Breathing Effect via Solvent Inclusions on the Linker Rotational Dynamics of Functionalized MIL-53
Breathing Effect via Solvent Inclusions on the Linker Rotational Dynamics of Functionalized MIL-53
复制标题
溶剂包裹体对功能化 MIL™53 连接基旋转动力学的呼吸效应
DOI：
10.1002/chem.202102419
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Deng Feng
中科院分区：
文献类型：
--
作者：
Tang Jing;Chu Yueying;Li Shenhui;Xu Jun;Xiong Wenpeng;Wang Qiang;Deng Feng
The breathing effects of functionalized MIL‐53‐X (X=H, CH3, NH2, OH, and NO2) induced by the inclusions of water, methanol, acetone, and N,N‐dimethylformamide solvents were comprehensively investigated by solid‐state NMR spectroscopy. 2D homo‐nuclear correlation NMR provided direct experimental evidence for the host‐guest interaction between the guest solvents and the MOF frameworks. The variations of the1H and13C NMR chemical shifts in functionalized MIL‐53 from the narrow pore phase transitions to large pore forms due to solvent inclusions were clearly identified. The influence of functionalized linkers and their host‐guest interactions with the confined solvents on the rotational dynamics of the linkers was examined by separated‐local‐field MAS NMR experiments in conjunction with DFT theoretical calculations. It is found that the linker rotational dynamics of functionalized MIL‐53 in narrow pore form is closely related to the computational rotational energy barrier. The BDC‐NO2linker of activated MIL‐53‐NO2undergoes relatively faster rotation, whereas the BDC‐NH2and BDC‐OH linkers of activated MIL‐53‐NH2and MIL‐53‐OH exhibit relatively slower rotation. The host‐guest interactions between confined solvents and MIL‐53‐NO2, MIL‐53‐CH3would significantly induce an increase of the order parameters of unsubstituted carbon and reduce the rotational frequency of linkers. This study provides a spectroscopic approach for the investigation of linker rotation in functionalized MOFs at natural abundance with solvents inclusions.
