State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, Gansu 730000, China.
College of Chemistry and Molecular Engineering, Beijing National Laboratory for Molecular Sciences, Peking University, Beijing 100871, China.
Science. 2018 Jul 6;361(6397):48-52. doi: 10.1126/science.aat7679.
The crystallization problem is an outstanding challenge in the chemistry of porous covalent organic frameworks (COFs). Their structural characterization has been limited to modeling and solutions based on powder x-ray or electron diffraction data. Single crystals of COFs amenable to x-ray diffraction characterization have not been reported. Here, we developed a general procedure to grow large single crystals of three-dimensional imine-based COFs (COF-300, hydrated form of COF-300, COF-303, LZU-79, and LZU-111). The high quality of the crystals allowed collection of single-crystal x-ray diffraction data of up to 0.83-angstrom resolution, leading to unambiguous solution and precise anisotropic refinement. Characteristics such as degree of interpenetration, arrangement of water guests, the reversed imine connectivity, linker disorder, and uncommon topology were deciphered with atomic precision-aspects impossible to determine without single crystals.
结晶问题是多孔共价有机骨架（COFs）化学中的一个突出挑战。它们的结构表征仅限于基于粉末 X 射线或电子衍射数据的建模和解决方案。尚未报道可用于 X 射线衍射表征的 COFs 单晶。在这里，我们开发了一种通用程序来生长三种基于亚胺的 COFs（COF-300、COF-300 的水合形式、COF-303、LZU-79 和 LZU-111）的大单晶。这些晶体的高质量允许收集高达 0.83-埃分辨率的单晶 X 射线衍射数据，从而可以明确地解决和精确地各向异性精修。通过原子精度揭示了诸如互贯程度、水客体的排列、反向亚胺连接、连接体无序和不常见拓扑等特征——没有单晶就不可能确定这些特征。
