Hajime Ito

Graduate School of Engineering, Hokkaido University
A02 Group leader

Research AreasOrganic Chemistry, Coordination Chemistry

Mechanistic Study and Development of Novel Functions of Soft Crystals with Molecular Domino Transformation

Domino Transformation, Soft Crystal, Gold Complex, Crystal Jumping
Co-Investigator: Tatsuo Ishiyama (Graduate School of Engineering, Hokkaido University, Associate Professor)
Co-Investigator: Tomohiro Seki (Graduate School of Engineering, Hokkaido University, Assistant Professor)
Co-Researcher: Koji Kubota (Graduate School of Engineering, Hokkaido University,Specially Appointed Assistant Professor)
Co-Researcher: Mingoo Jin (WPI-ICReDD, Hokkaido University, Specially Appointed Assistant Professor)
Co-Researcher: Kenta Kato (WPI-ICReDD, Hokkaido University, doctor student)

Research Outline

An interesting feature of molecular crystals with domino transformation is the nature that a small stimulation on the crystals can change the molecular level structure and start phase change of the crystals. This phase change is amplified through a self-replication mechanism and develops the entire crystal to cause a drastic change of the crystal properties. This researcher will develop a variety of new molecular crystals with “Molecular domino transformation” and “Jumping crystals” and investigate the mechanism of the phase changing and establish a general molecular design concept of these molecules. The research subjects are (1) development of molecular crystals with domino transformation and the mechanism investigation (2) preparation and function of nanostructured molecular crystals through domino transformation (3) mechanistic study and functionalization of crystal jumping materials. The novel features of the domino transformation crystals, “transduction of macroscopic stimulation to molecules,”” microscopic molecular structure change affecting macroscopic nature of crystals,” can be an important clue for the study on the “direct relations between macroscopic and microscopic phenomena.”

Molecular Model Figure of Domino Transition
Color and Structure Changes of Domino Crystals

Representative Achievements

  • Mechano-Responsive Luminescence via Crystal-to-Crystal Phase Transitions between Chiral and Non-Chiral Space Groups
    Jin, M.; Seki, T.; Ito, H. J. Am. Chem. Soc. 2017, 139, 7452–7455.
    DOI: 10.1021/jacs.7b04073
  • Luminescent Mechanochromic 9-Anthryl Gold(I) Isocyanide Complex with an Emission Maximum at 900 nm after Mechanical Stimulation
    Seki, T.; Tokodai, N.; Omagari, S.; Nakanishi, T. ; Hasegawa, Y.; Iwasa, T.; Taketsugu, T.; Ito, H. J. Am. Chem. Soc.  2017, 139, 6514–6517.
    DOI: 10.1021/jacs.7b00587
  • A Screening Approach for the Discovery of Mechanochromic Gold(I) Isocyanide Complexes with Crystal-to-Crystal Phase Transitions
    Seki, T.; Takamatsu, Y; Ito, H. J. Am. Chem. Soc.  2016, 138, 6252–6260.
    DOI: 10.1021/jacs.6b02409
  • Controlling Mechano- and Seeding-Triggered Single-Crystal-to-Single-Crystal Phase Transition: Molecular Domino with a Disconnection of Aurophilic Bonds
    Seki, T.; Sakurada, K.; Ito, H. Angew. Chem., Int. Ed.  2013, 52, 12828–12832. (VIP paper)
    DOI: 10.1002/anie.201307672
  • Mechanical stimulation and solid seeding trigger single-crystal-to-single-crystal molecular domino transformations
    Ito, H.; Muromoto, M.; Kurenuma, S.; Ishizaka, S.; Kitamura, N.; Sato, H.; Seki, T. Nature Commun.  2013, 4, Article number: 2009.
    DOI: 10.1038/ncomms3009



