1
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Freudenberg J, Bunz UHF. How to Stabilize Large Soluble (Hetero-)Acenes. J Am Chem Soc 2024. [PMID: 38862130 DOI: 10.1021/jacs.4c03484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2024]
Abstract
The higher acenes and azaacenes (>(aza)heptacenes) are fascinating, yet elusive materials. Their reactivity and sensitivity increases concomitantly with their size. In recent years, confinement techniques, that is isolation of acenes in matrices and on surfaces, has surpassed solution-based chemistry with respect to accessing the larger (hetero)acenes at the price of the accessibility of no more than a couple thousands of molecules. Isolating acenes in bulk quantities and in processable form is vital for applications in organic electronics as well as from a viewpoint from basic research. In this Perspective, we will discuss after a short historical outline their degradation pathways, and then will selectively highlight recent efforts in stabilizing soluble (aza)acenes.
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Affiliation(s)
- Jan Freudenberg
- Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany
| | - Uwe H F Bunz
- Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany
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2
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Liu X, Jin Z, Qiu F, Guo Y, Chen Y, Sun Z, Zhang L. Hexabenzoheptacene: A Longitudinally Multihelicene Nanocarbon with Local Aromaticity and Enhanced Stability. Angew Chem Int Ed Engl 2024:e202407547. [PMID: 38725308 DOI: 10.1002/anie.202407547] [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: 04/21/2024] [Indexed: 06/13/2024]
Abstract
We report the synthesis of a longitudinally helical molecular nanocarbon, hexabenzoheptacene (HBH), along with its dimethylated derivative (HBH-Me), which are composed of six benzene rings periodically benzannulated to both zigzag edges of a heptacene core. This benzannulation pattern endows the resulting nanocarbons with a helical heptacene core and local aromaticity, imparting enhanced solubility and stability to the system. The chiral HBH-Me adopts a more highly twisted conformation with an end-to-end twist angle of 95°, enabling the separation of the enantiomers. Both HBH and HBH-Me can be facilely oxidized into their corresponding dications, which exhibit enhanced planarity and aromaticity upon loss of electrons. Notably, both longitudinally helical nanocarbons readily promote solid state packing into two-dimensional (2D) arrangement. Single-crystal microbelts of HBH-Me show hole mobility up to 0.62 cm2 V-1 s-1, illustrating the promising potential of these longitudinally helical molecules for organic electronic devices.
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Affiliation(s)
- Xinyue Liu
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, State Key Lab of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing, 100029, P. R. China
| | - Zhengxiong Jin
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, State Key Lab of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing, 100029, P. R. China
| | - Fei Qiu
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, State Key Lab of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing, 100029, P. R. China
| | - Yupeng Guo
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformation, Tianjin University, 92 Weijin Road, Tianjin, 300072, P. R. China
| | - Yan Chen
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, State Key Lab of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing, 100029, P. R. China
| | - Zhe Sun
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformation, Tianjin University, 92 Weijin Road, Tianjin, 300072, P. R. China
| | - Lei Zhang
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, State Key Lab of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing, 100029, P. R. China
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3
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Sun Z, Fan W, Han Y, Yuan W, Ni Y, Wang J, Wei H, Zhao Y, Sun Z, Wu J. Helical fused 1,2:8,9-dibenzozethrene oligomers with up to 201° end-to-end twist: "one-pot" synthesis and chiral resolution. Chem Sci 2023; 14:7922-7927. [PMID: 37502331 PMCID: PMC10370577 DOI: 10.1039/d3sc02285d] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 06/19/2023] [Indexed: 07/29/2023] Open
Abstract
Twisted polyarenes with persistent chirality are desirable but their synthesis has remained a challenge. In this study, we present a "one-pot" synthesis of 1,2:8,9-dibenzozethrene (DBZ) and its vertically fused dimers and trimers using nickel-catalyzed cyclo-oligomerization reactions. X-ray crystallographic analysis confirmed highly twisted helical structures that consist of equal parts left- and right-handed enantiomers. Notably, the end-to-end twist between the terminal anthracene units measured 66°, 130°, and 201° for the DBZ monomer, dimer, and trimer, respectively, setting a new record among twisted polyarenes. Furthermore, the chiral resolution by HPLC yielded two enantiomers for the fused DBZ dimer and trimer, both of which maintained stable configurations and showed absorption dissymmetry factors of around 0.008-0.009. Additionally, their optical and electrochemical properties were investigated, which exhibited a chain-length dependence.
