研究者基本情報

• 博士（理学）, 北海道大学, 2022年09月

• https://researchmap.jp/kazumasugawara

• https://jglobal.jst.go.jp/detail?JGLOBAL_ID=202601014052485488
• https://orcid.org/0009-0009-5316-9444
• https://wwwchem.sci.hokudai.ac.jp/~org1/

• 21039539

• https://orcid.org/0009-0009-5316-9444

• 202601014052485488

研究活動情報

• 2022年08月, Best Poster Presentation Award
  The 13th CSE International Autumn School & The 10th ALP International Symposium

• Dual-State Mechano- and Electrochromic Responses Enabled by Sterically Strained Diazaanthraquinodimethanes
  Karin Noro; Ayano Tani; Tomoki Tadokoro; Takashi Harimoto; Kazuma Sugawara; Takanori Suzuki; Toshikazu Ono; Yusuke Ishigaki
  The Journal of Organic Chemistry, 90, 36, 12727, 12733, American Chemical Society (ACS), 2025年09月02日, ［査読有り］
  研究論文（学術雑誌）
• Isolation of a Transition-State Geometry via Intermolecular Stabilization in the Solid State
  Yusuke Ishigaki; Saki Kikuchi; Tomoki Tadokoro; Kazuma Sugawara; Takanori Suzuki
  Organic Letters, 27, 32, 9002, 9006, American Chemical Society (ACS), 2025年08月06日, ［査読有り］
  研究論文（学術雑誌）
• Thermal Equilibrium Between Quinoid/Biradical Forms Enhancing Electrochemical Amphotericity
  Yusuke Ishigaki; Shin‐ichi Mizuno; Kazuma Sugawara; Takumi Hashimoto; Shuichi Suzuki; Takanori Suzuki
  Chemistry – A European Journal, 30, 35, Wiley, 2024年05月27日, ［査読有り］
  研究論文（学術雑誌）, Abstract
  
  Upon dibenzo annulation on Thiele's hydrocarbon (tetraphenyl‐p‐quinodimethane), the quinoid form and the biradical form adopt quite different geometries, and thus are no longer resonance structures. When these two forms can interconvert rapidly due to the small energy barrier (ΔG^≠), the equilibrated mixture contains both forms in a ratio that is determined by the energy difference (ΔG^o) between the two forms. For a series of tetrakis[5‐(4‐methoxyphenyl)‐2‐thienyl]‐substituted derivatives, the more stable quinoid form and the metastable biradical form coexist in solution as an equilibrated mixture due to small ΔG^≠ (<15 kcal mol⁻¹) and ΔG^o (1–4 kcal mol⁻¹), in which the proportion of the two forms can be regulated by temperature. Since the biradical form can undergo easy two‐electron (2e) oxidation to the corresponding dications as well as easy 2e‐reduction to the dianions, it exhibits very high electrochemical amphotericity. This character with a record‐small span for not only the first oxidation and reduction potentials but also the second those, [E₁^sum≈E₂^sum=E₂^ox−E₂^red=ca. 1.4 V], is attained through thermally enhanced conversion to the biradical form from the corresponding quinoid form, the latter of which is less amphoteric due to higher E^ox and lower E^red values.
• On-Surface Synthesis of Multiple Cu Atom-Bridged Organometallic Oligomers
  Kewei Sun; Kazuma Sugawara; Andrey Lyalin; Yusuke Ishigaki; Kohei Uosaki; Oscar Custance; Tetsuya Taketsugu; Takanori Suzuki; Shigeki Kawai
  ACS Nano, 17, 23, 24355, 24362, American Chemical Society (ACS), 2023年12月04日, ［査読有り］
  研究論文（学術雑誌）
• Double Dynamic Structural Change Enabling Tricolor Chromism by the Realization of Apparent Two‐Electron Transfer to Skip the Open‐Shell State
  Takashi Harimoto; Yuka Sugai; Kazuma Sugawara; Takanori Suzuki; Yusuke Ishigaki
  Chemistry – A European Journal, 29, 51, Wiley, 2023年07月24日, ［査読有り］
  研究論文（学術雑誌）, Abstract
  
