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Takase M, Takata T, Oki K, Mori S, Uno H. Substituent effects on paratropicity and diatropicity in π-extended hexapyrrolohexaazacoronene. Chem Sci 2023; 14:7036-7043. [PMID: 37389264 PMCID: PMC10306074 DOI: 10.1039/d2sc07037e] [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: 12/23/2022] [Accepted: 06/04/2023] [Indexed: 07/01/2023] Open
Abstract
Research into the application of antiaromatic compounds as molecular materials is an attractive strategy in the development of electronic materials. Antiaromatic compounds have traditionally been considered to be unstable, and thus, the creation of stable antiaromatic compounds has been sought in the field of organic chemistry. Recently, some studies have been reported on the synthesis, isolation, and elucidation of the physical properties of compounds with stability and definitive antiaromatic properties. In general, antiaromatic compounds are considered to be more susceptible to substituents due to their inherently narrow HOMO-LUMO gap compared to aromatic compounds. However, there have been no studies examining substituent effects in antiaromatic compounds. In this study, we have developed a synthetic method to introduce various substituents into π-extended hexapyrrolohexaazacoronene (homoHPHAC+), one of the stable and clearly antiaromatic compounds, and investigated the substituent effects on the optical, redox, and geometrical properties and paratropicity of a series of compounds. In addition, the properties of the two-electron oxidized form, homoHPHAC3+, were investigated. Control of electronic properties by introducing substituents into antiaromatic compounds provides a new design guideline for molecular materials.
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Affiliation(s)
- Masayoshi Takase
- Graduate School of Science and Engineering, Ehime University Matsuyama 790-8577 Japan
- Research Unit on Molecular Materials Science for Toroidal π-Electron Systems, Ehime University Matsuyama 790-8577 Japan
| | - Toranosuke Takata
- Graduate School of Science and Engineering, Ehime University Matsuyama 790-8577 Japan
| | - Kosuke Oki
- Graduate School of Science and Engineering, Ehime University Matsuyama 790-8577 Japan
| | - Shigeki Mori
- Research Unit on Molecular Materials Science for Toroidal π-Electron Systems, Ehime University Matsuyama 790-8577 Japan
- Advanced Research Support Center (ADRES), Ehime University Matsuyama 790-8577 Japan
| | - Hidemitsu Uno
- Graduate School of Science and Engineering, Ehime University Matsuyama 790-8577 Japan
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2
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Takase M, Sagawa A, Mori S, Okujima T, Uno H. Pyrrole-Fused Azacoronene Analog with Sulfur Embedded in the Outer Periphery. J Org Chem 2023. [PMID: 37256912 DOI: 10.1021/acs.joc.3c00196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The synthesis of sulfur-embedded hexapyrrolohexaazacoronene (HPHAC) analog 2 and its corresponding desulfurized and rearranged compounds was achieved from tetrafluoroisothianaphthene. Structures of all the new π-skeletons were determined by X-ray crystallography. Comparison of the electronic spectrum of 2 with those of its derivatives revealed less involvement of the sulfur atom in π-conjugation. Similar to the reference HPHAC (1), compound 2 and its derivatives exhibited reversible oxidation behavior. The aromaticity of both neutral and dication states has been investigated through DFT calculations.
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Affiliation(s)
- Masayoshi Takase
- Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577, Japan
- Research Unit on Molecular Materials Science for Toroidal π-Electron Systems, Ehime University, Matsuyama 790-8577, Japan
| | - Aiki Sagawa
- Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577, Japan
| | - Shigeki Mori
- Research Unit on Molecular Materials Science for Toroidal π-Electron Systems, Ehime University, Matsuyama 790-8577, Japan
- Advanced Research Support Center, Ehime University, Matsuyama 790-8577, Japan
| | - Tetsuo Okujima
- Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577, Japan
| | - Hidemitsu Uno
- Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577, Japan
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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: 210] [Impact Index Per Article: 105.0] [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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Biagiotti G, Perini I, Richichi B, Cicchi S. Novel Synthetic Approach to Heteroatom Doped Polycyclic Aromatic Hydrocarbons: Optimizing the Bottom-Up Approach to Atomically Precise Doped Nanographenes. Molecules 2021; 26:6306. [PMID: 34684887 PMCID: PMC8537472 DOI: 10.3390/molecules26206306] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 10/11/2021] [Accepted: 10/13/2021] [Indexed: 11/16/2022] Open
Abstract
The success of the rational bottom-up approach to nanostructured carbon materials and the discovery of the importance of their doping with heteroatoms puts under the spotlight all synthetic organic approaches to polycyclic aromatic hydrocarbons. The construction of atomically precise heteroatom doped nanographenes has evidenced the importance of controlling its geometry and the position of the doping heteroatoms, since these parameters influence their chemical-physical properties and their applications. The growing interest towards this research topic is testified by the large number of works published in this area, which have transformed a once "fundamental research" into applied research at the cutting edge of technology. This review analyzes the most recent synthetic approaches to this class of compounds.