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Affiliation(s)
- Zhitao Sun
- Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University Binhai New City Fuzhou 350507 China
- Department of Chemistry, National University of Singapore 3 Science Drive 3 117543 Singapore
| | - Wei Fan
- 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
| | - Wei Yuan
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University 637371 Singapore
| | - Yong Ni
- Department of Chemistry, National University of Singapore 3 Science Drive 3 117543 Singapore
| | - Jinyi Wang
- Department of Chemistry, National University of Singapore 3 Science Drive 3 117543 Singapore
| | - Haipeng Wei
- Department of Chemistry, National University of Singapore 3 Science Drive 3 117543 Singapore
| | - Yanli Zhao
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University 637371 Singapore
| | - Zhe Sun
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin University Tianjin 300072 China
| | - Jishan Wu
- Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University Binhai New City Fuzhou 350507 China
- Department of Chemistry, National University of Singapore 3 Science Drive 3 117543 Singapore
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4
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Abstract
ConspectusUnderstanding and harnessing the properties of nanoscale molecular entities are considered as new frontiers in basic chemistry. In this regard, synthetic nanographene with atomic precision has attracted much attention recently. For instance, taking advantage of the marvelous bonding capability of carbon, flat, curved, ribbon-type, or cone-shaped nanographenes have been prepared in highly controllable and elegant manner, allowing one to explore fascinating molecular architectures with intriguing optical, electrochemical, and magnetic characteristics. This stands in stark contrast to other carbon-rich nanomaterials, such as graphite oxides or carbon quantum dots, which preclude thorough investigations because of complicate structural defects. Undoubtedly, synthetic nanographene contributes strongly to modern aromatic chemistry and represents a vibrant field that may deliver transforming functional materials crucial for optoelectronics, nanotechnologies, and biomedicine.Nonetheless, in many cases, synthesis and characterization of nanographene compounds are highly demanding. Low solubility, high molecular strain, undesired selectivity, as well as incomplete or excessive C-C bond formation are common impediments, that require formidable efforts to control the molecular geometry, to modulate the edge structure, to achieve accurate doping, or to push the upper size boundary. These endeavors are indispensable for establishing structure-property relationships, and lay down foundation for exploring synthetic nanographenes at a high level of sophistications.In this Account, we summarize our contributions to this field by presenting a series of helical synthetic nanographenes, such as hexapole [7]helicene (H7H), nitrogen-doped H7H, hexapole [9]helicene (H9H), superhelicene, and supertwistacene. This kind of giant synthetic nanographene reaches the size domain of carbon quantum dots, albeit has precise atomic structure. It provides a unique platform to study aromatic chemistry and chirality at the nanoscale. We discuss synthetic methods and point out, in particular, the strengths and pitfalls of Scholl oxidation, which are expected to be valuable for making synthetic nanographenes in general. In addition, we illustrate their exciting electrochemical and photophysical performance, which include, but are not limited to, reversible multielectron redox chemistry, record high panchromatic absorption, impressive photothermal behavior, and extremely strong Cotton effect. These unusual characteristics are convincingly traced back to their three-dimensional conjugated architectures, highlighting the critical roles of π-electron delocalization, heteroatom-doping, substitution, and molecular symmetry in determining nanographenes' properties and functions. Lastly, we put forward our understanding on the challenges and opportunities that lies ahead and hope this Account will inspire ever more ambitious achievements from this attractive area of research.
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Affiliation(s)
- Yanpeng Zhu
- School of Chemistry, Sun Yat-Sen University, Guangzhou 510275, China
| | - Jiaobing Wang
- School of Chemistry, Sun Yat-Sen University, Guangzhou 510275, China
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5
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Matsuoka W, Kawahara KP, Ito H, Sarlah D, Itami K. π-Extended Rubrenes via Dearomative Annulative π-Extension Reaction. J Am Chem Soc 2023; 145:658-666. [PMID: 36563098 PMCID: PMC9837837 DOI: 10.1021/jacs.2c11338] [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: 10/26/2022] [Indexed: 12/24/2022]
Abstract
Among a large variety of organic semiconducting materials, rubrene (5,6,11,12-tetraphenyltetracene) represents one of the most prominent molecular entities mainly because of its unusually high carrier mobility. Toward finding superior rubrene-based organic semiconductors, several synthetic strategies for related molecules have been established. However, despite its outstanding properties and significant attention in the field of materials science, late-stage functionalizations of rubrene remains undeveloped, thereby limiting the accessible chemical space of rubrene-based materials. Herein, we report on a late-stage π-extension of rubrene by dearomative annulative π-extension (DAPEX), leading to the generation of rubrene derivatives having an extended acene core. The Diels-Alder reaction of rubrene with 4-methyl-1,2,4-triazoline-3,5-dione occurred to give 1:1 and 1:2 cycloadducts which further underwent iron-catalyzed annulative diarylation. The thus-formed 1:1 and 1:2 adducts were subjected to radical-mediated oxidation and thermal cycloreversion to furnish one-side and two-side π-extended rubrenes, respectively. These π-extended rubrenes displayed a marked red shift in absorption and emission spectra, clearly showing that the acene π-system of rubrene was extended not only structurally but also electronically. The X-ray crystallographic analysis uncovered interesting packing modes of these π-extended rubrenes. Particularly, two-side π-extended rubrene adopts a brick-wall packing structure with largely overlapping two-dimensional face-to-face π-π interactions. Finally, organic field-effect transistor devices using two-side π-extended rubrene were fabricated, and their carrier mobilities were measured. The observed maximum hole mobility of 1.49 × 10-3 cm2V-1 s-1, which is a comparable value to that of the thin-film transistor using rubrene, clearly shows the potential utility of two-side π-extended rubrene in organic electronics.
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Affiliation(s)
- Wataru Matsuoka
- Department
of Chemistry, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan
| | - Kou P. Kawahara
- Department
of Chemistry, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan
| | - Hideto Ito
- Department
of Chemistry, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan
| | - David Sarlah
- Department
of Chemistry, University of Illinois, Urbana, Illinois 61801, United States
| | - Kenichiro Itami
- Department
of Chemistry, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan
- Institute
of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Nagoya 464-8602, Japan
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6
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Hisada M, Shimizu D, Matsuda K. Heptagon-Embedded π-Expanded Thieno- and N-Methylpyrrolo-Pyridazines with Substantial Out-of-Plane Dipole Moment. J Org Chem 2022; 87:9034-9043. [PMID: 35749313 DOI: 10.1021/acs.joc.2c00709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Herein, we describe the synthesis and characterization of fully fused tetraphenylthieno[3,4-d]pyridazine 1 and N-methylpyrrolo[3,4-d]pyridazine 2 with two embedded seven-membered rings. Owing to the incorporated heptagon, 1 and 2 exhibited Cs-symmetric saddle conformations in the solid state with mean plane deviation around 0.38 Å. π-Expanded thienopyridazine 1 showed a one-dimensional (1-D) columnar packing along the b axis with net dipole moment aligning perpendicular to the b axis in the polar crystal system Pc. On the other hand, 2 formed a partially π-stacked brick-work structure. In addition to the Cs-symmetric saddle conformations found in the crystals, density functional theory (DFT) calculation found C2-symmetric twisted conformations of both 1 and 2 close in energy to the saddle conformations. The barrier of conformational interconversion was calculated to be 32 (1) and 31 kJ·mol-1 (2), and the interconversion occurs fast even at -60 °C as evidenced by variable-temperature (VT)-NMR studies. While 1 and 2 have moderately curved structures, optical and electrochemical studies revealed effective π-conjugation over the fused diphenylene units, which is also supported by DFT calculation. As the result of the intrinsic large dipole moment of thieno- and pyrrolo-pyridazines and the notably curved structure, 1 (2) has a substantial out-of-plane dipole moment of 2.0 (3.3) D in the saddle conformations.
