1
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Jiang Z, Kuninobu Y. Synthesis of a novel twisted π-conjugated macrocycle via double Friedel-Crafts reaction and its physical properties. Chem Commun (Camb) 2024; 60:7642-7645. [PMID: 38963239 DOI: 10.1039/d4cc00890a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/05/2024]
Abstract
We synthesized a cyclic molecule from diarylalkynes and Meldrum's acid derivatives as the methylenation reagent via double Friedel-Crafts reaction. Single-crystal X-ray structure analysis confirmed the twisted structure of the molecule. We also investigated their physical properties and homoconjugation by UV-Vis, photoluminescence, DFT and TD-DFT calculations.
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Affiliation(s)
- Zhiyan Jiang
- 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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Borstelmann J, Schneider L, Rominger F, Deschler F, Kivala M. Helically Chiral π-Expanded Azocines Through Regioselective Beckmann Rearrangement and Their Charged States. Angew Chem Int Ed Engl 2024; 63:e202405570. [PMID: 38716767 DOI: 10.1002/anie.202405570] [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: 03/21/2024] [Indexed: 06/16/2024]
Abstract
We report a synthetic approach to π-expanded [6]helicenes incorporating tropone and azocine units in combination with a 5-membered ring, which exhibit intriguing structural, electronic, and chiroptical properties. The regioselective Beckmann rearrangement allows the isolation of helical scaffolds containing 8-membered lactam, azocine, and amine units. As shown by X-ray crystallographic analysis, the incorporation of tropone or azocine units leads to highly distorted [6]helicene moieties, with distinct packing motifs in the solid state. The compounds exhibit promising optoelectronic properties with considerable photoluminescence quantum yields and tunable emission wavelengths depending on the relative position of the nitrogen center within the polycyclic framework. Separation of the enantiomers by chiral high-performance liquid chromatography (HPLC) allowed characterization of their chiroptical properties by circular dichroism (CD) and circularly polarized luminescence (CPL) spectroscopy. The azocine compounds feature manifold redox chemistry, allowing for the characterization of the corresponding radical anions and cations as well as the dications and dianions, with near-infrared (NIR) absorption bands extending beyond 3000 nm. Detailed theoretical studies provided insights into the aromaticity evolution upon reduction and oxidation, suggesting that the steric strain prevents the azocine unit from undergoing aromatization, while the indene moiety dominates the observed redox chemistry.
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Affiliation(s)
- Jan Borstelmann
- Organisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Lars Schneider
- Physikalisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 253, 69120, Heidelberg, Germany
| | - Frank Rominger
- Organisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Felix Deschler
- Physikalisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 253, 69120, Heidelberg, Germany
| | - Milan Kivala
- Organisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
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3
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Xu Y, Leung MY, Yan L, Chen Z, Li P, Cheng YH, Chan MHY, Yam VWW. Synthesis, Characterization, and Resistive Memory Behaviors of Highly Strained Cyclometalated Platinum(II) Nanohoops. J Am Chem Soc 2024; 146:13226-13235. [PMID: 38700957 DOI: 10.1021/jacs.4c01243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2024]
Abstract
Strained carbon nanohoops exhibit attractive photophysical properties due to their unique π-conjugated structure. However, incorporation of such nanohoops into the pincer ligand of metal complexes has rarely been explored. Herein, a new family of highly strained cyclometalated platinum(II) nanohoops has been synthesized and characterized. Strain-promoted C-H bond activation has been observed during the metal coordination process, and Hückel-Möbius topology and random-columnar packing in the solid state are found. Transient absorption spectroscopy revealed the size-dependent excited state properties of the nanohoops. Moreover, the nanohoops have been successfully employed as active materials in the fabrication of solution-processable resistive memory devices, including the use of the smallest platinum(II) nanohoop for the fabrication of a binary memory, with low switching threshold voltages of ca. 1.5 V, high ON/OFF current ratios, and good stability. These results demonstrate that strain incorporation into the structure can be an effective strategy to fundamentally fine-tune the reactivity, optoelectronic, and resistive memory properties.
