1
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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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2
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Zhou M, Mao L, Niu YF, Zhao XL, Shi X, Yang HB. Triphenylamines consisting of bulky 3,5-di‑tert‑butyl‑4-anisyl group: Synthesis, redox properties and their radical cation species. CHINESE CHEM LETT 2022. [DOI: 10.1016/j.cclet.2021.11.054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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3
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Borissov A, Maurya YK, Moshniaha L, Wong WS, Żyła-Karwowska M, Stępień M. Recent Advances in Heterocyclic Nanographenes and Other Polycyclic Heteroaromatic Compounds. Chem Rev 2022; 122:565-788. [PMID: 34850633 PMCID: PMC8759089 DOI: 10.1021/acs.chemrev.1c00449] [Citation(s) in RCA: 213] [Impact Index Per Article: 106.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Indexed: 12/21/2022]
Abstract
This review surveys recent progress in the chemistry of polycyclic heteroaromatic molecules with a focus on structural diversity and synthetic methodology. The article covers literature published during the period of 2016-2020, providing an update to our first review of this topic (Chem. Rev. 2017, 117 (4), 3479-3716).
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Affiliation(s)
| | | | | | | | | | - Marcin Stępień
- Wydział Chemii, Uniwersytet
Wrocławski, ul. F. Joliot-Curie 14, 50-383 Wrocław, Poland
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4
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Mao L, Zhou M, Shi X, Yang HB. Triphenylamine (TPA) radical cations and related macrocycles. CHINESE CHEM LETT 2021. [DOI: 10.1016/j.cclet.2021.05.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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5
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Kumar R, Aggarwal H, Srivastava A. Of Twists and Curves: Electronics, Photophysics, and Upcoming Applications of Non-Planar Conjugated Organic Molecules. Chemistry 2020; 26:10653-10675. [PMID: 32118325 DOI: 10.1002/chem.201905071] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 02/02/2020] [Indexed: 01/02/2023]
Abstract
Non-planar conjugated organic molecules (NPCOMs) contain π-conjugation across their length and also exhibit asymmetry in their conformation. In other words, certain molecular fragments in NPCOMs are either twisted or curved out of planarity. This conformational asymmetry in NPCOMs leads to non-uniform charge-distribution across the molecule, with important photophysical and electronic consequences such as altered thermodynamic stability, chemical reactivity, as well as materials properties. Majorly, NPCOMs can be classified as having either Fused or Rotatable architectures. NPCOMs have been the focus of significant scientific attention in the recent past due to their exciting photophysical behavior that includes intramolecular charge-transfer (ICT), thermally activated delayed fluorescence (TADF) and long-lived charge-separated states. In addition, they also have many useful materials characteristics such as biradical character, semi-conductivity, dynamic conformations, and mechanochromism. As a result, rational design of NPCOMs and mapping their structure-property correlations has become imperative. Researchers have executed conformational changes in NPCOMs through a variety of external stimuli such as pH, temperature, anions-cations, solvent, electric potential, and mechanical force in order to tailor their photophysical, optoelectronic and magnetic properties. Converging to these points, this review highlights the lucrative electronic features, photophysical traits and upcoming applications of NPCOMs by a selective survey of the recent scientific literature.