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Affiliation(s)
- Masato Hisada
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Daiki Shimizu
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Kenji Matsuda
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
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7
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Mahlmeister B, Mahl M, Reichelt H, Shoyama K, Stolte M, Würthner F. Helically Twisted Nanoribbons Based on Emissive Near-Infrared Responsive Quaterrylene Bisimides. J Am Chem Soc 2022; 144:10507-10514. [PMID: 35649272 DOI: 10.1021/jacs.2c02947] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Graphene nanoribbons (GNRs) have the potential for next-generation functional devices. So far, GNRs with defined stereochemistry are rarely reported in literature and their optical response is usually bound to the ultraviolet or visible spectral region, while covering the near-infrared (NIR) regime is still challenging. Herein, we report two novel quaterrylene bisimides with either one- or twofold-twisted π-backbones enabled by the steric congestion of a fourfold bay arylation leading to an end-to-end twist of up to 76°. The strong interlocking effect of the π-stacked aryl substituents introduces a rigidification of the chromophore unambiguously proven by single-crystal X-ray analysis. This leads to unexpectedly strong NIR emissions at 862 and 903 nm with quantum yields of 1.5 and 0.9%, respectively, further ensuring high solubility as well as resolvable and highly stable atropo-enantiomers. Circular dichroism spectroscopy of these enantiopure chiral compounds reveals a strong Cotton effect Δε of up to 67 M-1 cm-1 centered far in the NIR region at 849 nm.
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Affiliation(s)
- Bernhard Mahlmeister
- Center for Nanosystems Chemistry (CNC), Universität Würzburg, Würzburg 97074, Germany
| | - Magnus Mahl
- Institut für Organische Chemie, Universität Würzburg, Würzburg 97074, Germany
| | | | - Kazutaka Shoyama
- Institut für Organische Chemie, Universität Würzburg, Würzburg 97074, Germany
| | - Matthias Stolte
- Center for Nanosystems Chemistry (CNC), Universität Würzburg, Würzburg 97074, Germany.,Institut für Organische Chemie, Universität Würzburg, Würzburg 97074, Germany
| | - Frank Würthner
- Center for Nanosystems Chemistry (CNC), Universität Würzburg, Würzburg 97074, Germany.,Institut für Organische Chemie, Universität Würzburg, Würzburg 97074, Germany
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8
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Bergman HM, Beattie DD, Kiel GR, Handford RC, Liu Y, Tilley TD. A sequential cyclization/π-extension strategy for modular construction of nanographenes enabled by stannole cycloadditions. Chem Sci 2022; 13:5568-5573. [PMID: 35694352 PMCID: PMC9116291 DOI: 10.1039/d2sc00397j] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 03/29/2022] [Indexed: 01/16/2023] Open
Abstract
The synthesis of polycyclic aromatic hydrocarbons (PAHs) and related nanographenes requires the selective and efficient fusion of multiple aromatic rings. For this purpose, the Diels–Alder cycloaddition has proven especially useful; however, this approach currently faces significant limitations, including the lack of versatile strategies to access annulated dienes, the instability of the most commonly used dienes, and difficulties with aromatization of the [4 + 2] adduct. In this report we address these limitations via the marriage of two powerful cycloaddition strategies. First, a formal Cp2Zr-mediated [2 + 2 + 1] cycloaddition is used to generate a stannole-annulated PAH. Secondly, the stannoles are employed as diene components in a [4 + 2] cycloaddition/aromatization cascade with an aryne, enabling π-extension to afford a larger PAH. This discovery of stannoles as highly reactive – yet stable for handling – diene equivalents, and the development of a modular strategy for their synthesis, should significantly extend the structural scope of PAHs accessible by a [4 + 2] cycloaddition approach. Stannoles are introduced as a new, spontaneously aromatizing diene for [4 + 2] cycloadditions that can be easily introduced into diverse conjugated systems, facilitating the efficient synthesis of complex PAHs and their π-extension.![]()
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Affiliation(s)
- Harrison M Bergman
- Department of Chemistry, University of California Berkeley California 94720 USA
| | - D Dawson Beattie
- Department of Chemistry, University of California Berkeley California 94720 USA
| | - Gavin R Kiel
- Department of Chemistry, University of California Berkeley California 94720 USA
| | - Rex C Handford
- Department of Chemistry, University of California Berkeley California 94720 USA
| | - Yi Liu
- Molecular Foundry, Lawrence Berkeley National Laboratory Berkeley California 94720 USA
| | - T Don Tilley
- Department of Chemistry, University of California Berkeley California 94720 USA
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9
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Hisada M, Shimizu D, Matsuda K. π-Expansion of 2,3,6,7-Tetraazanaphthalene with Two Embedded Heptagons: Highly Twisted Structure and Lone-Pair/π* Interaction in the Crystal. Org Lett 2022; 24:3707-3711. [PMID: 35561030 DOI: 10.1021/acs.orglett.2c01345] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Synthesis and characterization of doubly diphenylene-fused 2,3,6,7-tetraazanaphthalene 1 are described. Single-crystal X-ray diffraction analysis showed the highly twisted structure of 1 with a degree of twisting of 13.0°/Å, which is one of the largest values for a π-system. In the crystal, molecules of 1 formed an orthogonal one-dimensional column with π-stacking of diphenylene moieties and a short intermolecular C···N distance due to lone-pair/π* interaction, which is a rare example of lone-pair/π* interaction in a supramolecular assembly.
