51
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Glaser F, Kerzig C, Wenger OS. Multi-Photon Excitation in Photoredox Catalysis: Concepts, Applications, Methods. Angew Chem Int Ed Engl 2020; 59:10266-10284. [PMID: 31945241 DOI: 10.1002/anie.201915762] [Citation(s) in RCA: 183] [Impact Index Per Article: 45.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 01/16/2020] [Indexed: 01/28/2023]
Abstract
The energy of visible photons and the accessible redox potentials of common photocatalysts set thermodynamic limits to photochemical reactions that can be driven by traditional visible-light irradiation. UV excitation can be damaging and induce side reactions, hence visible or even near-IR light is usually preferable. Thus, photochemistry currently faces two divergent challenges, namely the desire to perform ever more thermodynamically demanding reactions with increasingly lower photon energies. The pooling of two low-energy photons can address both challenges simultaneously, and whilst multi-photon spectroscopy is well established, synthetic photoredox chemistry has only recently started to exploit multi-photon processes on the preparative scale. Herein, we have a critical look at currently developed reactions and mechanistic concepts, discuss pertinent experimental methods, and provide an outlook into possible future developments of this rapidly emerging area.
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Affiliation(s)
- Felix Glaser
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland
| | - Christoph Kerzig
- 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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52
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Affiliation(s)
- Joshua P. Barham
- Universität Regensburg Fakultät für Chemie und Pharmazie 93040 Regensburg Deutschland
| | - Burkhard König
- Universität Regensburg Fakultät für Chemie und Pharmazie 93040 Regensburg Deutschland
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53
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Discovery and characterization of an acridine radical photoreductant. Nature 2020; 580:76-80. [PMID: 32238940 PMCID: PMC7138348 DOI: 10.1038/s41586-020-2131-1] [Citation(s) in RCA: 219] [Impact Index Per Article: 54.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 02/18/2020] [Indexed: 11/12/2022]
Abstract
Photoinduced electron transfer (PET) is a phenomenon wherein the absorption of light by a chemical species provides an energetic driving force for an electron transfer reaction.1–4 This mechanism is relevant in many areas of chemistry, including the study of natural and artificial photosynthesis, photovoltaics, and photosensitive materials. In recent years, research in the area of photoredox catalysis has leveraged PET for the catalytic generation of both neutral and charged organic free radical species. These technologies have enabled a wide range of previously inaccessible chemical transformations and have seen widespread utilization in both academic and industrial settings. These reactions are often catalyzed by visible-light absorbing organic molecules or transition-metal complexes of ruthenium, iridium, chromium, or copper.5,6 While a wide variety of closed shell organic molecules have been shown to behave as competent electron transfer catalysts in photoredox reactions, there are only limited reports of PET reactions involving neutral organic radicals as an excited state donor or acceptor. This is perhaps somewhat unsurprising in light of previously reported doublet excited state lifetimes for neutral organic radicals, which are typically several orders of magnitude shorter than singlet lifetimes for known transition metal photoredox catalysts.7–11 Herein we document the discovery, characterization, and reactivity of a neutral acridine radical with a maximum excited state oxidation potential of −3.36 V vs. SCE: significantly more reducing than elemental lithium and marking it as one of the most potent chemical reductants reported.12 Spectroscopic, computational, and chemical studies indicate that the formation of a twisted intramolecular charge transfer species enables the population of higher energy doublet excited states, leading to the observed potent photoreductant behavior. We demonstrate that this catalytically-generated PET catalyst facilitates several chemical reactions that typically require alkali metal reductants and bodes well for the adoption of this system in additional organic transformations requiring dissolving metal reductants.
