Series of Chloranilate-Bridged Dinuclear Lanthanide Complexes: Kramers Systems Showing Field-Induced Slow Magnetic Relaxation
Series of Chloranilate-Bridged Dinuclear Lanthanide Complexes: Kramers Systems Showing Field-Induced Slow Magnetic Relaxation
复制标题
DOI：
10.3390/magnetochemistry5020030
复制
发表时间：
2019-06-01
期刊：
影响因子：
2.7
通讯作者：
Kawata, Satoshi
中科院分区：
文献类型：
--
作者：
Ishikawa, Ryuta;Michiwaki, Shoichi;Kawata, Satoshi
合成了一系列具有中心点2CH（2）Cl（2）的氯邻苯二甲酸根桥联的双核镧系元素配合物[{Ln（III）（Tp）（2）}（2）（μ-Cl（2）An）]，其中Cl（2）An（2）（-）和Tp（-）分别代表氯邻苯二甲酸根和硼酸氢三（吡唑基）酯配体，Ln = Gd（1），Tb（2），Ho（3），Er（4），Yb（5）.所有五个配合物，其特征在于通过元素分析，红外光谱，单晶X-射线衍射和SQUID测量。配合物1-5均为同结构配合物。这些配合物的直流磁化率数据的温度依赖性的比较显示出明显的差异，这取决于镧系中心。交流磁化率测量结果表明，没有五个复合物表现出缓慢的磁弛豫下施加的直流磁场为零。另一方面，Kramers系统（配合物4和5）在施加直流场的情况下清楚地显示出缓慢的磁弛豫，这表明通过Orbach和拉曼弛豫过程发生的场诱导单分子磁体。
A series of chloralilate-bridged dinuclear lanthanide complexes of formula [{Ln(III)(Tp)(2)}(2)(mu-Cl(2)An)]center dot 2CH(2)Cl(2), where Cl(2)An(2)(-) and Tp(-) represent the chloranilate and hydrotris (pyrazolyl) borate ligands, respectively, and Ln = Gd (1), Tb (2), Ho (3), Er (4), and Yb (5) was synthesized. All five complexes were characterized by an elemental analysis, infrared spectroscopy, single crystal X-ray diffraction, and SQUID measurements. The complexes 1-5 in the series were all isostructural. A comparison of the temperature dependence of the dc magnetic susceptibility data of these complexes revealed clear differences depending on the lanthanide center. Ac magnetic susceptibility measurements revealed that none of the five complexes exhibited a slow magnetic relaxation under a zero applied dc field. On the other hand, the Kramers systems (complexes 4 and 5) clearly displayed a slow magnetic relaxation under applied dc fields, suggesting field-induced single-molecule magnets that occur through Orbach and Raman relaxation processes.