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Affiliation(s)
- Masato Hisada
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Daiki Shimizu
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Kenji Matsuda
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
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10
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Weber JA, Clennan E, Arulsamy N. A Computational Physical Organic Study of a Torque, Lock, and Propagate Approach and Validation with the Synthesis of Configurationally Stable First‐Generation Heli‐Twisted Acenes. European J Org Chem 2022. [DOI: 10.1002/ejoc.202101533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Edward Clennan
- University of Wyoming Dept. of Chemistry Room 403 Physical Building . 82071-3838 Laramie UNITED STATES
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11
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Orozco-Ic M, Valiev RR, Sundholm D. Non-intersecting ring currents in [12]infinitene. Phys Chem Chem Phys 2022; 24:6404-6409. [PMID: 35262148 DOI: 10.1039/d2cp00637e] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The aromaticity of the newly synthesized [12]infinitene is addressed via analysis of the magnetically induced current density and the induced magnetic field. Our calculations reveal that [12]infinitene responds to an external magnetic field by creating two current-density pathways that flow diatropically along the edges of the molecule. The current-density pathways do not intersect. The entire structure is completely shielded suggesting that the infinitene molecule is aromatic, contrary to what the Möbius rule for twisted annulene structures predicts. We also studied the dication of [12]infinitene, which sustains two paratropic ring currents flowing along the edges. The space between the stacked rings at the crossing point is shorter for the dication as compared to the neutral molecule. Hence, a strong through-space current density appears at the crossing point of π-π stacked rings.
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Affiliation(s)
- Mesías Orozco-Ic
- Department of Chemistry, Faculty of Science, University of Helsinki, P.O. Box 55, A. I. Virtasen aukio 1, FIN-00014 Helsinki, Finland.
| | - Rashid R Valiev
- Department of Chemistry, Faculty of Science, University of Helsinki, P.O. Box 55, A. I. Virtasen aukio 1, FIN-00014 Helsinki, Finland. .,Research School of Chemistry and Applied Biomedical Sciences, National Research Tomsk Polytechnic University, Tomsk 634050, Russia
| | - Dage Sundholm
- Department of Chemistry, Faculty of Science, University of Helsinki, P.O. Box 55, A. I. Virtasen aukio 1, FIN-00014 Helsinki, Finland.
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12
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Li X, Zhang S, Chen W, Han H, Qiu M, Chen J, Zhang Q. Relationship Between Molecular Structure, Single crystal Packing and Self-Assembly Behavior: A Case Based on Pyrene Imide Derivatives. Chemistry 2021; 28:e202103808. [PMID: 34812551 DOI: 10.1002/chem.202103808] [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: 10/22/2021] [Indexed: 11/07/2022]
Abstract
Development of new n-type one-dimensional (1D) self-assembly nanostructure and a clear understanding of the relationship between molecular structure and self-assembly behavior are important prerequisites for further designing and optimizing organic optoelectronic nanodevice. In this article, a series of n-type organic semiconductor materials based on pyrene imide were successfully synthesized through [4+2] cycloaddition reactions and their preliminary optical and electrochemical properties were studied. The simulated HOMO-LUMO bandgaps via DFT tallied with the experimental data well. The self-assembly of these materials showed needle or fiber-like morphologies, indicating that different conjugation degree or alkyl group had significant influence on their self-assembly behaviors. Furthermore, the single-crystal packing for these molecules were analyzed and it was found out that the changes of conjugated backbone and functional group would affect certain crystal lattice parameter significantly, such as the intermolecular packing distance and crystal size etc, which would further result in different self-assembly morphology.
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Affiliation(s)
- Xiaojun Li
- School of South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, 510006, P. R. China
| | - Shilong Zhang
- School of South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, 510006, P. R. China
| | - Wangqiao Chen
- School of South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, 510006, P. R. China
| | - Hongjing Han
- School of South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, 510006, P. R. China
| | - Meizhen Qiu
- School of South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, 510006, P. R. China
| | - Jiawen Chen
- School of South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, 510006, P. R. China
| | - Qichun Zhang
- Department of Materials Science and Engineering, City University of Hong Kong, Hong Kong, 999077, P. R. China.,Center of Super-Diamond and Advanced Films (COSDAF), City University of Hong Kong, Hong Kong, 999077, P. R. China
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13
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Tsurusaki A, Kamikawa K. Multiple Helicenes Featuring Synthetic Approaches and Molecular Structures. CHEM LETT 2021. [DOI: 10.1246/cl.210409] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Akihiro Tsurusaki
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
| | - Ken Kamikawa
- Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
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14
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Ishigaki Y, Sugawara K, Tadokoro T, Hayashi Y, Harimoto T, Suzuki T. Redox-active tetraaryldibenzoquinodimethanes. Chem Commun (Camb) 2021; 57:7201-7214. [PMID: 34169942 DOI: 10.1039/d1cc02260a] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Quinodimethanes (QDs) are a class of non-aromatic π-conjugated compounds that are well-known to be interconvertible scaffolds in many response systems. While parent ortho- and para-QDs (o-QD and p-QD) can be easily converted to benzocyclobutenes or oligomers/polymers by the formation of C-C bonds at α-positions, the attachment of four phenyl groups to these reactive sites makes o-Ph4QD and p-Ph4QD long-lived. We have demonstrated that further dibenzo-annulation of such tetraaryl QD units also drastically increases their stability, and many tetraarylated dibenzoquinodimethane derivatives have been developed. This Feature Article shows our milestones in creating functional redox systems, where drastic changes in structure occur upon electron transfer (dynamic redox "dyrex" behaviour).
