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Innocent M, Tanguy C, Gavelle S, Aubineau T, Guérinot A. Iron-Catalyzed, Light-Driven Decarboxylative Alkoxyamination. Chemistry 2024; 30:e202401252. [PMID: 38736425 DOI: 10.1002/chem.202401252] [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: 03/28/2024] [Revised: 05/07/2024] [Accepted: 05/12/2024] [Indexed: 05/14/2024]
Abstract
An iron-catalyzed visible-light driven decarboxylative alkoxyamination is disclosed. In the presence of FeBr2 and TEMPO, a large array of carboxylic acids including marketed drugs and biobased molecules is turned into the corresponding alkoxyamine derivatives. The versatility of the latter offers an entry towards molecular diversity generation from abundant starting materials and catalyst. Overall, this method proposes a unified and general approach for LMCT-based iron-catalyzed decarboxylative functionalization.
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Affiliation(s)
- Milan Innocent
- Molecular, Macromolecular Chemistry and Materials, ESPCI Paris - PSL, CNRS, 10 rue Vauquelin, 75005, Paris, France
| | - Clément Tanguy
- Molecular, Macromolecular Chemistry and Materials, ESPCI Paris - PSL, CNRS, 10 rue Vauquelin, 75005, Paris, France
| | - Sigrid Gavelle
- Molecular, Macromolecular Chemistry and Materials, ESPCI Paris - PSL, CNRS, 10 rue Vauquelin, 75005, Paris, France
| | - Thomas Aubineau
- Molecular, Macromolecular Chemistry and Materials, ESPCI Paris - PSL, CNRS, 10 rue Vauquelin, 75005, Paris, France
| | - Amandine Guérinot
- Molecular, Macromolecular Chemistry and Materials, ESPCI Paris - PSL, CNRS, 10 rue Vauquelin, 75005, Paris, France
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2
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Cao S, Chen JX, Zhang XL, Song X, Song WY, Wu YS, Zhang YH, Liu Z. Merging Quinoxalin-2(1 H)-ones Excitation with Cobaloxime Catalysis: C3 Alkylation of Quinoxalin-2(1 H)-ones with Unactivated Alkyl Iodides and Carboxylic Acids under Light. Org Lett 2024; 26:5833-5838. [PMID: 38934368 DOI: 10.1021/acs.orglett.4c02021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/28/2024]
Abstract
Reported herein is a practical, economical, and efficient construction of 3-alkylated quinoxalin-2(1H)-ones with alkyl carboxylic acids and alkyl iodides by quinoxalin-2(1H)-one excitation and cobaloxime catalysis. Primary, secondary, and tertiary alkyl iodides and carboxylic acids all could be efficiently transferred into target products with excellent functional group tolerance. Mechanism studies reveal that the quinoxalin-2(1H)-one derivatives could be directly excited and yield alkyl carbon radicals from alkyl carboxylic acids and alkyl iodides with the aid of the cobaloxime complex.
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Affiliation(s)
- Shuo Cao
- School of Pharmacy, Shandong Second Medical University Weifang, 261053 China
| | - Jia-Xin Chen
- School of Pharmacy, Shandong Second Medical University Weifang, 261053 China
| | - Xiu-Li Zhang
- School of Pharmacy, Shandong Second Medical University Weifang, 261053 China
| | - Xian Song
- School of Pharmacy, Shandong Second Medical University Weifang, 261053 China
| | - Wen-Yu Song
- School of Pharmacy, Shandong Second Medical University Weifang, 261053 China
| | - Yu-Sheng Wu
- School of Pharmacy, Shandong Second Medical University Weifang, 261053 China
| | - Yan-Hui Zhang
- School of Medical Imaging, Shandong Second Medical University Weifang, 261053 China
| | - Zan Liu
- School of Pharmacy, Shandong Second Medical University Weifang, 261053 China
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3
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Ghosh A, Yarranton JT, McCusker JK. Establishing the origin of Marcus-inverted-region behaviour in the excited-state dynamics of cobalt(III) polypyridyl complexes. Nat Chem 2024:10.1038/s41557-024-01564-3. [PMID: 38965436 DOI: 10.1038/s41557-024-01564-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Accepted: 05/24/2024] [Indexed: 07/06/2024]
Abstract
Growing interest in the use of first-row transition metal complexes in a number of applied contexts-including but not limited to photoredox catalysis and solar energy conversion-underscores the need for a detailed understanding of their photophysical properties. A recent focus on ligand-field photocatalysis using cobalt(III) polypyridyls in particular has unlocked unprecedented excited-state reactivities. Photophysical studies on Co(III) chromophores in general are relatively uncommon, and so here we carry out a systematic study of a series of Co(III) polypyridyl complexes in order to delineate their excited-state dynamics. Compounds with varying ligand-field strengths were prepared and studied using variable-temperature ultrafast transient absorption spectroscopy. Analysis of the data establishes that the ground-state recovery dynamics are operating in the Marcus inverted region, in stark contrast to what is typically observed in other first-row metal complexes. The analysis has further revealed the underlying reasons driving this excited-state behaviour, thereby enabling potential advancements in the targeted use of the Marcus inverted region for a variety of photolytic applications.
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Affiliation(s)
- Atanu Ghosh
- Department of Chemistry, Michigan State University, East Lansing, MI, USA
| | | | - James K McCusker
- Department of Chemistry, Michigan State University, East Lansing, MI, USA.
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4
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Ma F, Luo ZM, Wang JW, Ouyang G. Highly Efficient, Noble-Metal-Free, Fully Aqueous CO 2 Photoreduction Sensitized by a Robust Organic Dye. J Am Chem Soc 2024; 146:17773-17783. [PMID: 38888951 DOI: 10.1021/jacs.4c03128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/20/2024]
Abstract
The development of efficient, selective, and durable CO2 photoreduction systems presents a long-standing challenge in full aqueous solutions owing to the presence of scarce CO2 and the fierce competition against H2 evolution, which is even more challenging when noble metals are not utilized. Herein, we present the facile decorations of four phosphonic acid groups on a donor-acceptor-type organic dye to obtain a water-soluble photosensitizer (4P-DPAIPN), which succeeds the excellent photophysical and photoredox properties of its prototype, exhibiting long-lived delayed fluorescence (>10 μs) in aqueous solutions. Combining 4P-DPAIPN with a cationic cobalt porphyrin catalyst has accomplished record-high apparent quantum yields of 9.4-17.4% at 450 nm for CO2-to-CO photoconversion among the precedented systems (maximum 13%) in fully aqueous solutions. Remarkable selectivity of 82-93% and turnover number of 2700 for CO production can also be achieved with this noble-metal-free system, outperforming a benchmarking ruthenium photosensitizer and a commercial organic dye under parallel conditions. Such high performances of 4P-DPAIPN can be well maintained under real sunlight. More impressively, no significant decomposition of 4P-DPAIPN was detected during the long-term photocatalysis. Eventually, the photoinduced electron transfer pathways were proposed.
