Molecular Tectonics of Mixed-Ligand Metal-Organic Frameworks: Positional Isomeric Effect, Metal-Directed Assembly, and Structural Diversification

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• 作者：Miao Du ; Xiu-Juan Jiang ; Xiao-Jun Zhao
• 刊名：Inorganic Chemistry
• 出版年：2007
• 出版时间：May 14, 2007
• 年：2007
• 卷：46
• 期：10
• 页码：3984 - 3995
• 全文大小：853K
• 年卷期：v.46,no.10(May 14, 2007)
• ISSN：1520-510X

文摘

A series of nine mixed-ligand metal-organic frameworks (MOFs) have been prepared by the combination of a bentdipyridyl linker 4-amino-3,5-bis(4-pyridyl)-1,2,4-triazole (bpt) and three benzenedicarboxylate isomers (pa = phthalate,ip = isophthalate, and tp = terephthalate), respectively, with different metal ions such as Co^II, Ni^II, Cu^II, Zn^II, andCd^II. The framework structures of these neutral polymeric complexes have been determined by the X-ray single-crystal diffraction technique. Structural analysis reveals that the benzenedicarboxylate isomers display versatilecoordination modes to manage the metal ions to form 1-D chain or ribbon arrays, which are further extended viathe exo-bidentate bpt connectors to give rise to a variety of coordination networks, such as a simple (4,4) layer,2-D double layer with decorated (4,4) topology, 2-D layer with decorated (3,6) topology, 2-D bilayer with 8².10topology (2-fold interpenetration), 3-D polythreaded architecture (1-D + 2-D), and 2-fold interpenetrating porouslattice of (4,4) layers. The accessorial secondary interactions such as hydrogen bonding and/or aromatic stackingare also helpful for the extension and stabilization of the final supramolecular aggregates. This work evidentlyindicates that the isomeric effect of the anionic benzenedicarboxylate is significant in the construction of thesenetwork structures, which are also well regulated by the metal centers. The Zn^II and Cd^II MOFs exhibit strongsolid-state luminescence emissions at room temperature, which originate differently from intraligand transition orligand-to-metal charge transfer. Thermal stability of these crystalline materials has been explored by thermogravimetricanalysis of mass loss. The 3-D host frameworks of MOFs 8 and 9 show similar porous cavities, and their desorption/adsorption behaviors of guest solvents have also been investigated.