Academic papers/reviewed

  1. "Mechanochemistry allows carrying out sensitive organometallic reactions in air: glove-box-and-Schlenk-line-free synthesis of oxidative addition complexes from aryl halides and palladium(0)" K. Kubota, R. Takahashi, H. Ito, Chem. Sci., 2019, 10, 5837-5842.
  2. "Soft Crystals‐Flexible Response Systems with High Structural Order" M. Kato, H. Ito, M. Hasegawa, K. Ishii, Chemistry – A European Journal, 2019, 25, 5105-5112.
  3. "Soft Crystal Force Field for Reproducing the Crystal Structures of Gold Isocyanide Complexes" N. Nakayama, S. Obata, H. Goto, T. Seki, H. Ito, J. Comput. Chem., Jpn., 2018, 17, 155-157.
  4. "Spiral Eu(III) Coordination Polymers with Circularly Polarized Luminescence" Y. Hasegawa, Y. Miura, Y. Kitagawa, S. Wada, T. Nakanishi, K. Fushimi, T. Seki, H. Ito, T. Iwasa, T. Taketsugu, M. Gon, K. Tanaka, Y. Chujo, S. Hattori, M. Karasawa, K. Ishii, Chem. Comm., 2018, 54, 10695-10697.
  5. "Dependence of Absorption and Emission Spectra on Polymorphs of Gold(I) Isocyanide Complexes: Theoretical Study with QM/MM Approach" S. Aono, T. Seki, H. Ito, S. Sakaki, J. Phys. Chem. C, 2019, 123, 4773-4794.
  6. "Luminescent mechanochromism of gold N-heterocyclic carbene complexes with hypso- and bathochromic spectral shifts" T. Seki, K. Kashiyama, H. Ito, Dalton Trans., 2019, 48, 7105-7109.
  7. "Anisotropic strain release in a thermosalient crystal: correlation between the microscopic orientation of molecular rearrangements and the macroscopic mechanical motion" T. Seki, T. Mashimo, H. Ito, Chem. Sci., 2019, 10, 4185-4191.
  8. "Concise Synthesis of Potassium Acyltrifluoroborates from Aldehydes through Copper(I)-Catalyzed Borylation/Oxidation" J. Taguchi, T. Takeuchi, R. Takahashi, F. Masero, H. Ito, Angew. Chem. Int. Ed., 2019, 58, 7299-7303.
  9. "Iridium(I)-Catalyzed C-H Borylation in Air Using Mechanochemistry" Y. Pang, T. Ishiyama, K. Kubota, H. Ito, Chem. Eur. J., 2019, 25, 4654-4659.
  10. "Olefin-accelerated Solid-state C–N cross-coupling reactions using mechanochemistry" K. Kubota, T. Seo, K. Koide, Y. Hasegawa, H. Ito, Nature Commun., 2019, 10, 111.
  11. "A Gold Isocyanide Complex with a Pendant Carboxy Group: Orthogonal Molecular Arrangements and Hypsochromically Shifted Luminescent Mechanochromism" T. Seki, K. Kobatashi, T. Mashimo, H. Ito, Chem. Commun., 2018, 54, 11136-11139.
  12. "A meta-diisocyanide benzene-based aryl gold isocyanide complex exhibiting multiple solid-state molecular arrangements and luminescent mechanochromism" T. Seki, K. Ida, H. Ito, Mater. Chem. Front., 2018, 2, 1195-1200.
  13. "Phosphorescence Control Mediated by Molecular Rotation and Aurophilic Interactions in Amphidynamic Crystals of 1,4-Bis[tri-(p-fluorophenyl)phosphane-gold(I)-ethynyl]benzene" M. Jin, S. Chung, T. Seki, H. Ito, M. A. Garcia-Garibay, J. Am. Chem. Soc., 2017, 139 (49), 18115–18121.
  14. "Mechanical-Stimulation-Triggered and Solvent-Vapor-Induced Reverse Single-Crystal-to-Single-Crystal Phase Transitions with Alterations of the Luminescence Color" J. Mingoo, T. Sumitani, H. Sato, T. Seki, H. Ito, J. Am. Chem. Soc., 2018, 140, 2875-2879.
  15. "Synthesis of Acylborons by Ozonolysis of Alkenylboronates: Preparation of an Enantioenriched Amino Acid Acylboronate" J. Taguchi, T. Ikeda, R. Takahashi, I. Sasaki, Y. Ogasawara, T. Dairi, N. Kato, Y. Yamamoto, J. W. Bode, H. Ito, Angew. Chem. Int. Ed., 2017, 56, 13847-13851.

Attend international conferences and overseas dispatch

  1. "Copper-Catalyzed Borylation with Diboron: The Beginning and Our Recent Results" H. Ito (Invited), BK21+/Basic Science Research Institute (POSTECH) Mini-Symposium, Frontiers in Organic and Organometallic Chemistry (Pohang, Korea, Jun. 30-30, 2017)
  2. "Copper(I)-Catalyzed Selective Defluorination: Selective Synthesis of Stereodefined β-Monofluoroalkenes" K. Kubota, H. Ito, 20th European Symposium on Organic Chemistry (Cologne, Germany, Jul. 2-6, 2017)
  3. "Copper-Catalyzed Asymmetric Borylative Dearomatization: New Pathway to Optically Active Heterocyclic Compounds" H. Ito (Invited), 16th International Meeting on Boron Chemistry (Hong Kong, China, Jul. 9-13, 2017)
  4. "Concise Synthesis of Acylboronates by Ozonolysis of Alkenylboronates" T. Ikeda, I. Sasaki, J. W. Bode, H. Ito, 16th International Meeting on Boron Chemistry (Hong Kong, China, Jul. 9-13, 2017)
  5. "Gold Isocyanide Complexes with Mechanical Response" H. Ito (Invited), 24th Congress and General Assembly of the International Union of Crystallography (IUCr 2017) (Hyderabad, India, Aug. 20-29, 2017)
  6. "Aryl gold isocyanide complexes with mechanical responsive properties" H. Ito (Invited), 2017 KJF International Conference on Organic Materials for Electronics and Photonics (KJF-ICOMEP 2017) (Gwangju, Korea, Aug. 30-Sep. 2, 2017)
  7. "Mechano-responsive luminescence of gold(I) isocyanide complex via crystal-to-crystal phase transition between chiral and non-chiral space groups" T. Seki, H. Ito, 2017 KJF International Conference on Organic Materials for Electronics and Photonics (KJF-ICOMEP 2017) (Gwangju, Korea, Aug. 30-Sep. 2, 2017)
  8. "Low-temperature-selective luminescent mechanochromism of a gold(I) isocyanide complex" T. Seki, H. Ito, 2017 KJF International Conference on Organic Materials for Electronics and Photonics (KJF-ICOMEP 2017) (Gwangju, Korea, Aug. 30-Sep. 2, 2017)
  9. "Molecular Design of Luminescent Gold(I) Isocyanide Complexes with Mechanical Response Properties" H. Ito (Invited), The 7th Sino-Japanese Symposium on Organic Chemistry for Young Scientists (Shanghai, China, Oct.8-11, 2017)
  10. "Molecular Design of Gold(I) Isocyanide Complexes with Luminescent Mechanochromism and Phase Transitions" H. Ito (Invited), 3rd International Conference on Mechanoluminescence (Hong Kong, China, Dec. 15-17, 2017)

Related Website(s)
hajito [at] eng.hokudai.ac.jp