Liu Bo, Zhou Hui-Fang, Hou Lei, Wang Yao-Yu
College of Chemistry & Pharmacy, Northwest A&F University, Yangling 712100, P. R. China.
Dalton Trans. 2018 Apr 17;47(15):5298-5303. doi: 10.1039/c8dt00502h.
A new Zn(ii) metal-organic framework (MOF) [Me2NH2][Zn2(BDPP)(HTZ)]·4DMF (1) (H4BDPP = 3,5-bis(3,5-dicarboxylphenyl)pyridine, HTZ = 1H-tetrazole) has been constructed under solvothermal conditions by using a mixed-ligand strategy. Structural analysis demonstrates that 1 is a 3D framework based on four kinds of secondary building units (SBUs), which presents a rare structure constructed from quaternary SBUs and shows an uncommon (3,3,4,6)-connected topology. In particular, 1 contains two shapes of 1D open channels with suitable pore sizes, high porosity, and a highly polar pore system decorated with uncoordinated N atoms and carboxylic O atoms, providing a good environment for selective adsorption of CO2. Inspired by the structure of 1 and reticular chemistry, 5-amino-1H-tetrazole (ATZ) was used to replace 1H-tetrazole to enhance CO2 sorption capacity by pore surface modification; as a result, an amino-functionalized MOF, [Me2NH2][Zn2(BDPP)(ATZ)]·4DMF (1-NH2) was successfully built. 1-NH2 exhibits multipoint interactions between the CO2 molecules and the framework, resulting in better CO2 uptake and selectivity for CO2 over CH4 than 1.
一种新型的锌（II）金属有机框架（MOF）[Me2NH2][Zn2(BDPP)(HTZ)]·4DMF（1）（H4BDPP = 3,5-双（3,5-二羧基苯基）吡啶，HTZ = 1H-四唑）已通过混合配体策略在溶剂热条件下构建而成。结构分析表明，1是基于四种二级构筑单元（SBU）的三维框架，呈现出由四元SBU构建的罕见结构，并显示出罕见的（3,3,4,6）连接拓扑结构。特别地，1包含两种具有合适孔径、高孔隙率以及由未配位的N原子和羧基O原子修饰的高极性孔系统的一维开放通道，为CO2的选择性吸附提供了良好的环境。受1的结构和网状化学的启发，使用5-氨基-1H-四唑（ATZ）取代1H-四唑，通过孔表面修饰来提高CO2吸附容量；结果，成功构建了一种氨基功能化的MOF，[Me2NH2][Zn2(BDPP)(ATZ)]·4DMF（1-NH2）。1-NH2在CO2分子与框架之间表现出多点相互作用，导致其对CO2的吸附量比1更好，且对CO2相对于CH4的选择性更高。
