Wang Kai, Tang Shen, Hu Zhao-Bo, Zou Hua-Hong, Wang Xiao-Lu, Li Yan, Zhang Shu-Hua, Chen Zi-Lu, Liang Fu-Pei
Guangxi Key Laboratory of Electrochemical and Magnetochemical Functional Materials, College of Chemistry and Bioengineering, Guilin University of Technology Guilin 541004 China
State Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmacy, Guangxi Normal University Guilin 541004 China.
RSC Adv. 2018 Feb 7;8(12):6218-6224. doi: 10.1039/c7ra12844d. eCollection 2018 Feb 6.
The reactions of the diacylhydrazine ligands ,'-bisalicyl-2,6-pyridine dicarbohydrazide (Hsphz) and ,'-bis(3-methoxysalicyl)-2,6-pyridine dicarbohydrazide (Hmsphz) with various 3d metal salts, afforded a series of coordination clusters, namely, [Mn Mn(sphz)(acac)(CHOH)] (1, acac = acetylacetone anions), [Ni (msphz)(Py)] (2, Py = pyridine), [Cu (sphz)(Py)] (3) and [Cu (msphz)(Py)]·2DMF·2HO (4). Cluster 1 and 2 are single ligand assembled quasi-linear trinuclear structures. Both 3 and 4 consist a pair of quasi-linear {Cu} cores, which are linked together by two crossed ligands. The adjacent 3d metal ions in all trinuclear cores of 1-4 are bridged by N-N single bonds of ligands, which convey ferromagnetic (FM) interactions between 3d metal centers of 1, and antiferromagnetic (AFM) interactions between those of 2-4. In particular, the FM interactions and linear arrangement of mixed-valence Mn centers in 1 result in a large spin ground states value ( ) of 13/2, as well as single-molecule magnet (SMM) behavior of slow relaxation and hysteresis of magnetization.
二酰肼配体，即2,6 - 吡啶二甲酰双水杨酰肼（Hsphz）和2,6 - 吡啶二甲酰双（3 - 甲氧基水杨酰）肼（Hmsphz）与各种3d金属盐反应，得到了一系列配位簇，即[Mn₂Mn(sphz)(acac)(CH₃OH)]（1，acac = 乙酰丙酮阴离子）、[Ni₂(msphz)(Py)]（2，Py = 吡啶）、[Cu₂(sphz)(Py)]（3）和[Cu₂(msphz)(Py)]·2DMF·2H₂O（4）。簇1和2是单配体组装的准线性三核结构。3和4都由一对准线性的{Cu₂}核组成，它们通过两个交叉的配体连接在一起。在1 - 4所有三核核中的相邻3d金属离子通过配体的N - N单键桥连，这在1的3d金属中心之间传递铁磁（FM）相互作用，在2 - 4的3d金属中心之间传递反铁磁（AFM）相互作用。特别地，1中混合价态Mn中心的FM相互作用和线性排列导致了13/2的大自旋基态值（S），以及单分子磁体（SMM）的慢弛豫和磁化滞后行为。