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54
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Sigmund LM, Ebner F, Jöst C, Spengler J, Gönnheimer N, Hartmann D, Greb L. An Air-Stable, Neutral Phenothiazinyl Radical with Substantial Radical Stabilization Energy. Chemistry 2020; 26:3152-3156. [PMID: 31944465 PMCID: PMC7079145 DOI: 10.1002/chem.201905238] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Indexed: 01/12/2023]
Abstract
The vital effect of radical states on the pharmacological activity of phenothiazine-based drugs has long been speculated. Whereas cationic radicals of N-substituted phenothiazines show high stability, the respective neutral radicals of N-unsubstituted phenothiazines have never been isolated. Herein, the 1,9-diamino-3,7-di-tert-butyl-N1 ,N9 -bis(2,6-diisopropylphenyl)-10H-phenothiazin-10-yl radical (SQH2 . ) is described as the first air-stable, neutral phenothiazinyl free radical. The crystalline dark-blue species is characterized by means of EPR and UV/Vis/near-IR spectroscopy, as well as cyclic voltammetry, spectro-electrochemical analysis, single-crystal XRD, and computational studies. The SQH2 . radical stands out from other aminyl radicals by an impressive radical stabilization energy and its parent amine has one of the weakest N-H bond dissociation energies ever determined. In addition to serving as open-shell reference in medicinal chemistry, its tridentate binding pocket or hydrogen-bond-donor ability might enable manifold uses as a redox-active ligand or proton-coupled electron-transfer reagent.
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Affiliation(s)
- Lukas M. Sigmund
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Fabian Ebner
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Christoph Jöst
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Jonas Spengler
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Nils Gönnheimer
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Deborah Hartmann
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
| | - Lutz Greb
- Anorganisch-Chemisches InstitutRuprecht-Karls-Universität HeidelbergIm Neuenheimer Feld 27069120HeidelbergGermany
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55
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Chai Y, Liu X, Wu B, Liu L, Wang Z, Weng Y, Wang C. In Situ Switching of Photoinduced Electron Transfer Direction by Regulating the Redox State in Fullerene-Based Dyads. J Am Chem Soc 2020; 142:4411-4418. [DOI: 10.1021/jacs.9b13376] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yongqiang Chai
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Molecular Nanostructure and Nanotechnology, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaolong Liu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Molecular Nanostructure and Nanotechnology, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Bo Wu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Molecular Nanostructure and Nanotechnology, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Liping Liu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Molecular Nanostructure and Nanotechnology, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhuan Wang
- Beijing National Laboratory for Condensed Matter Physics, CAS Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Yuxiang Weng
- Beijing National Laboratory for Condensed Matter Physics, CAS Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chunru Wang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Molecular Nanostructure and Nanotechnology, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
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56
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Sartor SM, Chrisman CH, Pearson RM, Miyake GM, Damrauer NH. Designing High-Triplet-Yield Phenothiazine Donor–Acceptor Complexes for Photoredox Catalysis. J Phys Chem A 2020; 124:817-823. [DOI: 10.1021/acs.jpca.9b10400] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Steven M. Sartor
- Department of Chemistry, University of Colorado, Boulder, Colorado 80309, United States
| | - Cameron H. Chrisman
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Ryan M. Pearson
- Department of Chemistry, University of Colorado, Boulder, Colorado 80309, United States
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Garret M. Miyake
- Department of Chemistry, University of Colorado, Boulder, Colorado 80309, United States
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Niels H. Damrauer
- Department of Chemistry, University of Colorado, Boulder, Colorado 80309, United States
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57
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Attanayake NH, Kaur AP, Suduwella TM, Elliott CF, Parkin SR, Odom SA. A stable, highly oxidizing radical cation. NEW J CHEM 2020. [DOI: 10.1039/d0nj04434b] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Changes in adiabatic ionization potential and half wave oxidation potential withorthoandparasubstitution on anN-alkylated phenothiazine.
