Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710119, China.
Frontiers Science Center for High Energy Material, Advanced Technology Research Institute (Jinan), School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China.
J Am Chem Soc. 2020 Sep 2;142(35):14848-14853. doi: 10.1021/jacs.0c07257. Epub 2020 Aug 19.
Enzymes use a confined docking cavity and residual groups in the cavity to regulate substrate selectivity and catalytic activity. By mimicking enzymes, we herein report that metal-organic framework (MOF) -, with channels and inside-channel pyridyl groups, can promote orthoformate hydrolysis in basic solutions. By studying pH-dependent hydrolysis and using an analogue MOF that lacks inside-channel pyridyl groups, we proved protonated pyridyl groups as acid catalytic sites for orthoformate hydrolysis. By using MOFs with only open pyridyl groups, we demonstrated the necessity of the confined channels. X-ray diffraction structures of - with encapsulated substrates confirmed that these channels can regulate activity and size selectivity. Recycling tests and crystallographic studies confirmed that - kept its framework structure in catalysis. This work shows the potentials of using MOFs for host-guest catalysis that cannot be otherwise completed and underlines the advantages of using crystal engineering to identify active sites.
酶利用受限的对接腔和腔内残基来调节底物选择性和催化活性。通过模拟酶，我们在此报告金属-有机骨架（MOF）-具有通道和通道内吡啶基团，可以在碱性溶液中促进原甲酸酯的水解。通过研究 pH 依赖性水解并使用缺乏通道内吡啶基团的类似 MOF，我们证明了质子化吡啶基团是原甲酸酯水解的酸催化位点。通过使用只有开放吡啶基团的 MOFs，我们证明了受限通道的必要性。带有封装底物的 - 的 X 射线衍射结构证实了这些通道可以调节活性和尺寸选择性。回收测试和晶体学研究证实 - 在催化过程中保持其框架结构。这项工作表明了使用 MOF 进行主客体催化的潜力，这是其他方法无法完成的，并强调了使用晶体工程来识别活性位点的优势。
