研究者詳細 - 忍久保　洋

論文 - 忍久保　洋

分割表示 409 件中 21 - 40 件目／全件表示 >>

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

Close Stacking of Antiaromatic Ni(II) Norcorrole Originating from a Four-Electron Multicentered Bonding Interaction 査読有り国際共著国際誌

Kino, S; Ukai, S; Fukui, N; Haruki, R; Kumai, R; Wang, Q; Horike, S; Phung, QM; Sundholm, D; Shinokubo, H

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 146 巻 ( 13 ) 頁： 9311 - 9317 2024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：American Chemical Society (ACS)

A π-conjugated molecule with one electronic spin often forms a π-stacked dimer through molecular orbital interactions between two unpaired electrons. The bonding is recognized as a multicentered two-electron interaction between the two π-conjugated molecules. Here, we disclose a multicentered bonding interaction between two antiaromatic molecules involving four electrons. We have synthesized an antiaromatic porphyrin analogue, Ni(II) bis(pentafluorophenyl)norcorrole. Its dimer adopts a face-to-face stacked structure with an extremely short stacking distance of 2.97 Å. The close stacking originates from a multicenter four-electron bonding interaction between the two molecules. The bonding electrons were experimentally observed via synchrotron X-ray diffraction analysis and corroborated by theoretical calculations. The intermolecular interaction of the molecular orbitals imparts the stacked dimer with aromatic character that is distinctly different from that of its monomer.

DOI： 10.1021/jacs.4c01142

Interaction strength in molecular junctions consisting of π-stacked antiaromatic molecules 査読有り国際誌

Fujii, S; Tomida, R; Yamane, A; Nabeyama, K; Ohkura, H; Shinokubo, H; Nishino, T

JOURNAL OF MATERIALS CHEMISTRY C 12 巻 ( 5 ) 頁： 1640 - 1643 2024年2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：Royal Society of Chemistry (RSC)

<jats:p>The interaction force was measured as the adhesive force acting between norcorrole molecules anchored to the probe surface and the sample surface. This study reveals substantial interactions in π-stacked antiaromatics at the single-molecule scale.</jats:p>

DOI： 10.1039/d3tc04166b

Excimer Formation Driven by Excited-State Structural Relaxation in a Covalent Aminonaphthalimide Dimer 査読有り国際共著国際誌

Jing, R; Li, Y; Tajima, K; Wan, Y; Fukui, N; Shinokubo, H; Kuang, ZR; Xia, AD

JOURNAL OF PHYSICAL CHEMISTRY LETTERS 15 巻 ( 5 ) 頁： 1469 - 1476 2024年1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)

Strongly coupled excimer formation from interchromophoric charge transfer driven by the ultrafast excited-state structural dynamics of a 5,5′-linked 4-amino-1,8-naphthalimide covalent homodimer was investigated by ultrafast transient spectroscopy and chemical calculations. Theoretical calculations indicate that the structural relaxation associated with the dihedral motion leads to significantly enhanced interchromophoric charge transfer (CT) coupling, which favors the formation of an excimer-like symmetry-broken CT state. The formation and relaxation dynamics of the excimer state in the dimer are identified via ultrafast transient absorption and fluorescence spectroscopy. The structural relaxation following the photoexcitation occurs in tens of picoseconds and stabilizes the dimer to the strongly coupled excimer state. The highly polar solvents further stabilize the excimer state and enhance the CT character, which enable efficient electron and excitation energy transport in covalent molecular aggregates.

DOI： 10.1021/acs.jpclett.3c03337

Synthesis and properties of bay-functionalized 9,9′-bifluorenylidene derivatives 査読有り国際誌

Hirano, J; Shinokubo, H; Fukui, N

CHEMISTRY LETTERS 53 巻 ( 1 ) 頁： upad015 2024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：Oxford University Press (OUP)

<jats:title>Abstract</jats:title> <jats:p>Here, we disclose the effect of substitution at the bay-region of 9,9′-bifluorenylidene on its optical and electrochemical properties. Bay-brominated 9,9′-bifluorenylidene was synthesized by the reductive dimerization of 4,5-dibromofluorenone with triethyl phosphite. The subsequent Suzuki–Miyaura cross-coupling afforded arylated derivatives. X-ray diffraction analysis revealed that the bulky bay-substituents twist the overall structure through the relay of the steric repulsion from the bay-region to the fjord-region. The π-extension at the bay-region with tolyl and 4-dimethylaminophenyl groups increases the electron-donating ability, while the introduction of bromo groups enhances the electron-accepting ability.</jats:p>

DOI： 10.1093/chemle/upad015

その他リンク： https://academic.oup.com/chemlett/article-pdf/53/1/upad015/56961460/upad015.pdf

Syntheses of Thiophene-Thiophene-Linked Corrorin Dimers with Tunable Near-Infrared Absorption and Distinctive Reactivity 査読有り国際共著国際誌

