采用水热法通过Ln2O3、Zn(CH3COO)2·2H2O与2,5-吡啶二羧酸为配体的反应合成出两个新型三维杂金属配位聚合物[Ln2Zn2(2,5-pydc)5(H2O)2]·4H2O(Ln=Sm(1),Eu(2);2,5-pydc:2,5-吡啶二羧酸).通过元素分析、红外光谱、X射线粉末衍射方法以及X射线单晶衍射方法对配合物进行了表征.结构分析表明,配合物1和2的结构是相同的,其晶体均为单斜晶系,空间群为P21/c.配合物1和2中2,5-吡啶二羧酸配体共有两种配位方式.通过配位模式I连接Ln和Zn形成二维层状结构;而层与层之间通过配位模式II进一步连接起来形成三维复杂网状结构.此外,还对配合物的荧光性质和热分解过程进行了详细分析.荧光分析表明,金属Zn的引入有效增强了配合物中稀土金属的发光.
The new heterometallic coordination polymers [Ln2Znz(2,5-pydc)5(H2O)2]·4H2O (Ln=Sm (1) and Ln=Eu (2); 2,5-pydc: 2,5-pyridinedicarboxylic acid) were synthesized from the reaction of Ln2O3 and Zn(CH3COO)2·2H2O with corresponding ligands under hydrothermal conditions. The complexes were characterized by elemental analysis, IR spectroscopy, powder X-ray diffraction (XRD) and single crystal X-ray diffraction. Structural analyses reveals that complexes 1 and 2 are isomorphous and crystallize in the monoclinic space group P21/C. In complexes 1 and 2, there are two kinds of coordination modes for the 2,5-pyridinedicarboxylic acid ligand. Ln and Zn are connected to form a two dimensional (2D) layer structure by coordination mode I of 2,5-pyridinedicarboxylic acid and the layers further link to each other to form an intricate three dimensional (3D) network by coordination mode Ⅱ. In addition, the luminescent properties and thermogravimetric (TG) analyses of the title complexes were analyzed in detail. The luminescence of Sm and Eu in these complexes was greatly improved because of the introduction of Zn.