title: A salen-type Dy4 single-molecule magnet with an enhanced energy barrier and its analogues.
abstract: Four isomorphic tetranuclear lanthanide complexes, namely [Ln4(L)2(HL)2(NO3)2(OH)2](NO3)2·4H2O (Ln = Dy (1); Tb (2); Ho (3); Er (4)), constructed using hexadentate salen-type ligand N,N'-bis(3-methoxy-salicylidene)cyclohexane-1,2-diamine, have been isolated. X-ray crystallographic analysis reveals that all of the complexes 1-4 are of discrete tetranuclear structure with a unique {Ln4O8} core in which four lanthanide ions are coplanar in a rhombic frame. There are two crystallographically unequivalent lanthanide ions, that is the Ln1(III) ion which is nine-coordinated in a monocapped square-antiprismatic geometry of the C(4v) point group and the Ln2(III) ion which is eight-coordinated in a distorted bicapped trigonal-prismatic geometry of the C(2v) point group. Magnetic analysis reveals that complex 1 exhibits two slow magnetic relaxations with the highest energy barrier among the reported tetranuclear salen-type dysprosium SMMs. This further extends the available SMMs of salen-type lanthanide complexes.
authors.affiliation: Key Laboratory of Functional Inorganic Material Chemistry (MOE), School of Chemistry and Materials Science, Heilongjiang University, No. 74, Xuefu Road, Nangang District, Harbin, Heilongjiang 150080, P. R. China. gmli_2000@163.com.
authors.forename: Fang
authors.initials: F
authors.lastname: Luan
authors.forename: Pengfei
authors.initials: P
authors.lastname: Yan
authors.forename: Jing
authors.initials: J
authors.lastname: Zhu
authors.forename: Tianqi
authors.initials: T
authors.lastname: Liu
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Zou
authors.forename: Guangming
authors.initials: G
authors.lastname: Li
mesh_terms: D056831:Coordination Complexes / Q000737:chemistry*; D018360:Crystallography, X-Ray; D003514:Cyclohexylamines / Q000737:chemistry*; D028581:Lanthanoid Series Elements / Q000737:chemistry*; D060328:Magnetic Phenomena
chemical_list: D056831:Coordination Complexes; D003514:Cyclohexylamines; D028581:Lanthanoid Series Elements; C533174:N,N'-bis(salicylidene)-1',2'-cyclohexanediamine