School of Physical Science and Technology , ShanghaiTech University , Shanghai 201210 , China.
J Am Chem Soc. 2019 Jul 17;141(28):10962-10966. doi: 10.1021/jacs.9b04895. Epub 2019 Jun 27.
Understanding the dynamics of covalent organic frameworks (COFs) is desirable for developing smart materials with coherent responses to external stimulus. Here we illustrate the structural determination of dynamics at atomic level by cryo-electron diffraction tomography (EDT) with single crystals of COF-300 having only submicrometer sizes. We observe and elucidate the crystal contraction upon HO adsorption by structural solution of all non-hydrogen atoms of framework and unambiguous location of guest molecules in the pores. We also observe the crystal expansion of COF-300 upon inclusion of ionic liquid or polymer synthesized in the channels, whose conformational aspects of frameworks can be confirmed.
了解共价有机框架（COFs）的动力学特性对于开发对外界刺激具有连贯响应的智能材料是可取的。在这里，我们通过使用只有亚微米尺寸的 COF-300 单晶的低温电子衍射断层扫描（EDT）来阐明原子级动力学的结构测定。我们通过框架所有非氢原子的结构解决方案以及在孔中客分子的明确位置来观察和阐明 HO 吸附时的晶体收缩。我们还观察到在通道中合成的离子液体或聚合物包含时 COF-300 的晶体膨胀，其框架的构象方面可以得到证实。