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Affiliation(s)
- Fan Ma
- School of Chemical Engineering and Technology, Sun Yat-sen University, Zhuhai 519082, China
| | - Zhi-Mei Luo
- School of Chemical Engineering and Technology, Sun Yat-sen University, Zhuhai 519082, China
| | - Jia-Wei Wang
- School of Chemical Engineering and Technology, Sun Yat-sen University, Zhuhai 519082, China
| | - Gangfeng Ouyang
- School of Chemical Engineering and Technology, Sun Yat-sen University, Zhuhai 519082, China
- Chemistry College, Center of Advanced Analysis and Gene Sequencing, Zhengzhou University, Zhengzhou 450001, China
- Guangdong Provincial Key Laboratory of Emergency Test for Dangerous Chemicals, Guangdong Institute of Analysis (China National Analytical Center Guangzhou), Guangzhou 510070, China
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5
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Treacy SM, Rovis T. Photoinduced Ligand-to-Metal Charge Transfer in Base-Metal Catalysis. SYNTHESIS-STUTTGART 2024; 56:1967-1978. [PMID: 38962497 PMCID: PMC11218547 DOI: 10.1055/s-0042-1751518] [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] [Indexed: 07/05/2024]
Abstract
The absorption of light by photosensitizers has been shown to offer novel reactive pathways through electronic excited state intermediates, complementing ground state mechanisms. Such strategies have been applied in both photocatalysis and photoredox catalysis, driven by generating reactive intermediates from their long-lived excited states. One developing area is photoinduced ligand-to-metal charge transfer (LMCT) catalysis, in which coordination of a ligand to a metal center and subsequent excitation with light results in the formation of a reactive radical and a reduced metal center. This mini review concerns the foundations and recent developments in ligand-to-metal charge transfer in transition metal catalysis focusing on the organic transformations made possible through this mechanism.
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Affiliation(s)
- S M Treacy
- Columbia University, Department of Chemistry, 3000 Broadway, Havemeyer Hall, New York, NY 10027, USA
| | - T Rovis
- Columbia University, Department of Chemistry, 3000 Broadway, Havemeyer Hall, New York, NY 10027, USA
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6
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De Kreijger S, Cauët E, Elias B, Troian-Gautier L. Synthesis of Ru(II) and Os(II) photosensitizers bearing one 9,10-diamino-1,4,5,8-tetraazaphenanthrene scaffold. Dalton Trans 2024; 53:10270-10284. [PMID: 38829264 DOI: 10.1039/d4dt01077a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2024]
Abstract
The synthesis of eight Ru(II) and Os(II) photosensitizers bearing a common 9,10-disubstituted-1,4,5,8-tetraazaphenanthrene backbone is reported. With Os(II) photosensitizers, the 9,10-diNH2-1,4,5,8-tetraazaphenanthrene could be directly chelated onto the metal center via the heteroaromatic moiety, whereas similar conditions using Ru(II) resulted in the formation of an o-quinonediimine derivative. Hence, an alternative route, proceeding via the chelation of 9-NH2-10-NO2-1,4,5,8-tetraazaphenanthrene and subsequent ligand reduction of the corresponding photosensitizers was developed. Photosensitizers chelated via the polypyridyl-type moiety exhibited classical photophysical properties whereas the o-quinonediimine chelated Ru(II) analogues exhibited red-shifted absorption (520 nm) and no photoluminescence at room temperature in acetonitrile. The most promising photosensitizers were investigated for excited-state quenching with guanosine-5'-monophosphate in aqueous buffered conditions where reductive excited-state electron transfer was observed by nanosecond transient absorption spectroscopy.
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Affiliation(s)
- Simon De Kreijger
- UCLouvain, Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), Place Louis Pasteur 1/L4.01.02, B-1348 Louvain-la-Neuve, Belgium.
| | - Emilie Cauët
- Spectroscopy, Quantum Chemistry and Atmospheric Remote Sensing (CP 160/09), Université libre de Bruxelles (ULB), 50 av. F. D. Roosevelt, CP160/09, B-1050 Brussels, Belgium
| | - Benjamin Elias
- UCLouvain, Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), Place Louis Pasteur 1/L4.01.02, B-1348 Louvain-la-Neuve, Belgium.
| | - Ludovic Troian-Gautier
- UCLouvain, Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), Place Louis Pasteur 1/L4.01.02, B-1348 Louvain-la-Neuve, Belgium.
- Wel Research Institute, Avenue Pasteur 6, 1300 Wavre, Belgium
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7
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Fall A, Magdei M, Savchuk M, Oudeyer S, Beucher H, Brière JF. Iron-catalyzed decarboxylative radical addition to chiral azomethine imines upon visible light. Chem Commun (Camb) 2024; 60:6316-6319. [PMID: 38819219 DOI: 10.1039/d4cc01766h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2024]
Abstract
Herein, we disclose an eco-efficient redox-neutral iron-catalyzed decarboxylative radical addition to chiral azomethine imines upon visible light (427 nm) giving cyclic hydrazine derivatives with dr ranging from 82 : 18 to >96 : 4. This earth-abundant metal promoted sequence proceeds efficiently under ligand-free conditions based on a LMCT process and opens a route to new chiral heterocycles.
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Affiliation(s)
- Arona Fall
- INSA Rouen Normandie, Univ Rouen Normandie, CNRS, Normandie Univ, COBRA UMR 6014, INC3M FR 3038, F-76000 Rouen, France.
| | - Mihaela Magdei
- INSA Rouen Normandie, Univ Rouen Normandie, CNRS, Normandie Univ, COBRA UMR 6014, INC3M FR 3038, F-76000 Rouen, France.
| | - Mariia Savchuk
- INSA Rouen Normandie, Univ Rouen Normandie, CNRS, Normandie Univ, COBRA UMR 6014, INC3M FR 3038, F-76000 Rouen, France.
| | - Sylvain Oudeyer
- INSA Rouen Normandie, Univ Rouen Normandie, CNRS, Normandie Univ, COBRA UMR 6014, INC3M FR 3038, F-76000 Rouen, France.
| | - Hélène Beucher
- INSA Rouen Normandie, Univ Rouen Normandie, CNRS, Normandie Univ, COBRA UMR 6014, INC3M FR 3038, F-76000 Rouen, France.
| | - Jean-François Brière
- INSA Rouen Normandie, Univ Rouen Normandie, CNRS, Normandie Univ, COBRA UMR 6014, INC3M FR 3038, F-76000 Rouen, France.
