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 (Faculty of Science, Shizuoka University, Lecturer)
Co-Researcher: Koji Kubota (Graduate School of Engineering, Hokkaido University,Specially Associate Professor)
Co-Researcher: Mingoo Jin (WPI-ICReDD, Hokkaido University, Specially Appointed Assistant Professor)

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. "Solid-State C-N Cross-Coupling Reactions with Carbazoles as Nitrogen Nucleophiles Using Mechanochemistry" K. Kubota*, T. Endo, M. Uesugi, Y. Hayashi, H. Ito*, Chemsuschem 15, e202102132 (2022).
  2. "Efficient access to materials-oriented aromatic alkynes via the mechanochemical Sonogashira coupling of solid aryl halides with large polycyclic conjugated systems" Y. Gao, C. Feng, T. Seo, K. Kubota*, H. Ito*, Chem. Sci. 13, 430-438 (2022).
  3. "Insight into the Reactivity Profile of Solid-State Aryl Bromides in Suzuki-Miyaura Cross-Coupling Reactions Using Ball Milling" K. Kubota*, K. Kondo, T. Seo, H. Ito*, Synlett, 33, 898-902 (2022).
  4. "Synthesis of hydrosilylboronates via the monoborylation of a dihydrosilane Si-H bond and their application for the generation of dialkylhydrosilyl anions" T. Takeuchi, R. Shishido, K. Kubota*, H. Ito*, Chem. Sci. 12, 11799-11804 (2021).
  5. "Charge-transfer crystal with segregated packing structure constructed with hexaarylbenzene and tetracyanoquinodimethane" R. Ando, M. Jin*, H. Ito*, Crystengcomm 23, 5564-5568 (2021).
  6. "Regio- and Stereoselective Synthesis of Multi-Alkylated Allylic Boronates through Three-Component Coupling Reactions between Allenes, Alkyl Halides, and a Diboron Reagent" Y. Ozawa, K. Endo, H. Ito*, J. Am. Chem. Soc. 143, 13865-13877 (2021).
  7. "Mechanochemical synthesis of magnesium-based carbon nucleophiles in air and their use in organic synthesis" R. Takahashi, A. Q. Hu, P. Gao, Y. P. Gao, Y. D. Pang, T. Seo, J. L. Jiang, S. Maeda, H. Takaya, K. Kubota*, H. Ito*, Nat. Commun. 12, (2021).
  8. "Backbone-Modified C-2-Symmetrical Chiral Bisphosphine TMSQuinoxP*: Asymmetric Borylation of Racemic Allyl Electrophiles" H. Iwamoto, Y. Ozawa, Y. Takenouchi, T. Imamoto, H. Ito*, J. Am. Chem. Soc. 143, 6413-6422 (2021).
  9. "Synthesis of Chiral alpha-Amino Tertiary Boronates via the Catalytic Enantioselective Nucleophilic Borylation of Dialkyl Ketimines" K. Kubota*, D. Miura, T. Takeuchi, S. Osaki, H. Ito*, ACS Catal. 11, 6733-6740 (2021).
  10. "Introduction of a Luminophore into Generic Polymers via Mechanoradical Coupling with a Prefluorescent Reagent" K. Kubota*, N. Toyoshima, D. Miura, J. L. Jiang, S. Maeda, M. Jin*, H. Ito*, Angew. Chem. Int. Ed. 60, 16003-16008 (2021).
  11. "Palladium-Catalyzed Solid-State Polyfluoroarylation of Aryl Halides Using Mechanochemistry" R. Takahashi, T. Seo, K. Kubota*, H. Ito*, ACS Catal. 11, 14803-14810 (2021).
  12. "Distinct Fold-Mode Formation of Crystalline Cu(I) Helical Coordination Polymers with Alternation of the Solid-State Emission Using Shape of the Counter Anions" M. Jin*, R. Ando, H. Ito*, Inorg. Chem., 61, 3-9 (2022).
  13. "A Copper(I)-Catalyzed Radical-Relay Reaction Enabling the Intermolecular 1,2-Alkylborylation of Unactivated Olefins" S. Akiyama, N. Oyama, T. Endo, K. Kubota*, H. Ito*, J. Am. Chem. Soc. 143, 5260-5268 (2021).
  14. "(9-Isocyanoanthracene)gold(I) Complexes Exhibiting Two Modes of Crystal Jumps by Different Structure Change Mechanisms" K. Kato, T. Seki*, H. Ito, Inorg. Chem. 60, 10849-10856 (2021).
  15. "Tackling Solubility Issues in Organic Synthesis: Solid-State Cross-Coupling of Insoluble Aryl Halides" T. Seo, N. Toyoshima, K. Kubota*, H. Ito*, J. Am. Chem. Soc. 143, 6165-6175 (2021).
