1
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Lee CK, Gangadharappa C, Fahrenbach AC, Kim DJ. Harnessing Radicals: Advances in Self-Assembly and Molecular Machinery. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2408271. [PMID: 39177115 DOI: 10.1002/adma.202408271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2024] [Revised: 07/25/2024] [Indexed: 08/24/2024]
Abstract
Radicals, with their unpaired electrons, exhibit unique chemical and physical properties that have long intrigued chemists. Despite early skepticism about their stability, the discovery of persistent radicals has opened new possibilities for molecular interactions. This review examines the mechanisms and applications of radically driven self-assembly, focusing on key motifs such as naphthalene diimides, tetrathiafulvalenes, and viologens, which serve as models for radical assembly. The potential of radical interactions in the development of artificial molecular machines (AMMs) are also discussed. These AMMs, powered by radical-radical interactions, represent significant advancements in non-equilibrium chemistry, mimicking the functionalities of biological systems. From molecular switches to ratchets and pumps, the versatility and unique properties of radically powered AMMs are highlighted. Additionally, the applications of radical assembly in materials science are explored, particularly in creating smart materials with redox-responsive properties. The review concludes by comparing AMMs to biological molecular machines, offering insights into future directions. This overview underscores the impact of radical chemistry on molecular assembly and its promising applications in both synthetic and biological systems.
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Affiliation(s)
| | | | - Albert C Fahrenbach
- School of Chemistry, University of New South Wales, Sydney, NSW, 2052, Australia
- Australian Centre for Astrobiology, University of New South Wales, Sydney, NSW, 2052, Australia
- UNSW RNA Institute, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Dong Jun Kim
- School of Chemistry, University of New South Wales, Sydney, NSW, 2052, Australia
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2
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Dai D, Zhan Q, Shi T, Wang D, Zheng Y. Spin characteristics in conjugated stable diradicals. Chem Commun (Camb) 2024; 60:8997-9006. [PMID: 39081131 DOI: 10.1039/d4cc03067b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/21/2024]
Abstract
Spin properties are intrinsic characters of electrons. Radical molecules contain unpaired electron(s), and their unique chemical and physical properties make them an ideal platform for investigating spin properties in molecular systems. Among them, the burgeoning interest in stable conjugated diradicals is attributed to their distinctive characteristics, notably the dynamic resonance structures between open-shell and closed-shell forms, the malleability of their spin states, and the profound influence of intermolecular spin-spin interactions. A deep understanding of the spin characteristics of unpaired electrons in stable conjugated diradicals provides guidance for the design, synthesis, and characterization of radical-based materials. In this review, we discuss the unique spin delocalization, spin states, and spin-spin coupling characteristics of conjugated diradicals and emphasize how to precisely control these spin characteristics to understand their role in the molecules and as functional radical materials.
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Affiliation(s)
- Dacheng Dai
- School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China (UESTC), Chengdu 611731, People's Republic of China.
| | - Qian Zhan
- School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China (UESTC), Chengdu 611731, People's Republic of China.
| | - Tianfang Shi
- School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China (UESTC), Chengdu 611731, People's Republic of China.
| | - Dongsheng Wang
- School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China (UESTC), Chengdu 611731, People's Republic of China.
| | - Yonghao Zheng
- School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China (UESTC), Chengdu 611731, People's Republic of China.
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, 9 Wenyuan Road, Nanjing 210023, People's Republic of China
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3
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Zhang J, Sun T, Wang K, Hu R, Zhou C, Ge H, Li B. Rh(iii)-catalyzed building up of used heterocyclic cations: facile access to white-light-emitting materials. Chem Sci 2024; 15:12270-12276. [PMID: 39118641 PMCID: PMC11304525 DOI: 10.1039/d4sc02188f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Accepted: 06/10/2024] [Indexed: 08/10/2024] Open
Abstract
The first example of rhodium-catalyzed nondirected C-H activation/annulation reactions for the construction of fused heterocyclic cations is reported herein with excellent regioselectivity. Deuterium-labeling experiments indicated that the C(sp3)-H bond cleavage of the N-methyl group might be the rate-limiting step during the reaction process. This protocol provides an opportunity to rapidly access highly π-conjugated fused heterocyclic cations, which opens up a new avenue for efficient screening of single-molecular white-light-emitting materials, pure red-light-emitting materials, and π-conjugated radical materials. Importantly, novel white-light-emitting materials exhibited distinct anti-Kasha dual-emission and could rapidly be fabricated into robust organic and low-cost white light-emitting diodes.
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Affiliation(s)
- Jingxian Zhang
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, School of Pharmaceutical Sciences, Chongqing University Chongqing 401331 P. R. China
| | - Tao Sun
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, School of Pharmaceutical Sciences, Chongqing University Chongqing 401331 P. R. China
| | - Kangmin Wang
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, School of Pharmaceutical Sciences, Chongqing University Chongqing 401331 P. R. China
| | - Ruike Hu
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, School of Pharmaceutical Sciences, Chongqing University Chongqing 401331 P. R. China
| | - Chunlin Zhou
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, School of Pharmaceutical Sciences, Chongqing University Chongqing 401331 P. R. China
| | - Haibo Ge
- Department of Chemistry and Biochemistry, Texas Tech University Lubbock TX 79409-1061 USA
| | - Bijin Li
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, School of Pharmaceutical Sciences, Chongqing University Chongqing 401331 P. R. China
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4
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Pu Z, Xu Z, Zhang X, Guo Y, Sun Z. Unlocking the Multistage Redox Property of Graphenic Radicals by π-Extension. Angew Chem Int Ed Engl 2024:e202406078. [PMID: 38994912 DOI: 10.1002/anie.202406078] [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: 04/02/2024] [Revised: 07/09/2024] [Accepted: 07/12/2024] [Indexed: 07/13/2024]
Abstract
Delocalized organic π-radicals are intrinsically amphoteric redox systems; however, achieving their multistage redox capability presents a challenge. In addition, their instability often hampers their synthesis, isolation, and characterization. Herein, we report the synthesis of a stable π-extended nanographene π-radical (NR1) and its isolation in the crystalline form. NR1 exhibits an unusual four-stage amphoteric redox behavior, as revealed by cyclic voltammetry measurements. The stable charged species, including a cation and a radical dication, are characterized using spectroscopic methods. This study demonstrates that π-extension could serve as a viable approach to unlock the multistage redox ability of delocalized organic radicals.
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Affiliation(s)
- Zhaofangzhou Pu
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin University, 92 Weijin Road, Tianjin, 300072, China
| | - Zhuofan Xu
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin University, 92 Weijin Road, Tianjin, 300072, China
| | - Xin Zhang
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin University, 92 Weijin Road, Tianjin, 300072, China
| | - Yupeng Guo
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin University, 92 Weijin Road, Tianjin, 300072, China
| | - Zhe Sun
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin University, 92 Weijin Road, Tianjin, 300072, China
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5
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Xu R, Kuninobu Y. Synthesis and Properties of Cyclic π-Conjugated Molecules and Their Dication and Monoradical Cation. Org Lett 2024; 26:5582-5586. [PMID: 38900597 DOI: 10.1021/acs.orglett.4c02001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/22/2024]
Abstract
We synthesized cyclic π-conjugated molecules by double Friedel-Crafts reaction of amino group-substituted 1,2-bis(2-phenylethynyl)benzene with Meldrum's acid derivative. The structures of the cyclic π-conjugated molecules were determined by single-crystal X-ray structure analysis. The oxidation of the dimethylamino group-substituted π-conjugated molecule with NOBF4 gave a closed-shell dication that is stable at >210 °C. The monoradical cation of the di(4-methoxyphenyl)amino group-substituted π-conjugated molecule is stable in dichloromethane solution (half-life of nearly 15 days) and shows near-infrared absorption.
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Affiliation(s)
- Runjie Xu
- Department of Interdisciplinary Engineering Sciences, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 6-1 Kasugakoen, Kasuga-shi, Fukuoka 816-8580, Japan
| | - Yoichiro Kuninobu
- Institute for Materials Chemistry and Engineering, Kyushu University, 6-1 Kasugakoen, Kasuga-shi, Fukuoka 816-8580, Japan
- Department of Interdisciplinary Engineering Sciences, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 6-1 Kasugakoen, Kasuga-shi, Fukuoka 816-8580, Japan
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6
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Song S, Pinar Solé A, Matěj A, Li G, Stetsovych O, Soler D, Yang H, Telychko M, Li J, Kumar M, Chen Q, Edalatmanesh S, Brabec J, Veis L, Wu J, Jelinek P, Lu J. Highly entangled polyradical nanographene with coexisting strong correlation and topological frustration. Nat Chem 2024; 16:938-944. [PMID: 38374456 DOI: 10.1038/s41557-024-01453-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 01/17/2024] [Indexed: 02/21/2024]
Abstract
Open-shell nanographenes exhibit unconventional π-magnetism arising from topological frustration or strong electron-electron interaction. However, conventional design approaches are typically limited to a single magnetic origin, which can restrict the number of correlated spins or the type of magnetic ordering in open-shell nanographenes. Here we present a design strategy that combines topological frustration and electron-electron interactions to fabricate a large fully fused 'butterfly'-shaped tetraradical nanographene on Au(111). We employ bond-resolved scanning tunnelling microscopy and spin-excitation spectroscopy to resolve the molecular backbone and reveal the strongly correlated open-shell character, respectively. This nanographene contains four unpaired electrons with both ferromagnetic and anti-ferromagnetic interactions, harbouring a many-body singlet ground state and strong multi-spin entanglement, which is well described by many-body calculations. Furthermore, we study the magnetic properties and spin states in the nanographene using a nickelocene magnetic probe. The ability to imprint and characterize many-body strongly correlated spins in polyradical nanographenes paves the way for future advancements in quantum information technologies.
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Affiliation(s)
- Shaotang Song
- Department of Chemistry, National University of Singapore, Singapore, Singapore
| | - Andrés Pinar Solé
- Institute of Physics, Czech Academy of Sciences, Prague, Czech Republic
- Regional Centre of Advanced Technologies and Materials, Czech Advanced Technology and Research Institute, Palacký University Olomouc, Olomouc, Czech Republic
| | - Adam Matěj
- Institute of Physics, Czech Academy of Sciences, Prague, Czech Republic
- Regional Centre of Advanced Technologies and Materials, Czech Advanced Technology and Research Institute, Palacký University Olomouc, Olomouc, Czech Republic
| | - Guangwu Li
- Department of Chemistry, National University of Singapore, Singapore, Singapore
- Center of Single-Molecule Sciences, Frontiers Science Center for New Organic Matter, College of Electronic Information and Optical Engineering, Nankai University, Tianjin, China
| | | | - Diego Soler
- Institute of Physics, Czech Academy of Sciences, Prague, Czech Republic
| | - Huimin Yang
- Department of Chemistry, National University of Singapore, Singapore, Singapore
| | - Mykola Telychko
- Department of Chemistry, National University of Singapore, Singapore, Singapore
| | - Jing Li
- Department of Chemistry, National University of Singapore, Singapore, Singapore
| | - Manish Kumar
- Institute of Physics, Czech Academy of Sciences, Prague, Czech Republic
| | - Qifan Chen
- Institute of Physics, Czech Academy of Sciences, Prague, Czech Republic
| | | | - Jiri Brabec
- Department of Theoretical Chemistry, J. Heyrovsky Institute of Physical Chemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Libor Veis
- Department of Theoretical Chemistry, J. Heyrovsky Institute of Physical Chemistry, Czech Academy of Sciences, Prague, Czech Republic.
| | - Jishan Wu
- Department of Chemistry, National University of Singapore, Singapore, Singapore.
| | - Pavel Jelinek
- Institute of Physics, Czech Academy of Sciences, Prague, Czech Republic.
