Ligand field effect tuned magnetic behaviors of two chain compounds based on Mn(III)3O units: from slow magnetic relaxation to metamagnetism.
Ligand field effect tuned magnetic behaviors of two chain compounds based on Mn(III)3O units: from slow magnetic relaxation to metamagnetism.
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DOI：
10.1039/c2dt31944f
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发表时间：
2013-01
影响因子：
4
通讯作者：
Yue-Ling Bai;Xiaoli Bao;Shourong Zhu;Jian-hui Fang;J. Tao
中科院分区：
文献类型：
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作者：
Yue-Ling Bai;Xiaoli Bao;Shourong Zhu;Jian-hui Fang;J. Tao
合成并表征了两个具有抗醋酸酯桥联单元的链状化合物[Mn(3)O(Clppz)(3)(Etoh)(4)(OAc)](N)(1)和[Mn(3)O(Clppz)(3)(Etoh)(2)(OAc)](N)(2)。磁学研究表明，1是具有两个慢磁化弛豫过程的单链磁体，这是首次在这类链状络合物中发现的，而2表现出场致超磁行为。不同的配位乙醇分子数目不同导致了不同的磁性行为，其中4个乙醇分子配位为1，2个乙醇分子配位为2。对实验磁化率的最佳拟合为：J(1)=-2.72 cm(-1)，J(2)=-4.34 cm(-1)，ZJ=1.24 cm(-1)，J(1)=-5.91 cm(-1)，J(2)=-0.98 cm(-1)。对于高于30K的2，Zj=1.71，正的Zj值表明1和2中的三核单元之间存在通过醋酸桥的弱铁磁相互作用。
Two chain compounds built with anti-anti acetate bridged Mn(III)(3)O units, [Mn(3)O(Clppz)(3)(EtOH)(4)(OAc)](n) (1) and [Mn(3)O(Clppz)(3)(EtOH)(2)(OAc)](n) (2), were synthesized and characterized. The magnetic studies indicate that 1 is a single-chain magnet with two slow magnetization relaxation processes which has for the first time been found in this type of chain complex, while 2 shows a field-induced metamagnetic behavior. The quite different magnetic behaviors resulted from the different number of coordinated ethanol molecules on the Mn(III)(3)O unit, four ethanol molecules for 1, and two ethanol molecules for 2. The best fittings to the experimental magnetic susceptibilities gave J(1) = -2.72 cm(-1), J(2) = -4.34 cm(-1), zJ = 1.24 cm(-1) for 1 and J(1) = -5.91 cm(-1), J(2) = -0.98 cm(-1), zJ = 1.71 for 2 above 30 K. The positive zJ values indicate the presence of weak ferromagnetic interactions between the trinuclear units via acetate bridges in 1 and 2.