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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。
A new ligand, oxalic acid with special rigid planar structure as the second ligand, was synthesized by using flexible aminotriacetic acid as the first ligand. Two new three-dimensional network-like The rigid and flexible mixed polycarboxylic acid rare earth coordination polymers [KLn_2 (NTA) (ox) _2 (H_2O) _5] _n (Ln = Ce (1), Tb (2); H_3NTA = aminotriacetic acid and H_2ox = oxalic acid) Compound 1 and 2 were characterized by X-ray single crystal structure analysis, elemental analysis, infrared and thermal analysis. X-ray single crystal diffraction data analysis showed that compounds 1 and 2 are isomorphic, belonging to the monoclinic system, P2 (1) / m space group. In the three-dimensional network structure of two compounds, there is a one-dimensional pore in the a-axis direction. Topological analysis found that compounds 1 and 2 have two 4-linked inorganic nodes and one 4-linked organic node, forming a rare three-dimensional (4,4,4) -connected porous network topology. The results of solid-state fluorescence analysis of compound 2 showed that under the excitation wavelength of 340 nm, compound 2 could produce a strong Tb 3+ emission transition and emit purer green light.