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Ishigaki Y, Harimoto T, Shimajiri T, Suzuki T. Carbon-based Biradicals: Structural and Magnetic Switching. Chem Rev 2023; 123:13952-13965. [PMID: 37948658 DOI: 10.1021/acs.chemrev.3c00376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2023]
Abstract
Sterically hindered C═C double bonds often deform into a bent or twisted geometry. Thus, many overcrowded ethylenes or anthraquinodimethanes can adopt multiple conformations, such as a folded form or a twisted form, which are interconvertible under the application of external stimuli. A perpendicular form with biradical character can also be adopted when designed to incorporate a stable carbon-based radical unit, which is involved in stimuli-responsive magnetic switching accompanied by a structural change. This review focuses on recent advances in the development of such strained π-electron systems and reveals the factors that affect the mutual interconversion and switching behavior. The energy barrier for the interconversion of conformational isomers is affected by the tricyclic skeleton or bulky substituents on the C═C double bonds, whereas the relative stability of the perpendicular biradical form increases with the additional insertion of 9,10-anthrylene units into the C═C double bonds.
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Affiliation(s)
- Yusuke Ishigaki
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Takashi Harimoto
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Takuya Shimajiri
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
- Creative Research Institution, Hokkaido University, Sapporo 001-0021, Japan
| | - Takanori Suzuki
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
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Chang D, Zhu J, Sun Y, Chi K, Qiao Y, Wang T, Zhao Y, Liu Y, Lu X. From closed-shell edge-extended kekulenes to open-shell carbonylated cycloarene diradicaloid. Chem Sci 2023; 14:6087-6094. [PMID: 37293645 PMCID: PMC10246668 DOI: 10.1039/d3sc01295f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 05/13/2023] [Indexed: 06/10/2023] Open
Abstract
The precise synthesis of cycloarenes remains a challenging topic in both organic chemistry and materials science due to their unique fully fused macrocyclic π-conjugated structure. Herein, a series of alkoxyl- and aryl-cosubstituted cycloarenes (kekulene and edge-extended kekulene derivatives, K1-K3) were conveniently synthesized and an unexpected transformation of the anthryl-containing cycloarene K3 into a carbonylated cycloarene derivative K3-R was disclosed by controlling the temperature and gas atmosphere of the Bi(OTf)3-catalyzed cyclization reaction. All their molecular structures were confirmed by single-crystal X-ray analysis. The crystallographic data, NMR measurements, and theoretical calculations reveal their rigid quasi-planar skeletons, dominant local aromaticities, and decreasing intermolecular π-π stacking distance with extension of the two opposite edges. The much lower oxidation potential for K3 by cyclic voltammetry explains its unique reactivity. Moreover, carbonylated cycloarene derivative K3-R shows a remarkable stability, large diradical character, a small singlet-triplet energy gap (ΔES-T = -1.81 kcal mol-1), and weak intramolecular spin-spin coupling. Most importantly, it represents the first example of carbonylated cycloarene diradicaloids as well as the first example of radical-acceptor cycloarenes and will shed some light on synthesis of extended kekulenes and conjugated macrocyclic diradicaloids and polyradicaloids.
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Affiliation(s)
- Dongdong Chang
- Department of Materials Science, State Key Laboratory of Molecular Engineering of Polymers, Fudan University Shanghai 200433 China
| | - Jiangyu Zhu
- Department of Materials Science, State Key Laboratory of Molecular Engineering of Polymers, Fudan University Shanghai 200433 China
| | - Yutao Sun
- Department of Materials Science, State Key Laboratory of Molecular Engineering of Polymers, Fudan University Shanghai 200433 China
| | - Kai Chi
- Department of Materials Science, State Key Laboratory of Molecular Engineering of Polymers, Fudan University Shanghai 200433 China
| | - Yanjun Qiao
- Department of Materials Science, State Key Laboratory of Molecular Engineering of Polymers, Fudan University Shanghai 200433 China
| | - Teng Wang
- Department of Materials Science, State Key Laboratory of Molecular Engineering of Polymers, Fudan University Shanghai 200433 China
| | - Yan Zhao
- Department of Materials Science, State Key Laboratory of Molecular Engineering of Polymers, Fudan University Shanghai 200433 China
| | - Yunqi Liu
- Department of Materials Science, State Key Laboratory of Molecular Engineering of Polymers, Fudan University Shanghai 200433 China
| | - Xuefeng Lu
- Department of Materials Science, State Key Laboratory of Molecular Engineering of Polymers, Fudan University Shanghai 200433 China
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Hayashi Y, Suzuki S, Suzuki T, Ishigaki Y. Dibenzotropylium-Capped Orthogonal Geometry Enabling Isolation and Examination of a Series of Hydrocarbons with Multiple 14π-Aromatic Units. J Am Chem Soc 2023; 145:2596-2608. [PMID: 36606368 PMCID: PMC9896550 DOI: 10.1021/jacs.2c12574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A series of six dications composed of pure hydrocarbons with one to six non-substituted 9,10-anthrylene units end-capped with two dibenzotropyliums were designed and synthesized to elucidate the electronic properties of huge oligo(9,10-anthrylene) backbones. Their structures were successfully determined by X-ray analyses even in the case of eight planar 14π-electron units, revealing that all dications adopt almost orthogonally twisted structures between neighboring units. Spectroscopic and voltammetric analyses show that neither the significant overlap of orbitals nor the delocalization of electrons between 14π-electron units occurs due to the orthogonally twisted geometry even in solution. As a result, sequential oxidation processes were observed with the reversible formation of multivalent cations with the release of the same number of electrons as the number of anthrylene units. Upon two-electron reduction, a closed-shell butterfly-shaped form was obtained from the dication containing one anthrylene unit, whereas open-shell twisted biradicals were isolated as stable entities in the cases of derivatives containing three to six anthrylene units. Notably, from the derivative with two anthrylene units, a metastable open-shell isomer was obtained quantitatively and underwent slow thermal conversion to the most stable closed-shell isomer (Ea = 23.1 kcal mol-1). There is a drastic change in oxidation potentials between two neutral species (ΔE = 1.32 V in CH2Cl2). Since the present dications were regenerated upon oxidation of the isolated reduction products, these systems may contribute to the development of advanced response systems capable of switching color, magnetic properties, and oxidative properties by using a "cation-capped orthogonal geometry".
