Faculty Profiles - YAMAGUCHI, Shigehiro

Papers - YAMAGUCHI, Shigehiro

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Crystallographic and chiroptical studies on tetraarylferrocenes for use as chiral rotary modules for molecular machines.

Muraoka T, Kinbara K, Wakamiya A, Yamaguchi S, Aida T

Chemistry (Weinheim an der Bergstrasse, Germany) Vol. 13 ( 6 ) page： 1724 - 30 2007

Boron as a key component for new pi-electron materials

Yamaguchi Shigehiro, Wakamiya Atsushi

PURE AND APPLIED CHEMISTRY Vol. 78 ( 7 ) page： 1413 - 1424 2006.7

Bis-silicon-bridged stilbene homologues synthesized by new intramolecular reductive double cyclization

Yamaguchi S, Xu CH, Tamao K

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY Vol. 125 ( 45 ) page： 13662 - 13663 2003.11

Impact of boron desymmetrization on supramolecular polymerization of BODIPY dyes Reviewed International coauthorship Open Access

Tischer, TB; Fernández, Z; Borsdorf, L; Daniliuc, CG; Yamaguchi, S; Ogi, S; Fernández, G

ORGANIC CHEMISTRY FRONTIERS Vol. 12 ( 2 ) page： 414 - 421 2025.1

Secretion of mitochondrial DNA via exosomes promotes inflammation in Behçet's syndrome Reviewed

Konaka, H; Kato, Y; Hirano, T; Tsujimoto, K; Park, J; Koba, T; Aoki, W; Matsuzaki, Y; Taki, M; Koyama, S; Itotagawa, E; Jo, T; Hirayama, T; Kawai, T; Ishii, KJ; Ueda, M; Yamaguchi, S; Akira, S; Morita, T; Maeda, Y; Nishide, M; Nishida, S; Shima, Y; Narazaki, M; Takamatsu, H; Kumanogoh, A

EMBO JOURNAL Vol. 42 ( 20 ) page： e112573 2023.10

A Kinetically Stabilized Nitrogen‐Doped Triangulene Cation: Stable and NIR Fluorescent Diradical Cation with Triplet Ground State Reviewed

Shinobu Arikawa, Akihiro Shimizu, Daisuke Shiomi, Kazunobu Sato, Takeji Takui, Hikaru Sotome, Hiroshi Miyasaka, Masahito Murai, Shigehiro Yamaguchi, Ryo Shintani

Angewandte Chemie International Edition Vol. 62 ( 29 ) page： e202302714 2023.7

Flattened 1D fragments of fullerene C60 that exhibit robustness toward multi-electron reduction Reviewed

Masahiro Hayakawa, Naoyuki Sunayama, Shu I. Takagi, Yu Matsuo, Asuka Tamaki, Shigehiro Yamaguchi, Shu Seki, Aiko Fukazawa

Nature Communications Vol. 14 ( 1 ) page： 2741 2023.5

Language：English Publishing type：Research paper (scientific journal) Publisher：Springer Science and Business Media LLC

Abstract

Fullerenes are compelling molecular materials owing to their exceptional robustness toward multi-electron reduction. Although scientists have attempted to address this feature by synthesizing various fragment molecules, the origin of this electron affinity remains unclear. Several structural factors have been suggested, including high symmetry, pyramidalized carbon atoms, and five-membered ring substructures. To elucidate the role of the five-membered ring substructures without the influence of high symmetry and pyramidalized carbon atoms, we herein report the synthesis and electron-accepting properties of oligo(biindenylidene)s, a flattened one-dimensional fragment of fullerene C<sub>60</sub>. Electrochemical studies corroborated that oligo(biindenylidene)s can accept electrons up to equal to the number of five-membered rings in their main chains. Moreover, ultraviolet/visible/near-infrared absorption spectroscopy revealed that oligo(biindenylidene)s exhibit enhanced absorption covering the entire visible region relative to C<sub>60</sub>. These results highlight the significance of the pentagonal substructure for attaining stability toward multi-electron reduction and provide a strategy for the molecular design of electron-accepting π-conjugated hydrocarbons even without electron-withdrawing groups.