- Regional Centre of Advanced Technologies and Materials, Czech Advanced Technology and Research Institute, Palacký University Olomouc, Olomouc, Czech Republic.
| | - Jiong Lu
- Department of Chemistry, National University of Singapore, Singapore, Singapore.
- Institute for Functional Intelligent Materials, National University of Singapore, Singapore, Singapore.
- National University of Singapore (Suzhou) Research Institute, Suzhou, China.
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7
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Xiang Q, Ye L, Ma L, Sun Z. The Olympicenyl Radical and Its Derivatives. Chempluschem 2024; 89:e202300571. [PMID: 37916655 DOI: 10.1002/cplu.202300571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2023] [Revised: 11/02/2023] [Accepted: 11/02/2023] [Indexed: 11/03/2023]
Abstract
The olympicenyl radical (OR) has long been a fascinating spin doublet hydrocarbon radical that evoked theoretical and experimental research interests, but the chemistry of olympicenyl was limited by its inherent instability. Recently, this field was revived by the advent of stable, multi-substituted ORs and the isolation of them in the crystalline phase. In this minireview, we summarize the early studies on the pristine OR, as well as the recent advances on the substituted OR derivatives, heteroatom-containing OR derivatives, and OR-based diradicals and polyradicals. The synthetic chemistry, stabilization strategies, self-association behaviors, reactivities, and applications in the biological field of the abovementioned compounds were discussed.
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Affiliation(s)
- Qin Xiang
- Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin university, Tianjin, 300072, China
| | - Lei Ye
- Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | - Lan Ma
- Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | - Zhe Sun
- Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin university, Tianjin, 300072, China
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8
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Kino S, Ukai S, Fukui N, Haruki R, Kumai R, Wang Q, Horike S, Phung QM, Sundholm D, Shinokubo H. Close Stacking of Antiaromatic Ni(II) Norcorrole Originating from a Four-Electron Multicentered Bonding Interaction. J Am Chem Soc 2024; 146:9311-9317. [PMID: 38502926 PMCID: PMC10996016 DOI: 10.1021/jacs.4c01142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 03/04/2024] [Accepted: 03/05/2024] [Indexed: 03/21/2024]
Abstract
A π-conjugated molecule with one electronic spin often forms a π-stacked dimer through molecular orbital interactions between two unpaired electrons. The bonding is recognized as a multicentered two-electron interaction between the two π-conjugated molecules. Here, we disclose a multicentered bonding interaction between two antiaromatic molecules involving four electrons. We have synthesized an antiaromatic porphyrin analogue, Ni(II) bis(pentafluorophenyl)norcorrole. Its dimer adopts a face-to-face stacked structure with an extremely short stacking distance of 2.97 Å. The close stacking originates from a multicenter four-electron bonding interaction between the two molecules. The bonding electrons were experimentally observed via synchrotron X-ray diffraction analysis and corroborated by theoretical calculations. The intermolecular interaction of the molecular orbitals imparts the stacked dimer with aromatic character that is distinctly different from that of its monomer.
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Affiliation(s)
- Shota Kino
- Department
of Molecular and Macromolecular Chemistry, Graduate School of Engineering
and Integrated Research Consortium on Chemical Sciences (IRCCS), Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603, Japan
| | - Shusaku Ukai
- Department
of Molecular and Macromolecular Chemistry, Graduate School of Engineering
and Integrated Research Consortium on Chemical Sciences (IRCCS), Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603, Japan
| | - Norihito Fukui
- Department
of Molecular and Macromolecular Chemistry, Graduate School of Engineering
and Integrated Research Consortium on Chemical Sciences (IRCCS), Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603, Japan
- PRESTO, Japan
Science and Technology Agency (JST), Kawaguchi, Saitama 332-0012, Japan
| | - Rie Haruki
- Photon
Factory, Institute of Materials Structure
Science, High Energy Accelerator Research Organization (KEK), Tsukuba, 305-0801, Japan
| | - Reiji Kumai
- Photon
Factory, Institute of Materials Structure
Science, High Energy Accelerator Research Organization (KEK), Tsukuba, 305-0801, Japan
| | - Qian Wang
- Department
of Chemistry, Faculty of Science, University
of Helsinki, Helsinki, FIN-00014, Finland
| | - Satoshi Horike
- Department
of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Quan Manh Phung
- Department
of Chemistry, Graduate School of Science, Nagoya University, Furo-cho,
Chikusa-ku, Nagoya, 464-8602, Japan
| | - Dage Sundholm
- Department
of Chemistry, Faculty of Science, University
of Helsinki, Helsinki, FIN-00014, Finland
| | - Hiroshi Shinokubo
- Department
of Molecular and Macromolecular Chemistry, Graduate School of Engineering
and Integrated Research Consortium on Chemical Sciences (IRCCS), Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603, Japan
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9
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Ren L, Han Y, Hou X, Ni Y, Wu J. [2,2]Paracyclophane Bridged, Thiophene Based Macrocycles: Synthesis and Electronic Properties in Different Redox States. Chemistry 2024; 30:e202304088. [PMID: 38213066 DOI: 10.1002/chem.202304088] [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: 12/21/2023] [Revised: 01/10/2024] [Accepted: 01/11/2024] [Indexed: 01/13/2024]
Abstract
The study of through-space electronic coupling in π-conjugated systems remains an underexplored area. In this work, we present the facile synthesis of two isomeric macrocycles (1 and 2) bridged by [2,2]paracyclophane (pCp) and based on thiophene. The structures of these macrocycles have been confirmed through X-ray crystallographic analysis. Our investigation centers on their electronic properties across various redox states, with a specific focus on potential through-space electronic coupling and global aromaticity. Experimental measurements, including UV-vis-NIR electronic absorption, NMR, ESR spectra, and X-ray diffraction, combined with theoretical calculations, reveal that both the neutral compounds and their tetracations exhibit a closed-shell ground state. However, their dications manifest as diradical dications with a subtle magnetic exchange interaction. Consequently, the through-space electronic coupling facilitated by the pCp unit in their respective ground states appears to be weak.
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Affiliation(s)
- Longbin Ren
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore
| | - Yi Han
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore
| | - Xudong Hou
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore
| | - Yong Ni
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore
| | - Jishan Wu
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore
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10
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Barluzzi L, Ogilvie SP, Dalton AB, Kaden P, Gericke R, Mansikkamäki A, Giblin SR, Layfield RA. Triply Bonded Pancake π-Dimers Stabilized by Tetravalent Actinides. J Am Chem Soc 2024; 146:4234-4241. [PMID: 38317384 PMCID: PMC10870716 DOI: 10.1021/jacs.3c13914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2023] [Revised: 01/22/2024] [Accepted: 01/23/2024] [Indexed: 02/07/2024]
Abstract
Aromatic π-stacking is a weakly attractive, noncovalent interaction often found in biological macromolecules and synthetic supramolecular chemistry. The weak nondirectional nature of π-stacking can present challenges in the design of materials owing to their weak, nondirectional nature. However, when aromatic π-systems contain an unpaired electron, stronger attraction involving face-to-face π-orbital overlap is possible, resulting in covalent so-called "pancake" bonds. Two-electron, multicenter single pancake bonds are well known, whereas four-electron double pancake bonds are rare. Higher-order pancake bonds have been predicted, but experimental systems are unknown. Here, we show that six-electron triple pancake bonds can be synthesized by a 3-fold reduction of hexaazatrinaphthylene (HAN) and subsequent stacking of the [HAN]3- triradicals. Our analysis reveals a multicenter covalent triple pancake bond consisting of a σ-orbital and two equivalent π-orbitals. An electrostatic stabilizing role is established for the tetravalent thorium and uranium ions in these systems. We also show that the electronic absorption spectrum of the triple pancake bonds closely matches computational predictions, providing experimental verification of these unique interactions. The discovery of conductivity in thin films of triply bonded π-dimers presents new opportunities for the discovery of single-component molecular conductors and other spin-based molecular materials.
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Affiliation(s)
- Luciano Barluzzi
- Department
of Chemistry, School of Life Sciences, University
of Sussex, Brighton BN1 9QR, U.K.
| | - Sean P. Ogilvie
- Department
of Physics and Astronomy, School of Mathematical and Physical Sciences, University of Sussex, Brighton BN1 9QR, U.K.
| | - Alan B. Dalton
- Department
of Physics and Astronomy, School of Mathematical and Physical Sciences, University of Sussex, Brighton BN1 9QR, U.K.
| | - Peter Kaden
- Institute
of Resource Ecology, Helmoltz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, Dresden 01328, Germany
| | - Robert Gericke
- Institute
of Resource Ecology, Helmoltz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, Dresden 01328, Germany
| | - Akseli Mansikkamäki
- NMR
Research Unit, University of Oulu, P.O. Box 8000, Oulu FI-90014, Finland
| | - Sean R. Giblin
- School
of Physics and Astronomy, Cardiff University, Cardiff CF24 3AA, U.K.
| | - Richard A. Layfield
- Department
of Chemistry, School of Life Sciences, University
of Sussex, Brighton BN1 9QR, U.K.
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11
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Hu C, Kuhn L, Makurvet FD, Knorr ES, Lin X, Kawade RK, Mentink-Vigier F, Hanson K, Alabugin IV. Tethering Three Radical Cascades for Controlled Termination of Radical Alkyne peri-Annulations: Making Phenalenyl Ketones without Oxidants. J Am Chem Soc 2024; 146:4187-4211. [PMID: 38316011 DOI: 10.1021/jacs.3c13371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Abstract
Although Bu3Sn-mediated radical alkyne peri-annulations allow access to phenalenyl ring systems, the oxidative termination of these cascades provides only a limited selection of the possible isomeric phenalenone products with product selectivity controlled by the intrinsic properties of the new cyclic systems. In this work, we report an oxidant-free termination strategy that can overcome this limitation and enable selective access to the full set of isomerically functionalized phenalenones. The key to preferential termination is the preinstallation of a "weak link" that undergoes C-O fragmentation in the final cascade step. Breaking a C-O bond is assisted by entropy, gain of conjugation in the product, and release of stabilized radical fragments. This strategy is expanded to radical exo-dig cyclization cascades of oligoalkynes, which provide access to isomeric π-extended phenalenones. Conveniently, these cascades introduce functionalities (i.e., Bu3Sn and iodide moieties) amenable to further cross-coupling reactions. Consequently, a variety of polyaromatic diones, which could serve as phenalenyl-based open-shell precursors, can be synthesized.