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Affiliation(s)
- Yuki Hayashi
- Department
of Chemistry, Faculty of Science, Hokkaido
University, Sapporo 060-0810, Japan
| | - Shuichi Suzuki
- Graduate
School of Engineering Science, Osaka University, Osaka 560-8531, Japan
| | - Takanori Suzuki
- Department
of Chemistry, Faculty of Science, Hokkaido
University, Sapporo 060-0810, Japan
| | - Yusuke Ishigaki
- Department
of Chemistry, Faculty of Science, Hokkaido
University, Sapporo 060-0810, Japan,
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Ishigaki Y, Tadokoro T, Harabuchi Y, Hayashi Y, Maeda S, Suzuki T. Anthraquinodimethane Ring-flip in Sterically Congested Alkenes: Isolation of Isomer and Elucidation of Intermediate through Experimental and Theoretical Approach. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2021. [DOI: 10.1246/bcsj.20210355] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Yusuke Ishigaki
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Tomoki Tadokoro
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Yu Harabuchi
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
- Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, Sapporo 001-0021, Japan
| | - Yuki Hayashi
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Satoshi Maeda
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
- Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, Sapporo 001-0021, Japan
| | - Takanori Suzuki
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
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Wonink MBS, Corbet BP, Kulago AA, Boursalian GB, de Bruin B, Otten E, Browne WR, Feringa BL. Three-State Switching of an Anthracene Extended Bis-thiaxanthylidene with a Highly Stable Diradical State. J Am Chem Soc 2021; 143:18020-18028. [PMID: 34695359 PMCID: PMC8569810 DOI: 10.1021/jacs.1c05938] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
A multistable molecular switching system based on an anthracene-extended bis-thiaxanthylidene with three individually addressable states that can be interconverted by electrochemical, thermal, and photochemical reactions is reported. Besides reversible switching between an open-shell diradical- and a closed-shell electronic configuration, our findings include a third dicationic state and control by multiple actuators. This dicationic state with an orthogonal conformation can be switched electrochemically with the neutral open-shell triplet state with orthogonal conformation, which was characterized by EPR. The remarkably stable diradical shows kinetic stability as a result of a significant activation barrier for isomerization to a more stable neutral closed-shell folded geometry. We ascribe this activation barrier of ΔG⧧(293 K) = 25.7 kcal mol-1 to steric hindrance in the fjord region of the overcrowded alkene structure. The folded closed-shell state can be converted back to the diradical state by irradiation with 385 nm. The folded state can also be oxidized to the dicationic state. These types of molecules with multiple switchable states and in particular stable diradicals show great potential in the design of new functional materials such as memory devices, logic gates, and OFETs.
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Affiliation(s)
- Marco B S Wonink
- Stratingh Institute for Chemistry and Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Brian P Corbet
- Stratingh Institute for Chemistry and Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Artem A Kulago
- Stratingh Institute for Chemistry and Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Gregory B Boursalian
- Stratingh Institute for Chemistry and Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Bas de Bruin
- Van't Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Edwin Otten
- Stratingh Institute for Chemistry and Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Wesley R Browne
- Stratingh Institute for Chemistry and Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Ben L Feringa
- Stratingh Institute for Chemistry and Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
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Hirao Y, Marutani M, Tachibana N, Kubo T. Synthesis and Electronic Properties of the 1-Naphthoxyl Radical. CHEM LETT 2020. [DOI: 10.1246/cl.190821] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Yasukazu Hirao
- Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Miki Marutani
- Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Naoki Tachibana
- Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Takashi Kubo
- Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
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Nishiuchi T, Ito R, Stratmann E, Kubo T. Switchable Conformational Isomerization of an Overcrowded Tristricyclic Aromatic Ene. J Org Chem 2019; 85:179-186. [DOI: 10.1021/acs.joc.9b02432] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Tomohiko Nishiuchi
- Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Ryuoh Ito
- Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Erik Stratmann
- Department of Chemistry, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - Takashi Kubo
- Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
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