含有刚柔混合多羧酸配体的稀土配位聚合物的合成、结构及荧光性能

Syntheses,Structures and Fluorescent Properties of Lanthanide Coordination Polymers with Mixed Rigid and Flexible Carboxylate Ligands

以柔性的氨基三乙酸为第一配体,具有特殊刚性平面结构的草酸为第二配体,采用水热合成法在自生压力下与稀土硝酸盐自组装合成了两个新的三维网状含刚柔混合多羧酸稀土配位聚合物[KLn_2(NTA)(ox)_2(H_2O)_5]_n(Ln=Ce(1),Tb(2);H_3NTA=氨基三乙酸,H_2ox=草酸),并对化合物1和2进行了X射线单晶结构解析、元素分析、红外和热分析等表征。X射线单晶衍射数据解析表明化合物1和2是同构的,属于单斜晶系,P2(1)/m空间群。在两个化合物的三维网状结构中,存在着沿a轴方向的一维的孔道。拓扑学分析发现,化合物1和2具有两个4-连接的无机节点和一个4-连接的有机节点,形成了少有的三维(4,4,4)-连接的多孔网络拓扑结构。对化合物2进行固态荧光光谱分析,结果显示化合物2在340 nm的激发波长作用下,能够产生强的Tb^(3+)特征发射跃迁,发出较纯的绿光。

Utilized the hydrothermal synthesis method,two new isomorphic 3D lanthanide coordination polymers[KLn_2（NTA）（ox）_2（H_2O）_5]_n（Ln = Ce（1） and Tb（2）; H_3 NTA = nitrilotriacetic acid,H_2ox = oxalic acid）were synthesized by self-assembly of lanthanide nitrate（ cerium nitrate,terbium nitrate） with NTA and ox ligands.The structures of the two compounds were characterized by X-ray single crystal diffraction,elemental analysis,IR spectrum and TG. The X-ray single crystal diffraction data analyses revealed that compounds 1 and 2 were isomorphic,belonged to the monoclinic system,P2（1）/m space group,and there existed 1D channels along the two axis in its 3D structure. Additionally,through a topological approach,we can define a 4-link organic node and two 4-link inorganic nodes,which formed a rare 3D（4,4,4）-connected porous network topology structure. Furthermore,the fluorescence property of compound 2 was investigated in the visible region at the room temperature.The photoluminescence analysis indicated that the compound 2 exhibits the characteristic transitions of the Tb^（3＋）ion,and emits green light with maxima at 543 nm（ λ_（ex）= 340 nm）.