  Most redox systems generally cannot avoid the involvement of open‐shell species upon generating multiply charged species, which often reduces reversibility in multi‐color electrochromic systems. In this study, we newly synthesized octakis(aminophenyl)‐substituted pentacenebisquinodimethane (BQD) derivatives and their hybrids with alkoxyphenyl analogues. Thanks to apparent two‐electron transfer accompanied by double dramatic changes in the structure of the arylated quinodimethane skeleton, the dicationic and tetracationic states were generated and isolated quantitatively because of the negligible steady‐state concentration of intermediary open‐shell species such as monocation or trication radicals. When two electrophores with different donating abilities are attached to the BQD skeleton, a dicationic state with a different color can be isolated in addition to the neutral and tetracationic states. For these tetracations, an interchromophore interaction induces a red‐shift of the NIR absorptions, thus realizing tricolor UV/Vis/NIR electrochromic behavior involving only closed‐shell states.
• Bis(triarylmethylium)‐type Macrocyclic Dications: Mechanochromic Emission Extending to the Red Region
  Yusuke Ishigaki; Takuya Tachibana; Kazuma Sugawara; Moto Kikuchi; Takanori Suzuki
  ChemPlusChem, 88, 3, Wiley, 2023年03月23日, ［査読有り］
  研究論文（学術雑誌）, Abstract
  
  Macrocyclic dications 2²⁺ composed of two triarylmethylium units were designed and synthesized. In contrast to the reference monocations 1⁺, macrocyclic dications 2²⁺ exhibited mechanochromic emission extending to the red region (−900 nm), since the luminescence color in a solid state can reversibly change due to their constrained structures granted by alkylene linkers and the choice of a proper counterion. X‐ray diffraction and spectroscopic analyses revealed that such mechanochromic behavior was induced by the crystal‐to‐amorphous transition. A change in the intermolecular interaction of macrocyclic dications 2²⁺ would be the key to realizing a change in the emission pattern, since the color of the molecules did not change by applying mechanical stimuli. These findings may suggest a design strategy for creating a variety of stimuli‐responsive materials, especially for carbocation‐based fluorescent materials.
• Strain‐Sensitive On‐Surface Ladderization by Non‐Dehydrogenative Heterocyclization
  Yujing Ma; Kazuma Sugawara; Yusuke Ishigaki; Kewei Sun; Takanori Suzuki; Shigeki Kawai
  Chemistry – A European Journal, 29, 15, Wiley, 2023年02月13日, ［査読有り］
  研究論文（学術雑誌）, Abstract
  
  On‐surface cyclodehydrogenation recently became an important reaction to planarize π‐conjugated molecules and oligomers. However, the high‐activation barrier to cleave the C−H bond often requires high‐temperature annealing, consequently restricting structures of precursor molecules and/or leading to random fusion at their edges. Here, we present a synthesis of pyrrolopyrrole‐bridged ladder oligomers from 11,11,12,12‐tetrabromo‐1,4,5,8‐tetraaza‐9,10‐anthraquinodimethane molecules on Ag(111) with bond‐resolved scanning tunnelling microscopy. This non‐dehydrogenative cyclization between pyrazine and ethynylene/cumulene groups has a low‐activation barrier for forming intermediary dimeric oligomer containing dipyrazinopyrrolopyrrolopyrazine units, thus giving new insight into the strain‐sensitive in ladder‐oligomer formation.
• Exceptionally flexible quinodimethanes with multiple conformations: polymorph-dependent colour tone and emission of crystals
  Kazuma Sugawara; Toshikazu Ono; Yoshio Yano; Takanori Suzuki; Yusuke Ishigaki
  Materials Chemistry Frontiers, 7, 8, 1591, 1598, Royal Society of Chemistry (RSC), 2023年, ［査読有り］, ［筆頭著者］
  研究論文（学術雑誌）, Tetraazaanthraquinodimethanes can exhibit various colours and emissions depending on their multiple conformations, such as not only folded and twisted forms but also intermediate structures,e.g., planar and twisted-folded forms, in pseudopolymorphs.
• Geometrical and Electronic Structure of Cation Radical Species of Tetraarylanthraquinodimethane: An Intermediate for Unique Electrochromic Behavior
  Yusuke Ishigaki; Reina Fukagawa; Kazuma Sugawara; Takashi Harimoto; Takanori Suzuki
  Chemistry – An Asian Journal, 17, 22, Wiley, 2022年09月30日, ［査読有り］
  研究論文（学術雑誌）, Abstract
  
