Ladder Polymer Science: Innovation through Ladder Bonding

Members

A01 Group: Ikai (PL, PI), Shinohara (Co-PI)

Project Leader, Principle Investigator

Tomoyuki Ikai

Professor, Nagoya University

Project Leader, Principle Investigator

Tomoyuki Ikai

Professor, Nagoya University

Our research focuses on novel polymers with unprecedented three-dimensional molecular architectures. One of our primary focuses is “ladder polymers,” in which monomer units are linked by two or more chemical bonds. We aim to design π-conjugated systems with specific secondary structures and self-assembly capabilities to create ladder polymers with superior properties and novel functionalities that cannot be achieved with conventional linear polymers.

Representative publications:

  1. T. Ikai, T. Yoshida, K. Shinohara, T. Taniguchi, Y. Wada, T. M. Swager, J. Am. Chem. Soc. 2019, 141, 4696–4703.
  2. W. Zheng, T. Ikai, E. Yashima, Angew. Chem., Int. Ed. 2021, 60, 11294–11299.
  3. T. Ikai, S. Miyoshi, K. Oki, R. Saha, Y. Hijikata, E. Yashima, Angew. Chem., Int. Ed. 2023, 62, e202301962.
  4. W. Zheng, K. Oki, R. Saha, Y. Hijikata, E. Yashima, T. Ikai, Angew. Chem., Int. Ed. 2023, 62, e202218297.
  5. T. Ikai, N. Mishima, T. Matsumoto, S. Miyoshi, K. Oki, E. Yashima, Angew. Chem., Int. Ed. 2024, 63, e202318712.

Awards: APSJ Science Award (2025)、NAGASE Science Technology Award (2025)、Eno Science Promotion Foundation Award (2024), Organic Materials Best Paper Award (2024), Award for Encouragement of Research in Polymer Science (2016, The Society of Polymer Science, Japan)

Personal web page: https://ladpoly.chembio.nagoya-u.ac.jp/

Research promotion movie: https://onlinelibrary.wiley.com/doi/10.1002/ntls.20210047

Co-Principle Investigator

Ken-ichi Shinohara

Associate Professor, Japan Advanced Institute of Science and Technology (JAIST)

Co-Principle Investigator

Ken-ichi Shinohara

Associate Professor, Japan Advanced Institute of Science and Technology (JAIST)

I am conducting research into the synthesis of various polymers, including chiral polymers, aimed at the development of molecular motors, and into the observation of the structure and dynamics of single polymer chains at the nanoscale. For example, I have synthesized a new substituted phenylacetylene with an optically active substituent pendant, and observed its nanostructure with AFM and high-speed AFM. Furthermore, I am simulating the dynamics at the atomic level with all-atom molecular dynamics calculations using supercomputers.

Representative publications:

  1. Ken-ichi Shinohara, Yuu Makida, Takashi Oohashi, Ryoga Hori, “Single-Molecule Unidirectional Processive Movement along a Helical Polymer in Non-aqueous Medium”, Langmuir 38, 12173–12178 (2022).
  2. Kehan Cheng, Ken-ichi Shinohara, Osamu Notoya, Masahiro Teraguchi, Takashi Kaneko, and Toshiki Aoki, “Synthesis and Direct Observation of Molecules of 2D Polymers: With High Molecular Weights, Large Areas, Small Micropores, Solubility, Membrane Forming Ability, and High Oxygen Permselectivity, Small, 202308050 (2023).
  3. Ryoga Hori*, Osamu Notoya, Koichi Higashimine, Ken-ichi Shinohara*, “Synthesis and Direct Ovservation of Chiral Supramolecular Polymer of Porphirin having Cholesteryl Groups”, Langmuir 40, 5535-5544 (2024).
  4. Shuaishuai Huang, Ken-ichi Shinohara, Masahiro Teraguchi, Takashi Kaneko, Toshiki Aoki*, “Helix-sence-selective permeation of racemic helical oligoacetylenes though one-handed helical channels in polymer membranes” ACS Macro. Lett. 13, 627–631 (2024).
  5. Ryoga Hori and Ken-ichi Shinohara*, Direct Observation of the “End-Capping Effect” of a PEG@α-CD Polypseudorotaxane in Aqueous Media, Macromolecules 58 (6), 2939-2946 (2025).

