题目：Structure Study on Nano-porous Crystals

主讲人：Osamu Terasaki

时间：2024年5月8日（周三）10：00

地点：霞光楼220

邀请人：车顺爱 教授

报告人简介

Osamu Terasaki (OT) was born in Yamaguchi (next neighbour of Hiroshima), Japan in 1943 during the World War II. He graduated from Dept Phys, Tohoku Univ Japan in 1965. He was a faculty member of Department of Physics, Tohoku Univ, after receiving his MSc (1967), for 37 years.

During the period, he stayed at Cambridge Univ (1982.09-84.03) and Lund Univ (1988.03-09) to start his research on fine structure of nano-porous crystals. He was one of the first Research Directors of National CREST project, Japan on his project on “New Arrayed Clusters in Microporous Materials: Syntheses, Structures and Physical Properties”, (1995-2000).

He was Prof., Head of Structural Chemistry, Stockholm Univ (2003.04-2010.02) followed by Part-time Prof (4 months/year until 2016.12), KAIST, Korea (2009.09-2019.02), and visiting Prof UC Berkeley, USA (2014.01-2017.12)..

He is working at the Centre for High-resolution Electron Microscopy (CħEM), ShanghaiTech Univ as Distinguished Adjunct Prof (DAP), Prof and Director, and DAP (2015.05 - 2017.04 - 2022.04 -).  

He has received the Friendship Award (2003), the Donald W. Breck Award (2007 & 2019) and Humboldt-Research Award (2008) and the Magnolia Award (2018).

He has been selected as an honorary member of Scandinavian Electron Microscopy Society, Japan Association of Zeolite and Foreign Member of Academia Europaea since 2010, 2014 and 2020, respectively.

He has over 450 publications, average citations per item is 85.7 times and h-index is 89 (as of 2024.03.09, from Web of Science).

Abstract:

Centre for High-resolution Electron Microscopy (CℏEM), SPST and Shanghai Key Laboratory of High-resolution Electron Microscopy, ShanghaiTech University

Once, a set of crystal structure factor CSF(khkl) for all the wave vectors khkl  of hkl reflections, are obtained, then crystalline structure solution can be obtained in a straightforward way.  However diffraction intensity I(khkl) gives information of only amplitude of CSF, so we need to obtain phase information separately (“Phase Problem”)

Nano-porous crystals have unique features due to nanopores periodically arranged in a large unit cell, forming “cavity crystal” structure. They are supported by either (A) crystalline walls, as in zeolites, metal-organic frameworks (MOFs) and covalent-organic frameworks (COFs), or (B) amorphous walls, as in silica mesoporous crystal (SMC).

Taking a few examples, I will discuss briefly electron crystallography (EC) for structural study of the above cases.

For the case of (A), The highly complex structure of SSZ-48 zeolite (designated as framework- type SFE) was solved solely by a set of selected-area electron-diffraction (SAED) patterns, taking dynamical scattering effects into account. This approach established for the 1st time the power of EC in structure determination and characterization of zeolites [1]. The second case, combining high resolution PXRD and TEM data, we solved the structure of zeolite TNU-9 (Framework type TUN), which is the most complex zeolite framework at that time with 24 crystallographically distinct Si-atoms [2].

For the case of (B); We have developed a new method to obtain CSF(khkl), both amplitudes and phases, through Fourier analyses of a set of HRTEM images of a SMC. Numerous structures of SMCs have been solved using this approach [3, 4].

It is becoming increasingly important to determine an absolute structure through (a)HRTEM image change while rotating the crystal perpendicular to an electron incidence [5, 6] or (b) the difference in diffraction intensity between the Friedel pair (or Bijvoet pair) of hkl and -h-k-l reflections or symmetrically equivalent ones [5, 6].

References：

[1] P. Wagner, O. Terasaki, S. Ritsch, J. G. Nery, S. I. Zones, M. E. Davis & K. Hiraga, J. Phys. Chem. B 103 (1999), 8245-8250.

[2] F. Gramm, C. Baerlocher, L. B. McCusker, S. J. Warrender, P. A. Wright, B. Han, S. B, Hong, Z. Liu, T. Ohsuna & O. Terasaki, Nature 444 (2006), 79-81.

[3] Y. Sakamoto, M. Kaneda, O. Terasaki, D. Y. Zhao, J. M. Kim, G. Stucky, H. J. Shin & R. Ryoo, Nature 408 (2000), 449-453.

[4] L. Han, K. Miyasaka & O Terasaki; Chapter 4 Electron Crystallography in “Structure from Diffraction Methods” Pages: 201-258.

[5] T. Ohsuna, Z. Liu, S. Che, O. Terasaki, Small 1 (2005), 233-237.

[6] Y. Ma, P. Oleynikov & O. Terasaki, Nat. Mater. 16 (2017), 755–759.