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Affiliation(s)
- Giacomo Biagiotti
- Department of Chemistry “Ugo Schiff”, Università di Firenze, Via della Lastruccia 3-13, 50019 Sesto Fiorentino, Italy; (G.B.); (I.P.)
| | - Ilaria Perini
- Department of Chemistry “Ugo Schiff”, Università di Firenze, Via della Lastruccia 3-13, 50019 Sesto Fiorentino, Italy; (G.B.); (I.P.)
| | - Barbara Richichi
- Department of Chemistry “Ugo Schiff”, Università di Firenze, Via della Lastruccia 3-13, 50019 Sesto Fiorentino, Italy; (G.B.); (I.P.)
- National Interuniversity Consortium for Materials Science and Technology (INSTM), Via G. Giusti, 9, 50121 Firenze, Italy
| | - Stefano Cicchi
- Department of Chemistry “Ugo Schiff”, Università di Firenze, Via della Lastruccia 3-13, 50019 Sesto Fiorentino, Italy; (G.B.); (I.P.)
- National Interuniversity Consortium for Materials Science and Technology (INSTM), Via G. Giusti, 9, 50121 Firenze, Italy
- Institute of Chemistry of Organometallic Compounds, ICCOM-CNR, Via Madonna del Piano, 10, 50019 Sesto Fiorentino, Italy
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Sasaki Y, Fujikawa Y, Takase M, Uno H. Black HPHAC: Synthesis and properties of dinitroHPHAC and its reduced global aromaticity in the dication state. J PORPHYR PHTHALOCYA 2021. [DOI: 10.1142/s108842462150098x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Introduction of functional groups on a [Formula: see text]-conjugated system is one of the most promissing methods to modulate their chemical and physical properties. Here, dinitrohexapyrrolohexaazacoronene (dinitroHPHAC) was synthesized, in which two nitro groups are introduced at the same pyrrole ring. The dinitroHPHAC possesses a large dipole moment ([Formula: see text] = 11.7 D at B3LYP/6-31G(d,p)) and showed solvatochromism with decreased HOMO-LUMO energy gap. Interestingly, the colour of the solid is black to the naked eye. The global aromaticity of the dication state is decreased compared with those of pristine HPHAC and mononitroHPHAC.
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Affiliation(s)
- Yoshiki Sasaki
- Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577, Japan
| | - Yoshino Fujikawa
- Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577, Japan
| | - Masayoshi Takase
- Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577, Japan
| | - Hidemitsu Uno
- Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577, Japan
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Oki K, Takase M, Kobayashi N, Uno H. Synthesis and Characterization of Peralkylated Pyrrole-Fused Azacoronene. J Org Chem 2021; 86:5102-5109. [PMID: 33621082 DOI: 10.1021/acs.joc.0c03042] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A hexapyrrolohexaazacoronene (HPHAC) with 12 less-bulky peripheral ethyl groups than its aryl-containing HPHAC counterpart was synthesized to investigate the innate character of HPHAC. X-ray diffraction analysis revealed that HPHAC had a planar structure and close packing because of CH-π interactions between the alkyl groups and the HPHAC core. Compared to the previously reported HPHAC decorated with 12 peripheral aryl groups, this electron-rich π-system exhibited reversible multistep oxidations at low potentials and easily formed mono- and dicationic salts and charge-transfer (CT) complexes with 7,7,8,8-tetracyano-p-quinodimethane. These oxidized species exhibited clear changes in the bond-length alternation of the pyrrole units in the crystal state, indicating charge and spin delocalization. The distinct upfield shift of the central carbon signal of the dication in the 13C NMR spectrum affirms the global aromaticity from the viewpoint of a magnetic criterion. In the UV-vis/NIR spectra, broad absorption in the NIR region was observed only for HPHAC2+ and not the structurally similar cyclo[6]pyrrole. Magnetic circular dichroism measurements and time-dependent density functional theory calculations revealed that the broad absorption was assigned to the CT transition from the central benzene ring to the outer pyrrole rings.
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Affiliation(s)
- Kosuke Oki
- Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577, Japan
| | - Masayoshi Takase
- Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577, Japan
| | - Nagao Kobayashi
- Faculty of Textile Science and Technology, Shinshu University, Ueda 386-8567, Japan
| | - Hidemitsu Uno
- Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577, Japan
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7
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Sasaki Y, Takase M, Kobayashi N, Mori S, Ohara K, Okujima T, Uno H. Radially π-Extended Pyrrole-Fused Azacoronene: A Series of Crystal Structures of HPHAC with Various Oxidation States. J Org Chem 2021; 86:4290-4295. [DOI: 10.1021/acs.joc.0c02825] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Yoshiki Sasaki
- Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577, Japan
| | - Masayoshi Takase
- Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577, Japan
| | - Nagao Kobayashi
- Faculty of Textile Science and Technology, Shinshu University, Ueda 386-8567, Japan
| | - Shigeki Mori
- Advanced Research Support Center, Ehime University, Matsuyama 790-8577, Japan
| | - Keishi Ohara
- Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577, Japan
| | - Tetsuo Okujima
- Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577, Japan
| | - Hidemitsu Uno
- Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577, Japan
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