Awards:

  1. 篠原　健一、第9回 日本金属学会 奨励賞 [材料化学部門] (1999年11月20日).
  2. 篠原　健一、ヤングサイエンティスト講演賞、高分子学会および同関西支部、於：第51回高分子研究発表会(神戸) (2005年7月22日).
  3. 篠原　健一、高分子学会 広報委員会パブリシティ賞 (2018年5月8日).

Personal web page: https://www.jaist.ac.jp/ms/labs/shinohara/

A02 Group: Ito (PI), Matsuoka (Co-PI)

Principle Investigator

Hideto Ito

Associate Professor, Nagoya University

Principle Investigator

Hideto Ito

Associate Professor, Nagoya University

We aim to develop synthetic methodologies and catalysts for polycyclic aromatic compounds, nanographenes and ladder molecules. Utilizing originally developed methods such as annulative π-extension (APEX) and mechanochemical transformations/synthesis, we also focus on synthesis of structurally unique novel nanographenes and ladder aromatics/polymers.

Representative publications:

  1. Birch reductive arylation by mechanochemical anionic activation of polycyclic aromatic compounds.
    Yoshifumi Toyama, Akiko Yagi, Kenichiro Itami, Hideto Ito,* Nature Commun. 2025, 16, 5044.
    DOI: 10.1038/s41467-025-60318-y
  2. Expanded [2,1][n]Carbohelicenes with 15- and 17-Benzene Rings.Michihisa Toya, Takuya Omine, Fumitaka Ishiwari, Akinori Saeki, Hideto Ito,* Kenichiro Itami,* J. Am. Chem. Soc. 2023, 145, 11553–11565. DOI: 10.1021/jacs.3c00109
  3. Lithium-mediated mechanochemical cyclodehyrogenation.
    Kanna Fujishiro, Yuta Morinaka, Yohei Ono, Tsuyoshi Tanaka, Lawrence T. Scott, Hideto Ito,* Kenichiro Itami,* J. Am. Chem. Soc. 2023, 145, 8163–8175.  DOI: 10.1021/jacs.3c01185
  4. Infinitene: A Helically Twisted Figure-Eight [12]Circulene Topoisomer.
    Maciej Krzeszewski, Hideto Ito,* Kenichiro Itami,* J. Am. Chem. Soc. 2022, 144, 862–871. DOI: 10.1021/jacs.1c10807
  5. Diversity-oriented synthesis of nanographenes enabled by dearomative annulative π-extension.Wataru Matsuoka, Hideto Ito,* David Sarlah,* Kenichiro Itami,* Nature Commun., 2021,12, 4940. DOI: 10.1038/s41467-021-24261-y

Awards: The 68th Chemical Society of Japan Award for Young Chemists (2019), Akasaki Award (2019), Banyu Chemist Award (2023), The 28th Young Researcher Award (2023, Society of Silicon Chemistry, Japan), Thieme Chemistry Journals Award (2024)

Personal web page: https://hidetoito.jp/

Research promotion video & article:
https://www.youtube.com/watch?v=yAu7KVNViQs&t=3s&themeRefresh=1

https://www.thieme.de/statics/dokumente/thieme/final/en/dokumente/tw_chemistry/CFZ-Awardee-Interview-Hideto-Ito.pdf

Co-Principle Investigator

Wataru Matsuoka

Assistant Professor, Hokkaido University

Co-Principle Investigator

Wataru Matsuoka

Assistant Professor, Hokkaido University

My research focuses on the development of novel chemical reactions based on quantum chemical calculations. In particular, I aim to establish an in silico strategy that revolutionizes conventional catalyst design processes, using an original computational mathod called the “virtual ligand method.” This method transforms the discrete optimization problem of molecular design into a continuous one, enabling the efficient identification of promising catalyst candidates with significantly higher efficiency than conventional approaches.