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Affiliation(s)
- Rajesh Kumar
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal (IISER Bhopal), Bhauri, Bhopal Bypass Road, Bhopal, 462066, India
| | - Himanshu Aggarwal
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal (IISER Bhopal), Bhauri, Bhopal Bypass Road, Bhopal, 462066, India
| | - Aasheesh Srivastava
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal (IISER Bhopal), Bhauri, Bhopal Bypass Road, Bhopal, 462066, India
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6
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Norrehed S, Karlsson C, Light ME, Thapper A, Huang P, Gogoll A. Formation of persistent organic diradicals from N, N'-diphenyl-3,7-diazacyclooctanes. MONATSHEFTE FUR CHEMIE 2018; 150:77-84. [PMID: 30679878 PMCID: PMC6320754 DOI: 10.1007/s00706-018-2298-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 09/18/2018] [Indexed: 11/27/2022]
Abstract
ABSTRACT N,N'-Diphenyl-3,7-diazacyclooctane and structurally related N,N'-diphenylbispidine derivatives react with silver(I) ions in a high-yielding C-C coupling reaction to produce dication-diradical species, with the silver ions serving a double function both as template and as an oxidant. The resulting bis(benzidino)phane derivatives are persistent organic radicals, stable for several months in solution as well as in the solid state, at room temperature and above, as well as being exposed to the atmosphere. The molecular structure features a double-decker cyclophane motif, stabilized by intramolecular π-dimerization of two delocalized benzidinium radical segments. Intermolecular π-dimers are formed in the solid state. GRAPHICAL ABSTRACT
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Affiliation(s)
- Sara Norrehed
- Department of Chemistry - BMC, Uppsala University, Uppsala, Sweden
| | | | - Mark E. Light
- Department of Chemistry, University of Southampton, Highfield, Southampton, UK
| | - Anders Thapper
- Department of Chemistry - Ångström Laboratory, Uppsala University, Uppsala, Sweden
| | - Ping Huang
- Department of Chemistry - Ångström Laboratory, Uppsala University, Uppsala, Sweden
| | - Adolf Gogoll
- Department of Chemistry - BMC, Uppsala University, Uppsala, Sweden
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7
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Skórka Ł, Maurel V, Gosk JB, Puźniak R, Mouesca JM, Kulszewicz-Bajer I. Highly Efficient Tuning of Ferromagnetic Spin Interactions in High-Spin Arylamine Structures by Incorporation of Spin Bearing Carbazole Units. J Phys Chem B 2018; 122:9584-9591. [PMID: 30230334 DOI: 10.1021/acs.jpcb.8b07496] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Arylamine moieties oxidized to radical cations are considered promising spin bearing units in high-spin-type compounds. Here, we report the first use of carbazole-3,6-diamine units as efficient, rigid spin containing units. The use of rigid spin bearing units enhances significantly spin exchange interactions. The design using density functional theory calculations shows the progressive increase of the exchange coupling constant dependent on the considered model molecules. Two of the most representative molecules containing flexible (dimer 1) and rigid spin coupling unit (dimer 2) were synthesized. Electrochemical and pulsed-electron paramagnetic resonance nutation studies showed that both dimers can be oxidized to yield a majority of dicationic diradicals exhibiting S = 1 ground states. The high values of the dimer 2 exchange coupling constant obtained both computationally ( J/ kB = 145 K; HHeis. = - JS1 S2) and experimentally ( J/ kB = 90-100 K) indicate the beneficial role of the carbazole moiety incorporated into spin bearing units.
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Affiliation(s)
- Łukasz Skórka
- Faculty of Chemistry , Warsaw University of Technology , Noakowskiego 3 , 00-664 Warsaw , Poland
| | - Vincent Maurel
- Univ. Grenoble Alpes, CEA, CNRS, INAC, SyMMES , 38000 Grenoble , France
| | - Jacek B Gosk
- Faculty of Physics , Warsaw University of Technology , Koszykowa 75 , 00-662 Warsaw , Poland
| | - Roman Puźniak
- Institute of Physics , Polish Academy of Sciences , Lotników 32/46 , 02-668 Warsaw , Poland
| | | | - Irena Kulszewicz-Bajer
- Faculty of Chemistry , Warsaw University of Technology , Noakowskiego 3 , 00-664 Warsaw , Poland
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8
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De Leger W, Adriaensen K, Robeyns K, Van Meervelt L, Thomas J, Meijers B, Smet M, Dehaen W. Synthesis and post-functionalization of alternate-linked- meta-para-[2 n .1 n ]thiacyclophanes. Beilstein J Org Chem 2018; 14:2190-2197. [PMID: 30202471 PMCID: PMC6122333 DOI: 10.3762/bjoc.14.192] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 07/31/2018] [Indexed: 11/23/2022] Open
Abstract
In recent decades, considerable research attention has been devoted to new synthetic procedures for thiacyclophanes. Thiacyclophanes are widely used as host molecules for the molecular recognition of organic compounds as well as metals. Herein, we report the selective and high-yielding synthesis of novel alternate-linked-meta-para-thiacyclophanes. These novel thiacyclophanes are selectively synthesized in high-yielding procedures. Furthermore, post-functionalization of the phenolic moieties was successfully performed. The 3D structure of the alternate-linked-meta-para-[22.12]thiacyclophane was further elucidated via X-ray crystallographic analysis.
