Ligand Rigidification for Enhancing the Stability of Metal-Organic Frameworks
Ligand Rigidification for Enhancing the Stability of Metal-Organic Frameworks
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配体刚性化增强金属有机框架的稳定性
DOI：
10.1021/jacs.9b02947
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发表时间：
2019-07-03
影响因子：
15
通讯作者：
Zhou, Hong-Cai
中科院分区：
文献类型：
--
作者：
Lv, Xiu-Liang;Yuan, Shuai;Zhou, Hong-Cai
在过去的二十年里，金属有机骨架(MOF)以意想不到的速度发展。然而，大多数MOF的化学稳定性不令人满意，阻碍了这一领域的一些基础研究和这些材料的实际应用。MOF框架中的稳定性主要取决于M-L(M=金属离子，L=配体)配位键的稳定性。然而，有机连接物作为框架稳定剂的作用，特别是连接物的刚性/柔韧性，大多被忽视。在这项工作中，我们证明了配基强化策略可以提高MOF的稳定性。制备了连接性相同但柔韧性不同的三个系列的配体旋转体。合成了13个含Zr6O4(OH4)(-CO2)(N)单元(n=8或12)和相应配体的锆基MOF。这些MOF使我们能够评估配体的刚性、连接性和结构对所得材料稳定性的影响。研究发现，骨架中配体的刚性对相应MOF的稳定性有很大贡献。此外，在一些化学稳定的MOF上进行了水的吸附，表现出了良好的性能。利用这一策略，有望设计和构建更多具有良好稳定性的MOF，最终推动合成化学和实际应用领域具有更高稳定性的MOF的发展。
Metal-organic frameworks (MOFs) have been developing at an unexpected rate over the last two decades. However, the unsatisfactory chemical stability of most MOFs hinders some of the fundamental studies in this field and the implementation of these materials for practical applications. The stability in a MOF framework is mostly believed to rely upon the robustness of the M-L (M = metal ion, L = ligand) coordination bonds. However, the role of organic linkers as agents of stability to the framework, particularly the linker rigidity/flexibility, has been mostly overlooked. In this work, we demonstrate that a ligand-rigidification strategy can enhance the stability of MOFs. Three series of ligand rotamers with the same connectivity but different flexibility were prepared. Thirteen Zr-based MOFs were constructed with the Zr6O4(OH4)(-CO2)(n) units (n = 8 or 12) and corresponding ligands. These MOFs allow us to evaluate the influence of ligand rigidity, connectivities, and structure on the stability of the resulting materials. It was found that the rigidity of the ligands in the framework strongly contributes to the stability of corresponding MOFs. Furthermore, water adsorption was performed on some chemically stable MOFs, showing excellent performance. It is expected that more MOFs with excellent stability could be designed and constructed by utilizing this strategy, ultimately promoting the development of MOFs with higher stability for synthetic chemistry and practical applications.