  Two tetraarylanthraquinodimethane (Ar₄AQD) derivatives having two different aryl groups (aminophenyl and methoxyphenyl) were prepared by sequential dibromomethylation and Suzuki‐coupling reactions. X‐ray analyses showed that they adopt a folded structure in the neutral state whereas the corresponding dications have a planar anthracene ring, to which diarylmethylium units are perpendicularly attached. Different from Ar₄AQD having the same substituents that undergoes facile two‐electron transfer during interconversion with the dicationic state, the intermediary cation radical becomes long‐lived in the newly prepared unsymmetric derivatives. The geometric and electronic structures of the open‐shell intermediates were elucidated through electrochemical and theoretical investigation, with revealing that the cation radicals adopt the twisted geometry like dications. Upon electrolyses of the dications, the twisted cation radicals were involved in the electrochromism whereas their steady‐state concentration is negligible in the oxidation process, thus realizing unique tricolor electrochromic behavior with a hysteretic pattern of color change (colorless ‐> purple ‐> blue ‐> colorless).
• Multiple molecular interactions between alkyl groups and dissociated bromine atoms on Ag(111)
  Shigeki Kawai; Kazuma Sugawara; Yujing Ma; Kewei Sun; Oscar Custance; Yusuke Ishigaki; Takanori Suzuki
  Physical Chemistry Chemical Physics, 24, 36, 22191, 22197, Royal Society of Chemistry (RSC), 2022年, ［査読有り］
  研究論文（学術雑誌）, Bromine-mediated molecular self-assembled structures with different alkyl groups in length were investigated using low-temperature scanning tunnelling microscopy under ultrahigh vacuum.
• Heterocyclic Ring‐Opening of Nanographene on Au(111)
  Kewei Sun; Kazuma Sugawara; Andrey Lyalin; Yusuke Ishigaki; Kohei Uosaki; Tetsuya Taketsugu; Takanori Suzuki; Shigeki Kawai
  Angewandte Chemie International Edition, 60, 17, 9427, 9432, Wiley, 2021年03月12日, ［査読有り］
  研究論文（学術雑誌）, Abstract
  
  Cyclo‐dehydrogenation is of importance to induce the planarization of molecules on noble surfaces upon annealing. In contrast to a number of successful syntheses of polycyclic aromatic hydrocarbons by forming carbon–carbon bonds, it is still rare to conduct conjugation and cleavage of carbon–nitrogen bonds in molecules. Here, we present a systematic transformation of the C−N bonds in11,11,12,12‐tetraphenyl‐1,4,5,8‐tetraazaanthraquinodimethane as well as three other derivatives on Au(111). With bond‐resolved scanning tunneling microscopy, we discovered novel the “heterocyclic segregation” reaction of one pyrazine ring with two nitrogen atoms to form two quinoline rings with one nitrogen each. Density functional theory calculations showed that the intramolecular ring‐forming and ‐opening of N‐heterocycles are strongly affected by the initial hydrogen–substrate interaction.
• Hysteretic Three-State Redox Interconversion among Zigzag Bisquinodimethanes with Non-fused Benzene Rings and Twisted Tetra-/Dications with [5]/[3]Acenes Exhibiting Near-Infrared Absorptions
  Yusuke Ishigaki; Takashi Harimoto; Kazuma Sugawara; Takanori Suzuki
  Journal of the American Chemical Society, 143, 9, 3306, 3311, American Chemical Society (ACS), 2021年02月26日, ［査読有り］
  研究論文（学術雑誌）
• Redox-active tetraaryldibenzoquinodimethanes
  Yusuke Ishigaki; Kazuma Sugawara; Tomoki Tadokoro; Yuki Hayashi; Takashi Harimoto; Takanori Suzuki
  Chemical Communications, 57, 59, 7201, 7214, Royal Society of Chemistry (RSC), 2021年, ［査読有り］
  研究論文（学術雑誌）,