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Affiliation(s)
- Yusuke Ishigaki
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan.
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15
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Ishigaki Y, Harimoto T, Sugawara K, Suzuki T. Hysteretic Three-State Redox Interconversion among Zigzag Bisquinodimethanes with Non-fused Benzene Rings and Twisted Tetra-/Dications with [5]/[3]Acenes Exhibiting Near-Infrared Absorptions. J Am Chem Soc 2021; 143:3306-3311. [PMID: 33636078 DOI: 10.1021/jacs.1c00189] [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
Octaaryl-substituted bisquinodimethanes (BQDs) with a zigzag structure were designed as redox-switchable molecules that undergo four-electron oxidation to produce tetracationic pentacenes with a doubly twisted structure. In contrast to one-stage four-electron oxidation of BQDs, stepwise two-electron reduction of tetracationic pentacenes occurs to give dicationic anthracenes and then the original BQDs, step-by-step. Since both tetracations and dications exhibit near-infrared (NIR) absorptions (-1400 nm) based on an intramolecular charge-transfer interaction, changes in not only their structures but also their UV-vis-NIR spectra can be controlled by redox stimuli. In this Communication, we present an unprecedented one-step π-extension to pentacene from non-fused benzene rings by oxidation, and subsequent two-stage deannulation to benzene rings via anthracene upon reduction. All structures were determined by single-crystal X-ray analyses, and their properties were characterized by spectroscopic and theoretical studies.
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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
| | - Kazuma Sugawara
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Takanori Suzuki
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
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16
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Clegg W. Distortions, deviations and alternative facts: reliability in crystallography. IUCRJ 2021; 8:4-11. [PMID: 33520238 PMCID: PMC7793003 DOI: 10.1107/s205225252001458x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 11/04/2020] [Indexed: 05/26/2023]
Abstract
This feature article is derived from the author's presentation of the Lonsdale lecture at the BCA Spring Meeting in 2018. One of the research results for which Kathleen Lonsdale is best known was her 1929 demonstration that the benzene ring in crystalline hexa-methyl-benzene is planar and has essentially hexagonal symmetry, resolving decades of dispute among organic chemists. More recent crystallographic studies of hexa-methyl-benzene have shown that there are actually small deviations from planarity. Such deviations for aromatic compounds may be due to electronic, steric, and/or intermolecular factors. Some substituted benzene molecules display remarkably large deviations, both from a planar ring structure and from regular hexagonal angular geometry around the ring. Starting from this specific connection with Kathleen Lonsdale's research, a number of stories are recounted of structural distortions and deviations from expected results and explanations that have been suggested for them, across a wide range of chemical topics including macrocycles, metal clusters, unusual coordination geometry and isomerism. On the way we find genuine surprises and results that have led to new understanding, but also examples of poor experiments, misinterpretation of data, scientific bias and preconceived ideas, incompetence and even deliberate fraud. Some aspects of structure validation are discussed. While showcasing some interesting research in its own right, this account also serves an educational purpose.
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Affiliation(s)
- William Clegg
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
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17
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Ma S, Gu J, Lin C, Luo Z, Zhu Y, Wang J. Supertwistacene: A Helical Graphene Nanoribbon. J Am Chem Soc 2020; 142:16887-16893. [PMID: 32900184 DOI: 10.1021/jacs.0c08555] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
This work describes a synthetic chiral graphene nanoribbon, named supertwistacene 1. It has four superbenzene (HBC) units linearly fused in a helical manner. The structure of 1, 4.3 nm in length, with an end-to-end twist of 117°, was confirmed by single-crystal X-ray diffraction. In contrast to various twistacene compounds and their analogues, 1 has a very stable configuration. It resists thermal isomerization even when being heated at 200 °C for 16 h. Enantiopure 1 obtained by chiral HPLC shows distinct CD signals in a broad spectral range until 600 nm. In addition, two smaller congeners of 1, the trimer 2 and the dimer 3, were also prepared and systematically investigated. Combining theoretical and experimental studies on 1-3 presents a big picture on their (chir)optical and electronic characteristics.
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Affiliation(s)
- Shuang Ma
- School of Chemistry, Sun Yat-Sen University, Guangzhou 510275, China
| | - Jiajian Gu
- School of Chemistry, Sun Yat-Sen University, Guangzhou 510275, China
| | - Chaojun Lin
- School of Chemistry, Sun Yat-Sen University, Guangzhou 510275, China
| | - Zhixing Luo
- School of Chemistry, Sun Yat-Sen University, Guangzhou 510275, China
| | - Yanpeng Zhu
- School of Chemistry, Sun Yat-Sen University, Guangzhou 510275, China
| | - Jiaobing Wang
- School of Chemistry, Sun Yat-Sen University, Guangzhou 510275, China
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18
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Müller M, Maier S, Tverskoy O, Rominger F, Freudenberg J, Bunz UHF. Tetrabenzononacene: "Butterfly Wings" Stabilize the Core. Angew Chem Int Ed Engl 2020; 59:1966-1969. [PMID: 31724294 PMCID: PMC7004125 DOI: 10.1002/anie.201909614] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 10/24/2019] [Indexed: 11/29/2022]
Abstract
In combination with bulky substituents at the core, fourfold benzannulation at the cata‐positions stabilizes a nonacene sufficiently to allow its isolation and characterization by 1H NMR and X‐ray analysis. The four benzo units blueshift the absorption spectrum in comparison to a solely linear nonacene, but significantly increase the stability in the solid state.
