Takashi Tachikawa

Molecular Photoscience Research Center, Kobe University
Associate Professor
A03
Research AreasPhysical Chemistry, Photochemistry
Participating Group (2020-2021)

Single-Particle Emission Observation of Stimulation-Induced Structural Dynamics of Soft Crystals

Keywords
Single-Particle Spectroscopy, Fluorescence Imaging, Soft Crystal, Photochemical Reaction

Research Outline

A functional soft crystal that responds to a specific stimulus as if it is a biomolecule, and can instantaneously change its structure, physical properties, and reactivity can be a source of science and technology innovation. In soft crystals that have been subjected to external stimuli such as adsorption and uptake of molecules and ions, mechanical stimuli or light irradiation, dynamic structural transformation would proceed via localized nuclei. In this study, we will identify metastable states formed during photoinduced structural changes of organic and inorganic hybrid crystals or crystal-amorphous phase transition of mechanochromic organic dyes by means of by single-particle fluorescence spectroscopy. In particular, by monitoring emission behaviors in real time, we will capture elementary reaction steps such as structural transitions that are masked in bulk samples. Consequently, we will clarify the continuity and cooperativeness of structural changes in individual crystals experimentally.

Single-Particle Emission Observation of Stimulation-Induced Structural Changes of Soft Crystals
Participating Group (2018-2019)

Single-Particle Emission Observation of Stimulation-Induced Structural Changes of Soft Crystals

Keywords
Single-Particle Spectroscopy, Fluorescence Imaging, Soft Crystal, Photochemical Reaction, Structural Change

Research Outline

A functional soft crystal that responds to a specific stimulus as if it is a biomolecule, and can instantaneously change its structure, physical properties, and reactivity can be a source of science and technology innovation. In soft crystals that have been subjected to external stimuli such as adsorption and uptake of molecules and ions, mechanical stimuli or light irradiation, dynamic structural transformation would proceed via localized nuclei. In this study, we will identify organic and inorganic hybrid crystals and vapor-responsive organic crystals as soft crystals and observe correlated structure-emission changes induced by a few molecules, ultimately only one molecule or ion by single-particle fluorescence spectroscopy for understanding reaction mechanisms. In particular, by monitoring emission behaviors in real time, we will capture elementary reaction steps such as structural transitions that are masked in bulk samples. Consequently, we will clarify the continuity and cooperativeness of structural changes in individual crystals experimentally.

Single-Particle Emission Observation of Stimulation-Induced Structural Changes of Soft Crystals

Publications

Academic papers/reviewed

A03-17

  1. "Dynamic Symmetry Conversion in Mixed-Halide Hybrid Perovskite upon Illumination" *S. Tominaka, I. Karimata, T. Matsuoka, M. Sakamoto, T. Nakajima, K. Ohara, *T. Tachikawa, ACS Energy Lett., 6, 3858-3863 (2021).
    DOI: 10.1021/acsenergylett.1c01798
  2. "Formation of Mixed-Valence Luminescent Silver Clsters via Cation-Coupled Electron-Transfer in a Redox-Active Ionic Crystal Based on a Dawson-type Polyoxometalate with Closed Pores" N. Haraguchi, T. Okunaga, Y. Shimoyama, N. Ogiwara, S. Kikkawa, S. Yamazoe, M. Inada, T. Tachikawa, *S. Uchida, Eur. J. Inorg. Chem., 16, 1531-1535 (2021).
    DOI: 10.1002/ejic.202100101
  3. "Organic photostimulated luminescence associated with persistent spin-correlated radical pairs" M. Sakurai, *R. Kabe, M. Fuki, Z. Lin, K. Jinnai, Y. Kobori, C. Adachi, *T. Tachikawa, Commun. Mater., 2, 74 (2021).
    DOI: 10.1038/s43246-021-00178-3
  4. "Terahertz Spectroscopic Measurements and Solid-State Density Functional Calculations on CH3NH3PbBr3 Perovskites: Short-Range Order of Methylammonium" F.Zhang, I. Karimata, H.-W. Wang, *T. Tachikawa, *K. Tominaga, *M. Hayashi, T. Sasaki, J. Phys. Chem. C, 126, 339-348 (2022).
    DOI: 10.1021/acs.jpcc.1c06988
  5. "In Situ Exploration of the Structural Transition during Morphology- and Efficiency-Conserving Halide Exchange on a Single Perovskite Nanocrystal" I. Karimata, *T. Tachikawa, Angew. Chem. Int. Ed., 60, 2548-2553 (2021).
    DOI: 10.1002/anie.202013386
  6. "Ultra-Narrow Depletion Layers in a Hematite Mesocrystal-Based Photoanode for Boosting Multihole Water Oxidation" Z. Zhang, H. Nagashima, *T. Tachikawa, Angew. Chem. Int. Ed., 59, 9047-9054 (2020).
    DOI: 10.1002/anie.202001919
  7. "Interfacial oxygen vacancies yielding long-lived holes in hematite mesocrystal-based photoanodes" Z. Zhang, I. Karimata, H. Nagashima, S. Muto, K. Ohara, K. Sugimoto, *T. Tachikawa, Nat. Commun., 10, Article number: 4832 (2019).
    DOI: 10.1038/s41467-019-12581-z
  8. "Structural Dynamics of Lipid Bilayer Membranes Explored by Magnetic Field Effect Based Fluorescence Microscopy" M. Sakurai, Y. Kobori, *T. Tachikawa, J. Phys. Chem. B, 123, 10896-10902 (2019).
    DOI: 10.1021/acs.jpcb.9b09782
  9. "Mechanistic Insights into Photochemical Reactions on CH3NH3PbBr3 Perovskite Nanoparticles from Single-Particle Photoluminescence Spectroscopy" Y. Kimura, I. Karimata, Y. Kobori, T. Tachikawa, ChemNanoMat, 2019, 5, 340-345.
    DOI: 10.1002/cnma.201800569
  10. "Rapid Formation of Small Mixed-Valence Luminescent Silver Clusters via Cation-Coupled Electron-Transfer in Redox-Active Porous Ionic Crystal Based on Dodecamolybdophosphate" S. Uchida, T. Okunaga, Y. Harada, S. Magira, Y. Noda, T. Mizuno, T. Tachikawa, Nanoscale, 2019, 11, 5460-5466.
    DOI: 10.1039/C9NR00103D
  11. "Several Orders of Magnitude Difference in Charge-Transfer Kinetics Induced by Localized Trapped Charges on Mixed-Halide Perovskites" I. Karimata, K. Ohta, Y. Kobori, T. Tachikawa, ACS Appl. Mater. Interfaces, 2018, 10, 37057-37066.
    DOI: 10.1021/acsami.8b13346
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Contact
tachikawa[at]port.kobe-u.ac.jp