由混合配体构筑的三维铽金属有机框架的晶体结构及分子识别性能

Crystal structure and molecular recognition properties of A 3D Tb MOF constructed from mixed ligands

本文采用两种多功能有机羧酸配体:2-(对溴)苯基-4,5-咪唑二羧酸(p-BrPhH_3IDC)和对苯二甲酸(H_2DCB)为混合配体与六水合硝酸铽,通过溶剂热反应,成功制备了一个含有一维孔道的复杂三维金属有机框架{[Tb(p-BrPhHIDC)(DCB)_(0.5)H_2O]·H_2O}_n。采用红外光谱、元素分析以及单晶X射线衍射测试了其分子结构。发现所采用的两种羧酸配体均与中心金属Tb(Ⅲ)离子配位进而桥联邻近的金属离子构成了三维框架。采用X-射线粉末衍射技术测试了晶体纯度。热分析表明该金属有机框架显示出比较好的热稳定性。固体荧光测试以及小分子识别研究表明该配合物显示出强的特征荧光发射和一定的乙腈识别能力。

In this paper,two kinds of multifunctional organic carboxylic acid ligands,2-(to bromine)phenyl-4,5-imidazole(P-BrPhH3IDC)and 1,4-dicarboxybenzene(H2DCB)are used as mixed ligands to react with Tb(NO3)3·6 H2O,a three-dimensional(3 D)metal-organic framework,{[Tb(p-BrPhHIDC)(DCB)0.5H2O]·H2O}n containing one-dimensional channels is successfully prepared through solvothermal reaction.The molecular structure was tested by infrared spectroscopy,elemental analysis and single crystal X-ray diffraction.It was found that both the two kinds of carboxylate ligands coordinated to the central Tb(Ⅲ)ion and bridged adjacent metal ions to form a 3 D framework.The crystal purity was confirmed by X-ray powder diffraction.Thermal analysis shows that the framework shows better thermal stability.Solid fluorescence and small molecular recognition experiments show that the MOF illustrates characteristic Tb(III)fluorescence emission and certain acetonitrile recognition ability.