Hidehiro Uekusa

School of Science, Tokyo Institute of Technology
Associate Professor
A01

Research AreasChemical Crystallography
Participating Group (2020-2021)

Structural elucidation of gas-crystal reaction vapochromism in organic crystals

Co-Researcher
Co-Researcher: Akiko Sekine (School of Science, Tokyo Institute of Technology, Assistant Professor)
Co-Researcher: Haruki Sugiyama (The Research and Education Center for Natural Science, Keio University , Assistant Professor)

Research Outline

Vapochromic organic crystals, which react in response to vapor exposure to crystals, reversibly undergo phase transition and change in color. They are typical examples of “soft crystals” and are also important as gas sensor materials. In this research, we aim to create new vapochromic organic crystals and to clarify the principle of vapochromism based on the crystal structures. In particular, the detailed molecular structure and crystal structure changes are important, and it is possible to perform crystal analysis even if the single crystal is disintegrated by crystal transition, utilizing microcrystal analysis or powder crystal analysis method.
As the principle of new organic vapochromism, it is important that the electronic state change induced by the change of the intermolecular interaction due to dehydration. Thus, the target of this research is a molecular system showing molecular structure and property change due to inter- or intra-molecular proton transfer.
The mechanism and design principle of vapochromic organic crystals are expected to be applied to create gas sensor materials for detecting various harmful vapors.

Vapochromic organic crystals
Crystal structure analysis methods of before and after phase transition
Participating Group (2018-2019)

Structure Analysis of Organic Vapochromic crystals by SDPD

Keywords
Vapochromism, Soft Crystal, Organic Crystal, Structure Determination from Powder Diffraction Data, X-ray Crystal Structure Analysis, Vapor Induced Phase Transition, Dehydration Transition, Hydration Transition

Research Outline

Vapochromic organic crystals, which react in response to vapor exposure to crystals, reversibly undergo phase transition and change in color. They are typical examples of “soft crystals” and are also important as gas sensor materials. In this research, we aim to create new vapochromic organic crystals and to clarify the principle of vapochromism based on the crystal structures. In particular, the detailed molecular structure and crystal structure changes are important, and it is possible to perform crystal analysis even if the single crystal is disintegrated by crystal transition, utilizing microcrystal analysis or powder crystal analysis method.
As the principle of new organic vapochromism, it is important that the electronic state change induced by the change of the intermolecular interaction due to dehydration. Thus, the target of this research is a molecular system showing molecular structure and property change due to inter- or intra-molecular proton transfer.
The mechanism and design principle of vapochromic organic crystals are expected to be applied to create gas sensor materials for detecting various harmful vapors.

Vapochromic organic crystals
Crystal structure analysis methods of before and after phase transition

Publications

Academic papers/reviewed

A01-15

  1. "Isomeric Difference in the Crystalline-state Chemiluminescence Property of an Adamantylideneadamantane 1,2-Dioxetane with a Phthahlimide Chromophore" C. Matsuhashi, T. Ueno, H. Uekusa, A. Sato-Tomita, K. Ichiyanagi, S. Maki and T. Hirano, Chemical Communications, 2020, 56(23), 3369-3372.
  2. "Reversible on/off switching of photochromic properties in N-salicylideneaniline co-crystals by heating and humidification" H. Sugiyama, K. Johmoto, A. Sekine, H. Uekusa, CrystEngComm, 2019, 21, 3170-3175.
  3. "Triplon band splitting and topologically protected edge states in the dimerized antiferromagnet" K. Nawa, K. Tanaka, N. Kurita, T. J. Sato, H. Sugiyama, H. Uekusa, S. Ohira-Kawamura, K. Nakajima, H. Tanaka, Nature Commun., 2019, 10, 2096.
  4. "Capturing a new hydrate polymorph of amodiaquine dihydrochloride dihydrate via heterogeneous crystallisation" P. O. Dwichandra, A. Pettersen, S. O.N. Lill, D. Umeda, E. Yonemochi, Y. P. Nugraha, H. Uekusa, CrystEngComm, 2019, 21, 2053-2057.

Related Website(s)
Contact
uekusa[at]chem.titech.ac.jp