College of Life and Basic Sciences, Sichuan Agricultural University, Ya'an 625014, China.
Dalton Trans. 2013 Oct 1;42(41):14786-93. doi: 10.1039/c3dt51769a.
A series of lanthanide-based organic frameworks with formulas of {[PrL(H2O)2]·2H2O}n () and {[Ln3L3(H2O)2]·2H2O}n (Ln = Eu (), Gd (), Tb (), Dy (), Ho (), Er (); H3L = 4-(carboxymethoxy)isophthalic acid), were hydrothermally synthesized and structurally characterized. It is the first time that 4-(carboxymethoxy)isophthalic acid is employed in producing lanthanide compounds. The seven compounds exhibit two types of structures with the decreasing radius of the lanthanide ions, representing the lanthanide contraction effect. Compound with the large Pr(3+) ion displays a 2D layered structure with a binodal (4,4)-connected topology with the Schläfli symbol of (3(3)6(3))2, whereas compounds with small Ln(3+) ions feature a 3D framework constructed from carboxyl groups with a (5,6,8)-connected topology with the Schläfli symbol of (3(2)4(4)5(4))·(3(4)4(4)5(4)6(3))·(3(4)4(8)5(6)6(9)8). The luminescence and magnetic properties were investigated, and the results indicate that the H3L ligand can sensitize the lanthanide luminescence in compounds , and and makes a contribution to the antiferromagnetic interactions in compound or the uncertain magnetic interactions in compounds . Additionally, the thermal analyses suggest the high thermal stability of compounds .
一系列基于镧系元素的有机框架，化学式为{[PrL(H2O)2]·2H2O}n ()和{[Ln3L3(H2O)2]·2H2O}n (Ln = Eu (), Gd (), Tb (), Dy (), Ho (), Er (); H3L = 4-(carboxymethoxy)isophthalic acid)，通过水热合成法合成并进行了结构表征。这是首次使用 4-(carboxymethoxy)isophthalic acid 来制备镧系化合物。这七种化合物在减小镧系元素离子半径的情况下呈现出两种结构类型，代表了镧系收缩效应。具有较大 Pr(3+)离子的化合物呈现出二维层状结构，具有双节点（4,4）连接拓扑结构，Schläfli 符号为(3(3)6(3))2，而具有较小 Ln(3+)离子的化合物则具有由羧基构建的三维骨架，具有（5,6,8）连接拓扑结构，Schläfli 符号为(3(2)4(4)5(4))·(3(4)4(4)5(4)6(3))·(3(4)4(8)5(6)6(9)8)。对发光和磁性性质进行了研究，结果表明，H3L 配体可以敏化化合物 中的镧系元素发光，并对化合物 中的反铁磁相互作用或化合物 中的不确定磁性相互作用做出贡献。此外，热分析表明化合物具有较高的热稳定性。