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8
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Venkatraman RK, Tolba AH, Sølling TI, Cibulka R, El-Zohry AM. Ultrafast Events of Photoexcited Iron(III) Chloride for Activation of Benzylic C-H Bonds. J Phys Chem Lett 2024; 15:6202-6208. [PMID: 38836909 DOI: 10.1021/acs.jpclett.4c01116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2024]
Abstract
The usage of rare-earth-metal catalysts in the synthesis of organic compounds is widespread in chemical industries but is limited owing to its environmental and economic costs. However, recent studies indicate that abundant-earth metals like iron(III) chloride can photocatalyze diverse organic transformations using blue-light LEDs. Still, the underlying mechanism behind such activity is debatable and controversial, especially in the absence of ultrafast spectroscopic results. To address this urgent challenge, we performed femtosecond time-resolved electronic absorption spectroscopy experiments of iron(III) chloride in selected organic solvents relevant to its photocatalytic applications. Our results show that the long-lived species [Fe(II) ← Cl•]* is primarily responsible for both oxidizing the organic substrate and reducing molecular oxygen through the diffusion process, leading to the final product and regenerating the photocatalyst rather than the most widely proposed free chloride radical (Cl•). Our study will guide the rational design of efficient earth-abundant photocatalysts.
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Affiliation(s)
- Ravi Kumar Venkatraman
- Ultrafast Laser Spectroscopy Lab Center for Integrative Petroleum Research, King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia
| | - Amal Hassan Tolba
- Department of Organic Chemistry, University of Chemistry and Technology, Prague, Technická 5, 166 28 Prague, Czech Republic
- Chemistry Department, Faculty of Science, Assiut University, Assiut 2074020, Egypt
| | - Theis I Sølling
- Ultrafast Laser Spectroscopy Lab Center for Integrative Petroleum Research, King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia
| | - Radek Cibulka
- Department of Organic Chemistry, University of Chemistry and Technology, Prague, Technická 5, 166 28 Prague, Czech Republic
| | - Ahmed M El-Zohry
- Ultrafast Laser Spectroscopy Lab Center for Integrative Petroleum Research, King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia
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9
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Goodwin MJ, Dickenson JC, Ripak A, Deetz AM, McCarthy JS, Meyer GJ, Troian-Gautier L. Factors that Impact Photochemical Cage Escape Yields. Chem Rev 2024; 124:7379-7464. [PMID: 38743869 DOI: 10.1021/acs.chemrev.3c00930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
The utilization of visible light to mediate chemical reactions in fluid solutions has applications that range from solar fuel production to medicine and organic synthesis. These reactions are typically initiated by electron transfer between a photoexcited dye molecule (a photosensitizer) and a redox-active quencher to yield radical pairs that are intimately associated within a solvent cage. Many of these radicals undergo rapid thermodynamically favored "geminate" recombination and do not diffuse out of the solvent cage that surrounds them. Those that do escape the cage are useful reagents that may undergo subsequent reactions important to the above-mentioned applications. The cage escape process and the factors that determine the yields remain poorly understood despite decades of research motivated by their practical and fundamental importance. Herein, state-of-the-art research on light-induced electron transfer and cage escape that has appeared since the seminal 1972 review by J. P. Lorand entitled "The Cage Effect" is reviewed. This review also provides some background for those new to the field and discusses the cage escape process of both homolytic bond photodissociation and bimolecular light induced electron transfer reactions. The review concludes with some key goals and directions for future research that promise to elevate this very vibrant field to even greater heights.
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Affiliation(s)
- Matthew J Goodwin
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - John C Dickenson
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Alexia Ripak
- Université catholique de Louvain (UCLouvain), Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), Place Louis Pasteur 1, bte L4.01.02, 1348 Louvain-la-Neuve, Belgium
| | - Alexander M Deetz
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Jackson S McCarthy
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Gerald J Meyer
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Ludovic Troian-Gautier
- Université catholique de Louvain (UCLouvain), Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), Place Louis Pasteur 1, bte L4.01.02, 1348 Louvain-la-Neuve, Belgium
- Wel Research Institute, Avenue Pasteur 6, 1300 Wavre, Belgium
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10
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Ni H, Mao H, Huang Y, Lu Y, Liu Z. Mild Iron-Catalyzed Oxidative Cross-Coupling of Quinoxalinones with Indoles. Molecules 2024; 29:2649. [PMID: 38893523 PMCID: PMC11173961 DOI: 10.3390/molecules29112649] [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: 05/15/2024] [Revised: 05/28/2024] [Accepted: 05/28/2024] [Indexed: 06/21/2024] Open
Abstract
Utilizing iron chloride as a Lewis acid catalyst, we developed a straightforward and mild oxidative cross-coupling reaction between quinoxalinones and indoles, yielding a series of versatile 3-(indol-3-yl)quinoxalin-2-one derivatives. This approach allows for the incorporation of a wide array of functional groups into the final products, demonstrating its synthetic versatility. Notably, the method was successfully scaled up to gram-scale reactions while maintaining high yields. Our mechanistic investigation indicates that iron chloride serves as a catalyst to facilitate the formation of key intermediates which subsequently undergo oxidation to afford the desired products. The merits of this protocol include its cost effectiveness, operational simplicity, and the ease of product isolation via filtration.
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Affiliation(s)
- Hangcheng Ni
- College of Pharmacy, Jinhua Polytechnic, Jinhua 321007, China
| | - Hui Mao
- College of Pharmacy, Jinhua Polytechnic, Jinhua 321007, China
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Zhejiang Normal University, Jinhua 321004, China
| | - Ying Huang
- College of Pharmacy, Jinhua Polytechnic, Jinhua 321007, China
| | - Yi Lu
- College of Pharmacy, Jinhua Polytechnic, Jinhua 321007, China
| | - Zhenxiang Liu
- College of Pharmacy, Jinhua Polytechnic, Jinhua 321007, China
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11
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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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12
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Alías-Rodríguez M, Huix-Rotllant M. Control of Iron(II)-Tris(2,2'-Bipyridine) Light-Induced Excited-State Trapping via External Electromagnetic Fields. Chemphyschem 2024:e202400471. [PMID: 38797713 DOI: 10.1002/cphc.202400471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Revised: 05/22/2024] [Accepted: 05/22/2024] [Indexed: 05/29/2024]
Abstract
Light-induced excited spin-state trapping reactions in iron pyridinic complexes allow the iron's low-to-high spin transition in a sub-picosecond timescale. Employing a recently developed model for [Fe(2,2'-bipyridine)3]2+ photochemical spin-crossover reaction in conjunction with quantum wavepacket dynamics, we explore the possibility of controlling the reaction through external electromagnetic fields, aiming at stabilizing the initial metal-to-ligand charge transfer states. We show that simple Gaussian-shaped electromagnetic fields have a minor effect on the population kinetics. However, introducing vibrationally excited initial wavepacket representations allows for maintaining the population trapped in the metal-to-ligand charge transfer states. Using optimal control theory, we propose an electromagnetic field shape that increases the lifetime of metal-to-ligand charge transfer states. These results open the route for controlling the iron photochemistry through the action of external electric fields.
