Handke Marcel, Weber Hanna, Lange Marcus, Möllmer Jens, Lincke Jörg, Gläser Roger, Staudt Reiner, Krautscheid Harald
Fakultät für Chemie und Mineralogie, Universität Leipzig , Johannisallee 29, 04103 Leipzig, Germany.
Inorg Chem. 2014 Jul 21;53(14):7599-607. doi: 10.1021/ic500908r. Epub 2014 Jun 26.
An isostructural series of 15 structurally flexible microporous silver metal-organic frameworks (MOFs) is presented. The compounds with a dinuclear silver core as secondary building unit (Ag2N4) can be obtained under solvothermal conditions from substituted triazolyl benzoate linkers and AgNO3 or Ag2SO4; they exhibit 2-fold network interpenetration with lvt topology. Besides the crystal structures, the calculated pore size distributions of the microporous MOFs are reported. Simultaneous thermal analyses confirm the stability of the compounds up to 250 °C. Interconnected pores result in a three-dimensional pore structure. Although the porosity of the novel coordination polymers is in the range of only 20-36%, this series can be regarded as a model system for investigation of network flexibility, since the pore diameters and volumes can be gradually adjusted by the substituents of the 3-(1,2,4-triazol-4-yl)-5-benzamidobenzoates. The pore volumes of selected materials are experimentally determined by nitrogen adsorption at 77 K and carbon dioxide adsorption at room temperature. On the basis of the flexible behavior of the linkers a reversible framework transformation of the 2-fold interpenetrated network is observed. The resulting adsorption isotherms with one or two hysteresis loops are interpreted by a gate-opening process. Due to external stimuli, namely, the adsorptive pressure, the materials undergo a phase transition confirming the structural flexibility of the porous coordination polymer.
本文报道了由15种结构柔性微孔银金属有机框架（MOF）组成的同构系列。以双核银核作为二级构筑单元（Ag2N4）的化合物可在溶剂热条件下，由取代的三唑基苯甲酸酯连接体与AgNO3或Ag2SO4反应得到；它们呈现出具有lvt拓扑结构的2重网络互穿。除了晶体结构外，还报道了微孔MOF的计算孔径分布。同步热分析证实了这些化合物在250℃以下的稳定性。相互连通的孔形成了三维孔结构。尽管新型配位聚合物的孔隙率仅在20 - 36%范围内，但该系列可被视为研究网络柔性的模型体系，因为孔径和孔体积可通过3-(1,2,4-三唑-4-基)-5-苯甲酰胺基苯甲酸酯的取代基逐步调节。通过在77 K下的氮气吸附和室温下的二氧化碳吸附实验测定了所选材料的孔体积。基于连接体的柔性行为，观察到了2重互穿网络的可逆骨架转变。由此产生的具有一个或两个滞后环的吸附等温线通过门控开启过程进行解释。由于外部刺激，即吸附压力，材料发生相变，证实了多孔配位聚合物的结构柔性。
