Adaptability to Crystal Fields in a Series of COT/Monodentate Ligand-Based Dy and Er Single Ion Magnets.
Adaptability to Crystal Fields in a Series of COT/Monodentate Ligand-Based Dy and Er Single Ion Magnets.
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DOI：
10.1021/acs.inorgchem.3c00922
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发表时间：
2023-05
影响因子：
4.6
通讯作者：
Feng Pan;Rong Sun;Bingwu Wang;Song Gao
中科院分区：
文献类型：
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作者：
Feng Pan;Rong Sun;Bingwu Wang;Song Gao
本文利用典型的扁平和长形Kramers Ln离子DyIII和ErIII合成了一系列等结构对：2-5LN(Ln=Dy和Er)。在2LN的[(Cot)Ln(Thf)4]+阳离子片段中，中心离子被赤道配体环八碳四烯(CoT)和四氢呋喃(THF)溶剂配位，而在杂感配合物3LN((Cot)Ln(Oar‘))、4LN((Cot)Ln(Oar“))和5LN(Cot)Ln(N††)中，配位几何构型是由Cot和大分子芳氧化合物Oar’(2，6-二(二苯甲基)-4-甲基)，OAr”(2，6-双(1-烷基)-4-甲基)，苯基和酰胺N††(双(三异丙基硅基)酰胺)，分别为3LN、4LN和5LN。其中，2Er、3DY和4DY分别为零场SIMS，有效势垒分别为181.9、527.7和622.0 K，与结构分析和从头计算结果一致。3DY和4DY的阻挡温度(Tb)分别为4K和7K，由不同温度下的磁滞回线证实。5LN的结构呈现出几乎完美的伞状几何结构，其特征是5Dy和5Er的N-Ln-质心(COT)角分别为178.9和179.3°。利用这些结构的结晶学数据研究了配体排列对化合物磁性的影响。
Herein, DyIII and ErIII, the typical oblate and prolate Kramers Ln ions, were employed to synthesize a series of isostructural pairs: 2-5Ln (Ln = Dy and Er). In the [(COT)Ln(THF)4]+ cationic fragments of 2Ln, central ions were coordinated by the equatorial ligand cyclooctatetraenyl (COT) and THF solvents, while in the heteroleptic complexes 3Ln ((COT)Ln(OAr')), 4Ln ((COT)Ln(OAr″)), and 5Ln ((COT)Ln(N††)), the coordination geometries were formed by the cooperation of COT and bulky aryloxides OAr' (2,6-bis(diphenylmethyl)-4-methylphenyl), OAr″ (2,6-bis(1-adamantyl)-4-methylphenyl), and amide N†† (bis(triisopropylsilyl) amide) for 3Ln, 4Ln, and 5Ln, respectively. Among these complexes, with the combinations of varying coordination geometries and different anisotropies of f orbitals, 2Er, 3Dy, and 4Dy were found to be zero-field SIMs with effective energy barriers of 181.9, 527.7, and 622.0 K, respectively, which are consistent with the structural analyses and ab initio calculations. The blocking temperatures (TB) of 3Dy and 4Dy are 4 and 7 K, respectively, as confirmed by the hysteresis loops at varying temperatures. The structures of 5Ln exhibit an almost perfect umbrella-shaped geometry, characterized by N-Ln-Centroid (COT) angles measuring 178.9 and 179.3° for 5Dy and 5Er, respectively. Crystallographic data from these structures were utilized to investigate the impact of ligand alignment on the magnetic properties of the compounds.