Enhancing magnetic relaxation through subcomponent self-assembly from a Dy₂to Dy₄grid

Abstract

The subcomponent self-assembly of 4,6-dihydrazinopyrimidine and o-vanillin/salicylaldehyde with different DyIII salts lead to the formation of linear Dy2 (1−3) and grid-like Dy4 (4) compounds with formulas of [Dy2L(DMF)4(NO3)4]·2DMF (1), [Dy2L2(CH3COO)4(CH3OH)2]·10H2O...

Dysprosium Clusters from 3-Ethoxysalicylidene Terminal-Decorated Acylhydrazone Ligands: In Situ Ligand Transformation-Assisted Assembly and Zero-Field Single-Molecule Magnet Behaviors

“…Upon cooling, the χ M T values of 1 and 2 all decline gradually, finally reaching the minimum of 67.65 and 33.86 cm 3 K mol –1 at 2 K, respectively. These decreases could be ascribed to the combined effects of the quenching of Stark energy levels of Dy III ions and possible antiferromagnetic interactions between the Dy III centers in the systems. − The χ M T–T curve of 3 exhibits a gradually decreasing trend in a high-temperature region due to the thermal depopulation of the Stark levels of Dy ions. Note that a shoulder appears at about 20–10 K, after which the χ M T value starts to drop rapidly, finally reaching a minimum of 48.4 cm 3 K mol –1 at 2 K. This might be ascribed to the presence of weak ferromagnetic interactions between the Dy centers of 3 . ,− …”

Structure and assembly studies of two planar Dy(iii) single molecule magnets with double relaxations

“…Their w m T values of 57.87 and 79.34 cm 3 K mol À1 at 300 K are near to the corresponding theoretical values of 56.68 and 85.02 cm 3 K mol À1 based on four and six isolated Dy(III) ions ( 6 H 15/2 , S = 5/2, L = 5, J = 15/2, and g = 4/3) for 1 and 2, respectively. 21,56,57 Upon cooling the sample, a slight decrease was observed for the w M T values of 1 and 2 before 100 and 69 K, with an subsequent rapid decrease to 37.08 and 35.94 cm 3 K mol À1 at 2 K, respectively. This kind of behavior is believed to be caused by the synergistic effect of thermally reduced Stark energy levels and intermetallic magnetic interactions or dipole-dipole interactions.…”

Hierarchical subcomponent self-assembly of covalent triple-stranded complexes with 3d–4f vertices: luminescence and magnetic properties

“…A myriad of diverse metallo-supramolecular compounds with sophisticated structures and fascinating functions, including, but not limited to, macrocycles, [10][11][12] helicates, [13][14][15] grids, 16,17 catenanes, 18 rotaxanes, 19 and metal-organic polyhedra, [20][21][22][23] have been successfully fabricated by the subcomponent self-assembly approach. Besides these types of structures, there is another type of structure composed of a discrete covalent organic skeleton and metal ions, namely discrete covalent metallo-supramolecular architectures, in which the metal ions are located at the vertices or panels of the covalent organic skeleton.…”