Two 3D metal–organic frameworks with different topologies, thermal stabilities and magnetic properties
Two 3D metal–organic frameworks with different topologies, thermal stabilities and magnetic properties
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DOI：
10.1039/c2ce25442e
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发表时间：
2012-08
期刊：
影响因子：
3.1
通讯作者：
Ting Gao;Xiao-Zhu Wang;H. Gu;Yan Xu;Xuan Shen;Dunru Zhu
中科院分区：
文献类型：
--
作者：
Ting Gao;Xiao-Zhu Wang;H. Gu;Yan Xu;Xuan Shen;Dunru Zhu
使用 3,3'-二甲氧基-4,4'-联苯二甲酸 (H2L) 作为配体，在溶剂热条件下成功制备了两种新型 3D 金属有机骨架 [ML]n (M = Co, 1; Mn, 2)。 X 射线晶体学分析表明，MOF 1 在单斜晶系（空间群 P21/c）中结晶，而 MOF 2 在四方晶系（空间群 I）中结晶。MOF 1 包含一个拉长的 [CoO6] 八面体，在反式位置有两个结合的甲氧基，而 MOF 2 具有一个压缩的 [MnO6] 八面体，在顺式排列中有两个配位的甲氧基。配体L显示出一种新型的双(三齿)桥联配位模式。 MOF 1 呈现出具有 CdSO4 (cds) 拓扑的 3D 框架，该拓扑由两个不同的节点组成，具有良好的热稳定性 (313 °C)。 MOF 2 是一种双互穿 3D α-Po 骨架，具有更高的热稳定性 (368 °C)。对1.8–300 K温度范围内磁特性的研究表明，由于顺反羧酸桥，1中高自旋Co(II)离子之间出现弱铁磁相互作用(J = 0.15 K)，但2中Mn(II)离子之间出现弱反铁磁耦合(J = -0.15 cm−1)。
Two novel 3D metal–organic frameworks, [ML]n (M = Co, 1; Mn, 2) were successfully prepared in solvothermal conditions using 3,3′-dimethoxy-4,4′-biphenyldicarboxylic acid (H2L) as the ligand. X-Ray crystallography analysis reveals that MOF 1 crystallizes in the monoclinic system, space group P21/c in contrast to MOF 2 in the tetragonal system, space group I. MOF 1 contains an elongated [CoO6] octahedron with two bound methoxy groups in the trans position, whereas MOF 2 has a compressed [MnO6] octahedron with two coordinated methoxy groups in the cis arrangement. The ligand L shows a novel bis(tridentate) bridging coordination mode. MOF 1 exhibits a 3D framework with CdSO4 (cds) topology consisting of two different nodes and good thermal stability (313 °C). MOF 2 is a doubly interpenetrated 3D α-Po framework with a higher thermal stability (368 °C). The study of magnetic properties in the temperature range of 1.8–300 K shows the occurrence of weak ferromagnetic interactions (J = 0.15 K) between the high-spin Co(II) ions in 1, but a weak antiferromagnetic coupling (J = −0.15 cm−1) between Mn(II) ions in 2 due to the syn-anti carboxylate bridge.