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Affiliation(s)
- Chaowei Hu
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States
| | - Leah Kuhn
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States
| | - Favour D Makurvet
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States
| | - Erica S Knorr
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States
| | - Xinsong Lin
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States
| | - Rahul K Kawade
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States
| | - Frederic Mentink-Vigier
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
| | - Kenneth Hanson
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States
| | - Igor V Alabugin
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States
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12
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Wang W, Sun P, Liu X, Zhang X, Zhang L, Tan YZ, Wang X. Radical Cations of Bilayer Nanographenes. Org Lett 2024; 26:1017-1021. [PMID: 38295360 DOI: 10.1021/acs.orglett.3c04084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2024]
Abstract
Chemical redox reactions of bilayer nanographene complexes, (C96H24Ar6)2 (Ar = 2,6-dimethylphenyl) (12) and (C42H12R6)2 (R = tBu) (22), were investigated. Upon two-electron oxidation reactions, 12 and 22 were transformed to radical cations 122•+ and 222•+, respectively. SQUID and EPR measurements on 122•+ and 222•+ indicate that they possess an open-shell singlet ground state with antiferromagnetic interactions between two layers. The shortest separation distance between bilayers in 222•+ (3.30 Å) is shorter than that in 22 (3.44 Å) and 22•+ (3.40 Å), illustrating stronger interaction upon loss of electrons.
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Affiliation(s)
- Wenqing Wang
- College of Chemistry and Material Science, Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Laboratory of Molecule-Based Materials, Anhui Normal University, Wuhu, Anhui 241002, China
| | - Peiyang Sun
- College of Chemistry and Material Science, Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Laboratory of Molecule-Based Materials, Anhui Normal University, Wuhu, Anhui 241002, China
| | - Xiangjun Liu
- College of Chemistry and Material Science, Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Laboratory of Molecule-Based Materials, Anhui Normal University, Wuhu, Anhui 241002, China
| | - Xiudu Zhang
- College of Chemistry and Material Science, Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Laboratory of Molecule-Based Materials, Anhui Normal University, Wuhu, Anhui 241002, China
| | - Li Zhang
- School of Electronic Engineering, Guangxi University of Science and Technology, Liuzhou 545000, China
| | - Yuan-Zhi Tan
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, 361005 Xiamen, China
| | - Xinping Wang
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
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13
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Feng Z, Zhou J, He X, Wang B, Xie G, Qiao X, Liu L, Xie Z, Ma Y. Extremely Stable Perylene Bisimide-Bridged Regioisomeric Diradicals and Their Redox Properties. Chemistry 2024; 30:e202302943. [PMID: 37803935 DOI: 10.1002/chem.202302943] [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: 09/11/2023] [Revised: 10/05/2023] [Accepted: 10/06/2023] [Indexed: 10/08/2023]
Abstract
Excellent stability is an essential premise for organic diradicals to be used in organic electronic and spintronic devices. We have attached two tris(2,4,6-trichlorophenyl)methyl (TTM) radical building blocks to the two sides of perylene bisimide (PBI) bridges and obtained two regioisomeric diradicals (1,6-TTM-PBI and 1,7-TTM-PBI). Both of the isomers show super stability rather than the monomeric TTM under ambient conditions, due to the increased conjugation and the electron-withdrawing effects of the PBI bridges. The diradicals show distinct and reversible multistep redox processes, and a spectro-electrochemistry investigation revealed the generation of organic mixed-valence (MV) species during reduction processes. The two diradicals have singlet ground states, very small singlet-triplet energy gaps (ΔES-T ) and a pure open-shell character (with diradical character y0 =0.966 for 1,6-TTM-PBI and 0.967 for 1,7-TTM-PBI). This work opens a window to developing very stable diradicals and offers the opportunity of their further application in optical, electronic and magnetic devices.
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Affiliation(s)
- Zhibin Feng
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
| | - Jiadong Zhou
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
| | - Xiandong He
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
| | - Bohan Wang
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
| | - Guojing Xie
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
| | - Xianfeng Qiao
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
| | - Linlin Liu
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
| | - Zengqi Xie
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
| | - Yuguang Ma
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
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14
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Gao Y, Liu Z, Li T, Zhao W. Mixed-Valence BN-Doped Corannulene Trimer Radical Cations. Angew Chem Int Ed Engl 2023; 62:e202314006. [PMID: 37847644 DOI: 10.1002/anie.202314006] [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: 09/19/2023] [Revised: 10/13/2023] [Accepted: 10/16/2023] [Indexed: 10/19/2023]
Abstract
Mixed-valence (MV) dimers have been extensively investigated, however, the structure and properties of purely organic MV trimers based on open-shell polycyclic aromatic hydrocarbons remain elusive. Herein, unprecedented MV BN-doped corannulene radical cations [BN-Cor1]3 ⋅⋅2+ ⋅ 2[BArylF 4 ]- and [BN-Cor2]3 ⋅⋅2+ ⋅ 2[BArylF 4 ]- were synthesized via chemical oxidation, and their structures were unambiguously confirmed by single-crystal X-ray diffraction. These uncommon radical cations consist of three corannulene cores and two [BArylF 4 ]- anions, and three corannulene motifs [BN-Cor1]3 ⋅⋅2+ and [BN-Cor2]3 ⋅⋅2+ in the unit cell exhibit a trimer structure with a slipped π-stacking configuration. Detailed structural analyses further revealed that the corannulene cores exhibit an infinite layered self-assembly configuration, allowing their potential applications as building blocks for molecular conductors. The detection of a forbidden transition (Δms =±2) by electron paramagnetic resonance (EPR) spectroscopy further confirmed the existence of two unpaired electrons in the π-trimers and the MV characteristic of these two species. Variable-temperature EPR and conductivity measurements suggested that the BN-doped π-trimers exhibited antiferromagnetic coupling and conductivity properties.
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Affiliation(s)
- Yapei Gao
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, China
| | - Zheming Liu
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, China
| | - Tao Li
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, China
| | - Wanxiang Zhao
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, China
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15
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Ferrão LFA, Pontes MAP, Fernandes GFS, Bettanin F, Aquino AJA, Lischka H, Nachtigallova D, Machado FBC. Stability and Reactivity of the Phenalene and Olympicene Isomers. J Phys Chem A 2023; 127:9430-9441. [PMID: 37920974 DOI: 10.1021/acs.jpca.3c04331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2023]
Abstract
The phenalene (triangulene) and olympicene molecules belong to the polycyclic aromatic hydrocarbon class, which have attracted substantial technological interest due to their unique electronic properties. Electronic structure calculations serve as a valuable tool in investigating the stability and reactivity of these molecular systems. In the present work, the multireference calculations, namely, the complete active space second-order perturbation theory and multireference averaged quadratic coupled cluster (MR-AQCC), were employed to study the reactivity and stability of phenalene and olympicene isomers, as well as their modified structures where the sp3-carbon at the borders were removed. The harmonic oscillator model of aromaticity (HOMA) and the nucleus-independent chemical shift as geometric and magnetic indexes calculated with density functional theory were utilized to assess the aromaticity of the studied molecules. These indexes were compared with properties such as the excitation energy and natural orbitals occupation. The reactivity analyzed using the HOMA index combined with MR-AQCC revealed the radical character of certain structures as well as the weakening of their aromaticity. Moreover, the results suggest that the removal of sp3-carbon atoms and the addition of hydrogen atoms did not alter the π network and the excitation energies of the phenalene molecules.
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Affiliation(s)
- Luiz F A Ferrão
- Departamento de Química, Instituto Tecnológico de Aeronáutica, São José dos Campos 122228-900, SP, Brazil
| | - Marcelo A P Pontes
- Departamento de Química, Instituto Tecnológico de Aeronáutica, São José dos Campos 122228-900, SP, Brazil
| | - Gabriel F S Fernandes
- Departamento de Química, Instituto Tecnológico de Aeronáutica, São José dos Campos 122228-900, SP, Brazil
| | - Fernanda Bettanin
- Escola de Artes, Ciências e Humanidades (EACH) - Universidade de São Paulo (USP), São Paulo 03828-000, SP, Brazil
| | - Adélia J A Aquino
- Department of Mechanical Engineering, Texas Tech University, Lubbock, Texas 79409, United States
| | - Hans Lischka
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409-1061, United States
| | - Dana Nachtigallova
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nam. 2, CZ-16610 Prague 6, Czech Republic
- IT4Innovations, VŠB-Technical University of Ostrava, 17. listopadu 2172/15, 70800 Ostrava-Poruba, Czech Republic
| | - Francisco B C Machado
- Departamento de Química, Instituto Tecnológico de Aeronáutica, São José dos Campos 122228-900, SP, Brazil
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16
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Wang P, Xiang Q, Tian M, Tao S, Xu Z, Guo Y, Hu W, Sun Z. Spin-Distribution-Directed Regioselective Substitution Strategy for Highly Stable Olympicenyl Radicals. Angew Chem Int Ed Engl 2023; 62:e202313257. [PMID: 37771246 DOI: 10.1002/anie.202313257] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 09/26/2023] [Accepted: 09/27/2023] [Indexed: 09/30/2023]
Abstract
The synthesis of bench-stable conjugated π-radicals is challenging owing to the lack of modular approaches, which greatly hampers their practical material screens and applications. Here, we demonstrate a spin-distribution-directed regioselective substitution strategy to introduce substituents into the specific positions of an olympicenyl radical in a stepwise manner, resulting in a series of highly stable radical species. The substituents can also adjust the crystal packing by means of steric and electronic factors, enabling the changing from a π-dimer to a pseudo-one-dimensional chain. The first single crystal organic field-effect transistor device based on a graphenic radical is fabricated in air, showing a hole mobility of up to 0.021 cm2 V-1 s-1 and excellent device stability. This approach may be generalized to diverse spin-delocalized open-shell organic radicals.
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Affiliation(s)
- Peng Wang
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin University, 92 Weijin Road, Tianjin, 300072, China
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University, Tianjin, 300072, China
| | - Qin Xiang
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin University, 92 Weijin Road, Tianjin, 300072, China
| | - Miaoyue Tian
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin University, 92 Weijin Road, Tianjin, 300072, China
| | - Sheng Tao
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin University, 92 Weijin Road, Tianjin, 300072, China
| | - Zhuofan Xu
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin University, 92 Weijin Road, Tianjin, 300072, China
| | - Yupeng Guo
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin University, 92 Weijin Road, Tianjin, 300072, China
| | - Wenping Hu
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University, Tianjin, 300072, China
- Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Fuzhou, 350207, China
| | - Zhe Sun
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin University, 92 Weijin Road, Tianjin, 300072, China
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17
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Shu C, Yang Z, Rajca A. From Stable Radicals to Thermally Robust High-Spin Diradicals and Triradicals. Chem Rev 2023; 123:11954-12003. [PMID: 37831948 DOI: 10.1021/acs.chemrev.3c00406] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2023]
Abstract
Stable radicals and thermally robust high-spin di- and triradicals have emerged as important organic materials due to their promising applications in diverse fields. New fundamental properties, such as SOMO/HOMO inversion of orbital energies, are explored for the design of new stable radicals, including highly luminescent ones with good photostability. A relation with the singlet-triplet energy gap in the corresponding diradicals is proposed. Thermally robust high-spin di- and triradicals, with energy gaps that are comparable to or greater than a thermal energy at room temperature, are more challenging to synthesize but more rewarding. We summarize a number of high-spin di- and triradicals, based on nitronyl nitroxides that provide a relation between the experimental pairwise exchange coupling constant J/k in the high-spin species vs experimental hyperfine coupling constants in the corresponding monoradicals. This relation allows us to identify outliers, which may correspond to radicals where J/k is not measured with sufficient accuracy. Double helical high-spin diradicals, in which spin density is delocalized over the chiral π-system, have been barely explored, with the sole example of such high-spin diradical possessing alternant π-system with Kekulé resonance form. Finally, we discuss a high-spin diradical with electrical conductivity and derivatives of triangulene diradicals.
