title: Six-coordinate lanthanide complexes: slow relaxation of magnetization in the dysprosium(III) complex.
abstract: A series of six-coordinate lanthanide complexes {(H3O)[Ln(NA)2]⋅H2O}n (H2NA=5-hydroxynicotinic acid; Ln=Gd(III) (1⋅Gd); Tb(III) (2⋅Tb); Dy(III) (3⋅Dy); Ho(III) (4⋅Ho)) have been synthesized from aqueous solution and fully characterized. Slow relaxation of the magnetization was observed in 3⋅Dy. To suppress the quantum tunneling of the magnetization, 3⋅Dy diluted by diamagnetic Y(III) ions was also synthesized and magnetically studied. Interesting butterfly-like hysteresis loops and an enhanced energy barrier for the slow relaxation of magnetization were observed in diluted 3⋅Dy. The energy barrier (Δ(τ)) and pre-exponential factor (τ0) of the diluted 3⋅Dy are 75 K and 4.21×10(-5) s, respectively. This work illustrates a successful way to obtain low-coordination-number lanthanide complexes by a framework approach to show single-ion-magnet-like behavior.
authors.affiliation: Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry (MOE) and Collaborative Innovation Center of Chemical Science, and Engineering (Tianjin), Nankai University, Tianjin 300071 (P. R. China), Fax: (+86) 22-23502458.
authors.forename: Bo
authors.initials: B
authors.lastname: Na
authors.forename: Xue-Jing
authors.initials: XJ
authors.lastname: Zhang
authors.forename: Wei
authors.initials: W
authors.lastname: Shi
authors.forename: Yi-Quan
authors.initials: YQ
authors.lastname: Zhang
authors.forename: Bing-Wu
authors.initials: BW
authors.lastname: Wang
authors.forename: Chen
authors.initials: C
authors.lastname: Gao
authors.forename: Song
authors.initials: S
authors.lastname: Gao
authors.forename: Peng
authors.initials: P
authors.lastname: Cheng
keywords: dysprosium; lanthanide complexes; magnetization; slow relaxation; structure elucidation