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Affiliation(s)
| | | | | | | | - Sean R. Parkin
- Department of Chemistry
- University of Kentucky
- Lexington
- USA
| | - Susan A. Odom
- Department of Chemistry
- University of Kentucky
- Lexington
- USA
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58
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Kato SI, Matsuoka T, Suzuki S, Asano MS, Yoshihara T, Tobita S, Matsumoto T, Kitamura C. Synthesis, Structures, and Properties of Neutral and Radical Cationic S,C,C-Bridged Triphenylamines. Org Lett 2019; 22:734-738. [DOI: 10.1021/acs.orglett.9b04575] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Shin-ichiro Kato
- Department of Materials Science, School of Engineering, The University of Shiga Prefecture, 2500 Hassaka-cho, Hikone, Shiga 522-8533, Japan
| | - Takanori Matsuoka
- Department of Materials Science, School of Engineering, The University of Shiga Prefecture, 2500 Hassaka-cho, Hikone, Shiga 522-8533, Japan
| | - Shuichi Suzuki
- Department of Chemistry, Graduate School of Engineering Science, 1-3, Machikaneyama-cho, Toyonaka, Osaka 560-8531, Japan
| | - Motoko S. Asano
- Division of Molecular Science, Faculty of Science and Technology, Gunma University, 1-5-1, Tenjin-cho, Kiryu, Gunma 376-8515, Japan
| | - Toshitada Yoshihara
- Division of Molecular Science, Faculty of Science and Technology, Gunma University, 1-5-1, Tenjin-cho, Kiryu, Gunma 376-8515, Japan
| | - Seiji Tobita
- Division of Molecular Science, Faculty of Science and Technology, Gunma University, 1-5-1, Tenjin-cho, Kiryu, Gunma 376-8515, Japan
| | - Taisuke Matsumoto
- Institute for Materials Chemistry and Engineering (IMCE), Kyushu University, 6-1, Kasuga-koh-en, Kasuga, Fukuoka 816-8580, Japan
| | - Chitoshi Kitamura
- Department of Materials Science, School of Engineering, The University of Shiga Prefecture, 2500 Hassaka-cho, Hikone, Shiga 522-8533, Japan
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59
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Huang H, Strater ZM, Rauch M, Shee J, Sisto TJ, Nuckolls C, Lambert TH. Electrophotocatalysis with a Trisaminocyclopropenium Radical Dication. Angew Chem Int Ed Engl 2019; 58:13318-13322. [PMID: 31306561 PMCID: PMC7168342 DOI: 10.1002/anie.201906381] [Citation(s) in RCA: 134] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 06/18/2019] [Indexed: 01/04/2023]
Abstract
Visible-light photocatalysis and electrocatalysis are two powerful strategies for the promotion of chemical reactions. Here, these two modalities are combined in an electrophotocatalytic oxidation platform. This chemistry employs a trisaminocyclopropenium (TAC) ion catalyst, which is electrochemically oxidized to form a cyclopropenium radical dication intermediate. The radical dication undergoes photoexcitation with visible light to produce an excited-state species with oxidizing power (3.33 V vs. SCE) sufficient to oxidize benzene and halogenated benzenes via single-electron transfer (SET), resulting in C-H/N-H coupling with azoles. A rationale for the strongly oxidizing behavior of the photoexcited species is provided, while the stability of the catalyst is rationalized by a particular conformation of the cis-2,6-dimethylpiperidine moieties.
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Affiliation(s)
- He Huang
- Dr. H. Huang, Prof. T. H. Lambert, Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853, USA
| | - Zack M. Strater
- Z. M. Strater, M. Rauch, J. Shee, Dr. T. J. Sisto, Prof. C. Nuckolls, Prof. T. H. Lambert, Department of Chemistry, Columbia University, New York, NY 10027, USA
| | - Michael Rauch
- Z. M. Strater, M. Rauch, J. Shee, Dr. T. J. Sisto, Prof. C. Nuckolls, Prof. T. H. Lambert, Department of Chemistry, Columbia University, New York, NY 10027, USA
| | - James Shee
- Z. M. Strater, M. Rauch, J. Shee, Dr. T. J. Sisto, Prof. C. Nuckolls, Prof. T. H. Lambert, Department of Chemistry, Columbia University, New York, NY 10027, USA
| | - Thomas J. Sisto
- Z. M. Strater, M. Rauch, J. Shee, Dr. T. J. Sisto, Prof. C. Nuckolls, Prof. T. H. Lambert, Department of Chemistry, Columbia University, New York, NY 10027, USA
| | - Colin Nuckolls
- Z. M. Strater, M. Rauch, J. Shee, Dr. T. J. Sisto, Prof. C. Nuckolls, Prof. T. H. Lambert, Department of Chemistry, Columbia University, New York, NY 10027, USA
| | - Tristan H. Lambert
- Dr. H. Huang, Prof. T. H. Lambert, Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853, USA
- Z. M. Strater, M. Rauch, J. Shee, Dr. T. J. Sisto, Prof. C. Nuckolls, Prof. T. H. Lambert, Department of Chemistry, Columbia University, New York, NY 10027, USA
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60
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La Porte NT, Christensen JA, Krzyaniak MD, Rugg BK, Wasielewski MR. Spin-Selective Photoinduced Electron Transfer within Naphthalenediimide Diradicals. J Phys Chem B 2019; 123:7731-7739. [DOI: 10.1021/acs.jpcb.9b06303] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Nathan T. La Porte
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Joseph A. Christensen
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Matthew D. Krzyaniak
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Brandon K. Rugg
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Michael R. Wasielewski