Xu, Y; Zhu, B; Zhang, LF; Baryshnikov, G; Sha, F; Nishimoto, E; Takano, H; Li, CJ; Wu, XY; Ågren, H; Shinokubo, H; Xie, YS; Li, QZ

ORGANIC LETTERS 26 巻 ( 2 ) 頁： 571 - 576 2024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：American Chemical Society (ACS)

Thiahexaphyrinone 1 and thia-dipyrrin-appended corrorin 2 have been synthesized. Surprisingly, further oxidation of compound 2 with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) in dichloromethane afforded dimer 3 with two molecules of compound 2 linked at the α-carbon atoms of the thienyl units. Treatment of compound 3 with DDQ in MeOH and SnCl2 in tetrahydrofuran/H2O afforded the dimethoxy-attached dimer 4 and hydrogenated dihydroxy-attached dimer 5, respectively. These results provide the first examples for synthesizing thiophene-linked porphyrinoid dimers with tunable near-infrared absorption and chirality.

DOI： 10.1021/acs.orglett.3c04323

Metallaantiaromaticity of 10-Platinacorrole Complexes 査読有り国際共著国際誌

Miwa, K; Yokota, T; Wang, Q; Sakurai, T; Fliegl, H; Sundholm, D; Shinokubo, H

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 146 巻 ( 2 ) 頁： 1396 - 1402 2024年1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：American Chemical Society (ACS)

<jats:p>The aromaticity of cyclic π-conjugated organometallic compounds is known as metallaaromaticity. π-Conjugated metallacycles, such as metallabenzenes and metallapentalenes, have been investigated in order to understand the involvement of the d electrons from the metal center in the π-conjugated systems of the organic ligands. Here, we report the synthesis of Pd(II) 10-platinacorrole complexes with cyclooctadiene (COD) and norbornadiene (NBD) ligands. While the Pd(II) 10-platinacorrole COD complex adopts a distorted structure without showing appreciable antiaromaticity, the corresponding NBD complex exhibits distinct antiaromatic character due to its highly planar conformation. Detailed density-functional-theory (DFT) calculations revealed that two d orbitals are involved in the macrocyclic π-conjugation. We furthermore demonstrated that Craig–Möbius antiaromaticity is not present in the studied system. The synthesis of 10-platinacorroles enables the systematic comparison of the antiaromaticity and aromaticity of closely related porphyrin analogues, providing a better understanding of π-conjugation that involves d orbitals.</jats:p>

DOI： 10.1021/jacs.3c10250

Effect of Internal Substituents on the Properties of Dibenzo[<i>g</i>,<i>p</i>]chrysene 査読有り国際誌

Takeo, Y; Hirano, J; Fukui, N; Shinokubo, H

ORGANIC LETTERS 25 巻 ( 47 ) 頁： 8484 - 8488 2023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：American Chemical Society (ACS)

We investigated the chemical and physical properties of internally functionalized dibenzo[g,p]chrysene (DBC) derivatives. These molecules exhibit chiral double-helicene-like structures that are configurationally stable at ambient temperatures. The internal substituents control the conformational change in the excited state, thereby modulating the emission intensity. Notably, the DBC derivative with a methylenedioxy unit undergoes aromatization through elimination of the internal substituent upon photoexcitation, resulting in the formation of DBC.

DOI： 10.1021/acs.orglett.3c03428

Effect of internal oxygen substituents on the properties of bowl-shaped aromatic hydrocarbons 査読有り国際誌

Takeo, Y; Hirano, J; Shimizu, D; Fukui, N; Shinokubo, H

ORGANIC CHEMISTRY FRONTIERS 10 巻頁： 5895 - 5901 2023年10月

Intrinsic Photostability in Dithiolonaphthalimide Achieved by Disulfide Bond-Induced Excited-State Quenching 査読有り国際共著国際誌

Zeming Wang, Rui Jing, Yang Li, Di Song, Yan Wan, Norihito Fukui, Hiroshi Shinokubo, Zhuoran Kuang, Andong Xia

Journal of Physical Chemistry Letters 14 巻 ( 38 ) 頁： 8485 - 8492 2023年9月

Unique solvent effect of water in radical cyclization reaction 査読有り国際誌

Suzuki Sara, Govind Soni Aman, Imamura Kosuke, Yorimitsu Hideki, Shinokubo Hiroshi, Higashi Masahiro, Sato Hirofumi

CHEMICAL PHYSICS LETTERS 826 巻頁： 140641 2023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：Chemical Physics Letters

The radical cyclization reaction in the aqueous environment by Yorimitsu et al. is revisited using the RISM-SCF-cSED method, a hybrid of quantum chemistry and statistical mechanics theory for molecular liquids. The difference between the barrier height of the forward reaction from the intermediate E-rot, the cyclization step, and that of the backward reaction is crucial to the reaction yield. Considering the effect of hydrogen bonding through the RISM theory, we found that the barrier height for the forward reaction is lower, especially in water. In other words, considering microscopic solvation effects clearly shows the difference between water and DMSO solvents, explaining the remarkable acceleration of the reaction in the aqueous environment.