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Affiliation(s)
- Chan Shu
- Department of Chemistry, University of Nebraska, Lincoln, Nebraska 68588-0304, United States
| | - Zhimin Yang
- Department of Chemistry, University of Nebraska, Lincoln, Nebraska 68588-0304, United States
| | - Andrzej Rajca
- Department of Chemistry, University of Nebraska, Lincoln, Nebraska 68588-0304, United States
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18
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Ye L, Jiang S, Hu J, Wang M, Weng T, Wu F, Cai L, Sun Z, Ma L. Induction of Metabolic Reprogramming in Kidney by Singlet Diradical Nanoparticles. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2301338. [PMID: 37295411 DOI: 10.1002/adma.202301338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Revised: 06/05/2023] [Indexed: 06/12/2023]
Abstract
Polycyclic aromatic compounds with an open-shell singlet diradical ground state, namely singlet diradicals, have recently gained attention in the fields of organic electronics, photovoltaics, and spintronics owing to their unique electronic structures and properties. Notably, singlet diradicals exhibit tunable redox amphoterism, which makes them excellent redox-active materials for biomedical applications. However, the safety and therapeutic efficacy of singlet diradicals in biological systems have not yet been explored. Herein, the study presents a newly designed singlet diradical nanomaterial, diphenyl-substituted biolympicenylidene (BO-Ph), exhibiting low cytotoxicity in vitro, non-significant acute nephrotoxicity in vivo, and the ability to induce metabolic reprogramming in kidney organoids. Integrated transcriptome and metabolome analyses reveal that the metabolism of BO-Ph stimulates glutathione (GSH) synthesis and fatty acid degradation, increases the levels of intermediates in the tricarboxylic acid (TCA) and carnitine cycles, and eventually boosts oxidative phosphorylation (OXPHOS) under redox homeostasis. Benefits of BO-Ph-induce metabolic reprogramming in kidney organoids include enhancing cellular antioxidant capacity and promoting mitochondrial function. The results of this study can facilitate the application of singlet diradical materials in the treatment of clinical conditions induced by mitochondrial abnormalities in kidney.
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Affiliation(s)
- Lei Ye
- Institute of Biopharmaceutical and Health Engineering, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | - Shengwei Jiang
- Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, Shenzhen, 518055, China
| | - Jinlian Hu
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin University, Tianjin, 300072, China
| | - Mingzhe Wang
- Institute of Biopharmaceutical and Health Engineering, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | - Taoyu Weng
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin University, Tianjin, 300072, China
| | - Feng Wu
- Institute of Biopharmaceutical and Health Engineering, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | - Liangyu Cai
- Institute of Biopharmaceutical and Health Engineering, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | - Zhe Sun
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin University, Tianjin, 300072, China
| | - Lan Ma
- Institute of Biopharmaceutical and Health Engineering, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
- Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, Shenzhen, 518055, China
- State Key Laboratory of Chemical Oncogenomics, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
- Institute of Biomedical Health Technology and Engineering, Shenzhen Bay Laboratory, Shenzhen, 518132, China
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19
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Guo Y, Wu X, Hou B, Xiang Q, Ni Y, Li J, Sun Z. Synthesis and Characterization of a Persistent Benzoanthracenyl Radical Derivative. Chem Res Chin Univ 2023. [DOI: 10.1007/s40242-023-2360-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/31/2023]
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20
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Hou B, Li K, He H, Hu J, Xu Z, Xiang Q, Wang P, Chen X, Sun Z. Stable Crystalline Nanohoop Radical and Its Self-Association Promoted by van der Waals Interactions. Angew Chem Int Ed Engl 2023; 62:e202301046. [PMID: 36754831 DOI: 10.1002/anie.202301046] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 02/07/2023] [Accepted: 02/08/2023] [Indexed: 02/10/2023]
Abstract
A stable nanohoop radical (OR3) combining the structures of cycloparaphenylene and an olympicenyl radical is synthesized and isolated in the crystalline state. X-ray crystallographic analysis reveals that OR3 forms a unique head-to-tail dimer that further aggregates into a one-dimensional chain in the solid state. Variable-temperature NMR and concentration-dependent absorption measurements indicate that the π-dimer is not formed in solution. An energy decomposition analysis indicates that van der Waals interactions are the driving force for the self-association process, in contrast with other olympicenyl derivatives that favor π-dimerization. The physical properties in solution phase have been studied, and the stable cationic species obtained by one-electron chemical oxidation. This study offers a new molecular design to modulate the self-association of organic radicals for overcoming the spin-Peierls transition, and to prepare novel nanohoop compounds with spin-related properties.
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Affiliation(s)
- Bingxia Hou
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin university, 92 Weijin Road, Tianjin, 300072, China
| | - Ke Li
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin university, 92 Weijin Road, Tianjin, 300072, China
| | - Huijie He
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin university, 92 Weijin Road, Tianjin, 300072, China
| | - Jinlian Hu
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin university, 92 Weijin Road, Tianjin, 300072, China
| | - Zhuofan Xu
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin university, 92 Weijin Road, Tianjin, 300072, China
| | - Qin Xiang
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin university, 92 Weijin Road, Tianjin, 300072, China
| | - Peng Wang
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin university, 92 Weijin Road, Tianjin, 300072, China
| | - Xing Chen
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin university, 92 Weijin Road, Tianjin, 300072, China
| | - Zhe Sun
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin university, 92 Weijin Road, Tianjin, 300072, China
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21
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Wang P, Hu J, Xu Z, Pu Z, Sato S, Zhang X, Hu W, Sun Z. Synthesis and structure elucidation of triarylmethyl radicals with anthryl substitution. Chem Commun (Camb) 2023; 59:2015-2018. [PMID: 36723079 DOI: 10.1039/d2cc06083c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Two stable triarylmethyl radicals with one or two anthryl substitutions are synthesized in gram scale, and are isolated in the crystalline state. Detailed structural elucidation with X-ray crystallographic analysis and DFT calculations revealed that the twisted structure is more energetically favorable than the folded structure, and consequently, the spin density is mainly localized at the methyl carbon. The spin distribution leads to unique physical properties, making them promising open-shell organic materials.
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Affiliation(s)
- Peng Wang
- Institute of Molecular Plus, Department of Chemistry, Tianjin University, 92 Weijin Road, Tianjin, 300072, China. .,Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University, Tianjin 300072, China.
| | - Jinlian Hu
- Institute of Molecular Plus, Department of Chemistry, Tianjin University, 92 Weijin Road, Tianjin, 300072, China.
| | - Zhuofan Xu
- Institute of Molecular Plus, Department of Chemistry, Tianjin University, 92 Weijin Road, Tianjin, 300072, China.
| | - Zhaofangzhou Pu
- Institute of Molecular Plus, Department of Chemistry, Tianjin University, 92 Weijin Road, Tianjin, 300072, China.
| | - Sota Sato
- Department of Applied Chemistry, Integrated Molecular Structure Analysis Laboratory, Social Cooperation Program, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Xiaotao Zhang
- Institute of Molecular Aggregation Science, Tianjin University, Tianjin 300072, China.
| | - Wenping Hu
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University, Tianjin 300072, China. .,Haihe Laboratory of Sustainable Chemical Transformations, Tianjin 300192, China
| | - Zhe Sun
- Institute of Molecular Plus, Department of Chemistry, Tianjin University, 92 Weijin Road, Tianjin, 300072, China. .,Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University, Tianjin 300072, China. .,Haihe Laboratory of Sustainable Chemical Transformations, Tianjin 300192, China
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22
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Wang W, Ma XH, Liu M, Tang S, Ding X, Zhao Y, Tan YZ, Kertesz M, Wang X. A Triply Negatively Charged Nanographene Bilayer with Spin Frustration. Angew Chem Int Ed Engl 2023; 62:e202217788. [PMID: 36577698 DOI: 10.1002/anie.202217788] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 12/25/2022] [Accepted: 12/28/2022] [Indexed: 12/30/2022]
Abstract
We report on the largest open-shell graphenic bilayer and also the first example of triply negatively charged radical π-dimer. Upon three-electron reduction, bilayer nanographene fragment molecule (C96 H24 Ar6 )2 (Ar=2,6-dimethylphenyl) (12 ) was transformed to a triply negatively charged species 12 3.- , which has been characterized by single-crystal X-ray diffraction, electron paramagnetic resonance (EPR) spectroscopy and magnetic properties on a superconducting quantum interference device (SQUID). 12 3.- features a 96-center-3-electron (96c/3e) pancake bond with a doublet ground state, which can be thermally excited to a quartet state. It consists of 34 π-fused rings with 96 conjugated sp2 carbon atoms. Spin frustration is observed with the frustration parameter f>31.8 at low temperatures in 12 3.- , which indicates graphene upon reduction doping may behave as a quantum spin liquid.
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Affiliation(s)
- Wenqing Wang
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, 210023, Nanjing, China.,College of Chemistry and Materials Science, Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Laboratory of Molecule-Based Materials, Anhui Normal University, 241002, Wuhu, Anhui, China
| | - Xiao-Hui Ma
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, 361005, Xiamen, China
| | - Min Liu
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, 210023, Nanjing, China
| | - Shuxuan Tang
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, 210023, Nanjing, China
| | - Xuguang Ding
- College of Chemistry and Materials Science, Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Laboratory of Molecule-Based Materials, Anhui Normal University, 241002, Wuhu, Anhui, China
| | - Yue Zhao
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, 210023, Nanjing, China
| | - Yuan-Zhi Tan
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, 361005, Xiamen, China
| | - Miklos Kertesz
- Department of Chemistry and Institute of Soft Matter, Georgetown University, 20057-1227, Washington, DC, USA
| | - Xinping Wang
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, 210023, Nanjing, China
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23
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Yang B, Gu Y, Paternò GM, Teyssandier J, Maghsoumi A, Barker AJ, Mali KS, Scotognella F, De Feyter S, Tommasini M, Feng X, Narita A, Müllen K. Zigzag-Edged Polycyclic Aromatic Hydrocarbons from Benzo[m]tetraphene Precursors. Chemistry 2023; 29:e202203981. [PMID: 36695295 DOI: 10.1002/chem.202203981] [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: 12/20/2022] [Revised: 01/23/2023] [Accepted: 01/24/2023] [Indexed: 01/26/2023]
Abstract
A series of zigzag-edged polycyclic aromatic hydrocarbons (PAHs) (Z1-Z3) were synthesized from 2,12-dibromo-7,14-diphenyl-benzo[m]tetraphene (9) as a versatile building block. Their structures were unambiguously confirmed by laser desorption/ionization time-of-flight mass spectrometry, 1 H NMR, Raman, and Fourier-transformed infrared (FTIR) spectroscopies as well as scanning tunneling microscopy. The fingerprint vibrational modes were elucidated with theoretical support. The edge- and size-dependent optical properties were characterized by UV-Vis absorption and fluorescence spectroscopy and DFT calculations. Moreover, ultrafast transient absorption spectroscopy revealed distinct modulation of the photophysical properties upon π-extension from Z1 to Z2, the latter having a gulf edge.