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13
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Mandal T, Chaturvedi A, Azim A, Maji R, De Sarkar S. Earth-Abundant Recyclable Magnetic Iron Oxide Nanoparticles for Green-light Mediated C-H Arylation in Heterogeneous Phase. Chemistry 2024:e202401617. [PMID: 38788130 DOI: 10.1002/chem.202401617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Revised: 05/22/2024] [Accepted: 05/24/2024] [Indexed: 05/26/2024]
Abstract
A magnetically isolable iron oxide nanoparticles is introduced as an efficient heterogeneous photocatalyst for non-directed C-H arylation employing aryl diazonium salts as the aryl precursors. This first-row transition metal-based photocatalyst revealed versatile activities and is applicable to a wide range of substrates, demonstrating brilliant efficacy and superior recyclability. Detailed catalytic characterization describes the physical properties and redox behavior of the Fe-catalyst. Adequate control experiments helped to establish the radical-based mechanism for the C-H arylation.
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Affiliation(s)
- Tanumoy Mandal
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, 741246, India
| | - Ashwin Chaturvedi
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, 741246, India
| | - Aznur Azim
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, 741246, India
| | - Rohan Maji
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, 741246, India
| | - Suman De Sarkar
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, 741246, India
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14
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Doeven EH, Connell TU, Sinha N, Wenger OS, Francis PS. Electrochemiluminescence of a First-Row d 6 Transition Metal Complex. Angew Chem Int Ed Engl 2024; 63:e202319047. [PMID: 38519420 DOI: 10.1002/anie.202319047] [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: 12/11/2023] [Revised: 03/12/2024] [Accepted: 03/22/2024] [Indexed: 03/24/2024]
Abstract
We report the electrochemiluminescence (ECL) of a 3d6 Cr(0) complex ([Cr(LMes)3]; λem=735 nm) with comparable photophysical properties to those of ECL-active complexes of 4d6 or 5d6 precious metal ions. The electrochemical potentials of [Cr(LMes)3] are more negative than those of [Ir(ppy)3] and render the [Cr(LMes)3]* excited state inaccessible through conventional co-reactant ECL with tri-n-propylamine or oxalate. ECL can be obtained, however, through the annihilation route in which potentials sufficient to oxidise and reduce the luminophore are alternately applied. When combined with [Ir(ppy)3] (λem=520 nm), the annihilation ECL of [Cr(LMes)3] was greatly enhanced whereas that of [Ir(ppy)3] was diminished. Under appropriate conditions, the relative intensities of the two spectrally distinct emissions can be controlled through the applied potentials. From this starting point for ECL with 3d6 metal complexes, we discuss some directions for future development.
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Affiliation(s)
- Egan H Doeven
- Centre for Sustainable Bioproducts, Faculty of Science, Engineering and Built Environment, Deakin University Waurn Ponds, Victoria, 3216, Australia
| | - Timothy U Connell
- Centre for Sustainable Bioproducts, Faculty of Science, Engineering and Built Environment, Deakin University Waurn Ponds, Victoria, 3216, Australia
| | - Narayan Sinha
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland
- School of Chemical Sciences, Indian Institute of Technology (IIT) Mandi Kamand, Mandi, 175075, Himachal Pradesh, India
| | - Oliver S Wenger
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland
| | - Paul S Francis
- Centre for Sustainable Bioproducts, Faculty of Science, Engineering and Built Environment, Deakin University Waurn Ponds, Victoria, 3216, Australia
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15
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Zhang Y, Lee TS, Petersen JL, Milsmann C. Photophysical Studies of a Zr(IV) Complex with Two Pyrrolide-Based Tetradentate Schiff Base Ligands. Inorg Chem 2024; 63:9002-9013. [PMID: 38700497 PMCID: PMC11110004 DOI: 10.1021/acs.inorgchem.4c00365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 04/05/2024] [Accepted: 04/23/2024] [Indexed: 05/05/2024]
Abstract
The reaction of two equivalents of N,N'-bis(2-pyrrolylmethylidene)-1,2-phenylenediamine (H2bppda) with tetrabenzylzirconium provided the air- and moisture-stable eight-coordinate complex Zr(bppda)2. Temperature-dependent steady-state and time-resolved emission spectroscopy established weak photoluminescence (ΦPL = 0.4% at 293 K) by a combination of prompt fluorescence and thermally activated delayed fluorescence (TADF) upon visible light excitation at and around room temperature. TADF emission is strongly quenched by 3O2 and shows highly temperature-sensitive emission lifetimes of hundreds of microseconds. The lifetime of the lowest energy singlet excited state, S1, was established by transient absorption spectroscopy and shows rapid deactivation (τ = 142 ps) by prompt fluorescence and intersystem crossing to the triplet state, T1. Time-dependent density functional theory (TD-DFT) calculations predict moderate ligand-to-metal charge transfer (LMCT) contributions of 25-30% for the S1 and T1 states. A comparison of Zr(bppda)2 to related zirconium pyridine dipyrrolide complexes, Zr(PDP)2, revealed important electronic structure changes due to the eight-coordinate ligand environment in Zr(bppda)2, which were correlated to differences in the photophysical properties between the two compound classes.
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Affiliation(s)
- Yu Zhang
- C.
Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
- Department
of Chemistry, Tufts University, Medford, Massachusetts 02144, United States
| | - Tia S. Lee
- Department
of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Jeffrey L. Petersen
- C.
Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Carsten Milsmann
- C.
Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
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16
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Wenzel JO, Werner J, Allgaier A, van Slageren J, Fernández I, Unterreiner AN, Breher F. Visible-Light Activation of Diorganyl Bis(pyridylimino) Isoindolide Aluminum(III) Complexes and Their Organometallic Radical Reactivity. Angew Chem Int Ed Engl 2024; 63:e202402885. [PMID: 38511969 DOI: 10.1002/anie.202402885] [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: 02/08/2024] [Revised: 03/14/2024] [Accepted: 03/14/2024] [Indexed: 03/22/2024]
Abstract
We report on the synthesis and characterization of a series of (mostly) air-stable diorganyl bis(pyridylimino) isoindolide (BPI) aluminum complexes and their chemistry upon visible-light excitation. The redox non-innocent BPI pincer ligand allows for efficient charge transfer homolytic processes of the title compounds. This makes them a universal platform for the generation of carbon-centered radicals. The photo-induced homolytic cleavage of the Al-C bonds was investigated by means of stationary and transient UV/Vis spectroscopy, spin trapping experiments, as well as EPR and NMR spectroscopy. The experimental findings were supported by quantum chemical calculations. Reactivity studies enabled the utilization of the aluminum complexes as reactants in tin-free Giese-type reactions and carbonyl alkylations under ambient conditions, which both indicated radical-polar crossover behavior. A deeper understanding of the physical fundamentals and photochemical process was provided, furnishing in turn a new strategy to control the reactivity of bench-stable aluminum organometallics.
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Affiliation(s)
- Jonas O Wenzel
- Karlsruhe Institute of Technology (KIT), Institute of Inorganic Chemistry (AOC), Engesserstraße 15, 76131, Karlsruhe, Germany
| | - Johannes Werner
- Karlsruhe Institute of Technology (KIT), Institute of Physical Chemistry (IPC), Fritz-Haber-Weg 2, 76131, Karlsruhe, Germany
| | - Alexander Allgaier
- University of Stuttgart, Institute of Physical Chemistry, Pfaffenwaldring 55, 70569, Stuttgart, Germany
| | - Joris van Slageren
- University of Stuttgart, Institute of Physical Chemistry, Pfaffenwaldring 55, 70569, Stuttgart, Germany
| | - Israel Fernández
- Universidad Complutense de Madrid, Facultad de Ciencias Químicas, 28040, Madrid, Spain
| | - Andreas-Neil Unterreiner
- Karlsruhe Institute of Technology (KIT), Institute of Physical Chemistry (IPC), Fritz-Haber-Weg 2, 76131, Karlsruhe, Germany
| | - Frank Breher
- Karlsruhe Institute of Technology (KIT), Institute of Inorganic Chemistry (AOC), Engesserstraße 15, 76131, Karlsruhe, Germany
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17
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Shukla G, Singh M, Singh S, Singh MS. Iridium(III)-catalyzed photoredox cross-coupling of alkyl bromides with trialkyl amines: access to α-alkylated aldehydes. Chem Commun (Camb) 2024. [PMID: 38686503 DOI: 10.1039/d4cc01043d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
A C(sp3)-C(sp3) cross coupling approach based on an iridium-photocatalytic radical process has been developed enabling the synthesis of various α-alkylated aldehydes from easily available/synthesized alkyl bromides and trialkyl amines under mild photocatalytic conditions. The synthesized aldehydes are also explored as a functional handle for various useful products such as carboxylic acid, alcohol and N-heterocycle synthesis.
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Affiliation(s)
- Gaurav Shukla
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi-211005, India.
| | - Malkeet Singh
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi-211005, India.
| | - Saurabh Singh
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi-211005, India.
| | - Maya Shankar Singh
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi-211005, India.
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18
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De Kreijger S, Ripak A, Elias B, Troian-Gautier L. Investigation of the Excited-State Electron Transfer and Cage Escape Yields Between Halides and a Fe(III) Photosensitizer. J Am Chem Soc 2024; 146:10286-10292. [PMID: 38569088 DOI: 10.1021/jacs.4c02808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2024]
Abstract
Excited-state quenching and reduction of [Fe(phtmeimb)2]+, where phtmeimb is phenyl[tris(3-methyl-imidazolin-2-ylidene)]borate, with iodide, bromide, and chloride were studied in dichloromethane, acetonitrile, and acetonitrile/water 1:1 mixture by means of steady-state and time-resolved spectroscopic techniques. Quenching rate constants were almost diffusion-limited in dichloromethane and acetonitrile and followed the expected periodic trend, i.e., I- > Br- > Cl-. Confirmation of excited-state reductive electron transfer was only unambiguously obtained when iodide was used as a quencher. The cage escape yields, i.e., the separation of the geminate radical pair formed upon bimolecular excited-state electron transfer, were determined. These yields were larger in dichloromethane (0.079) than in acetonitrile (0.017), and no photoproduct could be observed in acetonitrile/water 1:1. This study further emphasizes that solvents with low dielectric constant are more suited for productive excited-state electron transfer using Fe(III) photosensitizers with 2LMCT excited state.
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Affiliation(s)
- Simon De Kreijger
- UCLouvain, Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), Place Louis Pasteur 1/L4.01.02, B-1348 Louvain-la-Neuve, Belgium
| | - Alexia Ripak
- UCLouvain, Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), Place Louis Pasteur 1/L4.01.02, B-1348 Louvain-la-Neuve, Belgium
| | - Benjamin Elias
- UCLouvain, Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), Place Louis Pasteur 1/L4.01.02, B-1348 Louvain-la-Neuve, Belgium
| | - Ludovic Troian-Gautier
- UCLouvain, Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), Place Louis Pasteur 1/L4.01.02, B-1348 Louvain-la-Neuve, Belgium
- Wel Research Institute, Avenue Pasteur 6, 1300 Wavre, Belgium
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19
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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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20
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Jin T, Wagner D, Wenger OS. Luminescent and Photoredox-Active Molybdenum(0) Complexes Competitive with Isoelectronic Ruthenium(II) Polypyridines. Angew Chem Int Ed Engl 2024; 63:e202314475. [PMID: 37885363 DOI: 10.1002/anie.202314475] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 10/25/2023] [Accepted: 10/25/2023] [Indexed: 10/28/2023]
Abstract
Ruthenium(II) complexes with chelating polypyridine ligands are among the most frequently investigated compounds in photophysics and photochemistry, owing to their favorable luminescence and photoredox properties. Equally good photoluminescence performance and attractive photocatalytic behavior is now achievable with isoelectronic molybdenum(0) complexes. The zero-valent oxidation state of molybdenum is stabilized by carbonyl or isocyanide ligands, and metal-to-ligand charge transfer (MLCT) excited states analogous to those in ruthenium(II) complexes can be established. Microsecond MLCT excited-state lifetimes and photoluminescence quantum yields up to 0.2 have been achieved in solution at room temperature, and the emission wavelength has become tunable over a large range. The molybdenum(0) complexes are stronger photoreductants than ruthenium(II) polypyridines and can therefore perform more challenging chemical reductions. The triplet nature of their luminescent MLCT states allows sensitization of photon upconversion via triplet-triplet annihilation, to convert low-energy input radiation into higher-energy output fluorescence. This review summarizes the current state of the art concerning luminescent molybdenum(0) complexes and highlights their application potential. Molybdenum is roughly 140 times more abundant and far cheaper than ruthenium, hence this research is relevant in the greater context of finding more sustainable alternatives to using precious and rare transition metals in photophysics and photochemistry.
