Solvent-tuned magnetic exchange interactions in Dy2 systems ligated by a μ-phenolato heptadentate Schiff base
| Autor: | Lin Sun, Sanping Chen, Zhijie Jiang, Haipeng Wu, Hongshan Ke, Zhengqiang Xia, Yi-Quan Zhang, Gang Xie, Min Li |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Materials science
Schiff base Ligand General Chemical Engineering Exchange interaction chemistry.chemical_element 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Square antiprism chemistry.chemical_compound Magnetization Crystallography Molecular geometry chemistry Ab initio quantum chemistry methods Dysprosium 0210 nano-technology |
| Zdroj: | RSC Advances. 9:39640-39648 |
| ISSN: | 2046-2069 |
| Popis: | A series of binuclear dysprosium compounds, namely, [Dy(api)]2 (1), [Dy(api)]2·2CH2Cl2 (2), [Dy(Clapi)]2·2C4H8O (3), and [Dy(Clapi)]2·2C3H6O (4) (H3api = 2-(2-hydroxyphenyl)-1,3-bis[4-(2-hydroxyphenyl)-3-azabut-3-enyl]-1,3-imidazoline; H3Clapi = 2-(2′-hydroxy-5′-chlorophenyl)-1,3-bis[3′-aza-4′-(2′′-hydroxy-5′′-chlorophenyl)prop-4′-en-1′-yl]-1,3-imidazolidine), have been isolated by the reactions of salen-type ligands H3api/H3Clapi with DyCl3·6H2O in different solvent systems. Structural analysis reveals that each salen-type ligand provides a heptadentate coordination pocket (N4O3) to encapsulate a DyIII ion and all of the DyIII centers in 1–4 adopt a distorted square antiprism geometry with D4d symmetry. Magnetic studies showed that compound 1 did not exhibit single-molecule magnetic (SMMs) behavior. With the introduction of different lattice solvents, compounds 2–4 showed filed-induced slow magnetic relaxation with barriers Ueff of 18.2 K (2), 28.0 K (3) and 16.4 K (4), respectively. Ab initio calculations were employed to interpret the magnetization behavior of 1–4. The combination of experimental and theoretical data reveal the importance of the weak exchange interaction between the DyIII ions in the observation of slow magnetic relaxation, and a relaxation mechanism has been developed to rationalize the observed difference in the Ueff values. The different lattice solvents influence Dy–O–Dy bond angles and thus alter the torsion of the square antiprism geometry, consequently resulting in distinct magnetic interactions and the magnetic behavior. |
| Databáze: | OpenAIRE |
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