department of Inorganic Analytical and Applied Chemistry, University of Geneva, 30 quai E. Ansermet, CH-1211 Geneva 4, Switzerland
| | - Julien Chong
- Department of Inorganic Analytical and Applied Chemistry, University of Geneva, 30 quai E. Ansermet, CH-1211 Geneva 4, Switzerland
| | - Carlos M Cruz
- Department of Organic Chemistry, Unidad de Excelencia de Química (UEQ) University of Granada, Avenida Fuente Nueva, ES-18071 Granada, Spain
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Céline Besnard
- Laboratory of Crystallography, University of Geneva, 24 quai E. Ansermet, CH-1211 Geneva 4, Switzerland
| | - Laure Guénée
- Laboratory of Crystallography, University of Geneva, 24 quai E. Ansermet, CH-1211 Geneva 4, Switzerland
| | - Arnulf Rosspeintner
- Department of Physical Chemistry, University of Geneva, 30 quai E. Ansermet, CH-1211 Geneva 4, Switzerland
| | - Claude Piguet
- Department of Inorganic Analytical and Applied Chemistry, University of Geneva, 30 quai E. Ansermet, CH-1211 Geneva 4, Switzerland
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8
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Sun Y, Zhan F, Huang D, Wang X, Dou L, Xu K, Yang YF, Li G, She Y. 8-Phenylquinoline-Based Tetradentate 6/6/6 Platinum(II) Complexes for Near-Infrared Emitters. Inorg Chem 2023; 62:13156-13164. [PMID: 37531143 DOI: 10.1021/acs.inorgchem.3c02356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/03/2023]
Abstract
A series of novel tetradentate 6/6/6 Pt(II) complexes containing an 8-phenylquinoline-benzo[d]imidazole-carbazole ligand was designed; the Pt(II) complexes could be synthesized by metalizing the corresponding ligand with K2PtCl4 in high isolated yields of 60-90%. Experimental and theoretical studies suggested that the ligand modification of the quinoline moieties of the Pt(II) complexes could tune their electrochemical, photophysical, and excited-state properties. Notably, all the Pt(II) complexes exhibited highly electrochemical stabilities with reversible redox processes except the quasi-reversible reduction of PtYL3. The large π-conjugation of the ligand together with increased metal-to-ligand charge-transfer (3MLCT) characters in T1 states enabled the Pt(II) complexes to show broad Gaussian-type NIR emission spectra with high photoluminescence quantum efficiencies of 1.2-1.5% and short τ of 0.8-1.5 μs in dichloromethane at room temperature. This work should provide a valuable reference for the design and development of monomer NIR emitters.
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Affiliation(s)
- Yulu Sun
- College of Chemical Engineering, State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, P. R. China
| | - Feng Zhan
- College of Chemical Engineering, State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, P. R. China
| | - Disheng Huang
- College of Chemical Engineering, State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, P. R. China
| | - Xia Wang
- College of Chemical Engineering, State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, P. R. China
| | - Lijie Dou
- College of Chemical Engineering, State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, P. R. China
| | - Kewei Xu
- College of Chemical Engineering, State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, P. R. China
| | - Yun-Fang Yang
- College of Chemical Engineering, State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, P. R. China
| | - Guijie Li
- College of Chemical Engineering, State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, P. R. China
| | - Yuanbin She
- College of Chemical Engineering, State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, P. R. China
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9
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Sinha N, Wenger OS. Photoactive Metal-to-Ligand Charge Transfer Excited States in 3d 6 Complexes with Cr 0, Mn I, Fe II, and Co III. J Am Chem Soc 2023; 145:4903-4920. [PMID: 36808978 PMCID: PMC9999427 DOI: 10.1021/jacs.2c13432] [Citation(s) in RCA: 40] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
Many coordination complexes and organometallic compounds with the 4d6 and 5d6 valence electron configurations have outstanding photophysical and photochemical properties, which stem from metal-to-ligand charge transfer (MLCT) excited states. This substance class makes extensive use of the most precious and least abundant metal elements, and consequently there has been a long-standing interest in first-row transition metal compounds with photoactive MLCT states. Semiprecious copper(I) with its completely filled 3d subshell is a relatively straightforward and well explored case, but in 3d6 complexes the partially filled d-orbitals lead to energetically low-lying metal-centered (MC) states that can cause undesirably fast MLCT excited state deactivation. Herein, we discuss recent advances made with isoelectronic Cr0, MnI, FeII, and CoIII compounds, for which long-lived MLCT states have become accessible over the past five years. Furthermore, we discuss possible future developments in the search for new first-row transition metal complexes with partially filled 3d subshells and photoactive MLCT states for next-generation applications in photophysics and photochemistry.
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Affiliation(s)
- Narayan Sinha
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
| | - Oliver S Wenger
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
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10
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Cheng Y, He J, Zou W, Chang X, Yang Q, Lu W. Circularly polarized near-infrared phosphorescence of chiral chromium(III) complexes. Chem Commun (Camb) 2023; 59:1781-1784. [PMID: 36723000 DOI: 10.1039/d2cc06548g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Homoleptic Cr(III) complexes containing anionic tridentate 1,8-(bisoxazolyl)carbazolide ligands are phosphorescent in deaerated solutions with peak maxima in the range of 813-845 nm. The ligand carbon-centred chirality has been transferred to the helical chirality of the complexes and hence induced circularly polarized NIR-emissions with dissymmetry factor in the scale of 2.0 × 10-3.
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Affiliation(s)
- Yang Cheng
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, Guangdong 518055, P. R. China.
| | - Jiang He
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, Guangdong 518055, P. R. China.
| | - Wenjie Zou
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, Guangdong 518055, P. R. China.
| | - Xiaoyong Chang
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, Guangdong 518055, P. R. China.
| | - Qingqing Yang
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, Guangdong 518055, P. R. China.
| | - Wei Lu
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, Guangdong 518055, P. R. China.
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