The assembly of N′-(amino-(pyrimidin-2-yl)methylene)-o-vanilloyl hydrazine ligands (H2L, Scheme 1) with different lanthanide perchlorates produces novel Y-shaped tetranuclear complexes, [Ln4(μ3-OH)(L2−)4(H2O)6]·(ClO4)3·6H2O, where Ln = Tb (1), Dy (2) and Ho (3). The formation of this unprecedented Y-shaped topology is largely ascribed to the versatility of the mixed-donor hydrazone ligands in terms of their potential denticity. Analysis of the susceptibility data shows that only the Dy-based molecule features SMM-like behaviour. The synthetic methodology of employing H2L and related ligands has provided a very promising route towards new families of magnetic coordination clusters with novel metal topologies and properties.
N′-(氨基-(嘧啶-2-基)亚甲基)-邻钒酰基肼配体(H2L,方案 1)与不同的镧系元素高氯酸盐组装产生了新型 Y 形四核配合物 [Ln4(μ3-OH)(L2-)4(H2O)6]-(ClO4)3-6H2O,其中 Ln = Tb (1)、Dy (2) 和 Ho (3)。这种前所未有的 Y 型拓扑结构的形成主要归功于混合供体腙配体在潜在齿性方面的多功能性。对电感数据的分析表明,只有基于镝的分子具有类似于 SMM 的行为。采用 H2L 和相关配体的合成方法为开发具有新型金属拓扑结构和特性的磁性配位簇新家族提供了一条非常有前景的途径。
Tuning the Magnetic Interactions and Relaxation Dynamics of Dy
<sub>2</sub>
Single‐Molecule Magnets
作者:Shufang Xue、Yun‐Nan Guo、Liviu Ungur、Jinkui Tang、Liviu F. Chibotaru
DOI:10.1002/chem.201501866
日期:2015.9.28
Efficient modulation of single‐moleculemagnet (SMM) behavior was realized by deliberate structural modification of the Dy2 cores of [Dy2(a′povh)2(OAc)2(DMF)2] (1) and [Zn2Dy2(a′povh)2(OAc)6]⋅4 H2O (2; H2a′povh=N′‐[amino(pyrimidin‐2‐yl)methylene]‐o‐vanilloyl hydrazine). Compound 1 having fourfold linkage between the two dysprosium ions shows high‐performance SMM behavior with a thermal energy barrier