  In this Feature Article, we focus on our research history for constructing functional response systems based on redox-active quinodimethanes with electron-donating aryl groups, which undergo reversible interconversion with twisted cations.

• Switching of Redox Properties Triggered by a Thermal Equilibrium between Closed‐Shell Folded and Open‐Shell Twisted Species
  Yusuke Ishigaki; Takumi Hashimoto; Kazuma Sugawara; Shuichi Suzuki; Takanori Suzuki
  Angewandte Chemie International Edition, 59, 16, 6581, 6584, Wiley, 2020年02月20日, ［査読有り］
  研究論文（学術雑誌）, Abstract
  
  Thermally switchable redox properties have been reported to be due to a change in the spin state of newly designed overcrowded ethylenes, which can adopt closed‐shell folded and open‐shell twisted forms. In this study, tetrathienylanthraquinodimethane derivatives were designed to be in thermal equilibrium between a more stable folded form and less stable but more donating twisted diradical in solution, so that the oxidation potential can be controlled by heating/cooling. This is the first example of a switching of redox properties based on a thermally equilibrated twisted diradical, which can be more readily oxidized to the twisted dication.
• A Novel Condensed Heterocyclic Quinone with a Dibenzofuranobisthiadiazole Skeleton
  Takanori Suzuki; Kazuma Sugawara; Wataru Nojo; Yusuke Ishigaki; Junko Ohkanda
  HETEROCYCLES, 101, 1, 99, 99, CLOCKSS Archive, 2020年, ［査読有り］
  研究論文（学術雑誌）
• Two-Way Chromic Systems Based on Tetraarylanthraquinodimethanes: Electrochromism in Solution and Mechanofluorochromism in a Solid State
  Yusuke Ishigaki; Kazuma Sugawara; Masaki Yoshida; Masako Kato; Takanori Suzuki
  Bulletin of the Chemical Society of Japan, 92, 7, 1211, 1217, Oxford University Press (OUP), 2019年06月26日, ［査読有り］
  研究論文（学術雑誌）, Abstract
  