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Affiliation(s)
- Wout De Leger
- Molecular Design and Synthesis, Department of Chemistry, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium
| | - Koen Adriaensen
- Molecular Design and Synthesis, Department of Chemistry, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium
| | - Koen Robeyns
- Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, Place Louis Pasteur 1, B-1348 Louvain-la-Neuve, Belgium
| | - Luc Van Meervelt
- Biomolecular Architecture, Department of Chemistry, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium
| | - Joice Thomas
- Molecular Design and Synthesis, Department of Chemistry, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium
| | - Björn Meijers
- Laboratory of Nephrology, Department of Immunology and Microbiology, KU Leuven, Herestraat 49, B-3000 Leuven, Belgium.,Department of Nephrology and Renal Transplantation, University Hospitals Leuven, Herestraat 49, B-3000 Leuven, Belgium
| | - Mario Smet
- Molecular Design and Synthesis, Department of Chemistry, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium
| | - Wim Dehaen
- Molecular Design and Synthesis, Department of Chemistry, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium
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9
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Wang W, Chen C, Shu C, Rajca S, Wang X, Rajca A. S = 1 Tetraazacyclophane Diradical Dication with Robust Stability: A Case of Low-Temperature One-Dimensional Antiferromagnetic Chain. J Am Chem Soc 2018; 140:7820-7826. [PMID: 29863339 DOI: 10.1021/jacs.8b02415] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
One-dimensional (1D) spin-1 ( S = 1) chain of organic radicals with low local magnetic anisotropy may provide a better understanding of the low-dimensional magnetism. We report solid-state studies, including single crystal X-ray crystallography, of air-stable tetraazacyclophane diradical dication salt 12·2+·2[Al(OC(CF3)2CH3)4]- with a triplet ground state (Δ EST ≈ 0.5 kcal mol-1). The magnetic behavior for 12·2+ at low temperature is best modeled by 1D spin S = 1 Heisenberg chain with intrachain antiferromagnetic coupling of J'/ k = -5.4 K, which is associated with the interaryl C···C contacts, including π-π interactions. Zero-field splitting value, | D/ hc| ≈ 5.6 × 10-3 cm-1, for 12·2+ is rather small; thus, the 1D chains are characterized by the high degree of isotropicity | D/2 J'| ≈ 7.5 × 10-4. The diradical dication salt possesses extraordinary stability with onset of decomposition at temperature of about 180 °C (∼450 K), based on thermogravimetric analysis and EPR spectroscopy.
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Affiliation(s)
- Wenqing Wang
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures , Nanjing University , Nanjing 210023 , China
| | - Chao Chen
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures , Nanjing University , Nanjing 210023 , China
| | - Chan Shu
- Department of Chemistry , University of Nebraska , Lincoln , Nebraska 68588 , United States
| | - Suchada Rajca
- Department of Chemistry , University of Nebraska , Lincoln , Nebraska 68588 , United States
| | - Xinping Wang
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures , Nanjing University , Nanjing 210023 , China
| | - Andrzej Rajca
- Department of Chemistry , University of Nebraska , Lincoln , Nebraska 68588 , United States
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10
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Rottschäfer D, Ho NKT, Neumann B, Stammler HG, van Gastel M, Andrada DM, Ghadwal RS. N-Heterocyclic Carbene Analogues of Thiele and Chichibabin Hydrocarbons. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201713346] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Dennis Rottschäfer
- Anorganische Molekülchemie und Katalyse, Lehrstuhl für Anorganische Chemie und Strukturchemie; Centrum für Molekulare Materialien; Fakultät für Chemie; Universität Bielefeld; Universitätsstr. 25 33615 Bielefeld Germany
| | - Nga Kim T. Ho
- Anorganische Molekülchemie und Katalyse, Lehrstuhl für Anorganische Chemie und Strukturchemie; Centrum für Molekulare Materialien; Fakultät für Chemie; Universität Bielefeld; Universitätsstr. 25 33615 Bielefeld Germany
| | - Beate Neumann
- Anorganische Molekülchemie und Katalyse, Lehrstuhl für Anorganische Chemie und Strukturchemie; Centrum für Molekulare Materialien; Fakultät für Chemie; Universität Bielefeld; Universitätsstr. 25 33615 Bielefeld Germany
| | - Hans-Georg Stammler
- Anorganische Molekülchemie und Katalyse, Lehrstuhl für Anorganische Chemie und Strukturchemie; Centrum für Molekulare Materialien; Fakultät für Chemie; Universität Bielefeld; Universitätsstr. 25 33615 Bielefeld Germany
