Ionic Conductivity in the Metal-Organic Framework UiO-66 by Dehydration and Insertion of Lithium tert-Butoxide
Ionic Conductivity in the Metal-Organic Framework UiO-66 by Dehydration and Insertion of Lithium tert-Butoxide
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DOI：
10.1002/chem.201300326
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发表时间：
2013-04-01
影响因子：
4.3
通讯作者：
Long, Jeffrey R.
中科院分区：
文献类型：
--
作者：
Ameloot, Rob;Aubrey, Michael;Long, Jeffrey R.
金属有机框架（MOF）是一类微孔材料，由通过多位有机配体连接在一起的金属离子节点组成。近年来，这些化合物因其创纪录的高表面积和广泛的相关潜在应用而被广泛研究。这方面的大多数研究都致力于气体储存和分离，[1]，有关液相分离、催化、传感和生物医学应用的报告数量迅速增加。[2] MOF 为此类应用带来的一个关键优势是可以引入复杂的化学表面功能，从而赋予材料预期的化学和物理性能。事实上，MOF 中有机连接体的存在与大多数其他多孔结晶固体具有重要区别，这引发了一系列旨在在这些位置引入官能团的合成策略的快速发展。 [3] MOF 晶格中存在的金属阳离子以明确的无机结构图案组织，通常称为二级结构单元 (SBU)，通常以一维链或零维簇的形式出现。 [4]尽管这些无机子结构可以表现出高密度的官能团，例如桥接 OH 基团，并且这些子结构对材料的吸附性能有显着贡献，[5] 令人惊讶的是，人们很少关注 MOF 内无机单元的合成后官能化。关于在许多重要 MOF 结构中发现的 OH 基团功能化的少数报告专门讨论了通过 OH 质子交换来固定反应物的方法。 [6]在这项工作中，我们展示了一种新颖的两步程序，涉及无机簇脱水，然后接枝锂醇盐，与直接去质子化制备的材料相比，如何产生优异的固体离子导体。由此产生的固体电解质可能有助于增强下一代锂电池的运行。 UiO-66 (Zr6O4 (OH) 4ACHTUNGTRENNUNG (bdc) 6; bdc2À= 1, 4-苯二甲酸酯) 的框架由 Zr6O4 (OH) 4-ACHTUNGTRENNUNG (O2CR) 12 个簇构成，其中 μ3-O 和 μ3-OH 配体源自合成过程中存在的水，并且羧酸根基团是bdc2À 配体将簇连接在一起（图 1）。[7]这种基于 Zr4+ 的 MOF 材料具有出色的热稳定性和化学稳定性，因此人们在合成 UiO-66 框架的功能化变体方面付出了巨大的努力。 [a] R. Ameloot 博士、M. Aubrey、BM Wiers、AP Gómora-Figueroa 博士、JR Long 教授的成功策略
Metal–organic frameworks (MOFs) are a class of microporous materials consisting of metal ion nodes linked together by multitopic organic ligands. These compounds have been studied extensively in recent years for their record high surface areas and a wide range of related potential applications. Most research in this context has been devoted to gas storage and separations,[1] with the number of reports on liquid-phase separations, catalysis, sensing, and biomedical applications increasing rapidly.[2] A key advantage that MOFs bring to such applications is the possibility of introducing complex chemical surface functionality, thereby imparting intended chemical and physical properties to the materials. Indeed, the presence of organic linkers in MOFs offers an important difference with most other porous crystalline solids, and this has sparked the rapid development of a collection of synthetic strategies aimed at introducing functional groups at these positions.[3] The metal cations present in the MOF crystal lattice are organized in well-defined inorganic structural motifs, commonly referred to as secondary building units (SBUs), which often occur as one-dimensional chains or zero-dimensional clusters.[4] Although these inorganic substructures can exhibit a high density of functional groups, such as bridging OH groups, and the substructures contribute significantly to the adsorption properties of the material,[5] surprisingly little attention has been devoted to the post-synthetic functionalization of the inorganic units within MOFs. The few reports that exist on functionalization of the OH groups found within a number of important MOF structures exclusively discuss approaches in which reactants are immobilized upon exchange of the OH proton.[6] In this work, we show how a novel two-step procedure involving dehydration of inorganic clusters followed by lithium alkoxide grafting leads to superior solid ionic conductors as compared to materials prepared by direct deprotonation. The resulting solid electrolytes are potentially useful for enhancing the operation of next-generation lithium batteries. The framework of UiO-66 (Zr6O4 (OH) 4ACHTUNGTRENNUNG (bdc) 6; bdc2À= 1, 4-benzenedicarboxylate) is constructed of Zr6O4 (OH) 4-ACHTUNGTRENNUNG (O2CR) 12 clusters in which the μ3-O and μ3-OH ligands originate from water present during the synthesis and the carboxylate groups are part of the bdc2À ligands linking the clusters together (Figure 1).[7] The remarkable thermal and chemical stability of this Zr4+-based MOF material led to significant efforts to synthesize functionalized variants of the UiO-66 framework. Successful strategies that have been [a] Dr. R. Ameloot, M. Aubrey, BM Wiers, Dr. AP Gómora-Figueroa, Prof. JR Long