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
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61
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Huang H, Strater ZM, Rauch M, Shee J, Sisto TJ, Nuckolls C, Lambert TH. Electrophotocatalysis with a Trisaminocyclopropenium Radical Dication. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201906381] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- He Huang
- Department of Chemistry and Chemical Biology Cornell University Ithaca NY 14853 USA
| | - Zack M. Strater
- Department of Chemistry Columbia University New York NY 10027 USA
| | - Michael Rauch
- Department of Chemistry Columbia University New York NY 10027 USA
| | - James Shee
- Department of Chemistry Columbia University New York NY 10027 USA
| | - Thomas J. Sisto
- Department of Chemistry Columbia University New York NY 10027 USA
| | - Colin Nuckolls
- Department of Chemistry Columbia University New York NY 10027 USA
| | - Tristan H. Lambert
- Department of Chemistry and Chemical Biology Cornell University Ithaca NY 14853 USA
- Department of Chemistry Columbia University New York NY 10027 USA
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62
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Beckwith JS, Lang B, Grilj J, Vauthey E. Ion-Pair Dynamics upon Photoinduced Electron Transfer Monitored by Pump-Pump-Probe Spectroscopy. J Phys Chem Lett 2019; 10:3688-3693. [PMID: 31194559 DOI: 10.1021/acs.jpclett.9b01431] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The excited-state dynamics of the radical anion of perylene (Pe) generated upon bimolecular photoinduced electron transfer (PET) with a donor was investigated using broadband pump-pump-probe spectroscopy. It was found to depend on the age of the anion, that is, on the time interval between the first pump pulse that triggers PET and the second one that excites the ensuing Pe anion (Pe•-). These differences, observed in acetonitrile but not in tetrahydrofuran, report on the evolution of the PET product from an ion pair to free ions. Two photoinduced charge recombination pathways of the ion pair to the neutral Pe*(S1) + donor state were identified: one occurring in a few picoseconds from Pe•-*(D1) and one taking place within 100-200 fs from Pe•-*(D n>1). Both processes are sensitive to the interionic distance over different length scales and thus serve as molecular rulers.
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Affiliation(s)
- Joseph S Beckwith
- Department of Physical Chemistry , University of Geneva , 30 Quai Ernest-Ansermet , CH-1211 Geneva , Switzerland
| | - Bernhard Lang
- Department of Physical Chemistry , University of Geneva , 30 Quai Ernest-Ansermet , CH-1211 Geneva , Switzerland
| | - Jakob Grilj
- Department of Physical Chemistry , University of Geneva , 30 Quai Ernest-Ansermet , CH-1211 Geneva , Switzerland
| | - Eric Vauthey
- Department of Physical Chemistry , University of Geneva , 30 Quai Ernest-Ansermet , CH-1211 Geneva , Switzerland
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63
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Sartor SM, Lattke YM, McCarthy BG, Miyake GM, Damrauer NH. Effects of Naphthyl Connectivity on the Photophysics of Compact Organic Charge-Transfer Photoredox Catalysts. J Phys Chem A 2019; 123:4727-4736. [PMID: 31083893 PMCID: PMC6941586 DOI: 10.1021/acs.jpca.9b03286] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Modular chromophoric systems with minimal electronic coupling between donor and acceptor moieties are well suited for establishing predictive relationships between molecular structure and excited-state properties. Here, we investigate the impact of naphthyl-based connectivity on the photophysics of phenoxazine-derived orthogonal donor-acceptor complexes. While compounds in this class are themselves interesting as potent organic photocatalysts useful for visible-light-driven organocatalyzed atom-transfer radical polymerization and small-molecule synthesis, many other systems (e.g., phenazine, phenothiazine, and acridinium) exploit charge-transfer excited states involving a naphthyl substituent. Therefore, aided by the facile tunability of the phenoxazine architecture, we aim to provide mechanistic insight into the effects of naphthyl connectivity that can help inform the understanding of other systems. We do so by employing time-resolved and steady-state spectroscopies, cyclic voltammetry, and temperature-dependent studies on two chemical series of phenoxazine compounds. In the first series ( N-aryl 3,7-dibiphenyl phenoxazine), we find high sensitivity of photophysical behavior to naphthyl connectivity at its 1 versus 2 positions, including a drop in the intersystem-crossing yield (ΦISC) from 0.91 ( N-1-naphthyl) to 0.54 ( N-2-naphthyl), which we attribute to the establishment of an excited-state equilibrium in the singlet manifold. Drawing on the synthetic tunability afforded by phenoxazine, a modified series ( N-aryl 3,7-diphenyl phenoxazine) is chosen to circumvent this equilibrium, thereby isolating the impact of naphthyl connectivity on charge-transfer energy and triplet formation. We conclude that donor-acceptor distance is a key design parameter that influences a host of excited-state and dynamical properties and can have an outsized impact on photochemical function.
