Three Series of 3d–4f Heterometallic Polymers Based on [LnCu6] or [Ln6Cu24] Clusters and Formate Bridges: Displaying Significant Magnetocaloric Effect
Three Series of 3d–4f Heterometallic Polymers Based on [LnCu6] or [Ln6Cu24] Clusters and Formate Bridges: Displaying Significant Magnetocaloric Effect
复制标题
DOI：
10.1021/cg400333d
复制
发表时间：
2013-07
影响因子：
3.8
通讯作者：
Zhongyi Li;Yu-Xian Wang;Jiang Zhu;Shuqin Liu;Gan Xin;Jianjun Zhang;Hendra Huang;Chunying Duan-Chunying
中科院分区：
文献类型：
--
作者：
Zhongyi Li;Yu-Xian Wang;Jiang Zhu;Shuqin Liu;Gan Xin;Jianjun Zhang;Hendra Huang;Chunying Duan-Chunying
以AA（HGly或HAla）和甲酸酯为混合配体，合成了三个系列的一维（1D）和三维（3D）3d-4f簇基聚合物，并对其结构和性质进行了表征。在pH值分别为6.0和5.2的条件下，得到了3个一维起伏链[Ln = Gd，（1）; Tb，（2）; Dy（3）]和2个三维骨架[Ln = Gd，（4）和Tb，（5）]，它们具有3个连接的pcu-h网络。这两个化合物都是以甘氨酸为配体的七核三棱柱[LnCu 6]簇合物和单核的Ln ~（3+）为节点，通过顺式-反式甲酸根配体连接而成。此外，三个三维聚合物[Ln = Gd，（6）; Tb，（7）;和Dy（8）]与6-连接的PCU网络构建从丙氨酸为基础的[Ln 6Cu 24]簇和甲酸桥。甲酸酯配体不仅对簇单元的构建，而且对它们进一步连接到扩展阵列发挥了重要作用。磁性分析表明，三种含Gd ~（3+）化合物均具有有趣的磁热效应，其−ΔSm（T）值分别为5.8，6.0和18.8.
The syntheses, structures, and characterization of three series of one-dimensional (1D) and three-dimensional (3D) 3d–4f cluster-based polymers with AA (HGly or HAla) and formate as mixed ligands are described. Under the pH values of 6.0 and 5.2, respectively, three 1D undulating chains [Ln = Gd, (1); Tb, (2); and Dy(3)] and two 3D frameworks [Ln = Gd, (4) and Tb, (5)] with a 3-connected pcu-h network were obtained. Both of them use Gly-based heptanuclear trigonal prism [LnCu6] clusters and mononuclear Ln3+ as nodes linked by syn–anti formate ligands. Moreover, three 3D polymers [Ln = Gd, (6); Tb, (7); and Dy (8)] with a 6-connected pcu network were built from Ala-based [Ln6Cu24] clusters and formate bridges. The formate ligand played an important role not only for the construction of the cluster units but also for their further linkage to extended arrays. Magnetic analyses indicate the three Gd3+-containing compounds bear an interesting magnetocaloric effect, and the −ΔSm(T) values are 5.8, 6.0, and 18.8...