Yasuchika Hasegawa

Graduate School of Engineering, Hokkaido University

Research AreasPhotochemistry, Coordination Chemistry
Participating Group (2020-2021)

Soft-crystal and photophysical transformations from lanthanide complex to coordination polymer

Luminescence, Soft Crystal, Lanthanide Complex, Lanthanide Coordination Polymer
Co-Researcher: Yuichi Kitagawa (Hokkaido University Institute for Chemical Reaction Design and Discover, Lecturer)

Research Outline

Luminescence properties of lanthanide complexes are strongly depended on their coordination geometrical structures (Laporte allowed transitions). In this study, new-type soft crystal transformation based on the changeable lanthanide coordination number and geometry under out-triggers is demonstrated. In particular, soft crystal transformation from seven- to eight-coordinated europium(III) complexes under out-trigger (addition/removement of pyridine derivatives) are investigated. The reversible soft crystal transformation in solid state are characterized using X-ray analyses, photophysical measurements (emission spectral analyses, emission quantum yields, emission lifetimes, radiative rate analyses, LMCT (ligand to Eu(III) charge transfer) analyses etc.). The soft crystal transformation and photophysical analysis (excited energy transfer process in transformed intermediates) from seven-coordinated lanthanide complex to eight-coordinated lanthanide coordination polymer are also studied.

Soft crystal transformation from lanthanide complex to coordination polymer
Transition state in soft crystal transformation
Participating Group (2018-2019)

Synthesis and Photo-functional Characterization of Chiral Lanthanide Coordination Polymer with Soft Crystals Transformation

Glass Transformation, Chiral, Lanthanide Complex, Luminescence
Co-Researcher: Takayuki Nakanishi (Graduate School of Industrial Science and Technology, Tokyo University of Science, Lecturer)
Co-Researcher: Yuichi Kitagawa (Hokkaido University Institute for Chemical Reaction Design and Discover, Lecturer)

Research Outline

Lanthanide complexes with chiral ligands shows circularly polarized luminescence (CPL) with large dissymmetry factor. The photo-functional properties of aggregations composed of chiral lanthanide coordination polymers open up a frontier field of science. In this study, synthesis and photo-functional characterization of chiral lanthanide coordination polymer with crystal-phase transition (soft crystals transformation) are explored. The chiral lanthanide coordination polymers are prepared by the complexation of chiral Eu(III) complexes with phosphine oxides with ethynyl groups. Their transformed structures and photophysical properties are characterized using X-ray analysis, circular dichroism (CD) and CPL spectra. The photosensitized energy transfer process of chiral Eu(III)/Tb(III)coordination polymers is also evaluated using Arrhenius analysis.

Chiral Lanthanide Coordination Polymer with Crystal-phase transitions
Lanthanide Coordination Polymer with ethynyl groups