  16. "Encapsulating N-Heterocyclic Carbene Binuclear Transition-Metal Complexes as a New Platform for Molecular Rotation in Crystalline Solid-State" M. Jin,* R. Ando, M. J. Jellen, M. A. Garcia-Garibay, H. Ito.* J. Am. Chem. Soc. 143, 1144-1153 (2021).
  17. "General Synthesis of Trialkyl- and Dilylative Dearomatization of Indoles and Pyrroles using Silylboronates" K. Hayama, R. Takahashi, K. Kubota,* H. Ito.* Chem. Lett. 50, 289-292 (2021).
  18. "General Synthesis of Trialkyl- and Dialkylarylsilylboranes: Versatile Silicon Nucleophiles in Organic Synthesis" R. Shishido, M. Uesugi, R. Takahashi, T. Mita, T. Ishiyama, K. Kubota,* H. Ito.* J. Am. Chem. Soc. 142, 14125-14133 (2020) (ACIE Cover) . (ACIE Cover)
  19. "Selective Mechanochemical Monoarylation of Unbiased Dibromoarenes by in Situ Crystallization" T. Seo, K. Kubota,* H. Ito.* J. Am. Chem. Soc. 142, 9884-9889 (2020). (JACS spotlight, JACS Cover))
  20. "Photoluminescent Ferroelastic Molecular Crystals" T. Seki,* C. Feng, K. Kashiyama, S. Sakamoto, Y. Takasaki, T. Sasaki, S. Takamizawa, H. Ito.* Angew. Chem. Int. Ed. 59, 8839-8843 (2020). (領域内共同研究 A01-02 高見澤) (ACIE Cover)
  21. "Solid-State Radical C-H Trifluoromethylation Reactions Using Ball Milling and Piezoelectric Materials" Y. Pang, J. W. Lee, K. Kubota,* H. Ito.* Angew. Chem. Int. Ed. 59, 22570-22576 (2020).
  22. "A Glove-Box- and Schlenk-Line-Free Protocol for Solid-State C-N Cross-Coupling Reactions Using Mechanochemistry" K. Kubota,* R. Takahashi, M. Uesugi, H. Ito.* ACS Sustainable Chem. Eng. 8, 16577-16582 (2020). (Cover)
  23. "Mechanochemical cross-coupling reactions" K. Kubota.* H. Ito* Trends Chem. 2, 1066-1081 (2020). (Cover)
  24. "Silyl-group-directed Linear-selective Allylation of Carbonyl Compounds with Trisubstituted Allylboronates Using a Copper(I) Catalyst" H. Iwamoto, Y. Hayashi, Y. Ozawa, *H. Ito, ACS Catal. 10, 2471-2476 (2020).
  25. "Synthesis of Chiral N-Heterocyclic Allylboronates via the Enantioselective Borylative Dearomatization of Pyrroles" K. Hayama, R. Kojima, *K. Kubota, *H. Ito, Org. Lett. 22, 739-744 (2020).
  26. "Synthesis and Tunable Optical Properties of C,N-Chelated Borate Luminophores Derived from Potassium Acyltrifluoroborates" J. Taguchi, S. Matsuura T. Seki, *H. Ito, Chem. Eur. J. 26,2450-2455 (2020).
  27. "Crystal Jumping of Simple Hydrocarbons: Cooling-Induced Salient Effect of Bis-, Tri-, and Tetraphenylethene through Anisotropic Lattice Dimension Changes without Thermal Phase Transitions" *T. Seki, T. Mashimo, *H. Ito, Chem. Lett. 49,174-177(2020).
  28. "Aurophilicity-mediated Construction of Emissive Porous Molecular Crystals as Versatile Hosts for Liquid and Solid Guests" *T. Seki, K. Ida, S. Aono, S. Sasaki, *H. Ito, Chem. Eur. J. 25, 1-11 (2019). (領域内共同研究 A01 公募班 榊)
  29. "Air- and moisture-stable Xantphos-ligated palladium dialkyl complex as a precatalyst for cross-coupling reactions" R. Takahashi, *K. Kubota, *H. Ito, Chem. Commun., 56, 407-410 (2020).
  30. "Redox Reactions of Small Organic Molecules Using Ball Milling and Piezoelectric Materials" *K. Kubota, Y. Pang, A. Miura, *H. Ito, Science 366, 1500-1504 (2019).
  31. "Anisotropic Thermal Expansion as the Source of Macroscopic and Molecular Scale Motion in Phosphorescent Amphidynamic Crystals" M. Jin, S. Yamamoto, T. Seki, *H. Ito, *M. A. Garcia-Garibay, Angew. Chem. Int. Ed. 58, 18003-18010 (2019).
  32. "The Direct Dimesitylborylation of Benzofuran Derivatives via an Iridium-Catalyzed C–H Activation with Silyldimesitylborane" R. Shishido, T. Seki, T. Ishiyama, , *H. Ito, Chem. Eur. J. 25, 12924-12928 (2019).