DOI： 10.1016/j.cplett.2023.140641

Easily Switchable 18π-, 19π-, and 20π-Conjugation of Diazaporphyrin Double-Pincer Bispalladium Complexes 査読有り国際誌

Sakurai T., Hiraoka Y., Tanaka H., Miyake Y., Fukui N., Shinokubo H.

Angewandte Chemie - International Edition 62 巻 ( 12 ) 頁： e202300437 2023年2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

NiII 3,7,13,17-tetrapyridyl-5,15-diazaporphyrin serves as a double tridentate ligand to PdII ions to provide a pincer-type bispalladium complex. Electrochemical analysis revealed that the bispalladium complex shows excellent ability to accept electrons and reversible redox properties due to the coordination of the two cationic PdII centers to the meso-nitrogen atoms. We isolated and characterized one- and two-electron reduction species of the bispalladium complex. The 20π antiaromatic nature of the two-electron reduction species was confirmed by 1H NMR spectroscopy, UV/Vis-near-IR (NIR) absorption spectra, and density functional theory (DFT) calculations. X-ray diffraction revealed highly twisted structures for the bispalladium complexes regardless of the oxidation state.

DOI： 10.1002/anie.202300437

その他リンク： https://onlinelibrary.wiley.com/doi/full-xml/10.1002/anie.202300437

Near-Infrared-Responsive Hydrocarbons Designed by π-Extension of Indeno[1,2,3,4-pgra]perylene at the 1,2,12-Positions 査読有り国際共著国際誌

Kato M., Kim J., Oh J., Shimizu D., Fukui N., Shinokubo H.

Chemistry - A European Journal 2023年1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

The relationship between the overall electronic structure of π-conjugated molecules and the arrangement of their constituent elements is of fundamental importance. Establishing rational design guidelines for conjugated hydrocarbons with narrow HOMO-LUMO gaps is useful to develop near-infrared (NIR) responsive dyes and redox-active materials. This study describes the synthesis and properties of three conjugated hydrocarbons, i. e., an indenonaphthoperylene, an indenoterrylene, and a diindenoterrylene. These molecules exhibit NIR absorption despite the absence of significant antiaromaticity and diradical character. Notably, the indenonaphthoperylene exhibits red-to-NIR emission in the 620–850 nm region. The indenoterrylene and the diindenoterrylene exhibit NIR absorption tailing to 870 and 940 nm, respectively. Moreover, the effect of the π-extension of indenoperylene is disclosed in order to propose guidelines for achieving a narrow HOMO-LUMO gap with negligible antiaromaticity and diradical character.

DOI： 10.1002/chem.202300249

Dinaphthooxepine Bisimide Undergoes Oxygen Extrusion Reaction upon Electron Injection at Room Temperature 査読有り国際誌

Odajima Mai, Fukui Norihito, Shinokubo Hiroshi

ORGANIC LETTERS 25 巻 ( 1 ) 頁： 282 - 287 2023年1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：Organic Letters

We report the synthesis and properties of a dinaphthooxepine bisimide (DNOBI), a nonplanar perylene bisimide (PBI) analogue with an inserted oxygen atom. A DNOBI underwent an oxygen-extrusion reaction smoothly upon electron injection at room temperature, affording PBI in good yield. Studies on the reaction mechanism suggest that the injection of two electrons triggers the isomerization of DNOBI to dinaphthooxanorcaradiene bisimide, which is a key step in inducing the oxygen-extrusion reaction.

DOI： 10.1021/acs.orglett.2c04173

One-dimensional stacking array of 10,20-diphenyl-5,15-diazaporphyrin metal complexes 招待有り査読有り国際誌

Mori S., Sakurai T., Nishimura T., Fukui N., Miyake Y., Shinokubo H.

Journal of Porphyrins and Phthalocyanines 27 巻頁： 1035 - 1041 2023年1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 Porphyrins and Phthalocyanines

We prepared a free-base 10,20-diphenyl-5,15-diazaporphyrin and its Ni(II), Cu(II), Pd(II), and Pt(II) complexes. These molecules uniformly form an infinite one-dimensional p-stacking array in the solid state. The four-fold intermolecular hydrogen bonding interactions between the meso-nitrogen atom of the diazaporphyrin core and the ortho-hydrogen atom of the phenyl substituent dominate the crystal packing arrangement. The present study revealed that the meso-nitrogen atom of diazaporphyrins would be used as an inherent hydrogen bonding acceptor to construct supramolecular assemblies.

DOI： 10.1142/s1088424622500997

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