研究者詳細 - 忍久保　洋

論文 - 忍久保　洋

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Effect of structural bending on the photophysical properties of perylene bisimide 招待有り査読有り国際誌

Hikaru Sotome, Masahiro Higashi, Yuki Tanaka, Hiroshi Shinokubo, Yasuhiro Kobori, Norihito Fukui

Journal of Chemical Physics 162 巻 ( 11 ) 頁： 114305 2025年3月

Captodative Approach to Stable Nitrogen-Centered Radicals, Anions, and Cations Exhibiting Near-Infrared Electrochromism 査読有り国際共著国際誌 Open Access

Tajima, K; Bucher, C; Shimizu, D; Fukui, N; Shinokubo, H

JACS AU 2025年3月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：JACS Au

Redox interconversion of the oxidation state of nitrogen via hydrogenation and dehydrogenation represents a powerful strategy for designing stimuli-responsive materials. In sharp contrast, the interconversion of nitrogen centers via electron transfer has been underexplored due to the high reactivity of aminyl radicals (R2N•), amide anions (R2N-), and nitrenium cations (R2N+). Herein, we demonstrate that a captodative approach, i.e., the dual incorporation of electron-donating and electron-accepting units, is effective to stabilize these three classes of nitrogen-centered species within the same molecular scaffold. We synthesized a 9,10-dihydroacridine derivative with nitrogen-doping at the 9-position and imide-substitution at the 2,3- and 6,7-positions. This molecule afforded an aminyl radical upon hydrogen abstraction with PbO2. The injection or removal of an electron of the aminyl radical furnished the corresponding amide anion and nitrenium cation, respectively. The aminyl radical, amide anion, and nitrenium cation exhibit significant stability under ambient conditions. Redox interconversion between the amide anion and nitrenium cation results in a drastic change in near-infrared (NIR) absorption due to switching of the local aromaticity of the central six-membered ring. These attractive properties lead to electrochromism in the NIR region (up to 1050 nm) between the closed-shell species.

DOI： 10.1021/jacsau.5c00037

その他リンク： https://doi.org/10.1021/jacsau.5c00037

Synthesis and Properties of Donor-Acceptor-Type Cyclobisbiphenylenecarbonyls 査読有り国際誌

Nishimoto, E; Ikai, T; Shinokubo, H; Fukui, N

CHEMISTRY-A EUROPEAN JOURNAL 31 巻 ( 15 ) 頁： e202404194 2025年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Chemistry - A European Journal

The scalable synthesis of figure-eight π-systems is challenging for the conventional bottom-up approach. We have recently reported that the oxidative inner-bond cleavage of commercially available dibenzo[g,p]chrysene efficiently furnishes a figure-eight π-acceptor, cyclobisbiphenylenecarbonyl (CBBC), in large quantity. Furthermore, its donor–acceptor-type derivative with four N-carbazolyl substituents at the meta-positions of the carbonyl groups exhibited thermally activated delayed fluorescence (TADF) and circularly polarized luminescence (CPL) with a high |gCPL| value of 1.0×10−2. Herein, we synthesized nine donor–acceptor-type CBBC derivatives by changing the donor substituents and their positions. Compared to previously reported carbazole-substituted CBBC, tetramethylcarbazole- and 9,10-dihydro-9,9-dimethylacridine-substituted derivatives exhibited enhanced emission quantum yields and accelerated reverse intersystem crossing. The functionalization of the para-positions of the carbonyl groups resulted in better tunability of emission colors rather than meta-functionalization, whose color variation ranges from light blue to red. The incorporation of bulky substituents at the meta-positions of the carbonyl groups induced the conformational change to a distorted ring structure. Investigation of the substituent effect on the chiroptical properties revealed that the introduction of less bulky donor units such as carbazole at the meta-positions of the carbonyl groups is effective in achieving high |gCPL| values.

DOI： 10.1002/chem.202404194

その他リンク： https://chemistry-europe.onlinelibrary.wiley.com/doi/10.1002/chem.202404194

Diradical character view of energy stabilization in π-stacked dimers of antiaromatic molecules 査読有り国際誌 Open Access

Sugimori, R; Kishi, R; Shinokubo, H; Kitagawa, Y

CHEMISTRY LETTERS 53 巻 ( 12 ) 頁： upae224 2024年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Chemistry Letters

We theoretically examined the energy stabilization mechanism of closely π-stacked dimers of antiaromatic molecules from the viewpoint of diradical character (y). Quantum chemical calculations for π-stacked dimer models of cyclobutadienes and Ni(II) norcorroles revealed that the balance between the destabilization due to structural deformation in each monomer and the stabilization due to intermolecular orbital interaction between 4nπ systems and dispersion force determined the stabilization in the π-dimer structures.