  Tetraarylanthraquinodimethane derivatives 1 with butterfly-shaped folded structures and the corresponding dications 12+ with twisted conformations can undergo interconversion upon two-electron transfer, which is accompanied by a drastic color change. While reversible electrochromic behavior occurs in solution, electron donors 1 exhibit fluorescence only in the solid state. The emission color changed upon grinding as-synthesized samples of 1, and the original emission color was recovered by a dissolving-drying process. Such mechanofluorochromic behavior can be accounted for by the results of powder X-ray diffraction (PXRD), for which as-synthesized crystalline sample was transformed into an amorphous state after grinding. Thus, the title electron donors 1 provided two-way chromic systems exhibiting electrochromism in solution as well as mechanofluorochromism in a solid state.
• Narrower HOMO-LUMO gap attained by conformational switching through peripheral polyarylation in 1,4,5,8-tetraaza-9,10-anthraquinodimethanes
  Takanori Suzuki; Yusuke Ishigaki; Kazuma Sugawara; Yu Umezawa; Ryo Katoono; Atsushi Shimoyama; Yoshiyuki Manabe; Koichi Fukase; Takanori Fukushima
  Tetrahedron, 74, 18, 2239, 2244, Elsevier BV, 2018年05月, ［査読有り］
  研究論文（学術雑誌）
• 9,10-Dihydrophenanthrene with Two Spiro(dibenzocycloheptatriene) Units: A Highly Strained Caged Hydrocarbon Exhibiting Reversible Electrochromic Behavior
  Yusuke Ishigaki; Yuki Hayashi; Kazuma Sugawara; Takuya Shimajiri; Wataru Nojo; Ryo Katoono; Takanori Suzuki
  Molecules, 22, 11, 1900, 1900, MDPI AG, 2017年11月04日, ［査読有り］
  研究論文（学術雑誌）, The title dispiro hydrocarbon 1 was designed as a new electrochromic material. This multiply clamped hexaphenylethane-type electron donor was prepared from 2,2’-diiodobiphenyl via biphenyl-2,2’-diylbis(dibenzotropylium) 22+ salt. X-ray analysis of 1 revealed a highly strained structure as reflected by an elongated “ethane” bond [bond length: 1.6665(17) Å] and nearly eclipsed conformation. The weakened bond was cleaved upon two-electron oxidation to regenerate the deeply colored dication 22+. The reversible interconversion between 1 and 22+ is accompanied not only by a drastic color change but also by C–C bond formation/cleavage. Thus, the voltammogram showed a pair of well-separated redox waves, which is characteristic of “dynamic redox (dyrex)” behavior. The tetrahydro derivative of 1 with two units of spiro(dibenzocycloheptadiene), which suffers from more severe steric congestion, was also prepared. The crystallographically determined bond length for the central C–C bond [1.705(4) Å] is greatest among the values reported for 9,9,10,10-tetraaryl-9,10-dihydrophenanthrene derivatives.