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Affiliation(s)
- Matthias Müller
- Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Steffen Maier
- Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Olena Tverskoy
- Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Frank Rominger
- Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Jan Freudenberg
- Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany.,InnovationLab, Speyerer Straße 4, 69115, Heidelberg, Germany
| | - Uwe H F Bunz
- Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany.,Centre for Advanced Materials, Im Neuenheimer Feld 225, 69120, Heidelberg, Germany
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19
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Liu G, Xiao C, Negri F, Li Y, Wang Z. Dodecatwistarene Imides with Zigzag-Twisted Conformation for Organic Electronics. Angew Chem Int Ed Engl 2020; 59:2008-2012. [PMID: 31736203 DOI: 10.1002/anie.201912356] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Indexed: 11/07/2022]
Abstract
1D nonplanar graphene nanoribbons generally have three possible conformers: helical, zigzag, and mixed conformations. Now, a kind of 1D nonplanar graphene nanoribbon, namely dodecatwistarene imides featuring twelve linearly fused benzene rings, was obtained by bottom-up synthesis of palladium-catalyzed Stille coupling and C-H activation. Single-crystal X-ray diffraction analyses revealed that it displays a zigzag-twisted conformation caused by steric hindrance between imide groups and neighboring annulated benzene rings with the pendulum angle of 53°. This conformation is very stable and could not convert into other conformations even when heated up to 250 °C for 6 h. Despite of the highly twisted topology, organic field-effect transistor based on it exhibits electron mobility up to 1.5 cm2 V-1 s-1 after annealing.
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Affiliation(s)
- Guogang Liu
- Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
- School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Chengyi Xiao
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Fabrizia Negri
- Dipartimento di Chimica "G. Ciamician", Università di Bologna, Via F. Selmi, 2, 40126, Bologna, Italy
| | - Yan Li
- Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
- School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhaohui Wang
- Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
- Key Laboratory of Organic Optoelectronics and Molecular Engineering, Department of Chemistry, Tsinghua University, Beijing, 100084, China
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20
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Imran M, Wehrmann CM, Chen MS. Open-Shell Effects on Optoelectronic Properties: Antiambipolar Charge Transport and Anti-Kasha Doublet Emission from a N-Substituted Bisphenalenyl. J Am Chem Soc 2019; 142:38-43. [DOI: 10.1021/jacs.9b10677] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Muhammad Imran
- Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015-3102, United States
| | - Caleb M. Wehrmann
- Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015-3102, United States
| | - Mark S. Chen
- Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015-3102, United States
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21
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Müller M, Maier S, Tverskoy O, Rominger F, Freudenberg J, Bunz UHF. Tetrabenzononacene: “Butterfly Wings” Stabilize the Core. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201909614] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Matthias Müller
- Organisch-Chemisches InstitutRuprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Steffen Maier
- Organisch-Chemisches InstitutRuprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Olena Tverskoy
- Organisch-Chemisches InstitutRuprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Frank Rominger
- Organisch-Chemisches InstitutRuprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Jan Freudenberg
- Organisch-Chemisches InstitutRuprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Germany
- InnovationLab Speyerer Straße 4 69115 Heidelberg Germany
| | - Uwe H. F. Bunz
- Organisch-Chemisches InstitutRuprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Germany
- Centre for Advanced Materials Im Neuenheimer Feld 225 69120 Heidelberg Germany
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22
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Liu G, Xiao C, Negri F, Li Y, Wang Z. Dodecatwistarene Imides with Zigzag‐Twisted Conformation for Organic Electronics. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201912356] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Guogang Liu
- Key Laboratory of Organic SolidsInstitute of ChemistryChinese Academy of Sciences Beijing 100190 China
- School of Chemistry and Chemical EngineeringUniversity of Chinese Academy of Sciences Beijing 100049 China
| | - Chengyi Xiao
- State Key Laboratory of Organic-Inorganic CompositesBeijing University of Chemical Technology Beijing 100029 China
| | - Fabrizia Negri
- Dipartimento di Chimica “G. Ciamician”Università di Bologna Via F. Selmi, 2 40126 Bologna Italy
| | - Yan Li
- Key Laboratory of Organic SolidsInstitute of ChemistryChinese Academy of Sciences Beijing 100190 China
- School of Chemistry and Chemical EngineeringUniversity of Chinese Academy of Sciences Beijing 100049 China
| | - Zhaohui Wang
- Key Laboratory of Organic SolidsInstitute of ChemistryChinese Academy of Sciences Beijing 100190 China
- Key Laboratory of Organic Optoelectronics and Molecular EngineeringDepartment of ChemistryTsinghua University Beijing 100084 China
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23
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Ishigaki Y, Hayashi Y, Suzuki T. Photo- and Thermal Interconversion of Multiconfigurational Strained Hydrocarbons Exhibiting Completely Switchable Oxidation to Stable Dicationic Dyes. J Am Chem Soc 2019; 141:18293-18300. [PMID: 31630518 DOI: 10.1021/jacs.9b09646] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Highly strained hydrocarbons with two di/tribenzocycloheptatriene units were designed as electrochromic overcrowded ethylenes that undergo reversible interconversion with stable dicationic dyes. Due to severe steric repulsion, two configurational isomers (anti,anti-folded and syn,anti-folded forms) were isolated as stable entities. Photo- and thermal interconversion of these isomers proceeded cleanly: one-way photoisomerization occurred from anti,anti- to syn,anti-form and one-way thermal isomerization was observed from syn,anti- to anti,anti-form. Even though both isomers undergo two-electron oxidation into the same twisted dications, quite different oxidation potentials enable completely selective oxidation of syn,anti-isomers. Thus, the present multiconfigurational strained hydrocarbons are capable of switching of activation/deactivation of their electrochromic properties by light/heat.