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Affiliation(s)
- Steven M. Sartor
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309, United States
| | - Yisrael M. Lattke
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309, United States
| | - Blaine G. McCarthy
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Garret M. Miyake
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Niels H. Damrauer
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309, United States
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64
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Kerzig C, Guo X, Wenger OS. Unexpected Hydrated Electron Source for Preparative Visible-Light Driven Photoredox Catalysis. J Am Chem Soc 2019; 141:2122-2127. [PMID: 30672694 DOI: 10.1021/jacs.8b12223] [Citation(s) in RCA: 89] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The hydrated electron is experiencing a renaissance as a superreductant in lab-scale reductions driven by light, both for the degradation of recalcitrant pollutants and for challenging chemical reactions. However, examples for its sustainable generation under mild conditions are scarce. By combining a water-soluble Ir catalyst with unique photochemical properties and an inexpensive diode laser as light source, we produce hydrated electrons through a two-photon mechanism previously thought to be unimportant for laboratory applications. Adding cheap sacrificial donors turns our new hydrated electron source into a catalytic cycle operating in pure water over a wide pH range. Not only is that catalytic system capable of detoxifying a chlorinated model compound with turnover numbers of up to 200, but it can also be employed for two novel hydrated electron reactions, namely, the decomposition of quaternary ammonium compounds and the conversion of trifluoromethyl to difluoromethyl groups.
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Affiliation(s)
- Christoph Kerzig
- Department of Chemistry , University of Basel , St. Johanns-Ring 19 , 4056 Basel , Switzerland
| | - Xingwei Guo
- 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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65
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Speck F, Rombach D, Wagenknecht HA. N-Arylphenothiazines as strong donors for photoredox catalysis - pushing the frontiers of nucleophilic addition of alcohols to alkenes. Beilstein J Org Chem 2019; 15:52-59. [PMID: 30680038 PMCID: PMC6334793 DOI: 10.3762/bjoc.15.5] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 12/12/2018] [Indexed: 12/26/2022] Open
Abstract
A new range of N-phenylphenothiazine derivatives was synthesized as potential photoredox catalysts to broaden the substrate scope for the nucleophilic addition of methanol to styrenes through photoredox catalysis. These N-phenylphenothiazines differ by their electron-donating and electron-withdrawing substituents at the phenyl group, covering both, σ and π-type groups, in order to modulate their absorbance and electrochemical characteristics. Among the synthesized compounds, alkylaminylated N-phenylphenothiazines were identified to be highly suitable for photoredox catalysis. The dialkylamino substituents of these N-phenylphenothiazines shift the estimated excited state reduction potential up to -3.0 V (vs SCE). These highly reducing properties allow the addition of methanol to α-methylstyrene as less-activated substrate for this type of reaction. Without the help of an additive, the reaction conditions were optimized to achieve a quantitative yield for the Markovnivkov-type addition product after 20 h of irradiation.
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Affiliation(s)
- Fabienne Speck
- Institute of Organic Chemistry, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany
| | - David Rombach
- Institute of Organic Chemistry, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany
| | - Hans-Achim Wagenknecht
- Institute of Organic Chemistry, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany
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66
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Pannwitz A, Wenger OS. Proton-coupled multi-electron transfer and its relevance for artificial photosynthesis and photoredox catalysis. Chem Commun (Camb) 2019; 55:4004-4014. [DOI: 10.1039/c9cc00821g] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Photoinduced PCET meets catalysis, and the accumulation of multiple redox equivalents is of key importance.