DOI： 10.1093/chemle/upae224

その他リンク： https://doi.org/10.1093/chemle/upae224

Catalytic Construction of Stereogenic Boron Center on BODIPY via Enantioselective Suzuki–Miyaura Coupling 査読有り国際誌

Aiko Kondo, Hideaki Takano, Hiroshi Shinokubo

Chemistry Letters 2024年11月

Bowl-Shaped Anthracene-Fused Antiaromatic Ni(II) Norcorrole: Synthesis, Structure, Assembly with C60, and Photothermal Conversion 査読有り国際誌

Wang, KS; Ghosh, A; Shimizu, D; Takano, H; Ishida, M; Kishi, R; Shinokubo, H

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION 64 巻 ( 7 ) 頁： e202419289 2024年11月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Angewandte Chemie - International Edition

The synthesis of bowl-shaped antiaromatic molecules is challenging because the molecular distortion further destabilizes these already inherently reactive molecules. Here, we report the synthesis and properties of bowl-shaped fused anthrylnorcorroles that exhibit near-infrared (NIR) absorption reaching 1900 nm. The oxidation of meso-anthryldibromodipyrrin provides fused anthryldibromodipyrrin, which was converted to the fused mono- and bisanthrylnorcorroles through Ni(0)-mediated intramolecular coupling with a bis(dibromodipyrrin) Ni(II) complex. Single-crystal X-ray diffraction analyses revealed bowl-shaped structures for the fused mono- and bisanthrylnorcorroles, which enables them to act as suitable receptors for C60 with bonding constants of 2.89×103 M−1 and 1.59×103 M−1, respectively. The formation of a 1 : 1 complex between the fused monoanthrylnorcorrole and C60 was confirmed by single-crystal X-ray diffraction analysis. The effective expansion of the π-conjugation through the triple fusion of the norcorrole with the anthracene units substantially enhances the near-infrared absorption bands, which endows these anthrylnorcorroles with effective photothermal conversion.

DOI： 10.1002/anie.202419289

その他リンク： https://onlinelibrary.wiley.com/doi/10.1002/anie.202419289

Zig-zag-fused π-extended BODIPYs via gold-catalysed cycloisomerisation 招待有り査読有り国際誌

Ohashi, F; Takano, H; Shinokubo, H

Chemical Communications 60 巻 ( 88 ) 頁： 12892 - 12895 2024年11月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Chemical Communications

π-Extension of the BODIPY core is an effective strategy to modulate the physical properties of BODIPYs. However, π-extension on the zig-zag edge of BODIPYs remains unexplored. Here, we disclose the synthesis of zig-zag-fused BODIPYs through gold-catalysed cycloisomerisation. The obtained BODIPYs show fascinating photophysical properties including near-infrared absorption and emission.

DOI： 10.1039/d4cc04416a

Synthesis and electron-transporting properties of phenazine bisimides 査読有り国際誌

Tajima, K; Moribe, T; Matsuo, K; Yamada, H; Seki, S; Yokokura, S; Shimada, T; Fukui, N; Shinokubo, H

JOURNAL OF MATERIALS CHEMISTRY C 13 巻 ( 2 ) 頁： 655 - 662 2024年10月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Materials Chemistry C

The dual incorporation of imide substituents and imine-type nitrogen atoms into π-systems represents an emerging guideline for the design of robust and high-performance n-type semiconductors. Herein, we have adapted this strategy to a simple molecular motif: anthracene, and thus synthesized phenazine bisimides (PzBIs). PzBIs exhibit superior electron affinity compared to anthracene bisimide and phenazine due to the presence of two types of functional electron-withdrawing units. The existence of imine-type nitrogen atoms in PzBI leads to the formation of two-dimensionally extended brickwork arrangements while anthracene bisimide forms one-dimensionally slipped-stacked arrays. Consequently, the electron mobility of the vacuum-deposited film of N,N′-dicyclohexyl PzBI is ten times higher than that of the corresponding anthracene bisimide. Furthermore, the OFET device of N,N′-bisheptafluorobutyl PzBI exhibits good air persistency, and its intrinsic electron mobility has been estimated to be approximately 0.7 cm2 V−1 s−1 by the time-resolved microwave conductivity measurement. The current study demonstrates that the dual incorporation strategy endows even a simple and small π-system with good performance as an n-type semiconductor.