DOI： 10.1038/s41467-023-38300-3

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PubMed

Other Link： https://www.nature.com/articles/s41467-023-38300-3

Manipulation of Spin Polarization in Boron-Substituted Graphene Nanoribbons Invited Reviewed International coauthorship

Kewei Sun, Orlando J. Silveira, Shohei Saito, Keisuke Sagisaka, Shigehiro Yamaguchi, Adam S. Foster, Shigeki Kawai

ACS NANO Vol. 16 ( 7 ) page： 11244 - 11250 2022.6

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

The design of magnetic topological states due to spin polarization in an extended pi carbon system has great potential in spintronics application. Although magnetic zigzag edges in graphene nanoribbons (GNRs) have been investigated earlier, real-space observation and manipulation of spin polarization in a heteroatom substituted system remains challenging. Here, we investigate a zero-bias peak at a boron site embedded at the center of an armchair-type GNR on a AuSiX/Au(111) surface with a combination of low-temperature scanning tunneling microscopy/spectroscopy and density functional theory calculations. After the tip-induced removal of a Si atom connected to two adjacent boron atoms, a clear Kondo resonance peak appeared and was further split by an applied magnetic field of 12 T. This magnetic state can be relayed along the longitudinal axis of the GNR by sequential removal of Si atoms.

DOI： 10.1021/acsnano.2c04563

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PubMed

Late-stage modification of π-electron systems based on asymmetric oxidation of a medium-sized sulfur-containing ring Reviewed

Masahiro Hayakawa, Satoshi Horike, Yuh Hijikata, Kosuke Yasui, Shigehiro Yamaguchi, Aiko Fukazawa

Chemical Communications Vol. 58 ( 15 ) page： 2548 - 2551 2022.2

Bridging pico-to-nanonewtons with a ratiometric force probe for monitoring nanoscale polymer physics before damage. Reviewed International journal

Ryota Kotani, Soichi Yokoyama, Shunpei Nobusue, Shigehiro Yamaguchi, Atsuhiro Osuka, Hiroshi Yabu, Shohei Saito

Nature communications Vol. 13 ( 1 ) page： 303 - 303 2022.1

Language：English Publishing type：Research paper (scientific journal)

Understanding the transmission of nanoscale forces in the pico-to-nanonewton range is important in polymer physics. While physical approaches have limitations in analyzing the local force distribution in condensed environments, chemical analysis using force probes is promising. However, there are stringent requirements for probing the local forces generated before structural damage. The magnitude of those forces corresponds to the range below covalent bond scission (from 200 pN to several nN) and above thermal fluctuation (several pN). Here, we report a conformationally flexible dual-fluorescence force probe with a theoretically estimated threshold of approximately 100 pN. This probe enables ratiometric analysis of the distribution of local forces in a stretched polymer chain network. Without changing the intrinsic properties of the polymer, the force distribution was reversibly monitored in real time. Chemical control of the probe location demonstrated that the local stress concentration is twice as biased at crosslinkers than at main chains, particularly in a strain-hardening region. Due to the high sensitivity, the percentage of the stressed force probes was estimated to be more than 1000 times higher than the activation rate of a conventional mechanophore.

DOI： 10.1038/s41467-022-27972-y

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PubMed

Extended π-Electron Delocalization in Quinoid-Based Conjugated Polymers Boosts Intrachain Charge Carrier Transport

Tsubasa Mikie, Masahiro Hayakawa, Kenta Okamoto, Keitaro Iguchi, Shuhei Yashiro, Tomoyuki Koganezawa, Masatomo Sumiya, Hiroyuki Ishii, Shigehiro Yamaguchi, Aiko Fukazawa, Itaru Osaka

Chemistry of Materials Vol. 33 ( 21 ) page： 8183 - 8193 2021.11

Excited-state conformation capture by supramolecular chains towards triplet-involved organic emitters Reviewed International coauthorship

Hao Liu, Naoki Ando, Shigehiro Yamaguchi, Pan{\v{c } }e Naumov, Hongyu Zhang

Chinese Chemical Letters Vol. 32 ( 5 ) page： 1669 - 1674 2021.5

Organic phosphorescent polymorphs induced by various halogen bonds with stimuli-responsive single/dual phosphorescence switching Reviewed International coauthorship

