Luan Fang, Yan Pengfei, Zhu Jing, Liu Tianqi, Zou Xiaoyan, Li Guangming
Key Laboratory of Functional Inorganic Material Chemistry (MOE), School of Chemistry and Materials Science, Heilongjiang University, No. 74, Xuefu Road, Nangang District, Harbin, Heilongjiang 150080, P. R. China.
Dalton Trans. 2015 Mar 7;44(9):4046-53. doi: 10.1039/c4dt02607a.
Four isomorphic tetranuclear lanthanide complexes, namely Ln4(L)2(HL)2(NO3)2(OH)22·4H2O (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 Ln1(III) ion which is nine-coordinated in a monocapped square-antiprismatic geometry of the C(4v) point group and the Ln2(III) ion which is eight-coordinated in a distorted bicapped trigonal-prismatic geometry of the C(2v) 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.
已分离出四种同构的四核镧系配合物，即Ln4(L)2(HL)2(NO3)2(OH)22·4H2O（Ln = Dy (1)；Tb (2)；Ho (3)；Er (4)），它们是使用六齿salen型配体N,N'-双(3-甲氧基水杨醛)环己烷-1,2-二胺构建的。X射线晶体学分析表明，所有配合物1 - 4均为离散的四核结构，具有独特的{Ln4O8}核心，其中四个镧系离子在菱形框架中共面。存在两种晶体学上不等价的镧系离子，即Ln1(III)离子，它在C(4v)点群的单帽方反棱柱几何构型中为九配位，以及Ln2(III)离子，它在C(2v)点群的扭曲双帽三角棱柱几何构型中为八配位。磁性分析表明，配合物1表现出两种缓慢的磁弛豫，在所报道的四核salen型镝单分子磁体中具有最高的能垒。这进一步扩展了salen型镧系配合物的可用单分子磁体。
