Dais Tyson N, Takano Rina, Ishida Takayuki, Plieger Paul G
School of Fundamental Sciences, Massey University, Private Bag 11 222, Palmerston North, New Zealand.
Department of Engineering Science, Graduate School of Informatics and Engineering, The University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo 182-8585, Japan.
Dalton Trans. 2022 Jan 25;51(4):1446-1453. doi: 10.1039/d1dt03742k.
The synthesis and structural characterisation of four new heterometallic tetranuclear complexes is reported. Three LNiLn type complexes, where Ln = La (C1), Eu (C2), and Gd (C3), have been fully characterised including DC and AC magnetic measurements. A fourth complex featuring a diamagnetic Ba ion at its centre is also reported with structural characterisation. Structural elucidation showed that all four complexes successfully self-assembled from a stoichiometric mixture of the acyclic ligand, 1,4-diformylnaphthalene-2,3-diol, with nickel(II) nitrate and the appropriate heavy metal salt to produce the same near planar NiMO core. Ferromagnetic interactions were found to dominate the ground state of C3, exhibiting a maximal spin ground state of 13/2. The exchange coupling is quantitatively discussed along with the nickel(II) zero-field splitting effect. AC magnetic susceptibility experiments were carried out, but no frequency dependent signals were observed and thus no observable slow relaxation of magnetisation.
报道了四种新型异金属四核配合物的合成及结构表征。已对三种LNiLn型配合物进行了全面表征，其中Ln = La（配合物C1）、Eu（配合物C2）和Gd（配合物C3），包括直流和交流磁性测量。还报道了第四种配合物，其中心为抗磁性Ba离子，并进行了结构表征。结构解析表明，所有四种配合物均由无环配体1,4 - 二甲酰基萘 - 2,3 - 二醇与硝酸镍（II）和适当的重金属盐按化学计量比混合成功自组装而成，形成相同的近平面NiMO核心。发现铁磁相互作用主导配合物C3的基态，呈现出最大自旋基态为13/2。对交换耦合以及镍（II）零场分裂效应进行了定量讨论。进行了交流磁化率实验，但未观察到频率相关信号，因此未观察到可察觉的磁化缓慢弛豫现象。
