A salen-type Dy-4 single-molecule magnet with an enhanced energy barrier and its analogues
A salen-type Dy-4 single-molecule magnet with an enhanced energy barrier and its analogues
复制标题
增强能垒的salen型Dy-4单分子磁体及其类似物
DOI：
10.1039/c4dt02607a
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发表时间：
2015
影响因子：
4
通讯作者：
Li Guangming
中科院分区：
文献类型：
--
作者：
Luan Fang;Yan Pengfei;Zhu Jing;Liu Tianqi;Zoua Xiaoyan;Li Guangming
以N，N′-双（3-甲氧基水杨叉基）环己烷-1，2-二胺为配体，合成了四个类质同晶的四核稀土配合物[Ln 4（L）2（HL）2（NO3）2（OH）2]（NO3）2·4 H2O（Ln = Dy（1）; Tb（2）; Ho（3）; Er（4））. X-射线衍射分析表明，配合物1-4均为具有独特{Ln_4 O_8}核的离散四核结构，其中四个镧系离子在菱形框架内共面。有两个晶体学上不等价的镧系元素离子，即Ln 1 III离子，这是九个协调的单帽正方形反棱柱几何的C4 v点群和Ln 2 III离子，这是八个协调的扭曲双帽三角棱柱几何的C2 v点群。磁性分析表明，配合物1具有两个慢磁弛豫，在已报道的四核Salen型镝SMMs中具有最高的能垒。这进一步扩展了Salen型镧系元素络合物的可用SMM。
Four isomorphic tetranuclear lanthanide complexes, namely [Ln4(L)2(HL)2(NO3)2(OH)2](NO3)2·4H2O (Ln = Dy (1); Tb (2); Ho (3); Er (4)), constructed using hexadentate salen-type ligand N,N′-bis(3-methoxy-salicylidene)cyclohexane-1,2-diamine, have been isolated. X-ray crystallographic analysis reveals that all of the complexes 1–4 are of discrete tetranuclear structure with a unique {Ln4O8} core in which four lanthanide ions are coplanar in a rhombic frame. There are two crystallographically unequivalent lanthanide ions, that is the Ln1III ion which is nine-coordinated in a monocapped square-antiprismatic geometry of the C4v point group and the Ln2III ion which is eight-coordinated in a distorted bicapped trigonal-prismatic geometry of the C2v point group. Magnetic analysis reveals that complex 1 exhibits two slow magnetic relaxations with the highest energy barrier among the reported tetranuclear salen-type dysprosium SMMs. This further extends the available SMMs of salen-type lanthanide complexes.