Phase Control in the Modulated Self-Assembly of Lanthanide MOFs of a Flexible Tetratopic Bis-Amide Linker
Phase Control in the Modulated Self-Assembly of Lanthanide MOFs of a Flexible Tetratopic Bis-Amide Linker
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柔性四位双酰胺连接体的镧系 MOF 调制自组装中的相位控制
DOI：
10.1002/zaac.202200171
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发表时间：
2022
期刊：
影响因子：
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通讯作者：
Thom A
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文献类型：
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作者：
Thom A
相纯金属有机框架（M0 F）的目标合成通常由于以下事实而复杂化：许多不同的产物可以由相同的金属-配体组合产生。镧系元素基MOF的自组装可能特别具有挑战性，因为f-嵌段的多功能配位化学允许由空间效应驱动的具有不规则几何形状的各种配位球。在本文中，我们表明，调制自组装-在溶剂热合成中添加小分子以控制pH和配位平衡-可以控制从四位双-（3，5-二羧基苯基）双酰胺配体制备镧系元素MOF时的相形成。我们报告了27种新的MOFs，其中21种通过单晶X射线衍射表征，可以分为六种结构类型。不同相的形成主要是由镧系离子半径的收缩驱动的，但是我们展示了溶剂和调制剂的仔细选择如何影响反应结果。例如，可以通过简单地改变密切相关的合成中使用的调节剂-乙酸、苯甲酸或硝酸来选择相同配体的三种Gd M0 F的相纯样品。这些结果表明，调制可以控制相位inf-block MOFs，就像它可以ind-block MOFs一样，并通过仔细探索单配体系统中镧系元素MOFs的化学参数空间，为揭示结构多样性提供设计规则。
The targeted synthesis of phase‐pure metal‐organic frameworks (MOFs) is often complicated by the fact that a number of different products can result from the same metal‐ligand combination. The self‐assembly of lanthanide‐based MOFs can be particularly challenging due to the versatile coordination chemistry of thef‐block allowing for diverse coordination spheres with irregular geometries driven by steric effects. Herein we show that modulated self‐assembly – the addition of small molecules to solvothermal synthesis in order to control pH and coordination equilibria – can control phase formation when preparing lanthanide MOFs from the tetratopic bis‐(3,5‐dicarboxyphenyl)terephthalamide ligand. We report 27 new MOFs, of which 21 are characterised by single crystal X‐ray diffraction, that can be categorised into six structure types. The formation of different phases is largely driven by the contraction in ionic radius across the lanthanide series, but we show how careful choice of both solvent and modulator can influence reaction outcome. As an example, phase pure samples of three Gd MOFs of the same ligand can be selected by simply changing the modulator – acetic acid, benzoic acid, or nitric acid – used in closely related syntheses. These results show that modulation can control phase inf‐block MOFs, just as it can ind‐block MOFs, and provide design rules for uncovering structural diversity by carefully exploring the chemical parameter space of lanthanide MOFs in single ligand systems.