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Affiliation(s)
- Youzhi Xu
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong 999077, P. R. China
| | - Ming-Yi Leung
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong 999077, P. R. China
| | - Liangliang Yan
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong 999077, P. R. China
| | - Ziyong Chen
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong 999077, P. R. China
| | - Panpan Li
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong 999077, P. R. China
| | - Yat-Hin Cheng
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong 999077, P. R. China
| | - Michael Ho-Yeung Chan
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong 999077, P. R. China
| | - Vivian Wing-Wah Yam
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong 999077, P. R. China
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4
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Brouillac C, McIntosh N, Heinrich B, Jeannin O, De Sagazan O, Coulon N, Rault‐Berthelot J, Cornil J, Jacques E, Quinton C, Poriel C. Grafting Electron-Accepting Fragments on [4]cyclo-2,7-carbazole Scaffold: Tuning the Structural and Electronic Properties of Nanohoops. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2309115. [PMID: 38251412 PMCID: PMC10987112 DOI: 10.1002/advs.202309115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2023] [Indexed: 01/23/2024]
Abstract
Since the first applications of nanohoops in organic electronics appear promising, the time has come to go deeper into their rational design in order to reach high-efficiency materials. To do so, systematic studies dealing with the incorporation of electron-rich and/or electron-poor functional units on nanohoops have to be performed. Herein, the synthesis, the electrochemical, photophysical, thermal, and structural properties of two [4]cyclo-2,7-carbazoles, [4]C-Py-Cbz, and [4]C-Pm-Cbz, possessing electron-withdrawing units on their nitrogen atoms (pyridine or pyrimidine) are reported. The synthesis of these nanohoops is first optimized and a high yield above 50% is reached. Through a structure-properties relationship study, it is shown that the substituent has a significant impact on some physicochemical properties (eg HOMO/LUMO levels) while others are kept unchanged (eg fluorescence). Incorporation in electronic devices shows that the most electrically efficient Organic Field-Effect transistors are obtained with [4]C-Py-Cbz although this compound does not present the best-organized semiconductor layer. These experimental data are finally confronted with the electronic couplings between the nanohoops determined at the DFT level and have highlighted the origin in the difference of charge transport properties. [4]C-Py-Cbz has the advantage of a more 2D-like transport character than [4]C-Pm-Cbz, which alleviates the impact of defects and structural organization.
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Affiliation(s)
| | - Nemo McIntosh
- Laboratory for Chemistry of Novel MaterialsUniversity of MonsMonsB‐7000Belgium
| | - Benoît Heinrich
- Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS)UMR 7504CNRS‐Université de Strasbourg23 rue du Loess, BP 43, Cedex 2Strasbourg67034France
| | | | | | | | | | - Jérôme Cornil
- Laboratory for Chemistry of Novel MaterialsUniversity of MonsMonsB‐7000Belgium
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5
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Liu Q, Onishi K, Miyazawa Y, Wang Z, Hatano S, Abe M. Energetically More Stable Singlet Cyclopentane-1,3-diyl Diradical with π-Single Bonding Character than the Corresponding σ-Single Bonded Compound. J Am Chem Soc 2023. [PMID: 37967336 DOI: 10.1021/jacs.3c10971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2023]
Abstract
Carbon-carbon σ-single bonds are crucial for constructing molecules like ethane derivatives (R3C-CR3), which are composed of tetrahedral four-coordinate carbons. Molecular functions, such as light absorption or emission, originate from the π-bonds existing in ethylene derivatives (R2C═CR2). In this study, a relatively stable cyclopentane-1,3-diyl species with π-single bonding system (C-π-C) with planar four-coordinate carbons is constructed. This diradicaloid is energetically more stable than the corresponding σ-single bonding system. The π-electron single bonding system provides deeper insights into the chemical bonding and the physical properties derived from the small energy gaps between the bonding and antibonding molecular orbitals.
