Tandem Postsynthetic Metal Ion and Ligand Exchange in Zeolitic Imidazolate Frameworks
Tandem Postsynthetic Metal Ion and Ligand Exchange in Zeolitic Imidazolate Frameworks
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DOI：
10.1021/ic400048g
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发表时间：
2013-04-01
影响因子：
4.6
通讯作者：
Cohen, Seth M.
中科院分区：
文献类型：
--
作者：
Fei, Honghan;Cahill, John F.;Cohen, Seth M.
在这里，我们报道了一种通用的后合成交换(PSE)方法，将氧化还原活性的过渡金属，特别是Mn(II)引入到金属-有机骨架(MOF)的一个子类--“惰性”沸石咪唑骨架(ZIF)中。结果表明，在常温条件下，金属离子PSE存在于ZIF-71(Rho拓扑)和ZIF-8(SOD拓扑)中。金属交换的ZIF是第一个多孔的、基于Mn(II)的ZIF，也是在一个晶格中具有两个过渡金属中心的ZIF的罕见例子。交换材料用扫描电子显微镜-能量分散X射线光谱(SEM-EDX)、气溶胶飞行时间质谱仪(ATOFMS)、X射线荧光光谱(XRF)和Brunauer-Emmett-Teller(BET)比表面积分析进行了表征。此外，还描述了在ZIF中连续交换金属离子和有机连接物的分步“串联”PSE策略。这些发现对于探索ZIF的化学动力学具有重要意义，尽管它们具有很高的结晶度和稳定性，并启发了PSE在制备多金属和多功能MOF方面的更广泛应用。
Herein, we report a general postsynthetic exchange (PSE) approach to introduce a redox-active transition metal, specifically Mn(II), into "inert" zeolitic imidazolate frameworks (ZIFs), a subclass of metal-organic frameworks (MOFs). It is shown that metal ion PSE occurs in ZIF-71 (RHO topology) and ZIF-8 (SOD topology) under ambient conditions. The metal exchanged ZIFs are the first porous, Mn(II)-based ZIFs and a rare example of ZIFs with two transition metal centers in a single lattice. Exchanged materials are characterized by scanning electron microscopy-energy dispersed X-ray spectroscopy (SEM-EDX), aerosol time-of-flight mass spectrometry (ATOFMS), X-ray fluorescence spectroscopy (XRF), and Brunauer-Emmett-Teller (BET) surface area analysis. In addition, stepwise "tandem" PSE strategies are described to exchange of metal ions and organic linkers consecutively in ZIFs. These findings are important for probing the chemical dynamics of ZIFs, despite their high crystallinity and robustness, and inspire the more widespread use of PSE to prepare multimetallic and multifunctional MOFs.