title: Structures, luminescent and magnetic properties of six lanthanide-organic frameworks: observation of slow magnetic relaxation behavior in the DyIII compound.
abstract: Six novel three-dimensional (3D) lanthanide metal-organic frameworks (LnMOFs), {[Ln(2)(ispc)(3)(H(2)O)(3)]·mH(2)O}(n) (Ln = Pr (1, m = 5); Eu (2, m = 5); Gd (3, m = 4); Tb (4, m = 5); Dy (5, m = 5) and Ho (6, m = 4)), ispc = 3-(4-carboxyphenylsulfonyloxy)-4-methoxybenzoic anion) have been synthesized under hydrothermal conditions. Single crystal X-ray diffraction revealed they are isostructural and crystallize in the triclinic crystal system, space group P1[combining macron]. The investigations on luminescent properties and lifetimes of 2 (Eu(III)), 4 (Tb(III)), and 5 (Dy(III)) exhibit characteristic emissions of Eu(III), Tb(III) and Dy(III) ions and the corresponding luminescent lifetimes are 0.14 ms, 9.93 μs and 1.25 ms, respectively. The different luminescent intensities and lifetimes among them were further discussed. Furthermore, magnetic studies of 1-6 reveal that 3-6 exhibit ferromagnetic coupling, and 5 (Dy(III)) exhibits remarkably slow magnetic relaxation behavior with the energy barrier ΔE/k(B) = 49.2 K.
authors.affiliation: Department of Chemistry, Tianjin University, Tianjin, 300072, China.
authors.forename: Yin-Ling
authors.initials: YL
authors.lastname: Hou
authors.forename: Gang
authors.initials: G
authors.lastname: Xiong
authors.forename: Bo
authors.initials: B
authors.lastname: Shen
authors.forename: Bin
authors.initials: B
authors.lastname: Zhao
authors.forename: Zhi
authors.initials: Z
authors.lastname: Chen
authors.forename: Jian-Zhong
authors.initials: JZ
authors.lastname: Cui