An Effective Method to Construct Cluster-based Frameworks with Multifarious Structures, Luminescence, and Sorption Properties

An effective method was developed for the synthesis of three cluster-based frameworks with multifarious secondary building units (SBUs) and various structures, which were formulated as [Me2NH2]2[Zn10(BTC)6(μ3-O)(μ4-O)(H2O)5]·3DMA·9H2O (FJI-3), [Me2NH2]2[Zn9(μ3-OH)2(BTC)6(H2O)3]·5DMA·6H2O (FJI-4) and [Me2NH2][Zn3(μ3-OH)(BTC)2DMF]·H2O (FJI-5) (H3BTC = 1,3,5-benzenetricarboxylic acid, DMA = N,N′-dimethyl acetamide and DMF = N,N′-dimethyl formamide), respectively. X-ray structural analysis reveals that FJI-3 displays 3D highly porous metal-organic framework with four kinds of microporous cages constructed by two paddle-wheel Zn2(CO2)4, trimeric Zn3O(CO2)6, and tetrameric Zn4O(CO2)6 SBUs. FJI-4 exhibits 3D microporous MOFs with a dodecahedral cavities built by paddle-wheel Zn2(CO2)4 and trimeric Zn3O(CO2)6. FJI-5 shows 3D microporous MOFs with an 1D channel assembled by the Zn3O(CO2)6 SBUs. In addition, the fluorescence and sorption properties in these cluster-based frameworks were also investigated. Furthermore, the method employed in this work may provide an useful approach to the design and synthesis of novel cluster-based frameworks.