  33. "Solid-State Suzuki-Miyaura Cross-Coupling Reactions: Olefin-Accelerated C–C Coupling Using Mechanochemistryeo" T. Seo, T. Ishiyama, *K. Kubota, *H. Ito, Chem. Sci., 10, 8202-8210 (2019).
  34. "Catalytic Enantioselective Synthesis of Allylic Boronates with a Trisubstituted Alkenyl Fluoride and Conversion to Compounds with a F-Substituted Stereogenic Quaternary Center" S. Akiyama, K. Kubota, M. S. Mikus, P. H. S. Paioti, F. Romiti, Q. Liu, Y. Zhou, *A. H. Hoveyda, *H. Ito, Angew. Chem. Int. Ed., 58, 11998-12003 (2019).
  35. "Copper(I)-Catalyzed Enantioconvergent Borylation of Racemic Benzyl Chlorides Enabled by Quadrant-by-Quadrant Structure Modulation of Chiral Bisphosphine Ligands" H. Iwamoto, K. Endo, Y. Ozawa, Y. Watanabe, K. Kubota, T. Imamoto, *H. Ito, Angew. Chem. Int. Ed., 58, 11112-11117 (2019).
  36. "Synthesis of 2-alkyl-2-boryl-substituted-tetrahydrofurans via copper(I)-catalysed borylative cyclization of aliphatic ketones" K. Kubota, M. Uesugi, S. Osaki, *H. Ito, Org. Biomol. Chem., 17, 5680-5683 (2019).
  37. "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., 10, 5837-5842 (2019).
  38. "Luminescent mechanochromism of gold N-heterocyclic carbene complexes with hypso- and bathochromic spectral shifts" *T. Seki, K. Kashiyama, *H. Ito, Dalton Trans., 48, 7105-7109 (2019).
  39. "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., 10, 4185-4191 (2019).
  40. "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., 58, 7299-7303 (2019).
  41. "Iridium(I)-Catalyzed C-H Borylation in Air Using Mechanochemistry" Y. Pang, T. Ishiyama, K. Kubota, *H. Ito, Chem. Eur. J., 25, 4654-4659 (2019).
  42. "Olefin-accelerated Solid-state C–N cross-coupling reactions using mechanochemistry" K. Kubota, T. Seo, K. Koide, Y. Hasegawa, *H. Ito, Nature Commun., 10, 111 (2019). (プレスリリース、領域内共同研究 A03公募 長谷川)
  43. "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., 54, 11136-11139 (2018).
  44. "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., 2, 1195-1200 (2018).
  45. "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., 140, 2875-2879 (2018).
  46. "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., 139, 18115-18121( 2017).
  47. "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., 56, 13847–13851 (2017).

International conferences

  1. ” Designing molecular rotation and luminescent properties in solid-state by utilizing crystalline N-heterocyclic carbene metal complexes”M. jin(Invited). 4th International Caparica Christmas Conference on Translational Chemistry 2021(Online, 11.7-8. 2021)
  2. ”Tackling Solubulity Issues in Organic Synthesis” K. Kubota(Invited), Joint Symposium of Engineering Information Science WPI-ICReDD in Hokkaido University(Online, April, 26, 2021)
  3. "Ball-Mill Organic Synthesis: Mechanoredox and Solid State Cross-Coupling", H. Ito (Invited), Department Webmnar, Indian Institute of Science Education and Research, Kolkata (IISER) (Online, Sep. 30, 2020)
  4. "Experimental Reaction Developments with Power of Computation" Hajime Ito (Invited), 3rd ICReDD International Symposium (Online, Feb. 22-24, 2021)
  5. "Mechanical Response of Gold(I) Complexes" H. Ito (Invited), The 6.5th Crystal Engineering and Emerging Materials Workshop of Ontario and Quebec(Online, May 30-31, 2020)
  6. "Molecular Correlated Rotation in Solid State via Stadium Shaped Hexa-arylbenzene" M. Jin, Cooperative phenomena in framework materials: Faraday Discussion (Online, Oct.13-16, 2020)
  7. "Redox reactions of small organic molecules using ball milling and piezoelectric catalysis" K. Kubota, Cooperative phenomena in framework materials: Faraday Discussion (Online, Oct.13-16, 2020)
  8. "Solid-state cross-coupling as a new tool for organic chemistry" H. Ito (Invited), Mechanochemistry Virtual Symposium #1 (Online, Jan 14, 2021)
  9. "Synthesis of Novel Silylboranes: Versatile Silicon-based Nucleophiles in Organic Synthesis" K. Kubota (Invited), Zoom Main Group Symposium: From Molecules and Materials (Online, Aug.27-28, 2020)
  10. "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)
  11. "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)
  12. "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)
  13. "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)
  14. "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)
  15. "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)
  16. "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)
  17. "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)
  18. "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)
  19. "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)

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