| | - Maurice van Gastel
- Max Planck Institut für Kohlenforschung; Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany
| | - Diego M. Andrada
- Allgemeine und Anorganische Chemie; Universität des Saarlandes; Campus C4.1 66123 Saarbrücken Germany
| | - Rajendra S. Ghadwal
- Anorganische Molekülchemie und Katalyse, Lehrstuhl für Anorganische Chemie und Strukturchemie; Centrum für Molekulare Materialien; Fakultät für Chemie; Universität Bielefeld; Universitätsstr. 25 33615 Bielefeld Germany
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11
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Rottschäfer D, Ho NKT, Neumann B, Stammler HG, van Gastel M, Andrada DM, Ghadwal RS. N-Heterocyclic Carbene Analogues of Thiele and Chichibabin Hydrocarbons. Angew Chem Int Ed Engl 2018; 57:5838-5842. [DOI: 10.1002/anie.201713346] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Indexed: 12/31/2022]
Affiliation(s)
- Dennis Rottschäfer
- Anorganische Molekülchemie und Katalyse, Lehrstuhl für Anorganische Chemie und Strukturchemie; Centrum für Molekulare Materialien; Fakultät für Chemie; Universität Bielefeld; Universitätsstr. 25 33615 Bielefeld Germany
| | - Nga Kim T. Ho
- Anorganische Molekülchemie und Katalyse, Lehrstuhl für Anorganische Chemie und Strukturchemie; Centrum für Molekulare Materialien; Fakultät für Chemie; Universität Bielefeld; Universitätsstr. 25 33615 Bielefeld Germany
| | - Beate Neumann
- Anorganische Molekülchemie und Katalyse, Lehrstuhl für Anorganische Chemie und Strukturchemie; Centrum für Molekulare Materialien; Fakultät für Chemie; Universität Bielefeld; Universitätsstr. 25 33615 Bielefeld Germany
| | - Hans-Georg Stammler
- Anorganische Molekülchemie und Katalyse, Lehrstuhl für Anorganische Chemie und Strukturchemie; Centrum für Molekulare Materialien; Fakultät für Chemie; Universität Bielefeld; Universitätsstr. 25 33615 Bielefeld Germany
| | - Maurice van Gastel
- Max Planck Institut für Kohlenforschung; Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany
| | - Diego M. Andrada
- Allgemeine und Anorganische Chemie; Universität des Saarlandes; Campus C4.1 66123 Saarbrücken Germany
| | - Rajendra S. Ghadwal
- Anorganische Molekülchemie und Katalyse, Lehrstuhl für Anorganische Chemie und Strukturchemie; Centrum für Molekulare Materialien; Fakultät für Chemie; Universität Bielefeld; Universitätsstr. 25 33615 Bielefeld Germany
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12
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Sakamaki D, Ito A, Tsutsui Y, Seki S. Tetraaza[14]- and Octaaza[18]paracyclophane: Synthesis and Characterization of Their Neutral and Cationic States. J Org Chem 2017; 82:13348-13358. [DOI: 10.1021/acs.joc.7b02437] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Daisuke Sakamaki
- Department of Molecular Engineering,
Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Akihiro Ito
- Department of Molecular Engineering,
Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Yusuke Tsutsui
- Department of Molecular Engineering,
Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Shu Seki
- Department of Molecular Engineering,
Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan
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13
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Iwanaga T, Yamauchi T, Toyota S, Suzuki S, Okada K. Oxidation State-Dependent Intramolecular Electronic Interaction of Carbazole-Based Azacyclophanes with 9,10-Anthrylene Units. J Org Chem 2017; 82:10699-10703. [DOI: 10.1021/acs.joc.7b01688] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Tetsuo Iwanaga
- Department
of Chemistry, Faculty of Science, Okayama University of Science, 1-1 Ridaicho, Kita-ku, Okayama 700-0005, Japan
| | - Tomokazu Yamauchi
- Department
of Chemistry, Faculty of Science, Okayama University of Science, 1-1 Ridaicho, Kita-ku, Okayama 700-0005, Japan
| | - Shinji Toyota
- Department
of Chemistry, School of Science, Tokyo Institute of Technology, 2-12-1
Ookayama, Meguro-ku, Tokyo 152−8551, Japan
| | - Shuichi Suzuki
- Department
of Chemistry, Graduate School of Science, Osaka City University, Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan
| | - Keiji Okada
- Department
of Chemistry, Graduate School of Science, Osaka City University, Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan
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14
