A new series of four heterometallic Cu(II)–Ln(III) complexes [where Ln = Tb (1Tb), Dy (2Dy), Ho (3Ho) or Er (4Er)] has been synthesized using a Cu(II) metalloligand of an N₂O₃-donor asymmetric ligand H₂L (H₂L = N-α-methylsalicylidene-N′-3-methoxysalicylidene-1,3-propanediamine) and structurally characterized. All these complexes are isostructural and consist of dinuclear [(CuL)Ln(NO₃)₃] units. The Ln(III) ions are nona-coordinated and the Cu(II) ions are tetra-coordinated with distorted square planar geometry in all the complexes. The DC magnetic susceptibility and field dependent magnetization measurements reveal that the Cu(II) and Ln(III) centres are ferromagnetically coupled in complexes 1Tb and 2Dy. In the AC magnetic susceptibility measurements at zero bias field, 1Tb exhibits an appreciable slow magnetic reorientation below 10 K with an effective energy barrier of approximately 17 K. Complex 3Ho shows a slight increase in out-of-phase susceptibility below 4 K. With an applied DC field of 2000 Oe, both 1Tb and 2Dy display slow magnetic reorientation with effective energy barriers of 28.5(5) and 53(2) K, respectively.

中文翻译：

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N ₂ O ₃供体不对称配体和可能的Cu ^II -Tb ^III SMM候选物的 一系列Cu ^II -Ln ^III络合物，无偏置场†

一个新的系列四异金属的Cu（II）-Ln（III）配合物[式中，Ln = TB（1Tb的），镝（2DY），何（3HO）或Er（4ER）]已被使用Cu合成（II）metalloligand的N ₂ ö ₃端供体不对称配体ħ ₂ L（ħ ₂ L = ñ -α-methylsalicylidene- ñ '-3- methoxysalicylidene -1,3-丙二胺）和结构表征。所有这些配合物都是同构的，由双核[（CuL）Ln（NO ₃）₃ ]单元组成。Ln（III）离子是非配位的，而Cu（II）离子是四配位的，在所有配合物中均具有扭曲的正方形平面几何形状。直流磁化率和磁场相关的磁化强度测量结果表明，Cu（II）和Ln（III）中心在复合体1Tb和2Dy中铁磁耦合。在零偏置磁场下的交流磁化率测量中，1Tb在10 K以下表现出明显的慢磁重取向，有效能垒约为17K。复合物3Ho在4 K以下显示出异相磁化率略有增加。施加的2000 Oe的直流磁场，1Tb和2Dy显示缓慢的磁重新定向，有效能垒分别为28.5（5）和53（2）K。