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Affiliation(s)
- Bo Yang
- Max Planck Institute for Polymer Research Ackermannweg 10, 55128, Mainz, Germany
| | - Yanwei Gu
- Max Planck Institute for Polymer Research Ackermannweg 10, 55128, Mainz, Germany
| | - Giuseppe M Paternò
- Physics Department, Politecnico di Milano Piazza L. da Vinci 32, Milano, 20133, Italy.,Istituto Italiano di Tecnologia, Center for Nano Science and Technology, Milano, 20133, Italy
| | - Joan Teyssandier
- Department of Chemistry, Division of Molecular Imaging and Photonics KU Leuven Celestijnenlaan 200F, B-3001, Leuven, Belgium
| | - Ali Maghsoumi
- Dipartimento di Chimica, Materiali e Ingegneria Chimica - Politecnico di Milano Piazza Leonardo da Vinci, 32-20133, Milano, Italy
| | - Alex J Barker
- Istituto Italiano di Tecnologia, Center for Nano Science and Technology, Milano, 20133, Italy
| | - Kunal S Mali
- Department of Chemistry, Division of Molecular Imaging and Photonics KU Leuven Celestijnenlaan 200F, B-3001, Leuven, Belgium
| | - Francesco Scotognella
- Physics Department, Politecnico di Milano Piazza L. da Vinci 32, Milano, 20133, Italy
| | - Steven De Feyter
- Department of Chemistry, Division of Molecular Imaging and Photonics KU Leuven Celestijnenlaan 200F, B-3001, Leuven, Belgium
| | - Matteo Tommasini
- Dipartimento di Chimica, Materiali e Ingegneria Chimica - Politecnico di Milano Piazza Leonardo da Vinci, 32-20133, Milano, Italy
| | - Xinliang Feng
- Center for Advancing Electronics and Faculty of Chemistry and Food Chemistry, Technical University of Dresden, 01062, Dresden, Germany.,Max Planck Institute of Microstructure Physics Weinberg 2, 06120, Halle, Germany
| | - Akimitsu Narita
- Max Planck Institute for Polymer Research Ackermannweg 10, 55128, Mainz, Germany
| | - Klaus Müllen
- Max Planck Institute for Polymer Research Ackermannweg 10, 55128, Mainz, Germany.,Department of Chemistry, Johannes Gutenberg University Mainz Duesbergweg 10-14, 55128, Mainz, Germany
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24
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Moles Quintero S, Haley MM, Kertesz M, Casado J. Polycyclic Hydrocarbons from [4n]Annulenes: Correlation versus Hybridization Forces in the Formation of Diradicaloids. Angew Chem Int Ed Engl 2022; 61:e202209138. [PMID: 35986661 PMCID: PMC9826091 DOI: 10.1002/anie.202209138] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Indexed: 01/11/2023]
Abstract
The conceptual connections between [4n] Hückel antiaromaticity, disjoint orbitals, correlation energy, pro-aromaticity and diradical character for a variety of extended π-conjugated systems, including some salient recent examples of nanographenes and polycyclic aromatic radicals, are provided based on their [4n]annulene peripheries. The realization of such structure-property relationships has led to a beneficial pedagogic exercise establishing design guidelines for diradicaloids. The antiaromatic fingerprint of the [4n]annulene peripheries upon orbital interactions due to internal covalent connectors gives insights into the diradicaloid property of a diversity of π-conjugated molecules that have fascinated chemists recently.
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Affiliation(s)
| | - Michael M. Haley
- Department of Chemistry & Biochemistry and Materials Science InstituteUniversity of OregonEugeneOR 97403-1253USA
| | - Miklos Kertesz
- Department of Chemistry and Institute of Soft MatterGeorgetown UniversityWashingtonDC 20057-1227USA
| | - Juan Casado
- Department of Physical ChemistryUniversity of Málaga29071MálagaSpain
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25
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Ye X, Chung LH, Li K, Zheng S, Wong YL, Feng Z, He Y, Chu D, Xu Z, Yu L, He J. Organic radicals stabilization above 300 °C in Eu-based coordination polymers for solar steam generation. Nat Commun 2022; 13:6116. [PMID: 36253477 PMCID: PMC9576730 DOI: 10.1038/s41467-022-33948-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 10/09/2022] [Indexed: 11/11/2022] Open
Abstract
Organic radicals feature unpaired electrons, and these compounds may have applications in biomedical technology and as materials for solar energy conversion. However, unpaired electrons tend to pair up (to form chemical bonds), making radicals unstable and hampering their applications. Here we report an organic radical system that is stable even at 350 °C, surpassing the upper temperature limit (200 °C) observed for other organic radicals. The system reported herein features a sulfur-rich organic linker that facilitates the formation of the radical centers; on the solid-state level, the molecules are crystallized with Eu(III) ions to form a 3D framework featuring stacks of linker molecules. The stacking is, however, somewhat loose and allows the molecules to wiggle and transform into sulfur-stabilized radicals at higher temperatures. In addition, the resulting solid framework remains crystalline, and it is stable to water and air. Moreover, it is black and features strong broad absorption in the visible and near IR region, thereby enhancing both photothermal conversion and solar-driven water evaporation. Organic radicals have potential applications in a variety of fields, including energy conversion. Here, the authors report Eu-based coordination polymers that enable the stabilization of organic radicals up to 350 °C; these systems can be used to enhance solar steam generation.
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Affiliation(s)
- Xinhe Ye
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou, 510006, China
| | - Lai-Hon Chung
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou, 510006, China
| | - Kedi Li
- Department of Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong, China
| | - Saili Zheng
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou, 510006, China
| | - Yan-Lung Wong
- Department of Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong, China
| | - Zihao Feng
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou, 510006, China
| | - Yonghe He
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou, 510006, China
| | - Dandan Chu
- Department of Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong, China
| | - Zhengtao Xu
- Institute of Materials Research and Engineering (IMRE), Agency of Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Singapore, 138634, Republic of Singapore.
| | - Lin Yu
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou, 510006, China
| | - Jun He
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou, 510006, China.
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26
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Wei H, Hou X, Xu T, Zou Y, Li G, Wu S, Geng Y, Wu J. Solution‐Phase Synthesis and Isolation of An Aza‐Triangulene and Its Cation in Crystalline Form. Angew Chem Int Ed Engl 2022; 61:e202210386. [DOI: 10.1002/anie.202210386] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Indexed: 11/07/2022]
Affiliation(s)
- Haipeng Wei
- Department of Chemistry National University of Singapore 3 Science Drive 3 Singapore 117543 Singapore
- Joint School of National University of Singapore and Tianjin University International Campus of Tianjin University Binhai New City Fuzhou 350207 China
| | - Xudong Hou
- Department of Chemistry National University of Singapore 3 Science Drive 3 Singapore 117543 Singapore
| | - Tingting Xu
- Department of Chemistry National University of Singapore 3 Science Drive 3 Singapore 117543 Singapore
| | - Ya Zou
- Department of Chemistry National University of Singapore 3 Science Drive 3 Singapore 117543 Singapore
| | - Guangwu Li
- Department of Chemistry National University of Singapore 3 Science Drive 3 Singapore 117543 Singapore
| | - Shaofei Wu
- Department of Chemistry National University of Singapore 3 Science Drive 3 Singapore 117543 Singapore
| | - Yanhou Geng
- Joint School of National University of Singapore and Tianjin University International Campus of Tianjin University Binhai New City Fuzhou 350207 China
| | - Jishan Wu
- Department of Chemistry National University of Singapore 3 Science Drive 3 Singapore 117543 Singapore
- Joint School of National University of Singapore and Tianjin University International Campus of Tianjin University Binhai New City Fuzhou 350207 China
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27
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Wei H, Hou X, Xu T, Zou Y, Li G, Wu S, Geng Y, Wu J. Solution‐Phase Synthesis and Isolation of An Aza‐Triangulene and Its Cation in Crystalline Form. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202210386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Haipeng Wei
- National University of Singapore Chemistry SINGAPORE
| | - Xudong Hou
- National University of Singapore Chemistry SINGAPORE
| | - Tingting Xu
- National University of Singapore Chemistry SINGAPORE
| | - Ya Zou
- National University of Singapore Chemistry SINGAPORE
| | - Guangwu Li
- National University of Singapore Chemistry SINGAPORE
| | - Shaofei Wu
- National University of Singapore Chemistry SINGAPORE
| | - Yanhou Geng
- National University of Singapore Chemistry SINGAPORE
| | - Jishan Wu
- National University of Singapore Chemistry 3 Science Drive 3 117543 Singapore SINGAPORE
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28
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Quintero SM, Haley MM, Kertesz M, Casado J. Polycyclic Hydrocarbons from [4n]annulenes: Correlation vs. Hybridization Forces in the Formation of Diradicaloids. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202209138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Sergio Moles Quintero
- University of Malaga: Universidad de Malaga Department of Physical Chemistry Facultad de CienciasCampus de Teatinos 29071 Málaga SPAIN
| | - Michael M. Haley
- University of Oregon Department of Chemistry & Biochemistry and Materials Science Institute UNITED STATES
| | - Miklos Kertesz
- Georgetown University Department of Chemistry and Institute of Soft Matter SPAIN
| | - Juan Casado
- University of Málaga Dept. of Physical Chemistry Campus de Teatinos s/n 29071 Málaga SPAIN
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29
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Gong Z, Xiang Q, Li K, Xu Z, Hu J, Ni Y, Sato S, Sun Z. Pentagon‐Containing
Doublet Graphene Fragments with
Edge‐Dependent
Spin/Charge Distribution. CHINESE J CHEM 2022. [DOI: 10.1002/cjoc.202200344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Zongcheng Gong
- Institute of Molecular Plus, Department of Chemistry Tianjin university 92 Weijin Road Tianjin 300072 China
| | - Qin Xiang
- Institute of Molecular Plus, Department of Chemistry Tianjin university 92 Weijin Road Tianjin 300072 China
| | - Ke Li
- Institute of Molecular Plus, Department of Chemistry Tianjin university 92 Weijin Road Tianjin 300072 China
| | - Zhuofan Xu
- Institute of Molecular Plus, Department of Chemistry Tianjin university 92 Weijin Road Tianjin 300072 China
| | - Jinlian Hu
- Institute of Molecular Plus, Department of Chemistry Tianjin university 92 Weijin Road Tianjin 300072 China
| | - Yong Ni
- Department of Chemistry Southern University of Science and Technology Shenzhen 518055 China
| | - Sota Sato
- Department of Applied Chemistry Integrated Molecular Structure Analysis Laboratory, Social Cooperation Program, The University of Tokyo
| | - Zhe Sun
- Institute of Molecular Plus, Department of Chemistry Tianjin university 92 Weijin Road Tianjin 300072 China
- Haihe Laboratory of Sustainable Chemical Transformations Tianjin 300192 China
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30
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Wang W, Li S, Wang Q, Ding X, Fang Y, Ruan H, Zhao Y, Wang X. S = 1/2 tetracene monoradical cation/anion: ion-based one-dimensional antiferromagnetic chains. Chem Commun (Camb) 2022; 58:8962-8965. [PMID: 35858289 DOI: 10.1039/d2cc02084j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The monoradical cation 1˙+ and anion 1˙- based on tetracene were generated by one-electron oxidation and one-electron reduction of the bulky tetracene (1), respectively, which contain the largest π-fused skeletons reported to date. For monoradical species, 1˙+ and 1˙-, EPR spectra and DFT calculation results indicate the spin density delocalized over the whole molecules. Notably, in the solid state, 1˙+ and 1˙-, respectively, pack into (1˙+)n and (1˙--K-crown)n, characterized by single-crystal X-ray diffraction studies. The intermolecular interactions of 1˙+ and 1˙- are, respectively, through van der Waals forces and exchange couplings supported by metal ions. The monoradical cation polymer (1˙+)n was the first example based on PAHs. The EPR spectra at 90 K of 1˙+ and 1˙- all show forbidden transitions (Δms = ±2), indicating the existence of electronic coupling between the neighboring radicals, with respective 2J = -6.54 K and 2J = -0.22 K characterized by SQUID measurements.
