Cui Jing-Wang, Hou Suo-Xia, Van Hecke Kristof, Cui Guang-Hua
College of Chemical Engineering, Hebei Key Laboratory for Environment Photocatalytic and Electrocatalytic Material, North China University of Science and Technology, Tangshan, Hebei 063009, P. R. China.
XStruct, Department of Inorganic and Physical Chemistry, Ghent University, Krijgslaan 281-S3, 9000 Ghent, Belgium.
Dalton Trans. 2017 Feb 28;46(9):2892-2903. doi: 10.1039/c6dt04626f.
The hydrothermal reactions of 1,2,4,5-cyclohexanetetracarboxylic acid (HL) with CoCl·2HO and rigid or semi-rigid bis(imidazole) ligands were able to generate two Co(ii) coordination polymers (CPs), {[Co(L)(1,4-bimb)(μ-OH)(HO)]·2HO} (1), {[Co(L)(1,4-bib)]·HO} (2) (1,4-bimb = 1,4-bis(imidazol-1-ylmethyl)benzene, 1,4-bib = 1,4-bis(1H-imidazol-1-yl)benzene). CPs 1 and 2 were structurally characterized by elemental analysis, IR spectroscopy, X-ray powder diffraction and single crystal X-ray diffraction. CP 1 features a 3D 3,3,4,4,5-connected framework with an unprecedented {4·8·10·12}{4·6·8}{4}{4}{6·8} topology, which represents the first example of CPs with such a topology. CP 2 possesses a three-fold interpenetration 3D framework with mog topology. The distinct structures of the two CPs may result from diverse coordination modes of the (L) ligands and different structural characteristics of rigid or semi-rigid N-donor ligands. The thermal stabilities, photoluminescence properties and electrochemical behavior in the solid state for CPs 1 and 2 have been investigated. The photophysical studies indicated that CPs 1 and 2 are potential semiconductive materials. Moreover, both CPs 1 and 2 show high photocatalytic efficiency for the degradation of methylene blue (MB) under UV light irradiation and exhibit good stability and recyclability. A possible photocatalytic mechanism is speculated by introducing t-butyl alcohol (TBA) as a widely used ˙OH scavenger.
1,2,4,5-环己烷四羧酸（HL）与CoCl·2HO以及刚性或半刚性双（咪唑）配体的水热反应能够生成两种钴（II）配位聚合物（CPs），{[Co(L)(1,4-bimb)(μ-OH)(H₂O)]·2H₂O}（1），{[Co(L)(1,4-bib)]·H₂O}（2）（1,4-bimb = 1,4-双（咪唑-1-基甲基）苯，1,4-bib = 1,4-双（1H-咪唑-1-基）苯）。通过元素分析、红外光谱、X射线粉末衍射和单晶X射线衍射对CPs 1和2进行了结构表征。CP 1具有三维3,3,4,4,5连接框架，具有前所未有的{4·8·10·12}{4·6·8}{4}{4}{6·8}拓扑结构，这是具有这种拓扑结构的CPs的首例。CP 2具有三重互穿的三维框架，具有莫格拓扑结构。这两种CPs的不同结构可能源于（L）配体的不同配位模式以及刚性或半刚性氮供体配体的不同结构特征。研究了CPs 1和2在固态下的热稳定性、光致发光性质和电化学行为。光物理研究表明CPs 1和2是潜在的半导体材料。此外，CPs 1和2在紫外光照射下对亚甲基蓝（MB）的降解均表现出高光催化效率，并且具有良好的稳定性和可回收性。通过引入叔丁醇（TBA）作为广泛使用的˙OH清除剂推测了一种可能的光催化机理。
