6533b823fe1ef96bd127df0a

RESEARCH PRODUCT

Capping N‐Donor Ligands Modulate the Magnetic Dynamics of Dy III β‐Diketonate Single‐Ion Magnets with D 4 d Symmetry

subject

description

A family of four mononuclear DyIII β-diketonate complexes with formulas [Dy(tmhd)3 (Br2 -bpy) (1), [Dy(tmhd)3 (Br-bpy)] (2), [Dy(tmhd)3 (dppz)] (3), and [Dy(tmhd)3 (mcdpq)] (4) (tmhd=2,2,6,6-tetramethyl-3,5-heptanedione, Br2 -bpy=5,5'-dibromo-2,2'-bipyridine, Br-bpy=5-bromo-2,2'-bipyridine, dppz=dipyrido [3,2-a:2',3'-c]phenazine, mcdpq=2-methoxyl-3-cyanodipyrido[3,2-f:2,3'-h]quinoxaline) were prepared by modifying the capping N-donor coligands. DyIII centers in these complexes feature an N2 O6 octacoordinate environment with distorted square-antiprismatic D4d symmetry. Magnetic investigations evidenced single-ion magnet behavior in all complexes with energy barriers Ueff of 42.10 (1), 61.47, (2), 77.53 (3), and 2.51 K (4) in the absence of static field, as well as 206.03 (1), 224.13 (2), 247.76 (3), and 49.70 K (4) under applied dc field (Hdc =1500 Oe for 1 and 2; Hdc =1200 Oe for 3 and 4). The different natures of the N-donor ligands induce changes in both the coordination geometry and their intermolecular interactions, which severely impact their magnetic dynamics. The disparities in their magnetic behaviors and the uniaxial anisotropies are also explained and substantiated by theoretical calculations.