Wöhlbrandt Stephan, Meier Christoph, Reinsch Helge, Svensson Grape Erik, Inge A Ken, Stock Norbert
Institut für Anorganische Chemie, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany.
Department of Materials and Environmental Chemistry, Stockholm University, Stockholm 10691, Sweden.
Inorg Chem. 2020 Sep 21;59(18):13343-13352. doi: 10.1021/acs.inorgchem.0c01703. Epub 2020 Sep 1.
Following the strategy of installing porosity in coordination polymers predefined by linker geometry, we employed the new tetratopic linker molecule 1,1,2,2-tetrakis[4-phosphonophenyl]ethylene (HTPPE) for the synthesis of new porous metal phosphonates. A high-throughput study was carried out using Ni and Co as metal ions, and a very strong influence of the reactor size on the product formation is observed while maintaining the same reaction parameters. Using small autoclaves ( = 250 μL), single crystals of isostructural mononuclear complexes of the composition [Ni(HDPBP)(HO)] () and [Co(HDPBP)(HO)] () are formed. They contain the linker molecule HDPBP (4,4'-diphosphonobenzophenone), which is formed in situ by oxidation of HTPPE. Using autoclaves with a volume of = 2 mL, two new 3D metal-organic frameworks (MOFs) of composition [Ni(HTPPE)(HO)]·4HO (CAU-46) and [Co(HTPPE)(HO)]·3HO (CAU-47) were isolated in bulk quantities, and their crystal structures were determined from three-dimensional electron diffraction (3D ED) and powder X-ray diffraction data. Using even larger autoclaves ( = 30 mL), another 3D MOF of the composition [Co(HTPPE)]·6HO (Co-CAU-48) was obtained, and a structure model was established via 3D ED measurements. Remarkably, the isostructural compound [Ni(HTPPE)]·9HO (Ni-CAU-48) is only obtained indirectly, i.e., via thermal activation of CAU-46. As the chosen linker geometry leads to the formation of MOFs, topological analyses were carried out, highlighting the different connectivities observed in the three frameworks. Porosity of the compounds was proven via water sorption experiments, resulting in uptakes of 126 mg/g (CAU-46), 105 mg/g (CAU-47), 210 mg/g (Ni-CAU-48), and 109 mg/g (Co-CAU-48).
遵循通过连接体几何结构预先定义在配位聚合物中引入孔隙率的策略，我们采用新型四齿连接体分子1,1,2,2-四[4-膦苯基]乙烯（HTPPE）来合成新型多孔金属膦酸盐。以镍和钴作为金属离子进行了高通量研究，结果发现在保持相同反应参数的情况下，反应器尺寸对产物形成有非常强烈的影响。使用小型高压釜（体积 = 250 μL），形成了组成为[Ni(HDPBP)(H₂O)]（化合物1）和[Co(HDPBP)(H₂O)]（化合物2）的同构单核配合物的单晶。它们包含连接体分子HDPBP（4,4'-二膦苯甲酮），其通过HTPPE的原位氧化形成。使用体积为2 mL的高压釜，大量分离出组成为[Ni(HTPPE)(H₂O)]·4H₂O（CAU - 46）和[Co(HTPPE)(H₂O)]·3H₂O（CAU - 47）的两种新型三维金属有机框架（MOF），并根据三维电子衍射（3D ED）和粉末X射线衍射数据确定了它们的晶体结构。使用甚至更大的高压釜（体积 = 30 mL），得到了组成为[Co(HTPPE)]·6H₂O（Co - CAU - 48）的另一种三维MOF，并通过3D ED测量建立了结构模型。值得注意的是，同构化合物[Ni(HTPPE)]·9H₂O（Ni - CAU - 48）只能间接获得，即通过CAU - 46的热活化。由于所选择的连接体几何结构导致MOF的形成，因此进行了拓扑分析，突出了在这三种框架中观察到的不同连接性。通过水吸附实验证明了化合物的孔隙率，CAU - 46的吸水量为126 mg/g，CAU - 47为105 mg/g，Ni - CAU - 48为210 mg/g，Co - CAU - 48为109 mg/g。
