Zr- and Hf-Based Metal-Organic Frameworks: Tracking Down the Polymorphism
Zr- and Hf-Based Metal-Organic Frameworks: Tracking Down the Polymorphism
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DOI：
10.1021/cg301691d
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发表时间：
2013-03-01
影响因子：
3.8
通讯作者：
Kaskel, Stefan
中科院分区：
文献类型：
--
作者：
Bon, Volodymyr;Senkovska, Irena;Kaskel, Stefan
六种新型的基于Zr（IV）和Hf（IV）的MOFs，即DUT-67、DUT-68和DUT-69（DUT，Dresden University of Technology），使用乙酸作为调节剂和弯曲的2，5-噻吩二羧酸酯（tdc（2-））作为配体的调节合成方法获得。该调节剂不仅增加了MOF微晶的尺寸，而且还起到了结构导向剂的作用，影响了所得框架的二级结构单元（SBU）连接性和拓扑结构。DUT-67的结构基于reo底层网络，其特征在于立方八面体和八面体孔，因此与DUT-51等网格。DUT-68材料具有更复杂的分级孔系统，包括菱形立方八面体中孔，被立方八面体、正方形反棱柱和八面体微笼包围。DUT-69是含有10个连接SBU的Zr基MOF的第一个示例。DUT-69具有bct拓扑结构，具有沿沿着一个晶体学方向延伸的八面体笼和通道。根据X射线单晶分析，在高调制剂浓度下获得的DUT-67和DUT-68的孔部分被另外的簇占据。发现所有新型材料都是坚固的、亲水的、化学和热稳定的。DUT-67（Zr）和DUT-67（HO）的BET比表面积分别为1064和810 m2.g（-1），DUT-68（Zr）和DUT-68（HO）的BET比表面积分别为891和749 m2.g（-1），DUT-69（Zr）和DUT-69（Hf）的BET比表面积分别为560和450 m2.g（-1）。
Six novel Zr(IV)- and Hf(IV)-based MOFs, namely DUT-67, DUT-68, and DUT-69 (DUT, Dresden University of Technology) were obtained using a modulated synthesis approach with the acetic acid as a modulator and the bent 2,5-thiophenedicarboxylate (tdc(2-)) as a ligand. The modulator not only increases the size of the MOF crystallites but also plays a role of a structure directing agent, affecting both the secondary building unit (SBU) connectivity and topology of the resulting frameworks. The structure of DUT-67 is based on the reo underlying net, characteristic for its cuboctahedral and octahedral pores and is therefore isoreticular to DUT-51. The DUT-68 material has a more complicated hierarchical pore system including rhombicuboctahedral mesopore, surrounded by cuboctahedral, square-antiprismatic and octahedral microcages. DUT-69 is the first example of Zr-based MOF containing 10-connected SBU. DUT-69 has bct topology, possessing octahedral cages and channels running along one crystallographic direction. In accordance with X-ray single crystal analysis, the pores of DUT-67 and DUT-68, which were obtained at high modulator concentrations, are partially occupied by additional clusters. All novel materials are found to be robust, hydrophilic, chemically, and thermally stable. The BET specific surface area amounts to 1064 and 810 m(2).g(-1) for DUT-67(Zr) and DUT-67(HO, 891 and 749 m(2).g(-1) for DUT-68(Zr) and DUT-68(HO, and 560 and 450 m(2).g(-1) for DUT-69(Zr) and DUT-69(Hf), respectively.