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Affiliation(s)
- Wenqing Wang
- Key Laboratory of Functional Molecular Solids, Ministry of Education, College of Chemistry and Materials Science, Anhui Normal University, Wuhu, 241002, China. .,State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.
| | - Shunjie Li
- Key Laboratory of Functional Molecular Solids, Ministry of Education, College of Chemistry and Materials Science, Anhui Normal University, Wuhu, 241002, China.
| | - Qianqian Wang
- Key Laboratory of Functional Molecular Solids, Ministry of Education, College of Chemistry and Materials Science, Anhui Normal University, Wuhu, 241002, China.
| | - Xuguang Ding
- Key Laboratory of Functional Molecular Solids, Ministry of Education, College of Chemistry and Materials Science, Anhui Normal University, Wuhu, 241002, China.
| | - Yong Fang
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.
| | - Huapeng Ruan
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.
| | - Yue Zhao
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.
| | - Xinping Wang
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.
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31
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Xiang Q, Sun Z. Doublet Open-Shell Graphene Fragments. Chem Asian J 2022; 17:e202200251. [PMID: 35438845 DOI: 10.1002/asia.202200251] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 04/13/2022] [Indexed: 11/11/2022]
Abstract
The recent advances on neutral delocalized radical species based on polycyclic aromatic hydrocarbons with fused hexagonal rings, herein defined as doublet open-shell graphene fragments, are summarized in this review. A few simple yet useful theoretical approaches for structural analysis and molecular design were introduced at first. Then, based on the number of fused hexagonal rings, molecular systems with different size, symmetry and edge structure were discussed with emphasis on those isolated in the crystalline form. Their unique self-association behavior, chemical reactivity and physical properties were summarized and discussed, and insights on their functions and potential applications were provided.
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Affiliation(s)
- Qin Xiang
- Tianjin University, Institute of Molecular Plus, CHINA
| | - Zhe Sun
- Tianjin University, Institute of molecular plus, No. 92 Weijin Road, Nankai District, 300072, Tianjin, CHINA
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32
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Nishiuchi T, Ishii D, Aibara S, Sato H, Kubo T. Synthesis, properties and chemical modification of a persistent triisopropylsilylethynyl substituted tri(9-anthryl)methyl radical. Chem Commun (Camb) 2022; 58:3306-3309. [PMID: 35178540 DOI: 10.1039/d2cc00548d] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In studies aimed at developing new organic spin materials, we prepared a triisopropylsilylethynyl substituted tri(9-anthryl)methyl (TAntM) radical. The TIPS-ethynyl group in this radical effectively suppresses its reactivity, resulting in extremely high stability in air for at least one month. Chemical modification of the radical using [4+2] Diels-Alder reaction proceeds even at room temperature. Because harsh conditions and metal-catalyzed reactions are not required, this post-modification strategy should be highly versatile for use in constructing unique spin-labelled molecules.
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Affiliation(s)
- Tomohiko Nishiuchi
- Department of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan. .,Innovative Catalysis Science Division, Institute for Open and Transdisciplinary Research Initiatives, (ICS-OTRI), Osaka University, Suita, Osaka 565-0871, Japan
| | - Daisuke Ishii
- Department of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.
| | - Seito Aibara
- Department of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.
| | - Hiroyasu Sato
- Rigaku Corporation, 3-9-12 Matsubara, Akishima, Tokyo 196-8666, Japan
| | - Takashi Kubo
- Department of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan. .,Innovative Catalysis Science Division, Institute for Open and Transdisciplinary Research Initiatives, (ICS-OTRI), Osaka University, Suita, Osaka 565-0871, Japan
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33
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Guo Y, Ding S, Zhang N, Xu Z, Wu S, Hu J, Xiang Q, Li ZY, Chen X, Sato S, Wu J, Sun Z. π-Extended Doublet Open-Shell Graphene Fragments Exhibiting One-Dimensional Chain Stacking. J Am Chem Soc 2022; 144:2095-2100. [PMID: 35099946 DOI: 10.1021/jacs.1c12854] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The hitherto elusive benzo[c]anthanthrenyl radical derivatives composed of seven fused six-membered rings are synthesized and isolated in the crystalline form, representing a laterally π-extended doublet open-shell graphene fragment compared to the phenalenyl and olympicenyl radical structures. X-ray crystallographic analysis revealed one-dimensional chain stacking with relatively close intermolecular contacts, which is an important precondition for achieving single-component conductors. The magnetic, optical, and redox properties are investigated in the solution phase. In combination with the good stability, such open-shell molecular systems have potentials as functional electronic materials.
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Affiliation(s)
- Yupeng Guo
- Institute of Molecular Plus, Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Tianjin University, 92 Weijin Road, Tianjin 300072, China
| | - Shuaishuai Ding
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University & Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
| | - Na Zhang
- Institute of Molecular Plus, Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Tianjin University, 92 Weijin Road, Tianjin 300072, China
| | - Zhuofan Xu
- Institute of Molecular Plus, Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Tianjin University, 92 Weijin Road, Tianjin 300072, China
| | - Shaofei Wu
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543
| | - Jinlian Hu
- Institute of Molecular Plus, Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Tianjin University, 92 Weijin Road, Tianjin 300072, China
| | - Qin Xiang
- Institute of Molecular Plus, Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Tianjin University, 92 Weijin Road, Tianjin 300072, China
| | - Zhao-Yang Li
- School of Materials Science and Engineering, Nankai University, 38 Tongyan Road, Haihe Educational Park, Tianjin 300350, China
| | - Xing Chen
- Institute of Molecular Plus, Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Tianjin University, 92 Weijin Road, Tianjin 300072, China
| | - Sota Sato
- Department of Applied Chemistry, Integrated Molecular Structure Analysis Laboratory, Social Cooperation Program, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Jishan Wu
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543
| | - Zhe Sun
- Institute of Molecular Plus, Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Tianjin University, 92 Weijin Road, Tianjin 300072, China
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34
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Zhang R, Ellern A, Winter AH. Steric Hindrance Favors σ Dimerization over π Dimerization for Julolidine Dicyanomethyl Radicals. J Org Chem 2022; 87:1507-1511. [PMID: 34985897 DOI: 10.1021/acs.joc.1c02246] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Metastable radicals exist in a steady-state equilibrium in solution with dimers, which can be either σ dimers or π dimers. Here, we show that steric hindrance at the para position causes julolidine-derived dicyanomethyl radicals to form σ dimers rather than π dimers, the opposite behavior as seen in other carbon-centered radicals, where steric hindrance typically favors pimerization. The change in dimerization mode can be attributed to weaker London dispersion forces and a decreased orbital overlap in the sterically hindered dicyanomethyl radical π dimers, while the bulky groups exert relatively little effect on the energy of the σ dimer.
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Affiliation(s)
- Rui Zhang
- Department of Chemistry, Iowa State University, 1651 Gilman Hall, Ames, Iowa 50010, United States
| | - Arkady Ellern
- Department of Chemistry, Iowa State University, 1651 Gilman Hall, Ames, Iowa 50010, United States
| | - Arthur H Winter
- Department of Chemistry, Iowa State University, 1651 Gilman Hall, Ames, Iowa 50010, United States
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35
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Benner F, Demir S. Isolation of the elusive bisbenzimidazole Bbim 3−˙ radical anion and its employment in a metal complex. Chem Sci 2022; 13:5818-5829. [PMID: 35685798 PMCID: PMC9132035 DOI: 10.1039/d1sc07245e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 04/05/2022] [Indexed: 11/28/2022] Open
Abstract
The discovery of singular organic radical ligands is a formidable challenge due to high reactivity arising from the unpaired electron. Matching radical ligands with metal ions to engender magnetic coupling is crucial for eliciting preeminent physical properties such as conductivity and magnetism that are crucial for future technologies. The metal-radical approach is especially important for the lanthanide ions exhibiting deeply buried 4f-orbitals. The radicals must possess a high spin density on the donor atoms to promote strong coupling. Combining diamagnetic 89Y (I = 1/2) with organic radicals allows for invaluable insight into the electronic structure and spin-density distribution. This approach is hitherto underutilized, possibly owing to the challenging synthesis and purification of such molecules. Herein, evidence of an unprecedented bisbenzimidazole radical anion (Bbim3−˙) along with its metalation in the form of an yttrium complex, [K(crypt-222)][(Cp*2Y)2(μ-Bbim˙)] is provided. Access of Bbim3−˙ was feasible through double-coordination to the Lewis acidic metal ion and subsequent one-electron reduction, which is remarkable as Bbim2− was explicitly stated to be redox-inactive in closed-shell complexes. Two molecules containing Bbim2− (1) and Bbim3−˙ (2), respectively, were thoroughly investigated by X-ray crystallography, NMR and UV/Vis spectroscopy. Electrochemical studies unfolded a quasi-reversible feature and emphasize the role of the metal centre for the Bbim redox-activity as neither the free ligand nor the Bbim2− complex led to analogous CV results. Excitingly, a strong delocalization of the electron density through the Bbim3−˙ ligand was revealed via temperature-dependent EPR spectroscopy and confirmed through DFT calculations and magnetometry, rendering Bbim3−˙ an ideal candidate for single-molecule magnet design. The long sought-after bisbenzimidazole radical was isolated through complexation to two rare earth metallocenes followed by reduction, and analysed through crystallography, VT EPR spectroscopy, electrochemistry, magnetometry, and DFT computations.![]()
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Affiliation(s)
- Florian Benner
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824, USA
| | - Selvan Demir
- Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824, USA
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36
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Arikawa S, Shimizu A, Shiomi D, Sato K, Shintani R. Synthesis and Isolation of a Kinetically Stabilized Crystalline Triangulene. J Am Chem Soc 2021; 143:19599-19605. [PMID: 34767718 DOI: 10.1021/jacs.1c10151] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The synthesis and isolation of hydrocarbons with a triplet ground state in crystalline forms have been sought in materials science. Triangulene is one of the most famous triplet-ground-state benzenoid hydrocarbons. Its unique electronic structure and highly symmetric structure have prompted many scientists to synthesize and isolate triangulene and its derivatives, but all attempts so far to isolate them as crystals have been unsuccessful. Herein we report the synthesis and isolation of a kinetically stabilized crystalline triangulene for the first time. The key to success is the introduction of bulky substituents onto the reactive zigzag edges. Its highly symmetric structure was confirmed by X-ray crystallography, and its fundamental properties, including the triplet ground state, were revealed. The achievement here will open the door for the synthesis and isolation of other hydrocarbons with higher spin multiplicity.
