Materials Characterization Support Team

Principal Investigator

PI Name Daisuke Hashizume
Degree D.Sci.
Title Team Leader
Brief Resume
1997 Tokyo Institute of Technology, PhD in Chemistry
1997 Research Associate, Department of Applied Physics and Chemistry, Univ. of Electro-Communications
2002 Research Scientist, Molecular Characterization Team, Advanced Development and Support Center, RIKEN
2011 Senior Research Scientist, Materials Characterization Team, Advanced Technology Support Division, RIKEN
2013 Unit Leader, Materials Characterization Support Unit, Supramolecular Chemistry Division, RIKEN Center for Emergent Matter Science
2018 Team Leader, Materials Characterization Support Team, Supramolecular Chemistry Division, RIKEN Center for Emergent Matter Science (-present)

Outline

Our team provides research support by means of X-ray diffractometry, electron microscopy, and elemental analysis. In addition to supporting the individual method, we propose multifaceted research support by combining these methods. To keep our support at the highest quality in the world, we always update our knowledge and make training in our skills. We make tight and deep collaboration with researchers to achieve their scientific purposes and to propose new insights into the research from an analytical point of view, in addition to providing routine analysis. Furthermore, we explore and develop new measurement methods directed to more advanced and sophisticated analyses.

Research Fields

Structural Chemistry, Analytical Chemistry, Materials Science

Keywords

X-ray crystal structure analysis
Electron microscopy
Chemical analysis

Results

Visualization of chemical bonds by accurate X-ray analysis

Our team has investigated the nature of molecules, which have unusual chemical bonds and show less stability, in the crystalline state by analyzing the distribution of valence electrons derived from accurate and precise single-crystal X-ray crystal structure analysis.

   The conventional X-ray diffraction method clarifies the arrangement of atoms in the crystalline state by modeling total electron density distribution using spherical atom (isolated atom) models. As widely recognized, the resulted structures give important information on the nature of molecules. However, valence density distribution, which plays a critical role in the chemistry of molecules, is not included in the resulted models. For deeply understanding of the nature and chemistry of the analyzed molecule, in particular, reactivity, charge separation, bonding mode, and intermolecular interaction, the valence densities should be analyzed. In this study, the valence densities are analyzed by applying multipole models instead of the spherical atom models to gain much direct information on the electronic structure of molecules.

Figure

Distribution of 3d-electrons in Ni(II) complex and bonding electrons.
Licensed under CC BY 4.0.

Members

Daisuke Hashizume

Team Leader hashi[at]riken.jp R

Keiko Suzuki

Senior Technical Scientist

Daishi Inoue

Expert Technician

Tomoka Kikitsu

Technical Staff I

Kiyohiro Adachi

Technical Staff I

Publications

  1. A. Li, S. Kong, C. Guo, H. Ooka, K. Adachi, D. Hashizume, Q. Jiang, H. Han, J. Xiao, and R. Nakamura

    Enhancing the stability of cobalt spinel oxide towards sustainable oxygen evolution in acid

    Nat. Catal. 5, 109–118 (2022)
  2. T. Kubo, Y. Suga, D. Hashizume, H. Suzuki, T. Miyamoto, H. Okamoto, R. Kishi, and M. Nakano

    Long Carbon-Carbon Bonding beyond 2 angstrom in Tris(9-fluorenylidene)methane

    J. Am. Chem. Soc. 143, 14360-14366 (2021)
  3. T. Kajitani, K. Motokawa, A. Kosaka, Y. Shoji, R. Haruki, D. Hashizume, T. Hikima, M. Takata, K. Yazawa, K. Morishima, M. Shibayama, and T. Fukushima

    Chiral crystal-like droplets displaying unidirectional rotational sliding

    Nat. Mater. 18, 266 (2019)
  4. S. Park, S. W. Heo, W. Lee, D. Inoue, Z. Jiang, K. Yu, H. Jinno, D. Hashizume, M. Sekino, T. Yokota, K. Fukuda, K. Tajima, and T. Someya

    Self-powered ultra-flexible electronics via nano-grating-patterned organic photovoltaics

    Nature 561, 516 (2018)
  5. Y. Sohtome, G. Nakamura, A. Muranaka, D. Hashizume, S. Lectard, T. Tsuchimoto, M. Uchiyama, and M. Sodeoka

    Naked d-orbital in a centrochiral Ni(II) complex as a catalyst for asymmetric [3+2] cycloaddition

    Nat. Commun. 8, 14875 (2017)

Articles

お問い合わせ

2-1 Hirosawa, Wako, Saitama 351-0198 Japan

E-mail:
hashi[at]riken.jp

Links