| Autor: |
Yu, You-Zhu, Hu, Yue-Qiao, Guo, Yu-Hua, Niu, Yong-Sheng, Yang, Li-Guo, Song, Hai-Xiang, Shen, Yan-Hong, Zheng, Xiao-Ming, Hou, Shao-Gang, Feng, Guo-Dong |
| Předmět: |
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| Zdroj: |
Dalton Transactions: An International Journal of Inorganic Chemistry; 8/14/2018, Vol. 47 Issue 30, p10124-10129, 6p |
| Abstrakt: |
Four unprecedented decanuclear heterometallic [Ln2CoII4CoIII4] clusters based on a diethanolamine ligand (H2dea), namely [Eu2CoII4CoIII4(dea)8(HCOO)4(OH)2(Cl)2(CH3OH)2]Cl2·4CH3OH·2H2O (1), [Gd2CoII4CoIII4(dea)8(HCOO)4(OH)2(Cl)2(CH3OH)2]Cl2·4CH3OH·2H2O (2), [Tb2CoII4CoIII4(dea)8(HCOO)4(OH)2(Cl)2(CH3OH)2]Cl2·2CH3OH·4H2O (3) and [Dy2CoII4CoIII4(dea)8(HCOO)4(OH)2(Cl)2(CH3OH)2]Cl2·2CH3OH·4H2O (4) were synthesized through a facile solution method. Single-crystal X-ray diffraction analyses reveal that complexes 1–4 consist of a [Ln2CoII4CoIII4] core, which is constructed by bridging a quasi-double cuboidal [Ln2CoII2CoIII2] core with two [CoIICoIII] units. Electrospray ionization mass spectrometry (ESI-MS) using methanol solution reveals that complexes 1–4 are stable in the solution, and the clusters undergo three different substitution reactions (Cl− replaced by OH−, OH− replaced by CH3O− and HCOO− replaced by OH−/CH3O−) at the same time in the ionization state. Magnetic susceptibilities reveal ferromagnetic couplings within complexes 3 and 4, and the magnetocaloric effect (MCE) for 2 was also evaluated and the maximum entropy change (−ΔSm) value reaches 16.3 J kg−1 K−1 at about 3 K and 5 T. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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