Coordination anion effects on the geometry and magnetic interaction of binuclear Dy-2 single-molecule magnets
Coordination anion effects on the geometry and magnetic interaction of binuclear Dy-2 single-molecule magnets
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配位阴离子对双核 Dy-2 单分子磁体几何结构和磁相互作用的影响
DOI：
10.1039/d1dt02071d
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发表时间：
2021
影响因子：
4
通讯作者：
Tang Jinkui
中科院分区：
文献类型：
--
作者：
Wu Jinjiang;Li Xiao-Lei;La Droitte Leo;Cador Olivier;Le Guennic Boris;Tang Jinkui
以H3 L多齿配体（H3 L = 2，2 ′-（2-羟基-5-甲基-1，3-亚苯基）二亚甲基））二（（吡啶-2-基甲基）氮烷二基）二亚甲基）联苯酚）为配体，合成了两个新的二聚镝（III）配合物[Dy 2（HL）2（SCN）2]·2CH 3CN（1）和[Dy 2（HL）2（NO3）2]·2CH 3CN·2 H2O（2）.使用不同的配位阴离子的两个配合物的结果在不同的金属网站的配位几何形状。配合物1和配合物2中Dy中心分别具有帽八面体和三角十二面体的配位构型。因此，这两种化合物表现出不同的直流和交流磁性能。配合物1表现为单分子磁体（SMM），而配合物2没有观察到SMM行为。虽然配合物1和2具有类似的Dy 2 O2的核心，但它们不同的配位阴离子导致两种不同的磁相互作用，即铁磁和反铁磁，分别。从头计算表明，这些相互作用可能是由于强的分子内偶极耦合是铁磁性的1，但反铁磁性的2，而交换耦合是反铁磁性的在这两种情况下。
Two new dimeric dysprosium(III) complexes, [Dy2(HL)2(SCN)2]·2CH3CN (1) and [Dy2(HL)2(NO3)2]·2CH3CN·2H2O (2), have been assembled using the H3L multidentate ligand (H3L = 2,2′-((((2-hydroxy-5-methyl-1,3-phenylene)bis(methylene))bis((pyridin-2-ylmethyl)azanediyl))bis(methylene))diphenol). The use of different coordination anions for the two complexes results in distinct coordination geometries of the metal sites. The Dy centers in complexes 1 and 2 display capped octahedron and triangular dodecahedron coordination geometries, respectively. Consequently, the two compounds exhibit distinct dc and ac magnetic properties. Complex 1 behaves as a single molecule magnet (SMM) while no SMM behavior is observed for complex 2. Although complexes 1 and 2 possess a similar core of Dy2O2, their different coordination anions lead to two distinct magnetic interactions, namely ferromagnetic and antiferromagnetic, respectively. Ab initio calculations reveal that these interactions may result from strong intramolecular dipolar couplings that are ferromagnetic for 1 but antiferromagnetic for 2, while exchange couplings are antiferromagnetic in both cases.