title: Pentanuclear lanthanide pyramids based on thiacalix[4]arene ligand exhibiting slow magnetic relaxation.
abstract: A series of pentanuclear Ln(III) clusters, [Ln5(μ4-OH)(μ3-OH)4(L1)(acac)6] (H4L1 = p-tert-butylthiacalix[4]arene; acac = acetylacetonate; Ln = Dy, Ho, Er) and [Ln5(μ5-OH)(μ3-OH)4(L1)(L2)2(acac)2(CH3OH)2] (H3L2 = 5,11,17,23-tetrakis(1,1-dimethylethyl)-25,26,27-trihydroxy-28-methoxy thiacalix[4]arene; Ln = Dy, Ho, Er), have been synthesized based on the thiacalix[4]arene ligand. All of these complexes feature a square-based pyramid with four triangular Ln3 structural motifs. One μ4-OH group bridges four Ln(III) ions in the basal plane of , while the OH group in complexes adopts the μ5-coordination mode. Our results illuminate the coordination modes of the versatile thiacalix[4]arene ligands and their application to new cluster compounds. The structural and magnetic studies confirm that the molecular symmetries and coordination geometries for lanthanide metal cores have a significant effect on some parameters as single-molecule magnets. Among them, two Dy5 pyramids exhibit distinct slow magnetic relaxation.
authors.affiliation: State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, P. R. China. zuojl@nju.edu.cn.
authors.forename: Jing-Yuan
authors.initials: JY
authors.lastname: Ge
authors.forename: Jing
authors.initials: J
authors.lastname: Ru
authors.forename: Feng
authors.initials: F
authors.lastname: Gao
authors.forename: You
authors.initials: Y
authors.lastname: Song
authors.forename: Xin-Hui
authors.initials: XH
authors.lastname: Zhou
authors.forename: Jing-Lin
authors.initials: JL
authors.lastname: Zuo