Representative publications:

  1. W. Matsuoka, Y. Harabuchi, S. Maeda, ACS Catal. 12, 3752–3766 (2022).
  2. W. Matsuoka, Y. Harabuchi, Y. Nagata, S. Maeda, Org. Biomol. Chem. 21, 3132–3142 (2023).
  3. W. Matsuoka, Y. Harabuchi, S. Maeda, ACS Catal. 13, 5697–5711 (2023).
  4. W. Matsuoka, T. Oki, R. Yamada, T. Yokoyama, S. Suda, C. M. Saunders, B. B. Skjelstad, Y. Harabuchi, N. Fey, S. Iwata, S. Maeda, ACS Catal. 14, 16297–16312 (2024).
  5. W. Matsuoka, K. Hirose, R. Yamada, T. Oki, S. Iwata, S. Maeda, J. Chem. Inf. Model. In Press. DOI: 10.1021/acs.jcim.5c00815 (2025).

Awards: The Outstanding Graduate Student Award (2020), Inoue Research Award for Young Scientists (2024)

Personal web page:https://researchmap.jp/wataru_matsuoka

https://github.com/WatMat1127

A03 Group: Ishiwari (PI), Ida (Co-PI)

Principle Investigator

Fumitaka Ishiwari

Associate Professor, Tokyo Metropolitan University

Principle Investigator

Fumitaka Ishiwari

Associate Professor, Tokyo Metropolitan University

Based on our “bifacial” molecular motif, we develop ladder polymers with unique chemical structures designed to further enhance their physical properties. Specifically, our efforts include the development of new PIMs (Polymers of Intrinsic Microporosity), as well as investigations into chirality-induced properties such as CISS (Chirality-Induced Spin Selectivity) and chiral NLO (Nonlinear Optics), which have recently attracted attention.

Representative publications:

  1. S. Li, *F. Ishiwari, et al., Chem. Commun. 2024, 60, 10870.
  2. N. Minoi, *F. Ishiwari, *A. Saeki et al., ACS Appl. Mater. Interfaces 2023, 15, 6708.
  3. *F. Ishiwari, *Y. Takeda et al., Chem. Eur. J. 2023, 29, e202202702.
  4. K. Inoue, *F. Ishiwari, et al., ChemNanoMat 2021, 7, 824.
  5. *F. Ishiwari, *T. Fukushima et al., ACS Macro Lett. 2017, 6, 775.

Awards: SHGSC Japan Award of Excellence (2025), the MEXT Young Scientists’ Prize (2024), The Japan Society of Applied Physics M&BE Award (2023)、the 70th Chemical Society of Japan Award for Young Chemists (2021), Award for Encouragement of Research in Polymer Science (2019, The Society of Polymer Science, Japan)

Personal web page: https://sites.google.com/view/ishiwarilab/

Others: https://www.chemistry.or.jp/division-topics/2025/01/ciss.html

https://www.chemistry.or.jp/division-topics/2018/03/post-111.html

Co-Principle Investigator

Daichi Ida

Associate Professor, Kyoto University

Co-Principle Investigator

Daichi Ida

Associate Professor, Kyoto University

We are studying polymer solution properties using theoretical, computational chemistry, and experimental methods. Our recent main topics are (1) phase behavior of aqueous solutions of non-ionic polymers and their intermolecular interactions in water, (2) dilute solution properties of cyclic polymers, and (3) dissolution behavior of amphiphilic copolymers. We will quantitatively evaluate the molecular-level characteristics of ladder polymers based on the research methods we have developed for polymer solution properties.

Representative publications:

  1. R. Watanabe, K. Takaseki, M. Katsumura, D. Matsushita, D. Ida, and M. Osa, Polym. J., 48, 621 (2016).
  2. A. Nakamura, Y. Aoki, M. Osa, D. Ida, and T. Yoshizaki, Polym. J., 50, 231 (2018).
  3. D. Ida, Topological Polymer Chemistry, Chap. 23, Ed. by Y. Tezuka and T. Deguchi (Springer, Singapore, 2022).
  4. K. Nakamura, K. Yano, S. Ida, D. Ida, A. Ryoki, S. Yamamoto, T. Terashima, and S. Kanaoka, Macromolecules, 57, 4439 (2024).

