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



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