2,6-吡啶二甲酸镝配位聚合物的合成、晶体结构及其发光性能研究

Synthesis,Crystal Structure and Luminescent Properties of a Dysprosium CoordinaAtion Polymer Based on Pyridine-2,6-Dicarboxylic Acid

以2,6-吡啶二甲酸为配体,在水热条件下合成出一个具有(4.82)拓扑结构的二维稀土镝配位聚合物[Dy(PDA)(HPDA)]n(1)(H2PDA=2,6-吡啶二甲酸)。通过元素分析,1H NMR,IR和X射线单晶衍射对其进行结构表征。X射线单晶衍射分析结果表明,该化合物属单斜晶系,P2(1)/c空间群。该化合物由配体的氧原子连接,形成具有(4.82)型拓扑的二维层状结构,相邻层间的π—π堆积弱相互作用使之形成三维超分子。测定了配体和1在固态室温条件的紫外吸收和荧光光谱。在室温下,配体和配合物均在280 nm处有一宽谱带强吸收,这可以归属于以配体为中心的π→π*跃迁。当激发波长为280 nm时,1呈现出基于配体为中心的荧光发射峰和稀土Dy3+的特征荧光发射峰。研究了配位聚合物1的固态荧光寿命,荧光衰减过程包含双组分,相应的荧光寿命1τ和2τ分别是3.61和12.81μs。

2-D layered Dy coordination polymer [Dy（PDA）（HPDA）]n（1）（H2PDA=pyridine-2,6-dicarboxylic acid） with（4.82） topological network was synthesized under hydrothermal conditions and was characterized by elemental analysis,IR spectrum,and single-crystal X-ray diffraction.X-ray diffraction analysis reveals that compound 1 is monoclinic,space group P2（1）/c.In the structure of compound 1,metal-centered Dy is connected via O atoms of H2PDA ligands to form a（4.82） topology network.The 3-D supramolecular structure of 1 is constructed through π—π stacking interactions between the adjacent layers.The luminescence properties of 1 were determined by UV-Vis and fluorescence spectrum in solid state at room temperature.The H2PDA and 1 exhibit the similar broad maximum absorption peak at 280 nm,which are attributed to ligand-centered π—π transition.The fluorescence emission band based on ligand-center and characteristic emission of Dy3＋ at the same maximum excitation wavelength of 280 nm were observed in 1.The fluorescence decay curve of complex 1 indicated that the processes of decay consists of two components,of which corresponding lifetimes τ1=3.61 μs and τ2=12.81 μs.