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Affiliation(s)
- Yusuke Ishigaki
- Department of Chemistry, Faculty of Science , Hokkaido University , Sapporo 060-0810 , Japan
| | - Yuki Hayashi
- Department of Chemistry, Faculty of Science , Hokkaido University , Sapporo 060-0810 , Japan
| | - Takanori Suzuki
- Department of Chemistry, Faculty of Science , Hokkaido University , Sapporo 060-0810 , Japan
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24
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Dyan OT, Borodkin GI, Zaikin PA. The Diels-Alder Reaction for the Synthesis of Polycyclic Aromatic Compounds. European J Org Chem 2019. [DOI: 10.1002/ejoc.201901254] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Ok Ton Dyan
- N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry; 9 Academician Lavrentiev Ave. 630090 Novosibirsk Russian Federation
| | - Gennady I. Borodkin
- N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry; 9 Academician Lavrentiev Ave. 630090 Novosibirsk Russian Federation
- Novosibirsk State University; 630090 Novosibirsk Russian Federation
| | - Pavel A. Zaikin
- N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry; 9 Academician Lavrentiev Ave. 630090 Novosibirsk Russian Federation
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25
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Bedi A, Gidron O. The Consequences of Twisting Nanocarbons: Lessons from Tethered Twisted Acenes. Acc Chem Res 2019; 52:2482-2490. [PMID: 31453688 DOI: 10.1021/acs.accounts.9b00271] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The properties of polycyclic aromatic hydrocarbons are determined by their size, shape, and functional groups. Equally important is their curvature, since deviation from planarity can affect their optical, electronic, and magnetic properties and also induce chirality. Acenes, which can be viewed as one-dimensional nanocarbons, are often twisted out of planarity. Although twisting is expected to affect the above-mentioned properties, it is often overlooked. This Account focuses on helically locked twistacenes (twisted acenes) having different twist angles and the effect of twisting on their electronic and optical properties. Various synthetic approaches to inducing backbone twist in acenes are discussed, with a focus on the introduction of a diagonal tether across the core, as this minimizes confounding substituent effects. Using such tethered acenes as our model, we then discuss the effects of twisting the aromatic core on twistacene properties. Electronic properties. Increasing the degree of twist only slightly affects the HOMO and LUMO energy levels. Twisting leads to a small increase in the HOMO level and a decrease in the LUMO level, which produces an overall decrease in the HOMO-LUMO gap. Optical properties. As the degree of twist increases, a slight bathochromic shift is observed in the absorption spectra, in accordance with the decrease in the HOMO-LUMO gap. The fluorescence quantum efficiency and the fluorescence lifetime also decrease. This is likely to be related to an increasing rate of intersystem crossing, which arises from increased spin-orbit coupling. In addition, computational studies indicate that the S0-T1 energy gap decreases with increasing twist. Chiroptical properties. Increased twisting results in a larger Cotton effect and anisotropy factor, with the anisotropy factors of Ant-Cn being higher than those of longer helicenes. The parallel orientation of electric and magnetic transition dipole moments in twistacenes underlies this behavior and renders them as excellent chiroptical materials. The same trend is observed for the radical cations of twistacenes, which absorb in the NIR spectral region. Conjugation and delocalization. Twisting the anthracene radical cation up to 40° (13° per benzene ring) does not significantly affect spin delocalization, with the EPR spectra of twistacene radical cations showing that only slight localization occurs. This is in line with computational studies, which show only a small decrease in π-overlap for large acene twist. Overall, modifying the length of the tether in diagonally tethered acenes allows chemists to control core twist and to induce chirality. Twisting affects key optical, electronic, and chiroptical properties of acenes. Consequently, controlling the twist angle can improve the future design of nanocarbons with desired properties.
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Affiliation(s)
- Anjan Bedi
- Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Jerusalem 91904, Israel
| | - Ori Gidron
- Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Jerusalem 91904, Israel
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26
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Radtke J, Schickedanz K, Bamberg M, Menduti L, Schollmeyer D, Bolte M, Lerner HW, Wagner M. Selective access to either a doubly boron-doped tetrabenzopentacene or an oxadiborepin from the same precursor. Chem Sci 2019; 10:9017-9027. [PMID: 32874487 PMCID: PMC7442282 DOI: 10.1039/c9sc03115d] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 07/31/2019] [Indexed: 01/05/2023] Open
Abstract
Depending on the solvent, a brominated arylborane gave the multiple helicene B2-TBPA (pyridine) or the oxadiborepin ODBE (THF) after intramolecular Yamamoto coupling.
The well-known red emitter tetrabenzo[de,hi,op,st]pentacene (TBPA) has been transformed into a bright blue emitter (B2-TBPA; λem = 472 nm; c-hexane) via substitutional doping with two boron atoms. In contrast to the electron-rich TBPA, which forms endo-peroxides with O2 under daylight, the benchtop-stable B2-TBPA is a good electron acceptor and undergoes reversible reduction at a moderate half-wave potential of E1/2 = –1.73 V (vs. FcH/FcH+; THF). Although the size of B2-TBPA falls within the nanoscale, the helically twisted compound readily dissolves in c-hexane and does not require solubilizing substituents. The synthesis of B2-TBPA is based on the nickel-mediated Yamamoto-type dehalogenation of tetrabrominated 9,10-di(naphth-1-yl)-9,10-dihydro-9,10-diboraanthracene. This intramolecular C–C heterocoupling reaction shows a remarkable solvent dependence: B2-TBPA forms only in pyridine (79% yield), whereas an oxadiborepin is obtained from THF solutions (ODBE, 81%; the reaction mixture is quenched with air in both cases). Insight into the corresponding reaction mechanism was gained from the isolation of intermediates and an investigation of their chemical properties. ODBE is an interesting blue emitter in its own right. Furthermore, it can be ring-opened with excess BBr3 at the B–O–B moiety to afford a dimeric borabenzo[de]anthracene.
