Materials Characterization Support Unit

Principal Investigator

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

Outline

Our unit provides research support by means of X-ray crystal structure analysis, electron microscopy, and elemental analysis. In addition to supporting on the individual method, we propose multifaceted research support by combining these methods. To keep our support at the highest level quality, 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 analytical point of view, in addition to providing routinely analysis. Furthermore, we challenge to develop unexplored measurement methods directed to more advanced and sophisticated analysis.

Research Fields

Structural Chemistry, Analytical Chemistry, Materials Sciences

Keywords

X-ray crystal structure analysis
Electron microscopy
Chemical analysis

Results

Visualization of chemical bonds by accurate X-ray analysis

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

   Conventional X-ray diffraction method clarifies 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 critical roles in chemistry of molecule, is not included in the resulted models. For deeply understanding 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.

Electron donation from σ (C−C) orbital to Si atom visualized by accurate X-ray analysis.

Members

Daisuke Hashizume

Unit Leader hashi[at]riken.jp R

Keiko Suzuki

Senior Technical Scientist

Daishi Inoue

Technical Scientist

Tomoka Kikitsu

Technical Staff I

Yoshio Maebashi

Technical Staff I

Chieko Kariya

Special Temporary Employee

Articles

お問い合わせ

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

E-mail:
hashi[at]riken.jp

Links