Slow magnetic relaxation of a three-dimensional metal-organic framework featuring a unique dysprosium(III) oxalate layer
Slow magnetic relaxation of a three-dimensional metal-organic framework featuring a unique dysprosium(III) oxalate layer
复制标题
具有独特草酸镝(III)层的三维金属有机骨架的慢磁弛豫
DOI：
10.1039/c5ra11621j
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发表时间：
2015
期刊：
影响因子：
3.9
通讯作者：
Zhu Dao-Ben
中科院分区：
文献类型：
--
作者：
Liu Cai-Ming;Zhang De-Qing;Zhu Dao-Ben
通过5-氯-6-羟基吡啶-3-羧酸(5-Cl-6-HOPy-3-CO2H)和Dy2O3在草酸[H2(OX)]存在下的水热反应得到了一种新型的镧系金属有机骨架，即{[Dy2(1H-5-Cl-6-Opy-3-CO2)2(OX)2(H2O)]·2H2O}∞ （1，1H-5-Cl-6-Opy-3-CO2− = 1-Hydro-5-Chloro-6-oxopyridine-3-carboxylate，由单个去质子化的 1H-5-Cl-6-HOpy-3-CO2− 阴离子自异构化形成）。镝(III)离子通过草酸阴离子桥接，构建了一个有趣的4连接层网络，其Schälfli拓扑符号为(32·52) (3·53)，这些层通过1H-5-Cl-6-HOpy-3-CO2−阴离子相互连接，形成三维框架。磁学研究表明，1是场感应单分子磁体，表现出两步热磁弛豫，有效热垒为37.6 K。令人惊讶的是，使用由于镧系元素的收缩效应，Gd2O3 代替了 Dy2O3。值得注意的是，2的晶体结构中存在独特的F形(H2O)6超分子聚集体。
A novel lanthanide metal–organic framework was yielded by a hydrothermal reaction of 5-chloro-6-hydroxypyridine-3-carboxylic acid (5-Cl-6-HOPy-3-CO2H) and Dy2O3 in the presence of oxalic acid [H2(OX)], namely, {[Dy2(1H-5-Cl-6-Opy-3-CO2)2(OX)2(H2O)]·2H2O}∞ (1, 1H-5-Cl-6-Opy-3-CO2− = 1-hydro-5-chloro-6-oxopyridine-3-carboxylate, which was formed by the autoisomerization of single deprotonated 1H-5-Cl-6-HOpy-3-CO2− anion). The dysprosium(III) ions are bridged by oxalate anions to construct an interesting 4-connected layer network with a Schälfli topology symbol of (32·52) (3·53), such layers are connected with each other by the 1H-5-Cl-6-HOpy-3-CO2− anions to form a three-dimensional framework. Magnetic investigations indicated that 1 is a field-induced single-molecule magnet, displaying two-step thermal magnetic relaxation, with an effective thermal barrier of 37.6 K. Surprisingly, a zigzag chain-like gadolinium(III) complex, {[Gd(1H-5-Cl-6-Opy-3-CO2)2(OX)0.5(H2O)3]·6H2O}∞ (2), was isolated using Gd2O3 instead of Dy2O3 owing to the lanthanide contraction effect. Notebaly, a unique F-shaped (H2O)6 supramolecular aggregate exists in the crystal structure of 2.