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Affiliation(s)
- Tao Jin
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland
| | - Dorothee Wagner
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland
| | - Oliver S Wenger
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland
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21
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Losada IB, Persson P. Photoredox matching of earth-abundant photosensitizers with hydrogen evolving catalysts by first-principles predictions. J Chem Phys 2024; 160:074302. [PMID: 38375904 DOI: 10.1063/5.0174837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Accepted: 01/09/2024] [Indexed: 02/21/2024] Open
Abstract
Photoredox properties of several earth-abundant light-harvesting transition metal complexes in combination with cobalt-based proton reduction catalysts have been investigated computationally to assess the fundamental viability of different photocatalytic systems of current experimental interest. Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations using several GGA (BP86, BLYP), hybrid-GGA (B3LYP, B3LYP*), hybrid meta-GGA (M06, TPSSh), and range-separated hybrid (ωB97X, CAM-B3LYP) functionals were used to calculate relevant ground and excited state reduction potentials for photosensitizers, catalysts, and sacrificial electron donors. Linear energy correction factors for the DFT/TD-DFT results that provide the best agreement with available experimental reference results were determined in order to provide more accurate predictions. Among the selection of functionals, the B3LYP* and TPSSh sets of correction parameters were determined to give the best redox potentials and excited states energies, ΔEexc, with errors of ∼0.2 eV. Linear corrections for both reduction and oxidation processes significantly improve the predictions for all the redox pairs. In particular, for TPSSh and B3LYP*, the calculated errors decrease by more than 0.5 V against experimental values for catalyst reduction potentials, photosensitizer oxidation potentials, and electron donor oxidation potentials. Energy-corrected TPSSh results were finally used to predict the energetics of complete photocatalytic cycles for the light-driven activation of selected proton reduction cobalt catalysts. These predictions demonstrate the broader usefulness of the adopted approach to systematically predict full photocycle behavior for first-row transition metal photosensitizer-catalyst combinations more broadly.
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Affiliation(s)
- Iria Bolaño Losada
- Division of Computational Chemistry, Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
| | - Petter Persson
- Division of Computational Chemistry, Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
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22
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Liu SH, Dong ZC, Zang ZL, Zhou CH, Cai GX. Selective α-oxidation of amides via visible-light-driven iron catalysis. Org Biomol Chem 2024; 22:1205-1212. [PMID: 38224270 DOI: 10.1039/d3ob01984e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2024]
Abstract
Hydroxyl radicals (˙OH) as one of the highly reactive species can react unselectively with a wide range of chemicals. The ˙OH radicals are typically generated under harsh conditions. Herein, we report hydroxyl radical-induced selective N-α C(sp3)-H bond oxidation of amides under greener and mild conditions via an Fe(NO3)3·9H2O catalyst inner sphere pathway upon irradiation with a 30 W blue LED light strip (λ = 455 nm) using NaBrO3 as the oxidant. This protocol exhibited high chemoselectivity and excellent functional group tolerance. A preliminary mechanism investigation demonstrated that the iron catalyst afforded hydroxyl radicals via the visible-light-induced homolysis (VLIH) of iron complexes followed by a hydrogen atom transfer (HAT) process to realize this transformation.
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Affiliation(s)
- Shu-Hong Liu
- Institute of Bioorganic & Medicinal Chemistry, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, P. R. China.
| | - Zhi-Chao Dong
- Institute of Bioorganic & Medicinal Chemistry, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, P. R. China.
| | - Zhong-Lin Zang
- Institute of Bioorganic & Medicinal Chemistry, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, P. R. China.
| | - Cheng-He Zhou
- Institute of Bioorganic & Medicinal Chemistry, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, P. R. China.
| | - Gui-Xin Cai
- Institute of Bioorganic & Medicinal Chemistry, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, P. R. China.
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23
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Ye Y, Garrido-Barros P, Wellauer J, Cruz CM, Lescouëzec R, Wenger OS, Herrera JM, Jiménez JR. Luminescence and Excited-State Reactivity in a Heteroleptic Tricyanido Fe(III) Complex. J Am Chem Soc 2024; 146:954-960. [PMID: 38156951 PMCID: PMC10786067 DOI: 10.1021/jacs.3c11517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 12/07/2023] [Accepted: 12/08/2023] [Indexed: 01/03/2024]
Abstract
Harnessing sunlight via photosensitizing molecules is key for novel optical applications and solar-to-chemical energy conversion. Exploiting abundant metals such as iron is attractive but becomes challenging due to typically fast nonradiative relaxation processes. In this work, we report on the luminescence and excited-state reactivity of the heteroleptic [FeIII(pzTp)(CN)3]- complex (pzTp = tetrakis(pyrazolyl)borate), which incorporates a σ-donating trispyrazolyl chelate ligand and three monodentate σ-donating and π-accepting cyanide ligands. Contrary to the nonemissive [Fe(CN)6]3-, a broad emission band centered at 600 nm at room temperature has been recorded for the heteroleptic analogue attributed to the radiative deactivation from a 2LMCT excited state with a luminescence quantum yield of 0.02% and a lifetime of 80 ps in chloroform at room temperature. Bimolecular reactivity of the 2LMCT excited state was successfully applied to different alcohol photo-oxidation, identifying a cyanide-H bonding as a key reaction intermediate. Finally, this research demonstrated the exciting potential of [Fe(pzTp)(CN)3]- as a photo-oxidant, paving the way for further exploration and development of emissive Fe-based photosensitizers competent for photochemical transformations.