Academic papers/reviewed


  1. "Asymmetric Lumino-Transformer: Circularly Polarized Luminescence of Chiral Eu(III) Coordination Polymer with Phase-Transition Behavior" Makoto Tsurui, Yuichi Kitagawa, Sunao Shoji, Hitomi Ohmagari, Miki Hasegawa, Masayuki Gon, Kazuo Tanaka, Masato Kobayashi, Tetsuya Taketsugu, Koji Fushimi, and Yasuchika Hasegawa*,Phys. Chem. B 2022, 126, 20, 3799–3807.(Cover Picture)(領域内共同研究A03長谷川美)
  2. Photonic molecular trains in soft-crystal polymerization of transformative lanthanide coordination centres
    Pedro Paulo Ferreira da Rosa,1 Yuichi Kitagawa,2,4 Sunao Shoji,2,4 Hironaga Oyama,5 Keisuke Imaeda,3 Naofumi Nakayama,6 Koji Fushimi,2 Hidehiro Uekusa,5 Kosei Ueno,3 Hitoshi Goto,7 and Yasuchika Hasegawa2,4*, Nature Commun. in press.(領域内共同研究 A02 後藤, A02公募植草)リョウイキナ
  3. “Amide-bridged Eu(III) coordination polymer for stable luminescent glass material” J. Hayashi, S. Shoji, Y. Kitagawa, K. Fushimi, Y. Hasegawa*, Mater. Lett. 297, 130012 (2021).
  4. “Bright red emission with high color purity from Eu(III)complexes with Pai-cinjugated polycyclic aromatic loigands and their sensing applications” Y. Kitagawa, M. Tsurui, Y. Hasegawa*, RSC Adv. 2022,12,810-821.
  5. “Charge-transfer excited states of p- and 4f orbitals for development of luminescent Eu(III) complexes”, Y. Kitagawa*, P.-p. Ferreira da Rosa, Y. Hasegawa*, Dalton Trans. 50, 14978-14984 (2021).
  6. “Hybrid Eu(III) Coordination luminophore Standing on Silica Nanoparticles By Two Legs for Enhanced Luminescence” T. Zhang, Y. Kitagawa, R. Moriake, P. P. Ferreira da Rosa, Md J. Islam, T. Yoneda, Y. Inokuma, K. Fushimi, Y. Hasegawa*, Chem. Eur.J. 27, 14438-14443 (2021). (Cover Feature)
  7. “Long-lived emission beyond 1000 nm: control of excited-state dynamics in a dinuclear Tb(III)-Nd(III) complex” Y. Kitagawa*, K. Matsuda, P. P. Ferreira da Rosa, K. Fushimi, Y. Hasegawa*, Chem. Comm. 57, 8047-8050 (2021).
  8. “Strong circularly polarized luminescence of mixed lanthanide coordination polymers with control of 4f electronic structures” Y. Kitagawa*, P.-P. Ferreira da Rosa, Y. Hasegawa*, Dalton Trans. 50, 5433-5436 (2021).
  9. Luminescent Lanthanide Coordination Polymers with Transformative Energy Transfer Processes for Physical and Chemical Sensing Applications, Y. Hasegawa*, Y. Kitagawa, J. Photochem. Photobio. C, Photochem. Rev. in press (2022).
  10. "Aggregation-induced emission of a Eu(III) complex via ligand-to-metal charge transfer" Y. Kitagawa*, M. Kumagai, K. Fushimi, Y. Hasegawa*, Chem. Phys. Lett., 749, 137437 (2020).
  11. "An Europium (III) Luminophore with Pressure-Sensing Units: Effective Back Energy Transfer in Coordination Polymers with Hexadentate Porous Stable Networks" Y. Hasegawa*, T. Sawanobori, Y. Kitagawa, S. Shoji, K. Fushimi, Y. Nakadaka, T. Masuda, I. Hisaki, ChemPlusChem., 85, 1989-1993 (2020).
  12. "Chiral lanthanide lumino-glass for a circularly polarized light security device" Y. Kitagawa*, S. Wada, MD J. Islam, K. Saita, M. Gon, K. Fushimi, K. Tanaka, S. Maeda, Y. Hasegawa*, Comms. Chem., 3, 119 (2020).
  13. "Circularly Polarized Absorption and Luminescence of Semiconductor Eu-OCN Nanocrystals in the Blue Region of the Electromagnetic Spectrum" Yasuchika Hasegawa, Katsumasa Koide, Makoto Tsurui, Yuichi Kitagawa,Takayuki Nakanishi, Yoshihiro Doi, Yukio Hinatsu, and Koji Fushimi, ChemPhysChem, 2020, 21, 2019-2024(Cover Feature)
  14. "Electronic strain effect on Eu(III) complexes for enhanced circularly polarized luminescence" M. Tsurui, Y. Kitagawa, K. Fushimi, M. Gon, K. Tanaka, Y. Hasegawa*, Dalton Trans., 49, 5352-5361 (2020).
  15. "First Tribo-excited Chemical Reaction of a Stacked Lanthanide Coordination Polymer with in Situ Reaction Monitor " Y. Kitagawa*, A. Naito, K. Fushimi, Y. Hasegawa*, Chem. Eur. J., 27(1), 2279-2283. (Cover Feature)
  16. "Long-range LMCT coupling in Eu(III) coordination polymers for an effective molecular luminescent thermometer" Y. Kitagawa*, M. Kumagai, P.-P. Ferreira da Rosa, K. Fushimi, Y. Hasegawa*, Chem. Eur. J., 27, 264-269 (2021). (Cover Feature)
  17. "Lifetimes of Lanthanide(III) Triboluminescence Excited by Aerodynamic Shock Waves" Y. Hirai, A. Kotani, H. Sakaue, Y. Kitagawa, Y. Hasegawa*, J. Phys. Chem. C, 123, 27251-27256 (2019).
  18. "Near-IR luminescent Yb(III) coordination polymers composed of pyrene derivatives for thermo-stable oxygen sensors" Y. Hasegawa*, T. Matsui, Y. Kitagawa, T. Nakanishi, T. Seki, H. Ito, Y. Nakasaka, T. Masuda, K. Fushimi, Chem. Eur. J., 25, 12308-12315 (2019). 
  19. "Temperature-sensitive Luminescent lanthanide complexes" *Y. Hasegawa, Y. Kitagawa, J. Mater. Chem. C, 2019, 7494-7511
  20. "Thermal and crystallographic investigation of luminescent Eu(III) coordination polymers with dithiane and dioxane hexyl rings" Y. Hirai, P. P. Ferreira da Rosa, Y.Kitagawa, Y. Hasegawa, Chem. Lett., 48, 1544-1546 (2019).
  21. "Electronic chirality inversion of lanthanide complex induced by achiral molecules" S. Wada, Y. Kitagawa, T. Nakanishi, M. Gon, K. Tanaka, K. Fushimi, Y. Chujo, Y. Hasegawa, Sci. Rep., 2018, 8, 16395.
  22. "Ligand-assisted Back Energy Transfer in Luminescent Tb(III) Complexes for Thermo-sensing Properties" M. Yamamoto, Y. Kitagawa, T. Nakanishi, K. Fushimi, Y. Hasegawa, Chem. Eur. J., 2018, 24, 17719-17726.(Cover Feature)
  23. "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.(領域内共同研究A02-01伊藤肇、A02岩佐、A03-01石井)

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