Jump to main content
Jump to site search

Issue 15, 2019
Previous Article Next Article

High local coordination symmetry around the spin center and the alignment between magnetic and symmetric axes together play a crucial role in single-molecule magnet performance

Author affiliations

Abstract

A tetradentate 8-hydroxyquinoline-based acyl hydrazone ligand (HL1 = 8-hydroxyquinoline-2-carboxaldehyde-(aminourea)hydrochloride) was elaborately used to construct a mononuclear dysprosium complex DyCl3HL1·CH3OH (1) with a nearly ideal pentagonal bipyramid coordination geometry (D5h) surrounding the Dy(III) ion to achieve the significant performance of single-molecule magnets (SMMs). Meanwhile, the isolated high local symmetry center was successfully kept intact and further bridged to a series of double bipyramid systems by two phenolic oxygen atoms of the acyl hydrazone ligands (HL1 and HL2 = 8-hydroxyquinoline-2-carboxaldehyde-(benzoyl)hydrazine), with the formulae [Dy2Cl4(L1)2(CH3OH)2]·4C5H5N (2) and [Dy2Cl4(L2)2]·2CH3CN (3). In addition, the monodentate co-ligand anion was replaced by a larger sterically hindered ligand and a bidentate monovalent β-diketonate anion to generate [Dy2(tfo)4(L2)2(EtOH)2] (4), [Dy2(tta)4(L2)2(EtOH)2]·2(EtOH) (5) and [Dy2(dbm)4(L2)2(EtOH)2] (6) (tfo = trifluoromethanesulfonic acid, dbm = dibenzoylmethane, tta = 4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione) with eight-coordinate geometry. Strikingly, the dynamic magnetic measurements revealed that complexes 1–3 did not display the expected significant SMM performance albeit they had high local symmetry. In combination with ab initio calculation, the alignment of the coordination symmetric axis and the magnetic easy axis dominates the molecular magnetic anisotropy, and the magnetic easy axis could be modulated by the distribution of coordination atoms with different electrostatic properties.

Graphical abstract: High local coordination symmetry around the spin center and the alignment between magnetic and symmetric axes together play a crucial role in single-molecule magnet performance

Back to tab navigation

Supplementary files

Publication details

The article was received on 04 Jan 2019, accepted on 06 Mar 2019 and first published on 08 Mar 2019


Article type: Paper
DOI: 10.1039/C9DT00058E
Dalton Trans., 2019,48, 4931-4940

  •   Request permissions

    High local coordination symmetry around the spin center and the alignment between magnetic and symmetric axes together play a crucial role in single-molecule magnet performance

    Z. Yang, Y. Tian, W. Zhang, P. Chen, H. Li, Y. Zhang and W. Sun, Dalton Trans., 2019, 48, 4931
    DOI: 10.1039/C9DT00058E

Search articles by author

Spotlight

Advertisements