• Polyaryl-substituted Quinodimethane Derivatives; Tunable Photophysical Properties Depending on Multiple conformations in Pseudopolymorphs
  K. Sugawara; T. Ono; Y. Yano; T. Suzuki; Y. Ishigaki
  The 13th CSE International Autumn School & The 10th ALP International Symposium, 2022年08月
• Polyaryl-substituted Quinodimethane Derivatives with Tunable Photophysical Properties Depending on Multi-conformations in Pseudopolymorphs
  K. Sugawara; T. Ono; Y. Yano; T. Suzuki; Y. Ishigaki
  The 25th IUPAC International Conference on Physical Organic Chemistry, 2022年07月
• Polyaryl-substituted Quinodimethane Derivatives with Unique Emission Properties Based on Multi-conformations in Pseudopolymorphs
  K. Sugawara; T. Ono; T. Suzuki; Y. Ishigaki
  The 12th CSE International Autumn School & The 9th ALP International Symposium, 2021年10月
• 柔軟なポリアリールキノジメタン誘導体：結晶擬多形中の立体配座に基づく特異な発光
  菅原一真; 小野利和; 鈴木孝紀; 石垣侑祐
  第31回基礎有機化学討論会, 2021年09月
• 柔軟なポリアリールキノジメタン誘導体：複数の立体構造を示す結晶多形
  菅原一真; 石垣侑祐; 鈴木孝紀
  化学系学協会北海道支部2021年冬季研究発表会, 2021年01月
• Polyaryl-substituted 1,4,5,8-tetraaza-9,10-anthraquinodimethane derivatives forming conformational polymorphs
  K. Sugawara; Y. Ishigaki; T. Suzuki
  The 11th CSE International Autumn School & The 8th ALP International Symposium, 2020年11月
• ポリアリールテトラアザアントラキノジメタン誘導体の結晶多形と⽴体配置
  菅原一真; 石垣侑祐; 鈴木孝紀
  日本化学会第100春季年会, 2020年03月
• 新規テトラアザアントラキノジメタン誘導体の構築
  菅原一真; 石垣侑祐; 鈴木孝紀
  日本化学会第100春季年会, 2020年03月
• Tetraarylanthraquinodimethane-type redox systems exhibiting different chromism in solution and in a solid state
  K. Sugawara; Y. Ishigaki; T. Suzuki
  The 20th RIES-HOKUDAI International Symposium, 2019年12月
• Two-way Chromic Systems Based on Tetraarylanthraquinodimethanes
  Y. Ishigaki; K. Sugawara; T. Suzuki
  CSE international student symposium 2019 （2nd Asian-French Workshop on Polymer Science）, 2019年07月
• Tetraarylanthraquinodimethanes exhibiting electrochromism in solution and mechanofluorochromism in solid state
  Y. Ishigaki; K. Sugawara; T. Suzuki
  The 18th International Symposium on Novel Aromatic Compounds, 2019年07月
• Multi-chromic behavior of tetraarylanthraquinodimethane derivatives: electrochromism in solution and mechanofluorochromism in solid state
  Y. Ishigaki; K. Sugawara; R. Katoono; T. Suzuki
  The 14th Hokkaido University-Nanjing University-NIMS/MANA Joint Symposium, 2018年12月
• Preparation of 11,11,12,12-tetraarylanthraquinodimethane-type electron donors exhibiting multi-chromic behavior
  Y. Ishigaki; K. Sugawara; R. Katoono; T. Suzuki
  The 4th International Symposium on Middle Molecular Strategy, 2018年11月
• 多重クロミズム挙動を示すテトラアリールアントラキノジメタン型電子供与体の構築
  石垣侑祐; 菅原一真; 上遠野亮; 鈴木孝紀
  第29回基礎有機化学討論会, 2018年09月
• テトラアリールアントラキノジメタン型電子供与体の構築とメカノフルオロクロミズム
  石垣侑祐; 菅原一真; 島尻拓哉; 上遠野亮; 鈴木孝紀
  化学系学協会北海道支部2018年冬季研究発表会, 2018年01月

• キノジメタン型酸化還元系分子の動的構造変化に基づく新奇応答系創出
  科学研究費助成事業
  2020年04月 - 2023年03月
  菅原 一真
  本研究に先立って、テトラアリールアントラキノジメタン誘導体の溶液及び固体状態における二重のクロミズム応答を明らかにした。そこで得られたテトラアリールアントラキノジメタンが持つ酸化還元特性を踏まえ、その特異な分子構造とそれに基づくdyrex特性を利用することで革新的な研究展開を行うことが可能である。
  昨年度に引き続き、テトラアリールアントラキノジメタン誘導体の分子構造に着目した研究を推進した。OCE類の一つであるテトラアザアントラキノジメタン誘導体において、擬多形結晶中でfolded型とtwisted型構造に加え、その中間ともいえる構造を複数発現することを見出した。また、結晶中で発現した構造に応じHOMO-LUMOギャップが変化し、folded型からtwisted型の寄与が高い構造になるにつれて結晶の色調や発光色が黄色から橙色、赤色へと連続的に変化することを明らかにした。すなわち本系では、立体配座に応じたHOMO／LUMO準位の変調が可能となり、通常の二状態間のスイッチングでは成し得ない、連続的な色調及び発光色の制御を実現した。また、これらの結晶をすりつぶすことで色調および発光色が変化するというメカノクロミック挙動を示すことを見出し、その機能性材料への応用可能性を明らかにした。
  一方、アントラキノジメタン誘導体のdyrex特性に焦点を当てた研究も推進した。電子ドナーあるいはアクセプターとして機能し得る誘導体を設計し、分子構造の多様性に基づく特異な酸化還元特性を利用した新奇のドナー-アクセプター系を構築した。
  日本学術振興会, 特別研究員奨励費, 北海道大学, 20J20972