A propeller-shaped μ₄-carbonate hexanuclear dysprosium complex with a high energetic barrier to magnetisation relaxation

Abstract

A Dy complex composed of two Dy triangular units, [Dy(μ-OH)(CO)(bsc)(MeOH)(HO)](Cl)·(HO)·(MeOH) (1), was isolated and found to exhibit slow relaxation of the magnetisation under zero applied dc field, resulting in a high energetic barrier to relaxation.

Lanthanide-Based Single-Molecule Magnets Derived from Schiff Base Ligands of Salicylaldehyde Derivatives

“…The AC magnetic susceptibility studies performed on a polycrystalline sample of 30 measured in the 2. In contrast to the report of similar ligands [71], the trans-trans conformations were switched to cis-trans conformation in 31, leading to the N-N pathway (Figure 18b) (N2-N3, N2a-N3a and N2b-N3b between Dy1-Dy1a, Dy1a-Dy1b and Dy1b-Dy1, respectively) [55]. On account of this, the three intramolecular Dy-Dy distances are 5.862 Å (Figure 18c), which are longer than other literature triangular complexes with Schiff base ligands [72] with Dy-Dy-Dy angles close to 60.0 • , giving a nearly perfect equilateral triangle.…”

“…Dy(III) in 31 was bonded to two H 4 L11 and two DMF terminal solvents, leading to an eight coordinated triangular dodecahedron [55]. The coordination modes of the three ligands between any two Dy(III) ions are similar, where the two Dy(III) ions are held together by µ-κ 3 :κ 3 -HL11 3− .In contrast to the report of similar ligands[71], the trans-trans conformations were switched to cis-trans conformation in 31, leading to the N-N pathway (Figure18b) (N2-N3, N2a-N3a and N2b-N3b between Dy1-Dy1a, Dy1a-Dy1b and Dy1b-Dy1, respectively)[55]. On account of this, the three intramolecular Dy-Dy distances are 5.862 Å (Figure18c), which are longer than other literature triangular complexes with Schiff base ligands[72] with Dy-Dy-Dy angles close to 60.0 • , giving a nearly perfect equilateral triangle.…”

Zero-field slow magnetic relaxation behavior of Zn2Dy in a family of trinuclear near-linear Zn2Ln complexes: synthesis, experimental and theoretical investigations

“…[46][47][48][49] Although spin-orbit coupling is a dominant factor in lanthanide ions, ligand field has a significant role in deter-mining the electronic structure of respective lanthanide complexes. 8,39,[50][51][52][53][54][55][56][57] Controlling suitable ligand field around anisotropic Ln(III) ions depending on its electronic structure is extremely challenging task. 45,58,59 By enhancing exchange interaction in Ln(III) complexes, QTM can be suppressed significantly, which is an elegant approach revealed by Long and co-workers in a series of lanthanide dimers bridged by N 2 3− radical ligand.…”

Alternate Synthetic Pathway Leading to Isolation of a Dinuclear Single‐Molecule Magnet

“…In order to isolate the dinuclear unit, 1,5‐bis(salicylidene)carbohydrazide (H 3 bsc) was designed without the methoxy group, which leads to only two potential coordination sites. An unexpected Dy 6 single‐molecule magnet, [Dy 6 (µ 3 ‐O)(bsc) 3 (CO 3 ) 3 (MeOH) 14 (H 2 O)](OH)Cl 3 · 2MeOH · 2H 2 O ( B· 2MeOH · 2H 2 O), was synthesized, which exhibits slow relaxation of the magnetization under zero applied dc field with a value of U eff / k B = 101.9 K. The structure was assembled thereafter by three dinuclear units in a triangular arrangement, which were linked through CO 3 2– bridges. With this in mind, we have focused our attention on synthesizing dinuclear or trinuclear units with the same ligand, H 3 bsc, whose magnetic properties may be further explored by simplifying the magnetic interaction or anisotropic axes alignments.…”