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Affiliation(s)
- Julian Radtke
- Institut für Anorganische Chemie , Goethe-Universität Frankfurt , Max-von-Laue-Strasse 7 , D-60438 Frankfurt (Main) , Germany .
| | - Kai Schickedanz
- Institut für Anorganische Chemie , Goethe-Universität Frankfurt , Max-von-Laue-Strasse 7 , D-60438 Frankfurt (Main) , Germany .
| | - Marcel Bamberg
- Institut für Anorganische Chemie , Goethe-Universität Frankfurt , Max-von-Laue-Strasse 7 , D-60438 Frankfurt (Main) , Germany .
| | - Luigi Menduti
- Institut für Anorganische Chemie , Goethe-Universität Frankfurt , Max-von-Laue-Strasse 7 , D-60438 Frankfurt (Main) , Germany .
| | - Dieter Schollmeyer
- Institute of Organic Chemistry , Johannes Gutenberg University Mainz , Duesbergweg 10-14 , D-55128 Mainz , Germany
| | - Michael Bolte
- Institut für Anorganische Chemie , Goethe-Universität Frankfurt , Max-von-Laue-Strasse 7 , D-60438 Frankfurt (Main) , Germany .
| | - Hans-Wolfram Lerner
- Institut für Anorganische Chemie , Goethe-Universität Frankfurt , Max-von-Laue-Strasse 7 , D-60438 Frankfurt (Main) , Germany .
| | - Matthias Wagner
- Institut für Anorganische Chemie , Goethe-Universität Frankfurt , Max-von-Laue-Strasse 7 , D-60438 Frankfurt (Main) , Germany .
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27
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Bedi A, Carmieli R, Gidron O. Radical cations of twisted acenes: chiroptical properties and spin delocalization. Chem Commun (Camb) 2019; 55:6022-6025. [PMID: 31062015 DOI: 10.1039/c9cc02735a] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We introduce the first series of enantiopure twistacene radical cations, which form reversibly upon chemical or electrochemical oxidation. Their vis-NIR chiroptical properties (Cotton effect and anisotropy factor) increase systematically with the backbone twist. The hyperfine constants observed by EPR demonstrate significant spin delocalization even for large backbone twist angles.
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Affiliation(s)
- Anjan Bedi
- Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Jerusalem 91904, Israel.
| | - Raanan Carmieli
- Chemical Research Support Unit, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Ori Gidron
- Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Jerusalem 91904, Israel.
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28
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Affiliation(s)
- Yonglong Xiao
- Department of ChemistryTulane University New Orleans LA 70118 USA
| | - Joel T. Mague
- Department of ChemistryTulane University New Orleans LA 70118 USA
| | | | - Farihah M. Haque
- Department of ChemistryTulane University New Orleans LA 70118 USA
| | - Robert A. Pascal
- Department of ChemistryTulane University New Orleans LA 70118 USA
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29
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30
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Müller M, Reiss H, Tverskoy O, Rominger F, Freudenberg J, Bunz UHF. Stabilization by Benzannulation: Butterfly Azaacenes. Chemistry 2018; 24:12801-12805. [DOI: 10.1002/chem.201803118] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Indexed: 11/10/2022]
Affiliation(s)
- Matthias Müller
- Organisch-Chemisches Institut; Ruprecht-Karls-Universität Heidelberg; Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Hilmar Reiss
- Organisch-Chemisches Institut; Ruprecht-Karls-Universität Heidelberg; Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Olena Tverskoy
- Organisch-Chemisches Institut; Ruprecht-Karls-Universität Heidelberg; Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Frank Rominger
- Organisch-Chemisches Institut; Ruprecht-Karls-Universität Heidelberg; Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Jan Freudenberg
- Organisch-Chemisches Institut; Ruprecht-Karls-Universität Heidelberg; Im Neuenheimer Feld 270 69120 Heidelberg Germany
- InnovationLab; Speyerer Strasse 4 69115 Heidelberg Germany
| | - Uwe H. F. Bunz
- Organisch-Chemisches Institut; Ruprecht-Karls-Universität Heidelberg; Im Neuenheimer Feld 270 69120 Heidelberg Germany
- Centre of Advanced Materials; Im Neuenheimer Feld 225 69120 Heidelberg Germany
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31
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Abstract
Twisting linear acenes out of planarity affects their electronic and optical properties, and induces chirality. However, it is difficult to isolate the effect of twisting from the substituent effect. Moreover, many twistacenes (twisted acenes) readily racemize in solution. Here, we introduce a series of twistacenes having an anthracene backbone diagonally tethered by an n-alkyl bridge, which induces a twist of various angles. This allows us to systematically monitor the effect of twisting on electronic and optical properties. We find that absorption is bathochromically shifted with increasing twist, while fluorescence quantum efficiency drops dramatically. The tethered twistacenes were isolated to their enantiomerically pure form, displaying strong chiroptical properties and anisotropy factor ( g-value). No racemization was observed even upon prolonged heating, rendering these tethered twistacenes suitable as enantiopure helical building units for π-conjugated backbones.
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Affiliation(s)
- Anjan Bedi
- Institute of Chemistry , The Hebrew University of Jerusalem, Edmond J. Safra Campus , Jerusalem 91904 , Israel
| | - Linda J W Shimon
- Chemical Research Support Unit , Weizmann Institute of Science , Rehovot 76100 , Israel
| | - Ori Gidron
- Institute of Chemistry , The Hebrew University of Jerusalem, Edmond J. Safra Campus , Jerusalem 91904 , Israel
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