Herein, we report a CN‐bridged alternating Fe^II−Ni^II 1D chain to ensure the alignment of axial anisotropy and improve the single molecule magnet (SMM) behavior in seven coordinated Fe^II compound. The chain was constructed from hepta coordinated Fe(II) complex as an anisotropic building unit and diamagnetic nickel tetra cyanate as a bridging ligand. The magnetic measurements show the easy‐axis anisotropy of the seven coordinated Fe(II) complex and field induced SMM behavior with spin reversal energy barrier U_eff=61(2) K (42 cm⁻¹) and pre‐exponential relaxation time τ₀=1.9×10⁻⁸ s. The detailed analysis of the relaxation dynamics discloses that the Orbach process plays an important role in slow relaxation of magnetization for this compound. Notably, this example represents a remarkable energy barrier observed in hepta coordinated Fe(II) SMMs. The ab initio calculations estimate the magnitude of axial anisotropy and show the parallel orientation of the anisotropic axis throughout the 1D polymeric chain. In addition, it is also reported that the presence of weak π accepter ligands in the distorted axial position enhance the easy‐axis anisotropy.

中文翻译：

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一维配位聚合物中的轴向各向异性排列表明，在单核七配位FeII配合物上，磁场诱导的单分子磁体行为得到改善。

在本文中，我们报告了一个CN桥联的交替Fe ^II -Ni ^II 1D链，以确保轴向各向异性的排列并改善七个配位Fe ^II化合物的单分子磁体（SMM）行为。该链是由七配位的Fe（II）配合物（作为各向异性的构建单元）和抗磁性的四氰酸镍（作为桥联配体）构建的。磁性测量显示的七个配位的Fe（II）配合物，并与自旋反转的能量势垒场感应SMM行为易磁化轴各向异性ù _EFF = 61（2）K（42厘米^-1）和预指数弛豫时间τ ₀ = 1.9×10 ^-8 s。弛豫动力学的详细分析表明，奥尔巴赫过程在该化合物的磁化缓慢弛豫中起重要作用。值得注意的是，该实例代表了在七配位的Fe（II）SMM中观察到的显着的能垒。从头算起可以估算轴向各向异性的大小，并显示整个1D聚合物链中各向异性轴的平行方向。此外，也有报道称，在扭曲的轴向位置上存在弱的π受体配体会增强易轴各向异性。