title: Local coordination geometry perturbed β-diketone dysprosium single-ion magnets.
abstract: A series of three β-diketone mononuclear dysprosium complexes, namely, Dy(TFI)3(H2O)2 (1), Dy(TFI)3(bpy) (2), and [Dy(TFI)3(Phen)]·0.02CHCl3 (3) (TFI = 2-(2,2,2-trifluoroethyl)-1-indone, bpy = 2,2'-bipyridine, phen = 1,10-phenanthroline) have been designed and synthesized. Crystal structure analysis reveals that complexes 1-3 have haveisomorphic structures in which the central Dy(III) ion is eight-coordinated by six oxygen atoms from three TFI ligands and two O/N atoms from auxiliary ligands, forming a distorted bicapped trigonal prismatic geometry for 1, a distorted dodecahedral geometry for 2, and a distorted square antiprismatic geometry for 3, respectively. Magnetic studies indicate that complex 2 with D(2d) symmetry and 3 with D(4d) symmetry exhibit slow magnetic relaxation with barrier heights (U(eff)/k(B)) of 48.8 K for 2 and 57.9 K for 3. Strikingly, the relaxation time (τ) of 0.0258 s for 3 is about 20 times that for 2, which is presumably associated with larger rotation of the SAP surroundings for 3. Further, complexes 2 and 3 exhibit essential magnetic hysteresis loops at 1.8 K. These extend the recent reports of the single-ion magnets (SIMs) of β-diketone mononuclear dysprosium complexes.
authors.affiliation: Key Laboratory of Functional Inorganic Material Chemistry (MOE); School of Chemistry and Materials Science, Heilongjiang University , Harbin 150080, P. R. China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhu
authors.forename: Changzheng
authors.initials: C
authors.lastname: Wang
authors.forename: Fang
authors.initials: F
authors.lastname: Luan
authors.forename: Tianqi
authors.initials: T
authors.lastname: Liu
authors.forename: Pengfei
authors.initials: P
authors.lastname: Yan
authors.forename: Guangming
authors.initials: G
authors.lastname: Li