Hao Liu, Wentao Liu, Naoki Ando, Shigehiro Yamaguchi, Hongyu Zhang

JOURNAL OF MATERIALS CHEMISTRY C Vol. 9 ( 8 ) page： 2738 - 2743 2021.2

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

Herein, we report the first example of two pure organic polymorphs with stimuli-responsive single/dual phosphorescence transformation. By analyzing the crystal structures and theoretical results, it could be understood that efficient intermolecular interactions could restrict the molecular movements and lock distinct molecular conformations, leading to different phosphorescence behaviors. Besides, single/dual phosphorescence could transform into each other by heating or under solvent vapor conditions. Considering such unique properties, logical sensors (AND gate and OR gate) were built by providing different emission colors as inputs. Our work provides not only important information for understanding the dual RTP mechanism but also unique stimuli-responsive pure organic phosphorescent materials to enrich material fields.

DOI： 10.1039/d0tc05468b

Web of Science

Dithieno[a,e]pentalenes: Highly Antiaromatic Yet Stable pi-Electron Systems without Bulky Substituents Reviewed

Junichi Usuba, Masahiro Hayakawa, Shigehiro Yamaguchi, Aiko Fukazawa

CHEMISTRY-A EUROPEAN JOURNAL Vol. 27 ( 5 ) page： 1482 - 1482 2021.1

Dithieno[a,e]pentalenes: Highly Antiaromatic Yet Stable pi-Electron Systems without Bulky Substituents

Junichi Usuba, Masahiro Hayakawa, Shigehiro Yamaguchi, Aiko Fukazawa

CHEMISTRY-A EUROPEAN JOURNAL Vol. 27 ( 5 ) page： 1638 - 1647 2021.1

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-V C H VERLAG GMBH

Dithieno[a,e]penalenes (DTPs) with various substituents were synthesized as a class of antiaromatic compounds. Annulation of thiophene rings imparts the pentalene moiety with high thermal stability even without bulky substituents, while retaining antiaromaticity. The higher magnitude of antiaromaticity in DTPs, in addition to the differences in the electronic structures of the fused aromatic rings, resulted in a narrower HOMO-LUMO gap than that of the corresponding dibenzo[a,e]pentalene analog, giving rise to red-shifted electronic absorption that reaches the near-infrared region. Moreover, systematic investigations on the solid-state packing structure revealed that DTPs prefer offset face-to-face packing motifs rather than face-centered pi-pi stacking. In particular, the thienyl-substituted DTP bearing hydrophilic side chains exhibited thermochromic behavior in polar solvents, which was ascribed to the formation of aggregates.

DOI： 10.1002/chem.202004244

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PubMed

Letters from Japan: Characteristic Approaches to Contemporary Organic Chemistry

Shigehiro Yamaguchi

ORGANIC LETTERS Vol. 22 ( 24 ) page： 9406 - 9407 2020.12

Hydrophobicity-driven folding and seeded polymerization of cystine-based dimeric diamides in aqueous media

Natsumi Fukaya, Soichiro Ogi, Midori Kawashiro, Shigehiro Yamaguchi

CHEMICAL COMMUNICATIONS Vol. 56 ( 85 ) page： 12901 - 12904 2020.11

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

Seeded supramolecular polymerization of cystine-based dimeric diamides with aromatic substituents at the C- and N-termini was achieved in aqueous media. Theoretical and spectroscopic studies reveal that the terminal groups play crucial roles in slowing spontaneous assembly through formation of a folded conformation and guiding molecular alignment in the aggregated state.

DOI： 10.1039/d0cc05255h

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PubMed

Covalent Self-Labeling of Tagged Proteins with Chemical Fluorescent Dyes in BY-2 Cells and Arabidopsis Seedlings([OPEN])

Ryu J. Iwatate, Akira Yoshinari, Noriyoshi Yagi, Marek Grzybowski, Hiroaki Ogasawara, Mako Kamiya, Toru Komatsu, Masayasu Taki, Shigehiro Yamaguchi, Wolf B. Frommer, Masayoshi Nakamura

PLANT CELL Vol. 32 ( 10 ) page： 3081 - 3094 2020.10

Language：English Publishing type：Research paper (scientific journal) Publisher：OXFORD UNIV PRESS INC

