Synthesis, Structures, and Magnetic Properties of Face-Sharing Heterodinuclear Ni(II)−Ln(III) (Ln = Eu, Gd, Tb, Dy) Complexes

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• 作者：Tomoka Yamaguchi ; Yukinari Sunatsuki ; Hiroyuki Ishida ; Masaaki Kojima ; Haruo Akashi ; Nazzareno Re ; Naohide Matsumoto ; Andrzej Pochaba ; Jerzy Mroziń ; ski
• 刊名：Inorganic Chemistry
• 出版年：2008
• 出版时间：July 7, 2008
• 年：2008
• 卷：47
• 期：13
• 页码：5736 - 5745
• 全文大小：1645K
• 年卷期：v.47,no.13(July 7, 2008)
• ISSN：1520-510X

文摘

Heterodinuclear [(Ni^IIL)Ln^III(hfac)₂(EtOH)] (H₃L = 1,1,1-tris[(salicylideneamino)methyl]ethane; Ln = Eu, Gd, Tb, and Dy; hfac = hexafluoroacetylacetonate) complexes (1·Ln) were prepared by treating [Ni(H_1.5L)]Cl_0.5 (1) with [Ln(hfac)₃(H₂O)₂] and triethylamine in ethanol (1:1:1). All 1·Ln complexes (1·Eu, 1·Gd, 1·Tb, and 1·Dy) crystallized in the triclinic space group P1̅ (No. 2) with Z = 2 with very similar structures. Each complex is a face-sharing dinuclear molecule. The Ni^II ion is coordinated by the L³⁻ ligand in a N₃O₃ coordination sphere, and the three phenolate oxygen atoms coordinate to an Ln^III ion as bridging atoms. The Ln^III ion is eight-coordinate, with four oxygen atoms of two hfac⁻’s, three phenolate oxygen atoms of L³⁻, and one ethanol oxygen atom coordinated. Temperature-dependent magnetic susceptibility and field-dependent magnetization measurements showed a ferromagnetic interaction between Ni^II and Gd^III in 1·Gd. The Ni^II−Ln^III magnetic interactions in 1·Eu, 1·Tb, and 1·Dy were evaluated by comparing their magnetic susceptibilities with those of the isostructural Zn^II−Ln^III complexes, [(ZnL)Ln(hfac)₂(EtOH)] (2·Ln) containing a diamagnetic Zn^II ion. A ferromagnetic interaction was indicated in 1·Tb and 1·Dy, while the interaction between Ni^II and Eu^III was negligible in 1·Eu. The magnetic behaviors of 1·Dy and 2·Dy were analyzed theoretically to give insight into the sublevel structures of the Dy^III ion and its coupling with Ni^II. Frequency dependence in the ac susceptibility signals was observed in 1·Dy.