Zhang Sheng, Tang Jiamin, Zhang Jin, Xu Fang, Chen Sanping, Hu Dengwei, Yin Bing, Zhang Jiangwei
Faculty of Chemistry and Chemical Engineering, Engineering Research Center of Advanced Ferroelectric Functional Materials, Key Laboratory of Phytochemistry of Shaanxi Province, Baoji University of Arts and Sciences, 1 Hi-Tech Avenue, Baoji, Shaanxi 721013, China.
Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an, Shaanxi 710127, China.
Inorg Chem. 2021 Jan 18;60(2):816-830. doi: 10.1021/acs.inorgchem.0c02863. Epub 2021 Jan 2.
Guided by the self-assembled process and mechanism, the strategy of in situ Schiff base reaction would be capable of bringing a feasible method to construct and synthesize lanthanide compounds with distinct structures and magnetic properties. A mononuclear Dy(III) compound was synthesized through a multidentate Schiff base ligand and a chelating β-diketonate ligand, which was named as [Dy(L)(bppd)]·CHOH [; HL = ,'-bis(2-hydroxy-5-methyl-3-formylbenzyl)-,'-bis(pyridin-2-ylmethyl)ethylenediamine and bppd = 3-bis(pyridin-2-yl)propane-1,3-dione]. Furthermore, a new binuclear Dy(III) compound, [Dy(HLox)(bppd)]·8CHOH [; HLox = ,'-bis[2-hydroxy-5-methyl-3-(hydroxyiminomethyl)benzyl]-,'-bis(pyridin-2-ylmethyl)ethylenediamine], was obtained via an in situ synthetic process. Under similar synthetic conditions, [Dy(L)(ctbd)] [; ctbd = 1-(4-chlorophenyl)-4,4,4-trifluoro-1,3-butanedione] and [Dy(HLox)(ctbd)]·CHOH·CHO () were synthesized by modifying the β-diketonate ligand and in situ Schiff base reaction. Compound is a mononuclear configuration, while compound exhibits a binuclear Dy(III) unit. Therein, formylbenzyl groups of HL in and were changed to (hydroxyiminomethyl)benzyl groups in and , respectively. In isomorphous and , two Dy(III) centers are connected through two phenol O atoms of the HLox ligand to form a binuclear structure. Eight-coordinated Dy(III) ions with different distortions can be observed in -. The crystals of and suffered dissolution/precipitation to obtain and , respectively. The relationship between the structure and magnetism in compounds - was discussed through the combination of structural, experimental, and theoretical investigations. Especially, the rates of quantum tunneling of magnetization of - were theoretically predicted and are consistent with the experimental results. For and , the theoretically calculated dipolar parameters are consistent with the experimental observation of weak ferromagnetic coupling.
在自组装过程和机理的指导下，原位席夫碱反应策略将能够提供一种可行的方法来构建和合成具有独特结构和磁性的镧系化合物。通过多齿席夫碱配体和螯合β - 二酮配体合成了一种单核Dy(III)化合物，其命名为[Dy(L)(bppd)]·CHOH [；HL = ，'-双(2 - 羟基 - 5 - 甲基 - 3 - 甲酰基苄基)-，'-双(吡啶 - 2 - 基甲基)乙二胺，bppd = 3 - 双(吡啶 - 2 - 基)丙烷 - 1,3 - 二酮]。此外，通过原位合成过程获得了一种新的双核Dy(III)化合物，[Dy(HLox)(bppd)]·8CHOH [；HLox = ，'-双[2 - 羟基 - 5 - 甲基 - 3 -(羟基亚氨基甲基)苄基]-，'-双(吡啶 - 2 - 基甲基)乙二胺]。在相似的合成条件下，通过修饰β - 二酮配体和原位席夫碱反应合成了[Dy(L)(ctbd)] [；ctbd = 1 -(4 - 氯苯基)-4,4,4 - 三氟 - 1,3 - 丁二酮]和[Dy(HLox)(ctbd)]·CHOH·CHO ()。化合物 为单核构型，而化合物 呈现双核Dy(III)单元。其中， 和 中HL的甲酰基苄基分别在 和 中变为(羟基亚氨基甲基)苄基。在同构的 和 中，两个Dy(III)中心通过HLox配体的两个酚O原子相连形成双核结构。在 - 中可以观察到具有不同畸变的八配位Dy(III)离子。 和 的晶体经过溶解/重结晶分别得到 和 。通过结构、实验和理论研究相结合的方式讨论了化合物 - 中结构与磁性之间的关系。特别是，对 - 的磁化量子隧穿速率进行了理论预测，并且与实验结果一致。对于 和 ，理论计算的偶极参数 与弱铁磁耦合的实验观察结果一致。