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Affiliation(s)
- Andrea Pannwitz
- Department of Chemistry
- University of Basel
- 4056 Basel
- Switzerland
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67
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Wu YC, Jiang SS, Song RJ, Li JH. A metal- and oxidizing-reagent-free anodic para-selective amination of anilines with phenothiazines. Chem Commun (Camb) 2019; 55:4371-4374. [DOI: 10.1039/c9cc01332f] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A highly para-selective amination of anilines with phenothiazines for producing various functionalized 10-aryl-10H-phenothiazines is reported.
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Affiliation(s)
- Yan-Chen Wu
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle
- Nanchang Hangkong University
- Nanchang 330063
- China
| | - Shuai-Shuai Jiang
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle
- Nanchang Hangkong University
- Nanchang 330063
- China
| | - Ren-Jie Song
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle
- Nanchang Hangkong University
- Nanchang 330063
- China
| | - Jin-Heng Li
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle
- Nanchang Hangkong University
- Nanchang 330063
- China
- State Key Laboratory of Chemo/Biosensing and Chemometrics
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68
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Zhu DL, Li HX, Xu ZM, Li HY, Young DJ, Lang JP. Visible light driven, nickel-catalyzed aryl esterification using a triplet photosensitiser thioxanthen-9-one. Org Chem Front 2019. [DOI: 10.1039/c9qo00536f] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The nickel-catalyzed esterification of carboxylic acids with aryl bromides using thioxanthen-9-one as a photosensitizer provided aryl esters with excellent yields.
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Affiliation(s)
- Da-Liang Zhu
- College of Chemistry
- Chemical Engineering and Materials Science
- Soochow University
- Suzhou 215123
- China
| | - Hong-Xi Li
- College of Chemistry
- Chemical Engineering and Materials Science
- Soochow University
- Suzhou 215123
- China
| | - Ze-Ming Xu
- College of Chemistry
- Chemical Engineering and Materials Science
- Soochow University
- Suzhou 215123
- China
| | - Hai-Yan Li
- Analysis and Testing Centre
- Soochow University
- Suzhou 215123
- China
| | - David J. Young
- College of Engineering
- Information Technology and Environment
- Charles Darwin University
- Northern Territory 0909
- Australia
| | - Jian-Ping Lang
- College of Chemistry
- Chemical Engineering and Materials Science
- Soochow University
- Suzhou 215123
- China
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69
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Liu C, Shen Y, Yuan K. Non-directed copper-catalyzed regioselective C–H sulfonylation of phenothiazines. Org Biomol Chem 2019; 17:5009-5013. [DOI: 10.1039/c9ob00705a] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A simple and general procedure for C3 sulfonylation of phenothiazines was developed by CuI/Li2CO3 catalyzed transformation of aryl/alkyl sulfonyl chlorides.
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Affiliation(s)
- Caiyan Liu
- Tianjin Key Laboratory of Advanced Functional Porous Materials
- Institute for New Energy Materials & Low-Carbon Technologies
- School of Materials Science and Engineering
- Tianjin University of Technology
- Tianjin 300384
| | - Yongli Shen
- Tianjin Key Laboratory of Advanced Functional Porous Materials
- Institute for New Energy Materials & Low-Carbon Technologies
- School of Materials Science and Engineering
- Tianjin University of Technology
- Tianjin 300384
| | - Kedong Yuan
- Tianjin Key Laboratory of Advanced Functional Porous Materials
- Institute for New Energy Materials & Low-Carbon Technologies
- School of Materials Science and Engineering
- Tianjin University of Technology
- Tianjin 300384
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70
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Wang J, Ding T, Wu K. Charge Transfer from n-Doped Nanocrystals: Mimicking Intermediate Events in Multielectron Photocatalysis. J Am Chem Soc 2018; 140:7791-7794. [DOI: 10.1021/jacs.8b04263] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Junhui Wang
- State Key Laboratory of Molecular Reaction Dynamics and Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Tao Ding
- State Key Laboratory of Molecular Reaction Dynamics and Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Kaifeng Wu
- State Key Laboratory of Molecular Reaction Dynamics and Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
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