Intramolecular Ferromagnetism in Di‐Nuclear 3d‐Transition‐Metal Single‐Molecule Magnets by Pseudo‐Serial Arrangement
Intramolecular Ferromagnetism in Di‐Nuclear 3d‐Transition‐Metal Single‐Molecule Magnets by Pseudo‐Serial Arrangement
复制标题
通过伪串联排列双核 3d 过渡金属单分子磁体中的分子内铁磁性
DOI：
10.1002/chem.202203421
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Yamashita Masahiro
中科院分区：
文献类型：
--
作者：
Wakizaka Masanori;Sato Tetsu;Yoshino Yuko;Takaishi Shinya;Yamashita Masahiro
合成了双核柠檬酸配合物[CH6N3]2[M2(Cith)2(H2O)4] ⋅ 2H2O(柠檬酸；M=FeII(Fe-2)，CoII(Co-2)，NiII(Ni-2))。配体CitH3−只在三个羧基上去质子化，这与以前报道的带有Cit4−配体的四核结构不同。磁性测量表明，这些配合物具有分子内铁磁性，j=∼0 cm−1(Ni-2)，0.0 2 cm−1(Co-2)，0.0 4 cm−1(Fe-2)。CO-2和Fe-2表现出缓慢的磁弛豫，是自旋反转激活能分别为27 cm−1(Co-2)和4.2 cm−1(Fe-2)的场感生SMM。密度泛函理论计算表明，每个金属离子中心沿z轴的单轴各向异性形成伪系列排列，通过磁偶极相互作用导致分子内铁磁性。这项工作展示了通过三维双核金属离子中心的磁偶极工程来创建铁磁性SMM。
Di‐nuclear citrate complexes, [CH6N3]2[M2(citH)2(H2O)4] ⋅ 2H2O (citH4=citric acid; M=FeII(Fe‐2), CoII(Co‐2), and NiII(Ni‐2)), are synthesized. The ligand, citH3−, is deprotonated only at the three carboxy groups, which is different from the previously reported tetra‐nuclear structures with cit4−ligands. Magnetic measurements reveal that these complexes have intramolecular ferromagnetism withJ=∼0 cm−1(Ni‐2), 0.02 cm−1(Co‐2), and 0.04 cm−1(Fe‐2). Co‐2 and Fe‐2 show slow magnetic relaxation, and are field‐induced SMMs with activation energy of spin‐reversalUeff=27 cm−1(Co‐2) and 4.2 cm−1(Fe‐2). Density functional theory calculations indicate that the uniaxial anisotropy along thez‐axis of each metal ion center forms thepseudo‐serial arrangement, leading to intramolecular ferromagnetism via the magnetic dipole interaction. This work demonstrates the creation of ferromagnetic SMMs by the magnetic dipole engineering of 3d di‐nuclear metal ion centers.