Slow relaxation processes and single-ion magnetic behaviors in dysprosium-containing complexes.
Slow relaxation processes and single-ion magnetic behaviors in dysprosium-containing complexes.
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DOI：
10.1021/ic901720a
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发表时间：
2010-02
影响因子：
4.6
通讯作者：
Ying Wang;Xi-Li Li-Xi-Li-Li-12074575;Tianwei Wang;You Song;X. You
中科院分区：
文献类型：
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作者：
Ying Wang;Xi-Li Li-Xi-Li-Li-12074575;Tianwei Wang;You Song;X. You
合成了一系列一维配合物[Ln(L(1))(3)(HOCH(2)CH(2)OH)](N)(L(1)=2-呋喃根阴离子；Ln=Nd(1)，Sm(2)，Gd(3)，Tb(4)，Dy(5)，Er(6))。晶体属单斜晶系，空间群为P2(1)/c，单晶X-射线衍射法确定其为链状结构。磁性研究表明，2-呋喃甲酸的羧基在轻、重稀土络合物中起着不同的磁偶联作用，即轻稀土离子之间的反铁磁性作用和重稀土离子之间的铁磁作用。值得注意的是，络合物5表现出强烈的交流电(AC)磁特性的频率依赖性。进一步的磁学研究表明，在5中存在单一的弛豫过程。当使用1，10-邻菲咯啉和邻苯二甲酸根(L(2))时，通过水热反应分离出[Dy(2)(L(2))(6)(H(2)O)](N)(7)并进行了磁性表征。研究结果还表明，尽管邻苯二甲酸盐阴离子在Dy(III)离子之间起反铁磁性耦合作用，但交流磁化率与频率有关。对分子式为[Dy(Tta)(3)(L(3))](8)的中性单核配合物[Dy(Tta)(3)(L(3))](8)(Tta=2-噻吩甲酰三氟丙酮；L(3)=4，5-蒎烯联吡啶)的进一步磁性研究表明，含Dy(III)的配合物的单离子磁性行为起源于慢弛豫。
A series of one-dimensional complexes [Ln(L(1))(3)(HOCH(2)CH(2)OH)](n) (L(1) = 2-furoate anion; Ln = Nd (1), Sm (2), Gd (3), Tb (4), Dy (5), Er (6)) have been synthesized. The complexes were crystallized in the monoclinic space group P2(1)/c and show a chain-like structure determined by single-crystal X-ray diffraction. Magnetic properties indicate that carboxyl group of 2-furoate mediates different magnetic couplings in light and heavy rare earth complexes, namely, antiferromagnetic interaction between light rare earth ions and ferromagnetic interaction between heavy ones. Noticeably, complex 5 displays a strong frequency dependence of alternating current (AC) magnetic properties. Further magnetic studies show a distribution of a single relaxation process in 5. While 1,10-phenanthroline and phthalate anion (L(2)) were employed, [Dy(2)(L(2))(6)(H(2)O)](n) (7) was isolated by hydrothermal reactions and characterized magnetically. Research results also show the frequency dependence of AC magnetic susceptibilities, although the phthalate anions mediate antiferromagnetic coupling between Dy(III) ions. Further magnetic investigation of a neutral mononuclear complex with the formula [Dy(TTA)(3)(L(3))] (8) (TTA = 2-thenoyltrifluoroacetonate; L(3) = 4,5-pinene bipyridine) suggests that the single-ion magnetic behavior originates the slow relaxation of Dy(III)-containing complexes.