title: Self-assembly of heterometallic Ln(III)-Co(II) coordination polymers: syntheses, structures, and magnetic studies.
abstract: A family of heterometallic 4f-3d 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]-Co-[LnO2Co] motifs. The results of the magnetic measurements displayed that ferromagnetic interactions occurred in the frameworks (3-7) containing "heavy" lanthanide ions (Gd, Tb, Dy, Ho, and Er), which should be ascribed to the coupling between the Ln(III) and Co(II) ions. Furthermore, compound 5, containing Dy(III) ions, displayed field-induced slow magnetic relaxation.
authors.affiliation: Department of Chemistry, Key Laboratory of Advanced Energy Material Chemistry of the Ministry of Education, and Collaborative Innovation Center of Chemical Science and Engineering, Nankai University, Tianjin 300071, China. zhaobin@nankai.edu.cn and College of Science, Sichuan Agricultural University, Ya'an 625014, China.
authors.forename: Xiao-Qing
authors.initials: XQ
authors.lastname: Zhao
authors.affiliation: Department of Chemistry, Key Laboratory of Advanced Energy Material Chemistry of the Ministry of Education, and Collaborative Innovation Center of Chemical Science and Engineering, Nankai University, Tianjin 300071, China. zhaobin@nankai.edu.cn.
authors.forename: Xu-Hui
authors.initials: XH
authors.lastname: Liu
authors.affiliation: Department of Chemistry, Key Laboratory of Advanced Energy Material Chemistry of the Ministry of Education, and Collaborative Innovation Center of Chemical Science and Engineering, Nankai University, Tianjin 300071, China. zhaobin@nankai.edu.cn.
authors.forename: Xiao-Min
authors.initials: XM
authors.lastname: Kang
authors.affiliation: Department of Chemistry, Key Laboratory of Advanced Energy Material Chemistry of the Ministry of Education, and Collaborative Innovation Center of Chemical Science and Engineering, Nankai University, Tianjin 300071, China. zhaobin@nankai.edu.cn.
authors.forename: Bin
authors.initials: B
authors.lastname: Zhao