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Affiliation(s)
- Qian Liu
- Department of Chemistry, Graduate School of Advanced Science and Engineering, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Hiroshima, Japan
| | - Keita Onishi
- Department of Chemistry, Graduate School of Advanced Science and Engineering, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Hiroshima, Japan
| | - Yuki Miyazawa
- Department of Chemistry, Graduate School of Advanced Science and Engineering, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Hiroshima, Japan
| | - Zhe Wang
- Department of Chemistry, Graduate School of Advanced Science and Engineering, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Hiroshima, Japan
| | - Sayaka Hatano
- Department of Chemistry, Graduate School of Advanced Science and Engineering, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Hiroshima, Japan
| | - Manabu Abe
- Department of Chemistry, Graduate School of Advanced Science and Engineering, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Hiroshima, Japan
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6
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Hou B, Li K, He H, Hu J, Xu Z, Xiang Q, Wang P, Chen X, Sun Z. Stable Crystalline Nanohoop Radical and Its Self-Association Promoted by van der Waals Interactions. Angew Chem Int Ed Engl 2023; 62:e202301046. [PMID: 36754831 DOI: 10.1002/anie.202301046] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 02/07/2023] [Accepted: 02/08/2023] [Indexed: 02/10/2023]
Abstract
A stable nanohoop radical (OR3) combining the structures of cycloparaphenylene and an olympicenyl radical is synthesized and isolated in the crystalline state. X-ray crystallographic analysis reveals that OR3 forms a unique head-to-tail dimer that further aggregates into a one-dimensional chain in the solid state. Variable-temperature NMR and concentration-dependent absorption measurements indicate that the π-dimer is not formed in solution. An energy decomposition analysis indicates that van der Waals interactions are the driving force for the self-association process, in contrast with other olympicenyl derivatives that favor π-dimerization. The physical properties in solution phase have been studied, and the stable cationic species obtained by one-electron chemical oxidation. This study offers a new molecular design to modulate the self-association of organic radicals for overcoming the spin-Peierls transition, and to prepare novel nanohoop compounds with spin-related properties.
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Affiliation(s)
- Bingxia Hou
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin university, 92 Weijin Road, Tianjin, 300072, China
| | - Ke Li
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin university, 92 Weijin Road, Tianjin, 300072, China
| | - Huijie He
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin university, 92 Weijin Road, Tianjin, 300072, China
| | - Jinlian Hu
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin university, 92 Weijin Road, Tianjin, 300072, China
| | - Zhuofan Xu
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin university, 92 Weijin Road, Tianjin, 300072, China
| | - Qin Xiang
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin university, 92 Weijin Road, Tianjin, 300072, China
| | - Peng Wang
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin university, 92 Weijin Road, Tianjin, 300072, China
| | - Xing Chen
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin university, 92 Weijin Road, Tianjin, 300072, China
| | - Zhe Sun
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin university, 92 Weijin Road, Tianjin, 300072, China
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7
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Sato R, Utagawa A, Fushimi K, Li F, Isono T, Tajima K, Satoh T, Sato SI, Hirata H, Kikkawa Y, Yamamoto T. Molecular Weight-Dependent Oxidation and Optoelectronic Properties of Defect-Free Macrocyclic Poly(3-hexylthiophene). Polymers (Basel) 2023; 15:polym15030666. [PMID: 36771966 PMCID: PMC9920727 DOI: 10.3390/polym15030666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 01/21/2023] [Accepted: 01/24/2023] [Indexed: 01/31/2023] Open
Abstract
The redox behaviors of macrocyclic molecules with an entirely π-conjugated system are of interest due to their unique optical, electronic, and magnetic properties. In this study, defect-free cyclic P3HT with a degree of polymerization (DPn) from 14 to 43 was synthesized based on our previously established method, and its unique redox behaviors arising from the cyclic topology were investigated. Cyclic voltammetry (CV) showed that the HOMO level of cyclic P3HT decreases from -4.86 eV (14 mer) to -4.89 eV (43 mer), in contrast to the linear counterparts increasing from -4.94 eV (14 mer) to -4.91 eV (43 mer). During the CV measurement, linear P3HT suffered from electro-oxidation at the chain ends, while cyclic P3HT was stable. ESR and UV-Vis-NIR spectroscopy suggested that cyclic P3HT has stronger dicationic properties due to the interactions between the polarons. On the other hand, linear P3HT showed characteristics of polaron pairs with multiple isolated polarons. Moreover, the dicationic properties of cyclic P3HT were more pronounced for the smaller macrocycles.
