Self-assembly of heterometallic Ln<sup>III</sup>–Co<sup>II</sup>coordination polymers: syntheses, structures, and magnetic studies
作者:Xiao-Qing Zhao、Xu-Hui Liu、Xiao-Min Kang、Bin Zhao
DOI:10.1039/c5dt02280k
日期:——
A family of heterometallic 4fâ3d coordination polymers with the common formula [LnCo1.5(L)2(H2O)5]n (Ln = Pr(1), Eu(2), Gd(3), Tb(4), Dy(5), Ho(6), and Er(7), and H3L = 4-(carboxymethoxy)isophthalic acid) was obtained under solvothermal conditions with the effect of NaN3, which was involved in the reactions but not in the final structure. All of the compounds were isostructural, and had a two-dimensional wave-like structure based on centrosymmetric [LnO2Co]âCoâ[LnO2Co] motifs. The results of the magnetic measurements displayed that ferromagnetic interactions occurred in the frameworks (3â7) containing âheavyâ lanthanide ions (Gd, Tb, Dy, Ho, and Er), which should be ascribed to the coupling between the LnIII and CoII ions. Furthermore, compound 5, containing DyIII ions, displayed field-induced slow magnetic relaxation.
在溶热条件下获得了一系列异金属 4fâ3d 配位聚合物,它们的共同分子式为 [LnCo1.5(L)2(H2O)5]n(Ln = Pr(1)、Eu(2)、Gd(3)、Tb(4)、Dy(5)、Ho(6)和 Er(7),H3L = 4-(羧基甲氧基)间苯二甲酸)。所有化合物都是等结构的,具有基于中心对称[LnO2Co]âCoâ[LnO2Co]图案的二维波状结构。磁性测量结果显示,含有 "重 "镧系离子(Gd、Tb、Dy、Ho 和 Er)的框架(3â7)中存在铁磁相互作用,这应归因于 LnIII 离子和 CoII 离子之间的耦合。此外,含有 DyIII 离子的化合物 5 显示出场诱导的缓慢磁弛豫。