Awards： 2015年高分子論文集高分子科学・工学のニューウェーブ，2012年度高分子研究奨励賞，2008年度Polymer Journal論文賞–日本ゼオン賞

Personal web page： http://www.molsci.polym.kyoto-u.ac.jp/DaichiIda/ida_jp.html

A04 Group: Kitao (PI)

Principle Investigator

Takeshi Kitao

Senior Researcher, Nano Carbon Device Research Center,
National Institute of Advanced Industrial Science and Technology (AIST)

Principle Investigator

Takeshi Kitao

Senior Researcher, Nano Carbon Device Research Center,
National Institute of Advanced Industrial Science and Technology (AIST)

Ladder polymers are expected to exhibit a range of outstanding properties, including excellent thermal and chemical stability as well as high charge-transport properties. However, their synthesis remains highly challenging. The use of monomers with multiple reactive sites often leads to undesirable side reactions such as cross-linking and branching during polymerization. In this study, we aim to suppress these side reactions by utilizing highly ordered reaction environments, such as metal–organic frameworks (MOFs), and to achieve the precise synthesis of ladder polymers that has been unattainable with conventional methods.

Representative publiations:

  1. T. Kitao, T. Miura, R. Nakayama, Y. Tsutsui, Y. S. Chan, H. Hayashi, H. Yamada, S. Seki, T. hitosugi, T. Uemura, Nat. Synth. 2023, 2, 848-854.
  2. S. W. Lo, T. Kitao, Y. Nada, K. Murata, K. Ishii, T. Uemura, Angew. Chem. Int. Ed., 2021, 60, 17947.
  3. X. Zhang, T. Kitao, D. Piga, R. Hongu, S. Bracco, A. Comotti, P. Sozzani, T. Uemura, Chem. Sci., 2020, 11, 10844-10849.
  4. T. Kitao, M. W. A. MacLean, K. Nakata, M. Takayanagi, M. Nagaoka, T. Uemura, J. Am. Chem. Soc., 2020, 142, 5509-5514.
  5. T. Kitao, Y. Nagasaka, M. Karasawa, T. Eguchi, N. Kimizuka, K. Ishii, T. Yamada, T. Uemura, J. Am. Chem. Soc., 2019, 141, 19565-19569.

Awards: The 73th Chemical Society of Japan Award for Young Chemists (2024), PCCP賞 (2022), Award for Encouragement of Research in Polymer Science (2021, The Society of Polymer Science, Japan)

Personal web page: https://unit.aist.go.jp/ncm/ja/member/kitao.html

A05 Group: Matsumoto (PI)

Principle Investigator

Kazuhiro Matsumoto

Group Leader
Research Institute for Chemical Process Technology,
National Institute of Advanced Industrial Science and Technology (AIST)

Principle Investigator

Kazuhiro Matsumoto

Group Leader
Research Institute for Chemical Process Technology,
National Institute of Advanced Industrial Science and Technology (AIST)

This research explores two approaches to the precise synthesis of ladder polymers, based on the unique properties of Si–O bonds—namely their thermodynamic stability, flexibility, and potential for sequence control. The first approach focuses on developing a defect-free ladder polymerization via Si–O sigma-bond metathesis. The second explores the use of sequence-defined oligosiloxane templates to guide the controlled assembly of ladder architectures. These approaches aim to provide multiple synthetic strategies for the precise construction of ladder architectures and to generate structurally diverse, novel silicon-containing ladder polymers.

Representative publications:

  1. S. Ito. K. Matsumoto, H. Sato, H. Watanabe, J. Polym. Sci. 2025, 63, 2626-2638.
  2. T. Kawatsu, H. Minamikawa, K. Sato, K. Matsumoto, Polym. Chem. 2024, 15, 2740-2746.
  3. T. Kawatsu, K. Fuchise, K. Takeuchi, J.-C. Choi, K. Sato, K. Matsumoto, Polym. Chem. 2021, 12, 2222-2227.
  4. T. Kawatsu, J.-C. Choi, K. Sato, K. Matsumoto, Macromol. Rapid Commun. 2021, 42, 2000593.
  5. K. Matsumoto, Y. Oba, Y. Nakajima, S. Shimada, K. Sato, Angew. Chem. Int. Ed. 2018, 57, 4637-4641.

Awards: The Japan Petroleum Institute Award for Encouragement of Research and Development (2019), The Society of Silicon Chemistry Japan Award for Young Chemist (2018), DAICEL Award in Synthetic Organic Chemistry (2017), Inoue Research Award for Young Scientist (2010)

Group web page: https://unit.aist.go.jp/cpt/en/groups/008_cpt-orxn.html

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