A Terminal Fluoride Ligand Generates Axial Magnetic Anisotropy in Dysprosium Complexes

Abstract

The first dysprosium complexes with a terminal fluoride ligand are obtained as air-stable compounds. The strong, highly electrostatic dysprosium-fluoride bond generates a large axial crystal-field splitting of the J=15/2 ground state, as evidenced by high-resolution luminescence spectroscopy and correlated with the single-molecule magnet behavior through experimental magnetic susceptibility data and ab initio calculations.

Magnetic Properties of LnIII–CuII 15‐Metallacrown‐5 Dimers with Terephthalate (LnIII = Pr, Nd, Sm, Eu)

“…Numerous studies of diverse lanthanide‐containing compounds have been provoked by their potential use in various catalytic processes, as MRI contrast agents, in sensors and optical materials, and in compounds with non‐trivial magnetic, and luminescence properties , . The significant magnetic anisotropy typical for Ln III ions in combination with their large ground state total spin can result in observation of SIM (single ion magnet), SMM (single molecule magnet) or SCM (single chain magnet) behavior in lanthanide‐containing discrete molecular complexes and coordination polymers , . Recently, multiple complexes with Ln III were reported to be able to demonstrate a considerable magnetocaloric effect, which has generated additional interest in this research area , …”

An Unusual LnIII‐Based Metal‐Organic Framework with Dinuclear Nodes Exhibiting Single‐Molecular Magnet Behavior

“…As Powell and Shi propose in their recent review, the organization of a Dy 2 unit in a MOF can significantly increase the energy barrier for magnetization reversal. [2b] This has also been observed for 2D chains of Dy 2 [3j] and Chilton in a low‐coordinate Dy III SMM with record hysteresis temperature of 80 K and 60 K. Other reports of low‐coordinate lanthanide ions also show SMMs with record energy barriers,[3g], however high‐temperature hysteresis has been elusive. One possibility is that relaxation pathways due to dipolar interactions with neighboring molecules in the crystal are readily accessible and QTM takes place.…”

The Influence of d‐f Coupling on Slow Magnetic Relaxation in NiIILnIIIMIII (Ln = Gd, Tb, Dy; M = Cr, Fe, Co) Clusters

“…With the drop of temperature, the value of Δ χ M T [ χ M T ( 1 )– χ M T ( 3 )] keeps constant (1.27 cm 3 K mol –1 ) above 20 K, and then decreases rapidly until reach –2.76 cm 3 K mol –1 . For the contribution of Dy III has been deducted from the χ M T value of 1 , such behavior can be assigned to be the contribution of single isotropic Cr III ion, indicating the magnetic coupling between Dy III and Cr III is very weak and negligible . The drop of the curve at very low temperature may be an indicative of the weak intramolecular antiferromagnetic Dy III –Cr III interactions and/or intermolecular antiferromagnetic interactions.…”