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Affiliation(s)
- Ryohei Sato
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo 060-8628, Japan
| | - Atsuo Utagawa
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo 060-8628, Japan
| | - Koji Fushimi
- Division of Applied Chemistry, Faculty of Engineering, Hokkaido University, Sapporo 060-8628, Japan
| | - Feng Li
- Division of Applied Chemistry, Faculty of Engineering, Hokkaido University, Sapporo 060-8628, Japan
| | - Takuya Isono
- Division of Applied Chemistry, Faculty of Engineering, Hokkaido University, Sapporo 060-8628, Japan
| | - Kenji Tajima
- Division of Applied Chemistry, Faculty of Engineering, Hokkaido University, Sapporo 060-8628, Japan
| | - Toshifumi Satoh
- Division of Applied Chemistry, Faculty of Engineering, Hokkaido University, Sapporo 060-8628, Japan
| | - Shin-ichiro Sato
- Division of Applied Chemistry, Faculty of Engineering, Hokkaido University, Sapporo 060-8628, Japan
| | - Hiroshi Hirata
- Division of Bioengineering and Bioinformatics, Faculty of Information Science and Technology, Hokkaido University, Sapporo 060-0814, Japan
| | - Yoshihiro Kikkawa
- National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba 305-8565, Japan
| | - Takuya Yamamoto
- Division of Applied Chemistry, Faculty of Engineering, Hokkaido University, Sapporo 060-8628, Japan
- Correspondence:
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8
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Hou P, Peschtrich S, Huber N, Feuerstein W, Bihlmeier A, Krummenacher I, Schoch R, Klopper W, Breher F, Paradies J. Impact of Heterocycle Annulation on NIR Absorbance in Quinoid Thioacene Derivatives. Chemistry 2022; 28:e202200478. [PMID: 35254693 PMCID: PMC9314731 DOI: 10.1002/chem.202200478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Indexed: 11/30/2022]
Abstract
The synthesis and characterisation of a homologous series of quinoid sulfur‐containing imidazolyl‐substituted heteroacenes is described. The optoelectronic and magnetic properties were investigated by UV/vis, fluorescence and EPR spectroscopy as well as quantum‐chemical calculations, and were compared to those of the corresponding benzo congener. The room‐temperature and atmospherically stable quinoids display strong absorption in the NIR region between 678 and 819 nm. The dithieno[3,2‐b:2′,3′‐d]thiophene and the thieno[2′,3′:4,5]thieno[3,2‐b]thieno[2,3‐d]thiophene derivatives were EPR active at room temperature. For the latter, variable‐temperature EPR spectroscopy revealed the presence of a thermally accessible triplet state, with a singlet‐triplet separation of 14.1 kJ mol−1.
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Affiliation(s)
- Peng Hou
- Chemistry Department Paderborn University Warburger Straße 100 33098 Paderborn Germany
| | - Sebastian Peschtrich
- Chemistry Department Paderborn University Warburger Straße 100 33098 Paderborn Germany
| | - Nils Huber
- Institute of Physical Chemistry Karlsruhe Institute of Technology (KIT) Kaiserstraße 12 76131 Karlsruhe Germany
| | - Wolfram Feuerstein
- Institute of Inorganic Chemistry Karlsruhe Institute of Technology (KIT) Engesserstraße 15 76131 Karlsruhe Germany
| | - Angela Bihlmeier
- Institute of Physical Chemistry Karlsruhe Institute of Technology (KIT) Kaiserstraße 12 76131 Karlsruhe Germany
| | - Ivo Krummenacher
- Institute of Inorganic Chemistry University of Würzburg Am Hubland 97074 Würzburg Germany
| | - Roland Schoch
- Chemistry Department Paderborn University Warburger Straße 100 33098 Paderborn Germany
| | - Wim Klopper
- Institute of Physical Chemistry Karlsruhe Institute of Technology (KIT) Kaiserstraße 12 76131 Karlsruhe Germany
| | - Frank Breher
- Institute of Inorganic Chemistry Karlsruhe Institute of Technology (KIT) Engesserstraße 15 76131 Karlsruhe Germany
| | - Jan Paradies
- Chemistry Department Paderborn University Warburger Straße 100 33098 Paderborn Germany
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10
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Kimura T, Nakahodo T, Suzuki E, Nakanishi Y, Misaki Y, Ogawa S. Preparation, Structure Determination, and Electrochemical Properties of 4,5‐Dialkylbenzo[1,2‐
d
:4,5‐
d’
]bis[1,2,3]triselenoles and Their Singlet and Triplet‐State Dications. ChemistrySelect 2021. [DOI: 10.1002/slct.202102375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Takeshi Kimura
- Center for Instrumental Analysis Iwate University Morioka 020-8551 Japan
| | - Tsukasa Nakahodo
- Department of Applied Chemistry Kindai University Higashi Osaka 577-8502 Japan
| | - Eiichi Suzuki
- Department of Chemistry and Biological Sciences Faculty of Science and Engineering Iwate University Morioka 020-8551 Japan
| | - Yoshiki Nakanishi
- Department of Physical Science and Materials Engineering Faculty of Science and Engineering Iwate University Morioka 020-8551 Japan