DOI： 10.1039/d4tc03306j

Synthesis of four regioisomeric Ni(II) azacorroles via oxidative ring-expansion of prefunctionalised norcorroles 査読有り国際共著国際誌

Li, S; Zhang, SW; Ohtake, K; Shinokubo, H; Li, XF

ORGANIC CHEMISTRY FRONTIERS 11 巻 ( 20 ) 頁： 5928 - 5937 2024年10月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Organic Chemistry Frontiers

We explored the synthesis of four regioisomeric formylated and brominated azacorroles via oxidative insertion of prefunctionalised Ni(ii) norcorroles. We also found that the reaction of Ni(ii) azacorroles with the Vilsmeier reagent afforded 2- and 3-formylazacorroles. The structures of all the products were characterised thoroughly by high-resolution mass spectrometry, NMR and UV-vis absorption spectroscopy together with X-ray diffraction analysis. The synthesis of four regioisomers of formyl- and bromoazacorroles allowed a detailed study of the substituent effect depending on the position of the functionality.

DOI： 10.1039/d4qo01415d

Inner-Bond-Cleavage Approach to Figure-Eight Macrocycles from Planar Aromatic Hydrocarbons 査読有り国際共著国際誌

Yoshina, R; Hirano, J; Nishimoto, E; Sakamoto, Y; Tajima, K; Minabe, S; Uyanik, M; Ishihara, K; Ikai, T; Yashima, E; Omine, T; Ishiwari, F; Saeki, A; Kim, J; Oh, J; Kim, D; Liu, GT; Yasuda, T; Shinokubo, H; Fukui, N

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 146 巻 ( 43 ) 頁： 29383 - 29390 2024年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of the American Chemical Society

Figure-eight-shaped nonplanar π-systems adopt distinctive chiral D2-symmetric structures, which are ideal for realizing efficient circularly polarized luminescence (CPL). However, the short-step and enantioselective synthesis of figure-eight π-systems represents a considerable challenge for the conventional bottom-up synthetic strategy. Herein, we report that the oxidative cleavage of the internal double bond of a commercially available polycyclic aromatic hydrocarbon, i.e., dibenzo[g,p]chrysene (DBC), catalytically affords a figure-eight electron-accepting macrocycle, i.e., cyclobisbiphenylenecarbonyl (CBBC), with high scalability (up to 3.3 g) and excellent enantioselectivity (94% ee). This inner-bond-cleavage approach also applies to larger PAHs, affording highly distorted molecular frameworks that comprise two figure-eight subunits. Furthermore, we demonstrate that the peripheral functionalization of CBBC with carbazole afforded donor-acceptor-type emitter, which shows thermally activated delayed fluorescence and emits CPL with a g value of 1.0 × 10-2. This g value is ten times higher than those of previously reported chiral TADF-active emitters for circularly polarized organic light-emitting diodes. These results demonstrate that oxidative inner-bond cleavage is a powerful synthetic strategy for creating innovative materials that incorporate molecules with figure-eight structures.

DOI： 10.1021/jacs.4c07985

An n-type semiconducting diazaporphyrin-based hydrogen-bonded organic framework 査読有り国際誌

Sakurai, T; Tanabe, T; Iguchi, H; Li, ZW; Matsuda, W; Tsutsui, Y; Seki, S; Matsuda, R; Shinokubo, H

CHEMICAL SCIENCE 15 巻 ( 32 ) 頁： 12922 - 12927 2024年8月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Chemical Science

Significant effort has been devoted to the development of materials that combine high electrical conductivity and permanent porosity. This paper discloses a diazaporphyrin-based hydrogen-bonded organic framework (HOF) with porosity and n-type semiconductivity. A 5,15-diazaporphyrin Ni(ii) complex with carboxyphenyl groups at the meso positions afforded a HOF due to hydrogen-bonding interactions between the carboxy groups and meso-nitrogen atoms. The thermal and chemical stabilities of the HOF were examined using powder X-ray diffraction analysis, and the charge-carrier mobility was determined to be 2.0 × 10−7 m2 V−1 s−1 using the flash-photolysis time-resolved microwave conductivity (FP-TRMC) method. An analogous diazaporphyrin, which does not form a HOF, exhibited mobility that was 20 times lower. The results presented herein highlight the crucial role of hydrogen-bonding networks in achieving conductive pathways that can tolerate thermal perturbation.