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Affiliation(s)
- Yating Ye
- Departamento
de Química Inorgánica, Facultad de Ciencias, Universidad de Granada and Unidad de Excelencia en
Química (UEQ), Avenida Fuente Nueva s/n, 18071, Granada, Spain
| | - Pablo Garrido-Barros
- Departamento
de Química Inorgánica, Facultad de Ciencias, Universidad de Granada and Unidad de Excelencia en
Química (UEQ), Avenida Fuente Nueva s/n, 18071, Granada, Spain
| | - Joël Wellauer
- Department
of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland
| | - Carlos M. Cruz
- Departamento
de Química Orgánica, Facultad de Ciencias, Universidad de Granada and Unidad de Excelencia en
Química (UEQ), Avenida Fuente Nueva s/n, 18071, Granada, Spain
| | - Rodrigue Lescouëzec
- Institut
Parisien de Chimie Moléculaire, CNRS, UMR 8232, Sorbonne Université, F-75252 Paris Cedex
5, France
| | - Oliver S. Wenger
- Department
of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland
| | - Juan Manuel Herrera
- Departamento
de Química Inorgánica, Facultad de Ciencias, Universidad de Granada and Unidad de Excelencia en
Química (UEQ), Avenida Fuente Nueva s/n, 18071, Granada, Spain
| | - Juan-Ramón Jiménez
- Departamento
de Química Inorgánica, Facultad de Ciencias, Universidad de Granada and Unidad de Excelencia en
Química (UEQ), Avenida Fuente Nueva s/n, 18071, Granada, Spain
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24
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Lindh L, Pascher T, Persson S, Goriya Y, Wärnmark K, Uhlig J, Chábera P, Persson P, Yartsev A. Multifaceted Deactivation Dynamics of Fe(II) N-Heterocyclic Carbene Photosensitizers. J Phys Chem A 2023; 127:10210-10222. [PMID: 38000043 DOI: 10.1021/acs.jpca.3c06983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2023]
Abstract
Excited state dynamics of three iron(II) carbene complexes that serve as prototype Earth-abundant photosensitizers were investigated by ultrafast optical spectroscopy. Significant differences in the dynamics between the investigated complexes down to femtosecond time scales are used to characterize fundamental differences in the depopulation of triplet metal-to-ligand charge-transfer (3MLCT) excited states in the presence of energetically accessible triplet metal-centered (3MC) states. Novel insights into the full deactivation cascades of the investigated complexes include evidence of the need to revise the deactivation model for a prominent iron carbene prototype complex, a refined understanding of complex 3MC dynamics, and a quantitative discrimination between activated and barrierless deactivation steps along the 3MLCT → 3MC → 1GS path. Overall, the study provides an improved understanding of photophysical limitations and opportunities for the use of iron(II)-based photosensitizers in photochemical applications.
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Affiliation(s)
- Linnea Lindh
- Division of Chemical Physics, Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
- Division of Computational Chemistry, Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
| | - Torbjörn Pascher
- Division of Chemical Physics, Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
| | - Samuel Persson
- Center for Analysis and Synthesis (CAS), Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
| | - Yogesh Goriya
- Center for Analysis and Synthesis (CAS), Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
| | - Kenneth Wärnmark
- Center for Analysis and Synthesis (CAS), Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
| | - Jens Uhlig
- Division of Chemical Physics, Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
| | - Pavel Chábera
- Division of Chemical Physics, Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
| | - Petter Persson
- Division of Computational Chemistry, Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
| | - Arkady Yartsev
- Division of Chemical Physics, Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
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25
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Sinha N, Wegeberg C, Häussinger D, Prescimone A, Wenger OS. Photoredox-active Cr(0) luminophores featuring photophysical properties competitive with Ru(II) and Os(II) complexes. Nat Chem 2023; 15:1730-1736. [PMID: 37580444 PMCID: PMC10695827 DOI: 10.1038/s41557-023-01297-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 07/19/2023] [Indexed: 08/16/2023]
Abstract
Coordination complexes of precious metals with the d6 valence electron configuration such as Ru(II), Os(II) and Ir(III) are used for lighting applications, solar energy conversion and photocatalysis. Until now, d6 complexes made from abundant first-row transition metals with competitive photophysical and photochemical properties have been elusive. While previous research efforts focused mostly on Fe(II), we disclose that isoelectronic Cr(0) gives access to higher photoluminescence quantum yields and excited-state lifetimes when compared with any other first-row d6 metal complex reported so far. The luminescence behaviour of the metal-to-ligand charge transfer excited states of these Cr(0) complexes is competitive with Os(II) polypyridines. With these Cr(0) complexes, the metal-to-ligand charge transfer states of first-row d6 metal complexes become exploitable in photoredox catalysis, and benchmark chemical reductions proceed efficiently under low-energy red illumination. Here we demonstrate that appropriate molecular design strategies open up new perspectives for photophysics and photochemistry with abundant first-row d6 metals.
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Affiliation(s)
- Narayan Sinha
- Department of Chemistry, University of Basel, Basel, Switzerland
| | | | | | | | - Oliver S Wenger
- Department of Chemistry, University of Basel, Basel, Switzerland.
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26
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Bian KJ, Lu YC, Nemoto D, Kao SC, Chen X, West JG. Photocatalytic hydrofluoroalkylation of alkenes with carboxylic acids. Nat Chem 2023; 15:1683-1692. [PMID: 37957278 PMCID: PMC10983801 DOI: 10.1038/s41557-023-01365-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Accepted: 10/09/2023] [Indexed: 11/15/2023]
Abstract
Incorporation of fluoroalkyl motifs in pharmaceuticals can enhance the therapeutic profiles of the parent molecules. The hydrofluoroalkylation of alkenes has emerged as a promising route to diverse fluoroalkylated compounds; however, current methods require superstoichiometric oxidants, expensive/oxidative fluoroalkylating reagents and precious metals, and often exhibit limited scope, making a universal protocol that addresses these limitations highly desirable. Here we report the hydrofluoroalkylation of alkenes with cheap, abundant and available fluoroalkyl carboxylic acids as the sole reagents. Hydrotrifluoro-, difluoro-, monofluoro- and perfluoroalkylation are all demonstrated, with broad scope, mild conditions (redox neutral) and potential for late-stage modification of bioactive molecules. Critical to success is overcoming the exceedingly high redox potential of feedstock fluoroalkyl carboxylic acids such as trifluoroacetic acid by leveraging cooperative earth-abundant, inexpensive iron and redox-active thiol catalysis, enabling these reagents to be directly used as hydroperfluoroalkylation donors without pre-activation. Preliminary mechanistic studies support the radical nature of this cooperative process.
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Affiliation(s)
- Kang-Jie Bian
- Department of Chemistry, Rice University, Houston, TX, USA
| | - Yen-Chu Lu
- Department of Chemistry, Rice University, Houston, TX, USA
| | - David Nemoto
- Department of Chemistry, Rice University, Houston, TX, USA
| | - Shih-Chieh Kao
- Department of Chemistry, Rice University, Houston, TX, USA
| | - Xiaowei Chen
- Department of Chemistry, Rice University, Houston, TX, USA
| | - Julian G West
- Department of Chemistry, Rice University, Houston, TX, USA.