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Affiliation(s)
- Shinobu Arikawa
- Division of Chemistry, Department of Materials Engineering Science, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan
| | - Akihiro Shimizu
- Division of Chemistry, Department of Materials Engineering Science, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan
| | - Daisuke Shiomi
- Department of Chemistry and Molecular Materials Science, Graduate School of Science, Osaka City University, Sumiyoshi-ku, Osaka 558-8585, Japan
| | - Kazunobu Sato
- Department of Chemistry and Molecular Materials Science, Graduate School of Science, Osaka City University, Sumiyoshi-ku, Osaka 558-8585, Japan
| | - Ryo Shintani
- Division of Chemistry, Department of Materials Engineering Science, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan
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37
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Han H, Zhang D, Zhu Z, Wei R, Xiao X, Wang X, Liu Y, Ma Y, Zhao D. Aromatic Stacking Mediated Spin-Spin Coupling in Cyclophane-Assembled Diradicals. J Am Chem Soc 2021; 143:17690-17700. [PMID: 34637282 DOI: 10.1021/jacs.1c08262] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
To investigate the capability of π-π stacking motifs to enable spin-spin coupling, we designed and synthesized three pairs of regio-isomers featuring two radical moieties joined by a [2.2]paracyclophane (CP) unit. By fusing indeno units to CP, two partially stacked fluorene radicals are covalently linked, exhibiting evident antiferromagnetic (AFM) coupling regardless of the orientation of two spins. Remarkably, while possessing high diradical indices of 0.8 and 0.9, the two molecules demonstrate good air stability by virtue of their singlet ground state. Single crystals help unravel the structural basis of their AFM coupling behaviors. When two radical centers are arranged at the pseudometa-positions around CP, the face-to-face stacked phenylene rings intrinsically confer orbital interactions that promote AFM coupling. On the other hand, if two radicals are directed in the pseudopara-orientation, significant orbital overlapping is observed between the radical centers (i.e., C9 of fluorene) and the aromatic carbons laid on the side, rendering AFM coupling between the two spins. In contrast, when two fluorene radicals are tethered to CP via C9 through a single C-C bond, ferromagnetic (FM) coupling is manifested by both diradical isomers featuring pseudometa- and pseudopara-connectivity. With minimal spin distributed on CP and thus limited contribution from π-π stacking, their spin-spin coupling properties are more similar to a pair of nitroxide diradical analogues, in which the two spins are dominantly coupled via through-space interactions. From these results, important conclusions are elucidated such as that although through-space interactions may confer FM coupling, with weakened strength shown by PAH radicals due to their lower polarity, face-to-face stacked π-frameworks tend to induce AFM coupling, because favorable orbital interactions are readily achieved by PAH systems hosting delocalized spins that are capable of adopting varied stacking motifs.
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Affiliation(s)
- Han Han
- Beijing National Laboratory for Molecular Sciences, Center for the Soft Matter Science and Engineering, the Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry, Peking University, Beijing 100871, China
| | - Di Zhang
- Beijing National Laboratory for Molecular Sciences, Center for the Soft Matter Science and Engineering, the Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry, Peking University, Beijing 100871, China
| | - Ziqi Zhu
- Beijing National Laboratory for Molecular Sciences, Center for the Soft Matter Science and Engineering, the Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry, Peking University, Beijing 100871, China
| | - Rong Wei
- Beijing National Laboratory for Molecular Sciences, Center for the Soft Matter Science and Engineering, the Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry, Peking University, Beijing 100871, China
| | - Xiao Xiao
- Beijing National Laboratory for Molecular Sciences, Center for the Soft Matter Science and Engineering, the Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry, Peking University, Beijing 100871, China
| | - Xiaoge Wang
- Beijing National Laboratory for Molecular Sciences, Center for the Soft Matter Science and Engineering, the Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry, Peking University, Beijing 100871, China
| | - Yiming Liu
- Beijing National Laboratory for Molecular Sciences, Center for the Soft Matter Science and Engineering, the Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry, Peking University, Beijing 100871, China
| | - Yuguo Ma
- Beijing National Laboratory for Molecular Sciences, Center for the Soft Matter Science and Engineering, the Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry, Peking University, Beijing 100871, China
| | - Dahui Zhao
- Beijing National Laboratory for Molecular Sciences, Center for the Soft Matter Science and Engineering, the Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry, Peking University, Beijing 100871, China
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38
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Cui ZH, Wang MH, Lischka H, Kertesz M. Unexpected Charge Effects Strengthen π-Stacking Pancake Bonding. JACS AU 2021; 1:1647-1655. [PMID: 34723268 PMCID: PMC8549058 DOI: 10.1021/jacsau.1c00272] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Indexed: 06/13/2023]
Abstract
Phenalenyls (PLYs) are important synthons in many functional and electronic materials, which often display favorable molecule-to-molecule overlap for electron or hole transport. They also serve as a prototype for π-stacking pancake bonding based on two-electron multicenter bonding (2e/mc). Unexpected near-doubling of the binding energy is obtained for the positively charged PLY2 + dimer with an effect similar to that seen for the positively charged olympicenyl (OPY) radical dimer. This charge effect is reversed for the perfluorinated (PF) dimers, and the negatively charged perfluorinated (PF) dimers PF-PLY2 - and PF-OPY2 - become strongly bound. Long-range interactions reflect these differences. Also surprising is that in this case the pancake bonding corresponds to single-electron (1e/mc) or a three-electron (3e/mc) multicenter bonding in contrast to the 2e/mc bonding that occurs for the neutral radical dimers. The strong preference for a large intermolecular overlap is maintained in these charged dimers. Importantly, the preference for π-bonding in the charged dimers compared to σ-bonding is strongly enhanced relative to the neutral PLY dimers.
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Affiliation(s)
- Zhong-hua Cui
- Institute
of Atomic and Molecular Physics, Key Laboratory of Physics and Technology
for Advanced Batteries (Ministry of Education), Jilin University, Changchun 130012, P. R. China
- Beijing
National Laboratory for Molecular Sciences, Beijing 100190, P. R. China
| | - Meng-hui Wang
- Institute
of Atomic and Molecular Physics, Key Laboratory of Physics and Technology
for Advanced Batteries (Ministry of Education), Jilin University, Changchun 130012, P. R. China
| | - Hans Lischka
- Department
of Chemistry and Biochemistry, Texas Tech
University, Lubbock, Texas 79409, United States
- A
School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, P. R. China
| | - Miklos Kertesz
- Chemistry
Department and Institute of Soft Matter, Georgetown University, Washington, D.C. 20057-1227, United States
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39
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A de novo strategy to develop NIR precipitating fluorochrome for long-term in situ cell membrane bioimaging. Proc Natl Acad Sci U S A 2021; 118:2018033118. [PMID: 33602816 DOI: 10.1073/pnas.2018033118] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Cell membrane-targeted bioimaging is a prerequisite for studying the roles of membrane-associated biomolecules in various physiological and pathological processes. However, long-term in situ bioimaging on the cell membrane with conventional fluorescent probes leads to diffusion into cells from the membrane surface. Therefore, we herein proposed a de novo strategy to construct an antidiffusion probe by integrating a fluorochrome characterized by strong hydrophobicity and low lipophilicity, with an enzyme substrate to meet this challenge. This precipitating fluorochrome HYPQ was designed by conjugating the traditionally strong hydrophobic solid-state fluorochrome 6-chloro-2-(2-hydroxyphenyl) quinazolin-4(3H)-one (HPQ) with a 2-(2-methyl-4H-chromen-4-ylidene) malononitrile group to obtain closer stacking to lower lipophilicity and elongate emission to the far-red to near-infrared wavelength. As proof-of-concept, the membrane-associated enzyme γ-glutamyltranspeptidase (GGT) was selected as a model enzyme to design the antidiffusion probe HYPQG. Then, benefiting from the precipitating and stable signal properties of HYPQ, in situ imaging of GGT on the membrane was successfully realized. Moreover, after HYPQG was activated by GGT, the fluorescence signal on the cell membrane remained unchanged, with incubation time even extending to 6 h, which is significant for in situ monitoring of enzymatic activity. In vivo testing subsequently showed that the tumor region could be accurately defined by this probe after long-term in situ imaging of tumor-bearing mice. The excellent performance of HYPQ indicates that it may be an ideal alternative for constructing universal antidiffusion fluorescent probes, potentially providing an efficient tool for accurate imaging-guided surgery in the future.
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40
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Murata T, Yamamoto Y, Ueda A, Ise T, Shiomi D, Sato K, Takui T, Morita Y. Synthesis and Physical Properties of Trioxotriangulene Having Methoxy and Hydroxy Groups at α-Positions: Electronic and Steric Effects of Substituent Groups and Intramolecular Hydrogen Bonds. J Org Chem 2021; 86:10154-10165. [PMID: 34282916 DOI: 10.1021/acs.joc.1c00880] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
New 4,8,12-trioxotriangulene (TOT) neutral radical derivatives having three methoxy and hydroxy groups at the α-positions were synthesized, and the substituent effects on the electronic spin and redox properties were elucidated in the theoretical and experimental methods. Due to the small SOMO coefficients at the α-positions of TOT, the methoxy groups in the TOT neutral radical had negligible effects on the electronic spin structure and redox ability. On the other hand, methoxy groups greatly increased the LUMO energy having large coefficients at α-positions and, thus, caused a remarkable negative-potential shift of the redox wave of anion species involving the dianion and trianion species. Converting the methoxy groups to hydroxy groups caused a dramatic change in the electronic structure of TOT, where the intramolecular hydrogen bonds between hydroxy groups and oxo groups strongly attracted a minus charge on the TOT skeleton. The HOMO energy of the monoanion species was significantly reduced, causing a blue shift of the HOMO-LUMO transition and an anodic shift of the redox potential. In addition, due to the steric repulsion smaller than that of the methoxy group, the hydroxy derivative showed a more planar molecular structure and a strong π-stacking ability.
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Affiliation(s)
- Tsuyoshi Murata
- Department of Applied Chemistry, Faculty of Engineering, Aichi Institute of Technology,1247 Yachigusa, Yakusa, Toyota, Aichi 470-0392, Japan
| | - Yosuke Yamamoto
- Department of Chemistry, Graduate School of Science, Osaka University, Machikaneyama 1-1, Toyonaka, Osaka 560-0043, Japan
| | - Akira Ueda
- Department of Chemistry, Kumamoto University, 2-39-1 Kurokami, Chuo-ku, Kumamoto 860-8555, Japan
| | - Tomoaki Ise
- Department of Chemistry and Molecular Materials Science, Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka, 558-8585, Japan
| | - Daisuke Shiomi
- Department of Chemistry and Molecular Materials Science, Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka, 558-8585, Japan
| | - Kazunobu Sato
- Department of Chemistry and Molecular Materials Science, Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka, 558-8585, Japan
| | - Takeji Takui
- Department of Chemistry and Molecular Materials Science, Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka, 558-8585, Japan
| | - Yasushi Morita
- Department of Applied Chemistry, Faculty of Engineering, Aichi Institute of Technology,1247 Yachigusa, Yakusa, Toyota, Aichi 470-0392, Japan
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41
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Kawashima H, Ukai S, Nozawa R, Fukui N, Fitzsimmons G, Kowalczyk T, Fliegl H, Shinokubo H. Determinant Factors of Three-Dimensional Aromaticity in Antiaromatic Cyclophanes. J Am Chem Soc 2021; 143:10676-10685. [PMID: 34170675 DOI: 10.1021/jacs.1c04348] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Three-dimensional aromaticity arising from the close stacking of two antiaromatic π-conjugated macrocycles has recently received considerable attention. Here, a cyclophane consisting of two antiaromatic Ni(II) norcorrole units tethered with two flexible alkyl chains was synthesized. The norcorrole cyclophane showed crystal polymorphism providing three different solid-state structures. Surprisingly, one of them adopted an aligned face-to-face stacking arrangement with negligible displacement along the slipping axis. Although the exchange repulsion between two π-clouds should be maximized in this orientation, the π-π distance is remarkably close (3.258 Å). Three-dimensional aromaticity in this conformation has been supported experimentally and theoretically as evidenced by small bond length alternations as well as the presence of a diatropic ring current. An analogous cyclophane with two aromatic Ni(II) porphyrin units was prepared for comparison. The porphyrin cyclophane exhibited a slipped-stacking conformation with a larger displacement (2.9 Å) and a larger interplanar distance (3.402 Å) without noticeable change of the aromaticity of each porphyrin unit. In solution, the norcorrole cyclophane forms a twist stacking arrangement with effective interplanar orbital overlap and exists in an equilibrium between stacked and nonstacked structures. Thermodynamic parameters of the stacking process were estimated, revealing an inherently large attractive interaction operating between two norcorrole units, which has been further supported by energy decomposition analysis.