DOI： 10.1039/d4sc03455d

その他リンク： https://doi.org/10.1039/D4SC03455D

Radical reactivity of antiaromatic Ni(II) norcorroles with azo radical initiators 招待有り査読有り国際誌

Shafie, SA; Nozawa, R; Takano, H; Shinokubo, H

BEILSTEIN JOURNAL OF ORGANIC CHEMISTRY 20 巻頁： 1967 - 1972 2024年8月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Beilstein Journal of Organic Chemistry

Norcorrole is a stable 16π-antiaromatic porphyrinoid that exhibits characteristic reactivities and physical properties. Here, we disclose the reaction of Ni(II) norcorroles with alkyl radicals derived from azo radical initiators. The radical selectively attacked the distal α-position relative to the meso-position to construct a nonaromatic bowl-shaped structure. The photophysical and electrochemical properties of the obtained radical adducts were compared to those of the parent Ni(II) norcorrole. The radical reactivity of Ni(II) norcorroles was investigated by density functional theory (DFT) calculations.

DOI： 10.3762/bjoc.20.172

Ultrafine Spatial Modulation of Diazapyrene-Based Two-Dimensional Conjugated Covalent Organic Frameworks 査読有り国際共著国際誌

Li, ZW; Tsuneyuki, T; Paitandi, RP; Nakazato, T; Odawara, M; Tsutsui, Y; Tanaka, T; Miyake, Y; Shinokubo, H; Takagi, M; Shimazaki, T; Tachikawa, M; Suzuki, K; Kaji, H; Ghosh, S; Seki, S

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 146 巻 ( 33 ) 頁： 23497 - 23507 2024年8月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of the American Chemical Society

Tailormade bottom-up synthesis of covalent organic frameworks (COFs) from various functional building blocks offer not only tunable topology and pore size but also multidimensional properties. High crystallinity is one of the prerequisites for their structures and associated physicochemical properties. Among different π-conjugated motifs for constructing COFs, pyrene-based tetragonal structures are effective in achieving highly ordered and crystalline states. In the present research, we demonstrated that the substitution of pyrene with 2,7-diazapyrene produces nearly “flat” structures of two-dimensional (2D) COF layers by controlling the torsional angle of linker molecules. Featuring finite pore diameters and excellent thermodynamic stability of ∼500 °C, ordered face-to-face (slipped AA) stacking arrangements were produced. Extended electrical conjugation spanning 2D frames with modest optical bandgaps (Eg) of ∼2.1 eV shows the planar character of diazapyrene-based COFs. The stacking of the conjugated 2D frames with small Eg values is also beneficial for the formation of highly stable conducting pathways in the crystalline state, which was confirmed by the results of the microwave conductivity measurements. Nitrogen centers in diazapyrene units also play a key role as the active sites for proton transfer, and the maximum proton conductivity of σ = 10-2 S cm-1 was achieved along the cocontinuous nanopore structures surrounded by the active sites. Results show that tetragonal COFs based on diazapyrene can be used as a highly crystalline two-dimensional material with special electrical and proton-conducting capabilities.

DOI： 10.1021/jacs.4c07091

Homochiral and Heterochiral Self-Sorting Assemblies of Antiaromatic Ni(II) Norcorrole Dimers 査読有り国際誌

Liu, SY; Li, S; Ukai, S; Nozawa, R; Fukui, N; Sugimori, R; Kishi, R; Shinokubo, H

CHEMISTRY-A EUROPEAN JOURNAL 30 巻 ( 39 ) 頁： e202400292 2024年7月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Chemistry - A European Journal

Recently, π–π stacked antiaromatic π-systems have received considerable attention because they can exhibit stacked-ring aromaticity due to substantial intermolecular orbital interactions. Here, we report three antiaromatic norcorrole dimers that self-assemble to form supramolecular architectures through chiral self-sorting. A 2,2’-linked norcorrole dimer with 3,5-di-tert-butylphenyl groups forms a π-stacked dimer both in solid and solution states via homochiral self-sorting. Its association constant in solution is (3.6±1.7)×105 M−1 at 20 °C. In the solid state, 3,3’-linked norcorrole dimers with 3,5-di-tert-butylphenyl and phenyl groups afford macrocyclic and helical supramolecular assemblies via heterochiral and homochiral self-sorting, respectively. Notably, the subtle modification in the substituent resulted in a complete change in the structure of the aggregates and the chiral self-sorting mode. The present findings demonstrate that structural manipulation in antiaromatic monomer units leads to the formation of various supramolecular assemblies on the basis of the attractive interactions between antiaromatic π-systems.

