Effect of Ligand Field Tuning on the SMM Behavior for Three Related Alkoxide-Bridged Dysprosium Dimers

Abstract

The synthesis and characterization of three Dy2 compounds, [Dy2(HL1)2(NO3)4] (1), [Dy2(L2)2(NO3)4] (2), and [Dy2(HL3)2(NO3)4] (3), formed using related tripodal ligands with a central tertiary amine bearing picolyl and alkoxy arms, 2-[(2-hydroxy-ethyl)-pyridin-2-ylmethylamino]-ethanol (H2L1), 2-(bis-pyridin-2-ylmethylamino)-ethanol (HL2), and 2-(bis-pyridin-2-ylmethylamino)-propane-1,3-diol (H2L3), are reported. The compounds are rare examples of alkoxide-bridged {Dy2} complexes and display capped square antiprism coordination geometry around each Dy(III) ion. Changes in the ligand field environment around the Dy(III) ions brought about through variations in the ligand donors can be gauged from the magnetic properties, with compounds 1 and 2 showing antiparallel coupling between the Dy(III) ions and 3 showing parallel coupling. Furthermore, slow relaxation of the magnetization typical of SMM behavior could be observed for compounds 2 and 3, suggesting that small variations in the ligand field can have a significant influence on the slow relaxation processes responsible for SMM behavior of Dy(III)-based systems.

Enhancement of TbIII–CuII Single‐Molecule Magnet Performance through Structural Modification

“…The enhancement of the anisotropy barrier may be attributed to changes in the electronic structure of the lanthanide ions due to changes in the local symmetry or crystal field effects related to the replacement of the auxiliary ligands . To probe the SMM behaviour of 4 , single‐crystal measurements were carried out.…”

“…Therefore, factors such as the choice of Ln III ion (Dy III and Tb III being the most favoured), or ligands capable of promoting certain local symmetries around these 4f centres have been explored. More recent studies suggest that perturbations in the ligand environment of the Ln III ions can cause changes in the CF that modify the overall magnetic behaviour of the complexes …”

Metal-Organic Framework of Lanthanoid Dinuclear Clusters Undergoes Slow Magnetic Relaxation

“…The crystal data for 1 and 2 are summarized in Table S1. We thought that these Ln-MOFs would exhibit SMM-like behaviour from the viewpoint of the structure because many Ln complexes exhibit SMM properties when they have square-antiprismatic [2,5,6,21,22] or monocapped square-antiprismatic [18,23,24] coordination geometries or when they have carboxylato-bridged dinuclear structures [18,25,26,27]. …”

Layered Ln(III) Complexes from a Sulfonate‐Based 1,8‐Naphthalimide: Structures, Magnetism and Photophysics

“…Analysis of the Cambridge Structural Database (CSD Version 5.40, Nov 2018) revealed that the majority of structurally characterised metal containing naphthalimide complexes contain transition metals, with only three groups recently reporting structurally characterised 1,8‐naphthalimide‐Ln(III) complexes . Trivalent lanthanide ions have many interesting properties, including potential use as single molecule magnets (SMMs) and the ability to generate luminescent materials for lighting and sensing applications . Consequently, the self‐assembly of functional Ln(III) containing materials is also an area of significant current interest .…”