Temperature-induced formation of two dinuclear dysprosium complexes with different magnetic properties |
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Authors: | Zhong-Hong Zhu Hai-Ling Wang Shui Yu Xiao-Xiao Fu Hua-Hong Zou Zilu Chen Fu-Pei Liang |
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Affiliation: | State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmacy of Guangxi Normal University, Guilin, 541004 P. R. China |
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Abstract: | A dinuclear Dy (III) complex [Dy2( L 1 )2(NO3)4]·2CH3CN ( 1 ) (H L 1 = 1,3-bis{[(E)-pyridin-2-ylmethylene]amino}propan-2-ol) was obtained via the reaction of 1,3-diamino-2-propanol, 2-pyridyaldehyde and Dy (NO3)3·6H2O at room temperature. In the structure of complex 1 , two Dy (III) ions are in the N4O6 coordination environment provided by NO3− and ( L 1 )−, and both of these ions are in the sphenocorona configuration. [Dy2( L 2 )2(NO3)4] ( 2 ) [H L 2 = 2-(pyridin-2-yl)hexahydropyrimidin-5-ol] was obtained using the same reaction material only when the reaction temperature was changed to 60°C. Structural analysis of complex 2 showed that the two Dy (III) ions with the same coordination configuration are in the N3O6 coordination environment provided by NO3− and ( L 2 )− and are in the distorted spherical-capped square antiprism. Surprisingly, H L 2 with the parent of bipyridine was synthesized by the Schiff base reaction of 1,3-diamino-2-propanol with 2-pyridoxaldehyde followed by the ring-closing reaction catalyzed by Dy (III) ions. Magnetic measurements of the Dy (III) complexes revealed no obvious frequency-dependent behavior of complex 1 . In contrast, complex 2 showed an obvious frequency dependence (Ueff = 0.49 K and τ0 = 6.62 × 10−4 s) under the condition of zero field and a weak double relaxation behavior (Ueff = 9.25 K and τ0 = 9.70 × 10−4 s) at 1500 Oe. |
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Keywords: | dinuclear dysprosium in situ reaction temperature-induced complexes magnetic properties |
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