DOI： 10.1002/chem.202400292

Synthesis of sterically congested double helicene by alkyne cycloisomerization 招待有り査読有り国際誌

Hirano, J; Miyoshi, S; Yashima, E; Ikai, T; Shinokubo, H; Fukui, N

CHEMICAL COMMUNICATIONS 60 巻 ( 47 ) 頁： 6035 - 6038 2024年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Chemical Communications

Alkyne cycloisomerization of 2,7,10,15-tetra(ortho-alkynylphenyl)benzo[g,p]chrysene containing bulky 4-alkoxy-2,6-dimethylphenyl groups at the alkyne terminals selectively proceeded at the sterically crowded bay-region. The obtained double helicene adopts a distorted structure with a high racemization barrier due to the intramolecular steric repulsion.

DOI： 10.1039/d4cc01573h

End-to-End Bent Perylene Bisimide Cyclophanes by Double Sulfur Extrusion 査読有り国際誌

Tanaka, Y; Tajima, K; Kusumoto, R; Kobori, Y; Fukui, N; Shinokubo, H

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 146 巻 ( 23 ) 頁： 16332 - 16339 2024年5月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of the American Chemical Society

Bending inherently planar π-cores consisting of only six-membered rings has traditionally been challenging because a powerful transformation is required to compensate for the significant strain energy associated with bending. Herein, we demonstrate that sulfur extrusion can achieve substantial molecular bending of a perylene structure to form a substructure of a Vögtle belt, a proposed yet hitherto elusive carbon nanotube fragment. Bent perylene bisimide (PBI) derivatives were synthesized through a double-sulfur-extrusion reaction from the corresponding sulfur-containing V-shaped precursors with an internal alkyl tether. The effect of bending the inherently planar PBI core, which is a recent topic of interest for the design of advanced organic electronic and optoelectronic materials, was investigated systematically. Increasing the curvature leads to a red shift in the absorption and emission spectra, while the fluorescence quantum yields remain high. This stands in contrast with the nonemissive features of previously reported nonplanar PBI derivatives based on conjugative tethers. Detailed photophysical measurements indicated that the increasing curvature with shorter alkyl tethers (i) slightly facilitates intersystem crossing and (ii) significantly suppresses the internal conversion in the excited state of the present bent PBI derivatives. The latter characteristics originate from the restricted dynamic motion associated with the charge-transfer (CT) character between the core chromophores and the N-aryl units.

DOI： 10.1021/jacs.4c05358

その他リンク： https://doi.org/10.1021/jacs.4c05358

Norcorroles as antiaromatic π-electronic systems that form dimension-controlled assemblies 査読有り国際誌

Ishikawa, S; Yamasumi, K; Sugiura, S; Sato, S; Watanabe, G; Koo, YH; Seki, S; Bando, Y; Haketa, Y; Shinokubo, H; Maeda, H

CHEMICAL SCIENCE 15 巻 ( 20 ) 頁： 7603 - 7609 2024年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Royal Society of Chemistry (RSC)

<jats:p>Norcorroles with 3,4,5-trialkoxyphenyl moieties were synthesized to form thermotropic liquid crystals (LCs), in which triple-decker stacking structures were formed. The LC state exhibited discotic columnar structures to exhibit high electric conductivity.</jats:p>

DOI： 10.1039/d4sc01633e

Changing aromatic properties through stacking: the face-to-face dimer of Ni(II) bis(pentafluorophenyl)norcorrole 査読有り国際共著国際誌

Wang, Q; Sundholm, D; Gauss, J; Nottoli, T; Lipparini, F; Kino, S; Ukai, S; Fukui, N; Shinokubo, H

