Li Xiao-Lei, Min Fan-Yong, Wang Chao, Lin Shuang-Yan, Liu Zhiliang, Tang Jinkui
State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China.
Dalton Trans. 2015 Feb 21;44(7):3430-8. doi: 10.1039/c4dt03713h.
The reaction of Mn(OAc)2·4H2O and Ln(NO3)3·6H2O with N-(2-aminopropyl)-2-hydroxybenzamide and salicylic aldehyde in methanol/methylene dichloride produces yellow crystals of Ln2Mn(C7H5O2)8 (Ln = Gd (), Tb (), Dy (), Ho () and Er ()), in the presence of triethylamine. Three metal ions are connected by six μ2-phenolate oxygen atoms of six salicylic aldehyde ligands, resulting in perfect linear [Ln(III)-Mn(II)-Ln(III)] structures. Magnetic studies of these complexes have been performed and AC susceptibility measurements show the presence of a temperature-dependent out-of-phase ac signal for complexes and indicating single-molecule magnet (SMM) behavior. The Dy(III)2Mn(II) compound shows double relaxation pathways which may originate from the single ion behavior of individual Dy(III) ions and the weak coupling between Dy(III) and Mn(II) ions, respectively. The Ueff of 92.4(2) K is a relatively high value among 3d-4f SMMs. Moreover, complexes and represent the first linear Mn-Ln SMMs containing only divalent manganese ions as far as we know. The result suggests the positive effects of magnetic coupling to enhance their SMM behavior, presenting a promising strategy for constructing efficient heterometallic SMMs.
在三乙胺存在下，乙酸锰四水合物（Mn(OAc)₂·4H₂O）和硝酸镧六水合物（Ln(NO₃)₃·6H₂O）与N-(2-氨丙基)-2-羟基苯甲酰胺及水杨醛在甲醇/二氯甲烷中反应，生成Ln₂Mn(C₇H₅O₂)₈（Ln = Gd（）、Tb（）、Dy（）、Ho（）和Er（））的黄色晶体。六个水杨醛配体的六个μ₂-酚氧原子连接三个金属离子，形成完美的线性[Ln(III)-Mn(II)-Ln(III)]结构。已对这些配合物进行了磁性研究，交流磁化率测量表明配合物存在与温度相关的异相交流信号，表明其具有单分子磁体（SMM）行为。Dy(III)₂Mn(II)化合物显示出双重弛豫途径，这可能分别源于单个Dy(III)离子的单离子行为以及Dy(III)与Mn(II)离子之间的弱耦合。92.4(2) K的有效磁矩（Ueff）在3d-4f单分子磁体中是相对较高的值。此外，据我们所知，配合物和代表了仅含二价锰离子的首个线性Mn-Ln单分子磁体。结果表明磁耦合对增强其单分子磁体行为具有积极作用，为构建高效异金属单分子磁体提供了一种有前景的策略。
