Two-dimensional heterometallic Cu(II)Ln(III) (Ln = Tb and Dy) coordination polymers bridged by dicyanamides showing slow magnetic relaxation behavior
Two-dimensional heterometallic Cu(II)Ln(III) (Ln = Tb and Dy) coordination polymers bridged by dicyanamides showing slow magnetic relaxation behavior
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由二氰胺桥联的二维异金属 Cu(II)Ln(III)（Ln = Tb 和 Dy）配位聚合物表现出慢磁弛豫行为
DOI：
10.1039/c9ce00673g
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发表时间：
2019
期刊：
影响因子：
3.1
通讯作者：
Huang Xing Cai
中科院分区：
文献类型：
--
作者：
Kong Jiao Jiao;Zhang Jia Chen;Jiang Yu Xuan;Tao Jin Xia;Wang Wen Yan;Huang Xing Cai
使用二氰胺，合成并表征了三种二维配位聚合物（CP）[CuII(valdmpn)LnIII(μ-1,5-dca)3]n（LnIII = Gd (1)、Tb (2) 和 Dy (3)）。化合物 1-3 是用 μ-1,5-dca 连接 [CuII(valdmpn)LnIII]3+ 单元桥接的二维配位聚合物。在化合物 1-3 中，Cu 原子呈五配位，具有细长的四角锥体 (C4v) 几何形状，而 Ln（Gd、Tb 和 Dy）原子则呈九配位，具有松饼 (Cs) 几何形状。详细的直流 (dc) 磁测量和模拟数据证明了化合物 1 存在铁磁 CuII-GdIII 相互作用。交流 (ac) 磁测量表明，化合物 2 在零直流场下表现出缓慢的磁弛豫行为。在化合物 2 中观察到 1.8 K 处的磁滞回线，这是典型单分子磁体 (SMM) 的特征。然而，化合物3在直流场下表现出缓慢的磁弛豫行为。该系统提供了一个很好的机会来确定掺入的 Ln(III) 离子的特征和/或慢磁弛豫行为的起源。
Using dicyanamides, three two-dimensional coordination polymers (CPs) [CuII(valdmpn)LnIII(μ-1,5-dca)3]n (LnIII = Gd (1), Tb (2) and Dy (3)) were synthesized and characterized. Compounds 1–3 are two-dimensional coordination polymers bridged with μ-1,5-dca connecting the [CuII(valdmpn)LnIII]3+ units. In compounds 1–3, the Cu atom was pentacoordinated with an elongated square pyramidal (C4v) geometry, while the Ln (Gd, Tb and Dy) atom was nine-coordinated with a muffin (Cs) geometry. Detailed direct current (dc) magnetic measurements and simulated data demonstrated the existence of a ferromagnetic CuII–GdIII interaction for compound 1. Alternating current (ac) magnetic measurements revealed that compound 2 exhibited a slow magnetic relaxation behavior under a zero dc field. A hysteresis loop at 1.8 K was observed in compound 2, characteristic of typical single-molecule magnets (SMMs). However, compound 3 showed a slow magnetic relaxation behavior under a dc field. This system provides a good opportunity to determine the character of the Ln(III) ions incorporated and/or the origin of the slow magnetic relaxation behavior.