PHYSICAL CHEMISTRY CHEMICAL PHYSICS 26 巻 ( 20 ) 頁： 14777 - 14786 2024年5月

担当区分：最終著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Physical Chemistry Chemical Physics

Nuclear magnetic resonance (NMR) shielding constants have been calculated for Ni(ii) bis(pentafluorophenyl)norcorrole and its face-to-face stacked dimer at the Hartree-Fock (HF), second-order Møller-Plesset perturbation theory (MP2), complete-active-space self-consistent-field (CASSCF) levels as well as at density functional theory (DFT) levels using several functionals. The calculated 1H NMR shielding constants agree rather well with the experimental ones. The shielding constants of N and Ni calculated at DFT, HF, and MP2 levels differ from those obtained in the CASSCF calculations due to near-degeneracy effects at the Ni atom. The calculated magnetically induced current densities show that the monomer is antiaromatic, sustaining a strong global paratropic ring current, and the dimer is aromatic, sustaining a strong diatropic ring current. Qualitatively the same current density is obtained at the employed levels of theory. The most accurate ring-current strengths are probably obtained at the MP2 level. The aromatic dimer has a short intermolecular distance of less than 3 Å. The intermolecular interaction changes the nature of the frontier orbitals leading to a formal double bond between the norcorrole macrocycles.

DOI： 10.1039/d4cp00968a

Inner-bond-cleavage approach to figure-eight macrocycles from planar aromatic hydrocarbons 査読有り国際誌

Reiji Yoshina, Junichiro Hirano, Emiko Nishimoto, Yuki Sakamoto, Keita Tajima, Shunsuke Minabe, Muhammet Uyanik, Kazuaki Ishihara, Tomoyuki Ikai, Eiji Yashima, Takuya Omine, Fumitaka Ishiwari, Akinori Saeki, Jinseok Kim, Juwon Oh, Dongho Kim, Guanting Liu, Takuma Yasuda, Hiroshi Shinokubo, Norihito Fukui

Journal of the American Chemical Society 146 巻頁： 29383 - 29390 2024年5月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：American Chemical Society (ACS)

<jats:p>Contemporary synthetic strategies in organic chemistry rely heavily on the stepwise formation of bonds between fragments of the target compound (‘bottom-up’ approach). Figure-eight aromatic macrocycles represent a considerable challenge for the bottom-up approach, and the lack of versatile synthetic routes to such macrocycles prevents the use of their distinctive chiral D2-symmetric structures in advanced materials. Herein, we demonstrate the oxidative cleavage of internal double bonds of planar polycyclic aromatic hydrocarbons enables the scalable, catalytic, and enantioselective synthesis of figure-eight macrocycles. These macrocycles, with incorporated carbonyl groups, serve as a chiral electron-acceptor unit to furnish a thermally activated delayed fluorescence material with efficient circularly polarized luminescence. The inner-bond-cleavage approach is thus an effective alternative to the bottom-up approach, proving access to hitherto inaccessible materials.</jats:p>

DOI： 10.26434/chemrxiv-2024-j1xxr

A Triply Linked Porphyrin-Norcorrole Hybrid with Singlet Diradical Character 査読有り国際共著国際誌

Wang, KS; Ito, S; Ren, S; Shimizu, D; Fukui, N; Kishi, R; Liu, Q; Osuka, A; Song, JX; Shinokubo, H

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION 63 巻 ( 16 ) 頁： e202401233 2024年4月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Angewandte Chemie - International Edition

Norcorrole Ni(II) complexes have recently received considerable attention because they are readily accessible antiaromatic molecules. Their high stability under ambient conditions and ease of synthesis have enabled the exploration of the intrinsic properties of antiaromatic molecules. Here, we report the synthesis and properties of meso–meso singly linked porphyrin-norcorrole hybrids and a triply linked porphyrin-norcorrole hybrid. The singly linked and triply linked porphyrin-norcorrole hybrids were fully characterized, including an X-ray structural analysis. Due to their orthogonal conformation, the singly linked hybrids maintain the individual electronic properties of their porphyrin and norcorrole subunits, while the triply linked hybrid shows a significantly smaller electrochemical HOMO–LUMO gap (0.45 eV) than that of Ni(II) dimesitylnorcorrole (1.08 eV). Furthermore, the triply linked hybrid exhibits singlet diradical characteristics, as confirmed by VT NMR, ESR, and SQUID experiments.

DOI： 10.1002/anie.202401233

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