| | - Yohji Misaki
- Department of Applied Chemistry Faculty of Engineering Ehime University Matsuyama 790-8577 Japan
| | - Satoshi Ogawa
- Department of Chemistry and Biological Sciences Faculty of Science and Engineering Iwate University Morioka 020-8551 Japan
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11
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Nukazawa T, Iwamoto T. π-Conjugated species with an unsupported Si-Si π-bond obtained from direct π-extension. Chem Commun (Camb) 2021; 57:9692-9695. [PMID: 34555142 DOI: 10.1039/d1cc04332c] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
1,3-Diethynylbicyclo[1.1.0]tetrasilanes that contain an unsupported bridgehead Si-Si π-bond and ethynyl π-moieties were synthesized by the reaction of a 1,3-dihalobicyclo[1.1.0]tetrasilane with the corresponding lithium acetylide. The substantial bathochromic shift of the longest-wavelength absorption band observed for the phenylethynyl-substituted bicyclo[1.1.0]tetrasilane in the solid state compared to that of the octynyl-substituted derivative suggested the presence of effective π-conjugation between the unsupported Si-Si π and ethynyl π units.
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Affiliation(s)
- Takumi Nukazawa
- Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku, Sendai 980-8578, Japan.
| | - Takeaki Iwamoto
- Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku, Sendai 980-8578, Japan.
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12
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Wang Z, Murata R, Abe M. SOMO-HOMO Conversion in Triplet Cyclopentane-1,3-diyl Diradicals. ACS OMEGA 2021; 6:22773-22779. [PMID: 34514248 PMCID: PMC8427779 DOI: 10.1021/acsomega.1c03125] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 07/22/2021] [Indexed: 06/13/2023]
Abstract
According to the Aufbau principle, singly occupied molecular orbitals (SOMOs) are energetically higher lying than a highest doubly occupied molecular orbital (HOMO) in the electronically ground state of radicals. However, in the last decade, SOMO-HOMO-converted species have been reported in a limited group of radicals, such as distonic anion radicals and nitroxides. In this study, SOMO-HOMO conversion was observed in triplet 2,2-difluorocyclopentane-1,3-diyl diradicals DR3F1, DR4F1, and 2-fluorocyclopentante-1,3-diyl diradical DR3HF1, which contain the anthracyl unit at the remote position. The high HOMO energy in the anthracyl moiety and the low-lying SOMO-1 due to the fluoro-substituent effect are the key to the SOMO-HOMO conversion phenomenon. Furthermore, the cation radical DR3F1 + generated through the one-electron oxidation of DR3F1 was found to be a SOMO-HOMO-converted monoradical.
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Affiliation(s)
- Zhe Wang
- Department
of Chemistry, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan
| | - Ryo Murata
- Department
of Chemistry, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan
| | - Manabu Abe
- Department
of Chemistry, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan
- Hiroshima
University Research Center for Photo-Drug-Delivery-System (HiU-P-DDS), Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan
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13
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Murata R, Wang Z, Miyazawa Y, Antol I, Yamago S, Abe M. SOMO-HOMO Conversion in Triplet Carbenes. Org Lett 2021; 23:4955-4959. [PMID: 34048267 DOI: 10.1021/acs.orglett.1c01137] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this study, the SOMO-HOMO conversion has been shown for the first time in triplet carbenes embedded in cycloparaphenylene units. The high-lying HOMO originating from the curved π-conjugated system and the low-lying SOMO-1 originating due to the small carbene angle are the key to endowing this interesting electronic configuration. Furthermore, simple planar triplet carbenes such as fluorenylidene were found to possess SOMO-HOMO energy-converted electronic configurations.
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Affiliation(s)
- Ryo Murata
- Department of Chemistry, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Hiroshima, Japan
| | - Zhe Wang
- Department of Chemistry, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Hiroshima, Japan
| | - Yuki Miyazawa
- Department of Chemistry, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Hiroshima, Japan
| | - Ivana Antol
- Laboratory for Physical Organic Chemistry, Division of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia
| | - Shigeru Yamago
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Manabu Abe
- Department of Chemistry, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Hiroshima, Japan
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