Wang Mengmeng, Guo Ying, Han Zongsu, Cheng Xi, Zhang Yi-Quan, Shi Wei, Cheng Peng
Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry (MOE), Renewable Energy Conversion and Storage Center (RECAST), College of Chemistry, Nankai University, Tianjin 300071, China.
School of Physical Science and Technology, Nanjing Normal University, Nanjing 210023, P. R. China.
Inorg Chem. 2022 Jun 27;61(25):9785-9791. doi: 10.1021/acs.inorgchem.2c01299. Epub 2022 Jun 14.
Two mononuclear Dy single-molecule magnets with different ligand substituents located far from the coordinating atoms, [Dy(L-NO)(NO)] () and [Dy(L-Me)(NO)] (), and their diamagnetic-ion diluted analogues, and , were structurally and magnetically characterized. and have nearly identical coordination environments of Dy ions with symmetry but different magnetization dynamics. No Orbach process was observed for and in the testing temperature and frequency range, but effective energy barriers of 575 and 829 K for and were obtained, respectively. The opened hysteresis loops were observed until 6 K for and 10 K for . Ab initio calculations reveal that the energy gaps between ground and low-lying excited states of are higher than those of and the relaxation rate through quantum tunneling of magnetization of is lower than that of due to the electronic effect of the axial coordinating oxygen atoms influenced by ligand substitutions.
两个具有远离配位原子的不同配体取代基的单核镝单分子磁体，[Dy(L-NO)(NO)]（）和[Dy(L-Me)(NO)]（），以及它们的抗磁性离子稀释类似物 和 ，进行了结构和磁性表征。 和 具有几乎相同的具有 对称性的镝离子配位环境，但磁化动力学不同。在测试温度和频率范围内，未观察到 和 的奥巴赫过程，但分别获得了 和 的有效能垒575 K和829 K。对于 观察到开放的磁滞回线直到6 K，对于 直到10 K。从头算计算表明，由于配体取代影响的轴向配位氧原子的电子效应， 的基态和低激发态之间的能隙高于 的，并且 通过磁化量子隧穿的弛豫率低于 的。