Synthetic chemical fluorescent dyes promise to be useful for many applications in biology. Covalent, targeted labeling, such as with a SNAP-tag, uses synthetic dyes to label specific proteins in vivo for studying processes such as endocytosis or for imaging via super-resolution microscopy. Despite its potential, such chemical tagging has not been used effectively in plants. A major drawback has been the limited knowledge regarding cell wall and membrane permeability of the available synthetic dyes. Of 31 synthetic dyes tested here, 23 were taken up into BY-2 cells, while eight were not. This creates sets of dyes that can serve to measure endocytosis. Three of the dyes that were able to enter the cells, SNAP-tag ligands of diethylaminocoumarin, tetramethylrhodamine, and silicon-rhodamine 647, were used to SNAP-tag alpha-tubulin. Successful tagging was verified by live cell imaging and visualization of microtubule arrays in interphase and during mitosis in Arabidopsis (Arabidopsis thaliana) seedlings. Fluorescence activation-coupled protein labeling with DRBG-488 was used to observe PIN-FORMED2 (PIN2) endocytosis and delivery to the vacuole as well as preferential delivery of newly synthesized PIN2 to the actively forming cell plate during mitosis. Together, the data demonstrate that specific self-labeling of proteins can be used effectively in plants to study a wide variety of cellular and biological processes.Multicolor imaging with SNAP-tagged tubulin and monitoring of PIN2 endocytosis with a chemical dye demonstrate that specific self-labeling of proteins can be used effectively in plants.

DOI： 10.1105/tpc.20.00439

Web of Science

PubMed

Magnetism of Topological Boundary States Induced by Boron Substitution in Graphene Nanoribbons

Niklas Friedrich, Pedro Brandimarte, Jingcheng Li, Shohei Saito, Shigehiro Yamaguchi, Iago Pozo, Diego Pena, Thomas Frederiksen, Aran Garcia-Lekue, Daniel Sanchez-Portal, Jose Ignacio Pascual

PHYSICAL REVIEW LETTERS Vol. 125 ( 14 ) page： 146801 2020.9

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER PHYSICAL SOC

Graphene nanoribbons (GNRs), low-dimensional platforms for carbon-based electronics, show the promising perspective to also incorporate spin polarization in their conjugated electron system. However, magnetism in GNRs is generally associated with localized states around zigzag edges, difficult to fabricate and with high reactivity. Here we demonstrate that magnetism can also be induced away from physical GNR zigzag edges through atomically precise engineering topological defects in its interior. A pair of substitutional boron atoms inserted in the carbon backbone breaks the conjugation of their topological bands and builds two spin-polarized boundary states around them. The spin state was detected in electrical transport measurements through boron-substituted GNRs suspended between the tip and the sample of a scanning tunneling microscope. First-principle simulations find that boron pairs induce a spin 1, which is modified by tuning the spacing between pairs. Our results demonstrate a route to embed spin chains in GNRs, turning them into basic elements of spintronic devices.

DOI： 10.1103/PhysRevLett.125.146801

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PubMed

A Near-Infrared Emissive pi-Conjugated Polymer Consisting of an Excited-State Intramolecular Proton Transfer Unit

Naoya Suzuki, Masayuki Wakioka, Fumiyuki Ozawa, Shigehiro Yamaguchi

ASIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 9 ( 9 ) page： 1326 - 1332 2020.9

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：WILEY-V C H VERLAG GMBH

Near infrared (NIR)-emissive polymers are attractive luminescent materials due to their utilities in biological, optoelectronic, and telecommunication applications. Herein we report the use of a dialkylamine-strapped dithienylpyrrole (DTP) as an excited-state intramolecular proton transfer (ESIPT) building block for producing NIR-emissive pi-conjugated polymers. The study of a series of model compounds showed that the extension of pi-conjugation with a moderately electron-accepting comonomer unit, dithientyl-substituted thiazolo[5,4-d]thiazole (TzTz), effectively stabilizes the zwitterionic ESIPT state while increasing the oscillator strength for the electronic transition from the ESIPT state. Consequently, a polymer consisted of DTP and TzTz units exhibited a significantly red-shifted emission, exceeding 750 nm, from the ESIPT state in polar solvents.

DOI： 10.1002/ajoc.202000234

Web of Science

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Papers - YAMAGUCHI, Shigehiro