High-Concentration Self-Assembly of Zirconium- and Hafnium-Based Metal-Organic Materials.
High-Concentration Self-Assembly of Zirconium- and Hafnium-Based Metal-Organic Materials.
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DOI：
10.1021/jacs.3c02787
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发表时间：
2023-06
影响因子：
15
通讯作者：
Ronald T. Jerozal;Tristan A. Pitt;S. MacMillan;P. Milner
中科院分区：
文献类型：
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作者：
Ronald T. Jerozal;Tristan A. Pitt;S. MacMillan;P. Milner
金属有机骨架（M0F）是由有机连接体和无机节点构造的结晶多孔固体，其有希望用于化学分离、气体储存和催化等。然而，包括高度可调和水解稳定的Zr基和Hf基框架的M0F的广泛实施的主要障碍是它们的实验室规模化合成，因为M0F通常在高度稀释（≤0.01 M）的溶剂热条件下制备。这需要使用数升的有机溶剂来制备仅几克的MOF。在本文中，我们证明了Zr和Hf基框架（八个实例）可以在比通常使用的高得多的反应浓度下自组装，在许多情况下高达1.00 M。将化学计量量的Zr或Hf前体与高浓度的有机连接剂组合产生高度结晶和多孔的MOF，如通过粉末X射线衍射（PXRD）和77 K N2表面积测量所证实的。此外，使用定义明确的新戊酸盐封端的簇前体避免了由标准金属氯化物盐引起的有序缺陷和杂质的形成。这些簇还引入了新戊酸缺陷，其增加了几种MOF的外部疏水性，如通过水接触角测量所证实的。总的来说，我们的研究结果挑战了标准假设，即必须在高度稀释的溶剂热条件下制备MOFs以获得最佳结果，为实验室中可扩展和用户友好的合成铺平了道路。
Metal-organic frameworks (MOFs) are crystalline, porous solids constructed from organic linkers and inorganic nodes that are promising for applications in chemical separations, gas storage, and catalysis, among many others. However, a major roadblock to the widespread implementation of MOFs, including highly tunable and hydrolytically stable Zr- and Hf-based frameworks, is their benchtop-scalable synthesis, as MOFs are typically prepared under highly dilute (≤0.01 M) solvothermal conditions. This necessitates the use of liters of organic solvent to prepare only a few grams of MOF. Herein, we demonstrate that Zr- and Hf-based frameworks (eight examples) can self-assemble at much higher reaction concentrations than are typically utilized, up to 1.00 M in many cases. Combining stoichiometric amounts of Zr or Hf precursors with organic linkers at high concentrations yields highly crystalline and porous MOFs, as confirmed by powder X-ray diffraction (PXRD) and 77 K N2 surface area measurements. Furthermore, the use of well-defined pivalate-capped cluster precursors avoids the formation of ordered defects and impurities that arise from standard metal chloride salts. These clusters also introduce pivalate defects that increase the exterior hydrophobicity of several MOFs, as confirmed by water contact angle measurements. Overall, our findings challenge the standard assumption that MOFs must be prepared under highly dilute solvothermal conditions for optimal results, paving the way for their scalable and user-friendly synthesis in the laboratory.