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Affiliation(s)
- Hiroyuki Kawashima
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603, Japan
| | - Shusaku Ukai
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603, Japan
| | - Ryo Nozawa
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603, Japan
| | - Norihito Fukui
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603, Japan
| | - Garrett Fitzsimmons
- Department of Chemistry, Advanced Materials Science & Engineering Center and Institute for Energy Studies, Western Washington University, Bellingham, Washington 98229, United States
| | - Tim Kowalczyk
- Department of Chemistry, Advanced Materials Science & Engineering Center and Institute for Energy Studies, Western Washington University, Bellingham, Washington 98229, United States
| | - Heike Fliegl
- Institute of Nanotechnology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Hiroshi Shinokubo
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603, Japan
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42
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Cai K, Zhang L, Astumian RD, Stoddart JF. Radical-pairing-induced molecular assembly and motion. Nat Rev Chem 2021; 5:447-465. [PMID: 37118435 DOI: 10.1038/s41570-021-00283-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/16/2021] [Indexed: 12/25/2022]
Abstract
Radical-pairing interactions between conjugated organic π-radicals are relative newcomers to the inventory of molecular recognition motifs explored in supramolecular chemistry. The unique electronic, magnetic, optical and redox-responsive properties of the conjugated π-radicals render molecules designed with radical-pairing interactions useful for applications in various areas of chemistry and materials science. In particular, the ability to control formation of radical cationic or anionic species, by redox stimulation, provides a flexible trigger for directed assembly and controlled molecular motions, as well as a convenient means of inputting energy to fuel non-equilibrium processes. In this Review, we provide an overview of different examples of radical-pairing-based recognition processes and of their emerging use in (1) supramolecular assembly, (2) templation of mechanically interlocked molecules, (3) stimuli-controlled molecular switches and, by incorporation of kinetic asymmetry in the design, (4) the creation of unidirectional molecular transporters based on pumping cassettes powered by fuelled switching of radical-pairing interactions. We conclude the discussion with an outlook on future directions for the field.
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43
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Yang Y, Blacque O, Sato S, Juríček M. Cycloparaphenylene-Phenalenyl Radical and Its Dimeric Double Nanohoop*. Angew Chem Int Ed Engl 2021; 60:13529-13535. [PMID: 33635576 PMCID: PMC8252656 DOI: 10.1002/anie.202101792] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Indexed: 12/17/2022]
Abstract
The first example of a neutral spin-delocalized carbon-nanoring radical was achieved by integration of the open-shell phenalenyl unit into cycloparaphenylene (CPP). Spin distribution in this hydrocarbon is localized primarily on the phenalenyl segment and partially on the CPP segment as a consequence of steric and electronic effects. The resulting geometry is reminiscent of a diamond ring, with pseudo-perpendicular arrangement of the radial and the planar π-surface. The phenylene rings attached directly to the phenalenyl unit give rise to a steric effect that governs a highly selective dimerization pathway, yielding a giant double nanohoop. Its π-framework made of 158 sp2 -carbon atoms was elucidated by single-crystal X-ray diffraction, which revealed a three-segment CPP-peropyrene-CPP structure. This nanocarbon shows a fluorescence profile characteristic of peropyrene, regardless of which segment gets excited. These results in conjunction with DFT suggest that adjusting the size of the CPP segments in this double nanohoop could deliver donor-acceptor systems.
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Affiliation(s)
- Yong Yang
- Department of ChemistryUniversity of ZurichWinterthurerstrasse 1908057ZurichSwitzerland
| | - Olivier Blacque
- Department of ChemistryUniversity of ZurichWinterthurerstrasse 1908057ZurichSwitzerland
| | - Sota Sato
- Department of Applied ChemistryThe University of TokyoHongo, Bunkyo-kuTokyo113-8656Japan
| | - Michal Juríček
- Department of ChemistryUniversity of ZurichWinterthurerstrasse 1908057ZurichSwitzerland
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44
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Xiang Q, Xu J, Guo J, Dang Y, Xu Z, Zeng Z, Sun Z. Unveiling the Hidden σ-Dimerization of a Kinetically Protected Olympicenyl Radical. Chemistry 2021; 27:8203-8213. [PMID: 33783053 DOI: 10.1002/chem.202100631] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Indexed: 11/05/2022]
Abstract
The σ-dimer of a kinetically protected olympicenyl radical, which evaded the experimental detection, was revealed by conversion into biolympicenylidene with E-configuration in a regioselective manner. The complicated stereochemistry and energetics of the σ-dimers derived from C2v symmetry and uneven spin distribution of the olympicenyl radical were revealed by the theoretical calculations, and the energetic preference of π-dimer over σ-dimer by a minute gap was disclosed. The E-biolympicenylidene, a polycyclic ene structure previously considered as reactive intermediate in the phenalenyl radical system, exhibited exceptional stability, which allowed for a detailed investigation on its singlet diradical character and physical properties by means of X-ray crystallography, UV-vis-NIR absorption/emission spectroscopy and cyclic voltammetry, and assisted by theoretical calculations. The E-biolympicenylidene showed high resistance towards both thermal and photochemical ring-cyclization reactions, which was attributed to high activation energies for the rate-determining electrocyclization operated on both disrotatory and conrotatory mode, as well as a small spin density at the bonding sites for the radical-radical coupling process.
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Affiliation(s)
- Qin Xiang
- Institute of Molecular Plus, Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Tianjin University, 92 Weijin Road, Tianjin, 300072, P. R. China
| | - Jun Xu
- Health Science Platform, Tianjin University, 92 Weijin Road, Tianjin, 300072, P. R. China
| | - Jing Guo
- State Key Laboratory of Chemo/Biosensing and Chemometrics, Center for Aggregation-Induced Emission, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, P. R. China
| | - Yanfeng Dang
- Department of Chemistry and Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Tianjin University and Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300072, P. R. China
| | - Zhanqiang Xu
- Institute of Molecular Plus, Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Tianjin University, 92 Weijin Road, Tianjin, 300072, P. R. China
| | - Zebing Zeng
- State Key Laboratory of Chemo/Biosensing and Chemometrics, Center for Aggregation-Induced Emission, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, P. R. China
| | - Zhe Sun
- Institute of Molecular Plus, Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Tianjin University, 92 Weijin Road, Tianjin, 300072, P. R. China
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Yang Y, Blacque O, Sato S, Juríček M. Cycloparaphenylene–Phenalenyl Radical and Its Dimeric Double Nanohoop**. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202101792] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Yong Yang
- Department of Chemistry University of Zurich Winterthurerstrasse 190 8057 Zurich Switzerland
| | - Olivier Blacque
- Department of Chemistry University of Zurich Winterthurerstrasse 190 8057 Zurich Switzerland
| | - Sota Sato
- Department of Applied Chemistry The University of Tokyo Hongo, Bunkyo-ku Tokyo 113-8656 Japan
| | - Michal Juríček
- Department of Chemistry University of Zurich Winterthurerstrasse 190 8057 Zurich Switzerland
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46
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Jiménez VG, Mayorga-Burrezo P, Blanco V, Lloveras V, Gómez-García CJ, Šolomek T, Cuerva JM, Veciana J, Campaña AG. Dibenzocycloheptatriene as end-group of Thiele and tetrabenzo-Chichibabin hydrocarbons. Chem Commun (Camb) 2020; 56:12813-12816. [PMID: 32966400 DOI: 10.1039/d0cc04489j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Thiele (Th) and tetrabenzo-Chichibabin (TBC) derivatives with terminal dibenzocycloheptatriene (DBHept) units were prepared. A clear correlation between their electronic and molecular structures was stablished. Insights into their closed- or open-shell ground states were gained, where particular contribution of the heptagonal carbocycles as end-groups was proved. Remarkably, a thermally accessible triplet diradical configuration was confirmed for the DBHept-TBC compound.
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Affiliation(s)
- Vicente G Jiménez
- Department of Organic Chemistry, Unidad de Excelencia de Química aplicada a Biomedicina y Medio Ambiente, University of Granada (UGR), C. U. Fuentenueva, Granada 18071, Spain.
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47
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Duan HD, Mohamed-Raseek N, Miller AF. Spectroscopic evidence for direct flavin-flavin contact in a bifurcating electron transfer flavoprotein. J Biol Chem 2020; 295:12618-12634. [PMID: 32661195 DOI: 10.1074/jbc.ra120.013174] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 07/10/2020] [Indexed: 12/15/2022] Open
Abstract
A remarkable charge transfer (CT) band is described in the bifurcating electron transfer flavoprotein (Bf-ETF) from Rhodopseudomonas palustris (RpaETF). RpaETF contains two FADs that play contrasting roles in electron bifurcation. The Bf-FAD accepts electrons pairwise from NADH, directs one to a lower-reduction midpoint potential (E°) carrier, and the other to the higher-E° electron transfer FAD (ET-FAD). Previous work noted that a CT band at 726 nm formed when ET-FAD was reduced and Bf-FAD was oxidized, suggesting that both flavins participate. However, existing crystal structures place them too far apart to interact directly. We present biochemical experiments addressing this conundrum and elucidating the nature of this CT species. We observed that RpaETF missing either FAD lacked the 726 nm band. Site-directed mutagenesis near either FAD produced altered yields of the CT species, supporting involvement of both flavins. The residue substitutions did not alter the absorption maximum of the signal, ruling out contributions from residue orbitals. Instead, we propose that the residue identities modulate the population of a protein conformation that brings the ET-flavin and Bf-flavin into direct contact, explaining the 726 nm band based on a CT complex of reduced ET-FAD and oxidized Bf-FAD. This is corroborated by persistence of the 726 nm species during gentle protein denaturation and simple density functional theory calculations of flavin dimers. Although such a CT complex has been demonstrated for free flavins, this is the first observation of such, to our knowledge, in an enzyme. Thus, Bf-ETFs may optimize electron transfer efficiency by enabling direct flavin-flavin contact.
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Affiliation(s)
- H Diessel Duan
- Department of Chemistry, University of Kentucky, Lexington, Kentucky, USA
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