Functional Versatility of a Series of Zr Metal-Organic Frameworks Probed by Solid-State Photoluminescence Spectroscopy
Functional Versatility of a Series of Zr Metal-Organic Frameworks Probed by Solid-State Photoluminescence Spectroscopy
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DOI：
10.1021/jacs.7b02184
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发表时间：
2017-05-03
影响因子：
15
通讯作者：
Forgan, Ross S.
中科院分区：
文献类型：
--
作者：
Marshall, Ross J.;Kalinovskyy, Yaroslav;Forgan, Ross S.
金属有机骨架(MOF)的许多理想性质可以通过有机配体的化学官能化来调节，这些有机配体将金属原子簇连接成多维网络固体。当这些连接体分子本质上是荧光的时，它们可以将这一特性传递给生成的MOF，潜在地产生固态传感器，因为分析物可以结合在它们多孔的内部。本文报道了通过官能化4，4‘-[1，4-phenylene-bis(ethyne-2，1-diyl)]-dibenzoate(PEB(2)-)配体连接的14个互穿结构的Zr和Hf MOF的合成，并分析了官能团的引入对其结构和性能的影响。甲基、氟、萘基和苯并噻二唑基团的加入不会影响基本的拓扑结构，但会导致微妙的结构变化，如配体旋转，并介导主客体相互作用。此外，我们还证明了固态光致发光光谱可以用来探测这些效应。例如，引入萘基和苯并噻二唑基单元可产生可用作稳定荧光水敏元件的MOF，二甲基改性的MOF表现出由互穿网络之间的空间碰撞控制的温度相关相变，尽管四氟类似物的有机主链只有部分氟化，但仍具有超疏水性。配体结构的这些细微变化加上一致的骨架拓扑结构导致了一系列具有不同物理性质的MOF，这些性质是仅用配体观察不到的。
Many of the desirable properties of metal-organic frameworks (MOFs) can be tuned by chemical functionalization of the organic ligands that connect their metal clusters into multidimensional network solids. When these linker molecules are intrinsically fluorescent, they can pass on this property to the resultant MOF, potentially generating solid-state sensors, as analytes can be bound within their porous interiors. Herein, we report the synthesis of a series of 14 interpenetrated Zr and Hf MOFs linked by functionalized 4,4'-[1,4-phenylene-bis(ethyne-2,1-diyl)]-dibenzoate (peb(2)-) ligands, and we analyze the effect of functional group incorporation on their structures and properties. Addition of methyl, fluoro, naphthyl, and benzothiadiazolyl units does not affect the underlying topology, but induces subtle structural changes, such as ligand rotation, and mediates host-guest interactions. Further, we demonstrate that solid-state photoluminescence spectroscopy can be used to probe these effects. For instance, introduction of naphthyl and benzothiadiazolyl units yields MOFs that can act as stable fluorescent water sensors, a dimethyl modified MOF exhibits a temperature dependent phase change controlled by steric clashes between interpenetrated nets, and a tetrafluorinated analogue is found to be superhydrophobic despite only partial fluorination of its organic backbone. These subtle changes in ligand structure coupled with the consistent framework topology give rise to a series of MOFs with a remarkable range of physical properties that are not observed with the ligands alone.