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Yang S, He M, Wang Y, Bao M, Yu X. Visible-light-induced iron-catalyzed reduction of nitroarenes to anilines. Chem Commun (Camb) 2023; 59:14177-14180. [PMID: 37961762 DOI: 10.1039/d3cc04324j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
An efficient visible-light-induced iron-catalyzed reduction of nitroarenes to anilines by using N-ethylmorpholine (NEM) as a reductant under mild conditions has been developed. The reaction proceeds with photosensitizer-free conditions and features good to excellent yields and broad functional group tolerance. Preliminary mechanistic investigations showed that this reaction was conducted via ligand-to-metal (NEM to Fe3+) charge transfer and nitro triplet biradical-induced hydrogen atom transfer processes.
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Affiliation(s)
- Shilei Yang
- State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, Dalian University of Technology, Dalian 116024, China.
| | - Min He
- School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, 103 Wenhua Road, Shenhe District, Shenyang, 110016, China
| | - Yi Wang
- State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, Dalian University of Technology, Dalian 116024, China.
| | - Ming Bao
- State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, Dalian University of Technology, Dalian 116024, China.
| | - Xiaoqiang Yu
- State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, Dalian University of Technology, Dalian 116024, China.
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Kumar S, Ali Shah B. Exploring the Divergent Reactivity of Vinyl Radicals Emanating from Alkynes and Thiols via Photoredox Catalysis. Chem Asian J 2023; 18:e202300693. [PMID: 37656003 DOI: 10.1002/asia.202300693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2023] [Revised: 08/30/2023] [Accepted: 09/01/2023] [Indexed: 09/02/2023]
Abstract
Organic chemistry has seen a surge in visible-light-driven transformations, which offer unique reaction pathways and access to new synthetic possibilities. We aim to provide a comprehensive understanding of state-of-the-art photo-mediated alkyne functionalization, with a focus on the reactive behavior of vinyl radicals. This review outlines our contributions to the field, including developing new methods for forming carbon-carbon and carbon-heteroatom bonds.
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Affiliation(s)
- Sourav Kumar
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
- Natural Products & Medicinal Chemistry Division, CSIR-Indian Institute of Integrative Medicine, Jammu, 180001, India
| | - Bhahwal Ali Shah
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
- Natural Products & Medicinal Chemistry Division, CSIR-Indian Institute of Integrative Medicine, Jammu, 180001, India
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Abstract
Cobalt compounds might enable cheaper and more-complex photocatalysis processes.
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Affiliation(s)
- Polina Yaltseva
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
| | - Oliver S Wenger
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
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30
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Johnson CE, Schwarz J, Deegbey M, Prakash O, Sharma K, Huang P, Ericsson T, Häggström L, Bendix J, Gupta AK, Jakubikova E, Wärnmark K, Lomoth R. Ferrous and ferric complexes with cyclometalating N-heterocyclic carbene ligands: a case of dual emission revisited. Chem Sci 2023; 14:10129-10139. [PMID: 37772113 PMCID: PMC10530338 DOI: 10.1039/d3sc02806b] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 08/27/2023] [Indexed: 09/30/2023] Open
Abstract
Iron N-heterocyclic carbene (FeNHC) complexes with long-lived charge transfer states are emerging as a promising class of photoactive materials. We have synthesized [FeII(ImP)2] (ImP = bis(2,6-bis(3-methylimidazol-2-ylidene-1-yl)phenylene)) that combines carbene ligands with cyclometalation for additionally improved ligand field strength. The 9 ps lifetime of its 3MLCT (metal-to-ligand charge transfer) state however reveals no benefit from cyclometalation compared to Fe(ii) complexes with NHC/pyridine or pure NHC ligand sets. In acetonitrile solution, the Fe(ii) complex forms a photoproduct that features emission characteristics (450 nm, 5.1 ns) that were previously attributed to a higher (2MLCT) state of its Fe(iii) analogue [FeIII(ImP)2]+, which led to a claim of dual (MLCT and LMCT) emission. Revisiting the photophysics of [FeIII(ImP)2]+, we confirmed however that higher (2MLCT) states of [FeIII(ImP)2]+ are short-lived (<10 ps) and therefore, in contrast to the previous interpretation, cannot give rise to emission on the nanosecond timescale. Accordingly, pristine [FeIII(ImP)2]+ prepared by us only shows red emission from its lower 2LMCT state (740 nm, 240 ps). The long-lived, higher energy emission previously reported for [FeIII(ImP)2]+ is instead attributed to an impurity, most probably a photoproduct of the Fe(ii) precursor. The previously reported emission quenching on the nanosecond time scale hence does not support any excited state reactivity of [FeIII(ImP)2]+ itself.
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Affiliation(s)
- Catherine Ellen Johnson
- Department of Chemistry -Ångström Laboratory, Uppsala University Box 523 SE-75120 Uppsala Sweden
| | - Jesper Schwarz
- Centre for Analysis and Synthesis, Department of Chemistry, Lund University Box 124 SE-22100 Lund Sweden
| | - Mawuli Deegbey
- Department of Chemistry, North Carolina State University Raleigh North Carolina 27695 USA
| | - Om Prakash
- Centre for Analysis and Synthesis, Department of Chemistry, Lund University Box 124 SE-22100 Lund Sweden
| | - Kumkum Sharma
- Centre for Analysis and Synthesis, Department of Chemistry, Lund University Box 124 SE-22100 Lund Sweden
| | - Ping Huang
- Department of Chemistry -Ångström Laboratory, Uppsala University Box 523 SE-75120 Uppsala Sweden
| | - Tore Ericsson
- Department of Physics - Ångström Laboratory, Uppsala University Box 523 SE-751 20 Uppsala Sweden
| | - Lennart Häggström
- Department of Physics - Ångström Laboratory, Uppsala University Box 523 SE-751 20 Uppsala Sweden
| | - Jesper Bendix
- Department of Chemistry, University of Copenhagen Universitetsparken 5 DK-2100 Copenhagen Denmark
| | - Arvind Kumar Gupta
- Centre for Analysis and Synthesis, Department of Chemistry, Lund University Box 124 SE-22100 Lund Sweden
| | - Elena Jakubikova
- Department of Chemistry, North Carolina State University Raleigh North Carolina 27695 USA
| | - Kenneth Wärnmark
- Centre for Analysis and Synthesis, Department of Chemistry, Lund University Box 124 SE-22100 Lund Sweden
| | - Reiner Lomoth
- Department of Chemistry -Ångström Laboratory, Uppsala University Box 523 SE-75120 Uppsala Sweden
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