期刊
JOURNAL OF MOLECULAR STRUCTURE
卷 1175, 期 -, 页码 686-697出版社
ELSEVIER SCIENCE BV
DOI: 10.1016/j.molstruc.2018.08.010
关键词
Single molecule magnets; Dinuclear lanthanide complexes; Nitrogen oxygen bridge
资金
- NSFC [21572048, 21102039, 51302068, 21272061, 51102081, 21302045]
- Educational Commission of Heilongjiang Province [1254G045, 12541639]
- Heilongjiang University [JCL201605]
- Natural Science Foundation of Jiangsu Province of China [BK20151542]
- Priority Academic Program Development of Jiangsu Higher Education Institutions
A series of dinuclear lanthanide complexes bridged by three pyridine-N-oxide (PyNO) ligands with formula [Dy-2(hfac)(6)(4-cpyNO)(3)]center dot 4H(2)O (Dy1), [Gd-2(hfac)(6)(4-cpyNO)(3)]center dot 4H(2)O (Gd1), [Dy-2(hfac)(6)(4-mepyNO)(3)] (Dy2), [Gd-2(hfac)(6)(4-mepyNO)(3)] (Gd2) (hfac(-) = hexafluoroacetylacetonate, 4-cpyNO = 4-cyanopyridine N-oxide, 4-mepyNO = 4-Methylpyridine N-oxide), and series of dinuclear lanthanide complexes bridged by two PyNO ligands with formula [Dy-2(hfac)(6)(4-cpyNO)(2)] (Dy3), [Y-2(hfac)(6)(4-cpyNO)(2)] (Y1), [Gd-2(hfac)(6)(4-cpyNO)(2)] (Gd3), [Dy-2(hfac)(6)(4-mepyNO)(2)] (Dy4), [Y-2(hfac)(6)(4-mepyNO)(2)] (Y2), [Gd-2(hfac)(6)(4-mepyNO)(2)] (Gd4), were structurally and magnetically characterized. The crystal structures revealed that pyridine-N-oxide serves as an effective bridge to link two Ln(III) centers, and periphery beta-diketonate ligands complete the coordination sphere. The number of PyNO bridge can be rationally controlled by the stoichiometric ratio of reagents, which leads to different local coordination models and intramolecular Ln-Ln distances. Furthermore, elaborate modulation on the strength of magnetic coupling transmitted by PyNO bridge was successfully carried out by introducing electron donating or-withdrawing substituents on the bridge ligand backbone. Magnetic measurements revealed that complex Dy3 displayed significant double zero-field slow magnetic relaxation process, while Dy1 and Dy2 showed field-induced SMM behavior. Significantly enhanced SMMs performance was observed in Dy4 with a hysteresis temperature of 2.5 K. The distinct slow magnetic relaxation behaviors were strongly related to their different individual Dy(III) ion magnetic anisotropy and Dy(III)-Dy(III) coupling, which were further confirmed by ab initio calculation. (C) 2018 Elsevier B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据