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Tan G, Wang X. Isolable Bis(triarylamine) Dications: Analogues of Thiele's, Chichibabin's, and Müller's Hydrocarbons. Acc Chem Res 2017; 50:1997-2006. [PMID: 28731693 DOI: 10.1021/acs.accounts.7b00229] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Since the pioneering work by Thiele and Chichibabin, who synthesized the first diradicals bridged by phenylene and biphenylene groups in 1904 and 1907, respectively, numerous efforts have been devoted to synthesizing stable diradicals during the last few decades, and several strategies have been developed to stabilize these highly reactive diradicals. In this Account, we describe the synthesis and characterization of isolable bis(triarylamine) dications, nitrogen analogues of Thiele's, Chichibabin's, and Müller's hydrocarbons, which represent facilely accessible, stable diradicals by replacing carbinyl centers with isoelectronic aminium centers. Along with discussing the molecular structures and electronic structures of the isolated bis(triarylamine) dications, their spectroscopic and magnetic properties are also introduced. Since 2011, we have reported the stabilization of a variety of radical cations bearing the weakly coordinating anion Al(ORF)4- (RF = polyfluorinated alkyl group), which we have recently successfully applied for the stabilization and crystallization of bis(triarylamine) dications, analogues of Thiele's, Chichibabin's, and Müller's hydrocarbons. Prior to our and Kamada's work, there have been only three stable bis(triarylamine) dications isolated in the solid state. The facile access of bis(triarylamine) dications in their crystalline forms allowed us to pursue a deep investigation of their solid-state structures, electronic structures, and physical properties. Similar to their hydrocarbon analogues, bis(triarylamine) dications possess characteristic resonance structures between open-shell singlet (OS) diradicals and closed-shell (CS) quinoidal forms. The combination of single-crystal X-ray diffraction (XRD) analysis and density functional theory (DFT) calculations has proved to be a robust strategy to gain a better understanding of the electronic structures of the obtained diradicals. The structural parameters obtained from XRD analysis reflect the overall contribution of each resonance structure to the crystal structure. The comparison of the parameters from the crystal structures with those from DFT calculations for the pure electronic configurations (CS, OS, and triplet states) affords an overview of the ground-state structures of the diradicals. To justify the "degree" of singlet diradical character, the diradical parameter y is applied, which is estimated by the occupancy of the lowest unoccupied natural orbital (LUNO) having antibonding nature (y = 0 for the closed-shell and y = 1 for the pure singlet diradical). In addition, magnetic susceptibility measurements serve as a practical experimental method to determine the singlet-triplet energy gaps of the isolable diradical dications. Through detailed studies on isolable bis(triarylamine) dications, magnetic bistability caused by intramolecular electron-exchange interactions was observed. Moreover, we also found that the singlet-triplet energy gaps of the diradicals could be thermally controlled. These investigations highlight the potential of bis(triarylamine) dications as building blocks for functional materials.
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Affiliation(s)
- Gengwen Tan
- State Key Laboratory of Coordination Chemistry,
School of Chemistry and Chemical Engineering, Collaborative Innovation
Center of Advanced Microstructures, Nanjing University, Nanjing 210023, China
| | - Xinping Wang
- State Key Laboratory of Coordination Chemistry,
School of Chemistry and Chemical Engineering, Collaborative Innovation
Center of Advanced Microstructures, Nanjing University, Nanjing 210023, China
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15
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Kurata R, Sakamaki D, Uebe M, Kinoshita M, Iwanaga T, Matsumoto T, Ito A. Isolable Triradical Trication of Hexaaza[16]paracyclophane with Embedded 9,10-Anthrylenes: A Frustrated Three-Spin System. Org Lett 2017; 19:4371-4374. [DOI: 10.1021/acs.orglett.7b02088] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ryohei Kurata
- Department of Molecular
Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Daisuke Sakamaki
- Department of Molecular
Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Masashi Uebe
- Department of Molecular
Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Mariko Kinoshita
- Department of Molecular
Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Tetsuo Iwanaga
- Department of Chemistry, Faculty of Science, Okayama University of Science, 1-1 Ridaicho, Kita-ku, Okayama 700-0005, Japan
| | - Takashi Matsumoto
- X-ray Research Laboratory, Rigaku Corporation, Matsubara-cho 3-9-12, Akishima, Tokyo 196-8666, Japan
| | - Akihiro Ito
- Department of Molecular
Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan
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