In situ hydrothermal synthesis of dysprosium(iii) single-molecule magnet with lanthanide salt as catalyst

Abstract

A family of six dinuclear lanthanide complexes have been obtained via in situ hydrothermal synthesis with lanthanide ions as catalyst. These six complexes are formulated as [Ln(2)(3-Htzba)(2)(3-tzba)(2)(H(2)O)(8)]·4H(2)O [Ln = Gd, 1; Dy, 2; Eu, 3; Tb, 4; Sm, 5; Er, 6; 3-H(2)tzba = 3-(1H-tetrazol-5-yl)benzoic acid]. The magnetic investigations show that complex 2 behaves as a single-molecule magnet (SMM) with a quantum relaxation time of ~10(-2) s.

Phenalenyl-based mononuclear dysprosium complexes

“…The bond lengths between the dysprosium and the oxygen atoms of the protonated phenalenyls vary from 2.280 to 2.309 Å for 2a and 2.249 to 2.324 Å for 2b ; and the bond angles range from 135.3 to 139.1° for 2a and from 137.5 to 139.1° for 2b . It is noteworthy that the bond distances between the dysprosium atom and the oxygen atoms of the HPLN ligands can be compared to those reported in other dysprosium–oxygen compounds [30–36]. Additionally, two intramolecular hydrogen bonds are formed: O8H8-O4 (2.39 Å) and O8H8-O7 (1.86 Å) in 2a , but three are formed in 2b .…”

“…At a frequency of 1500 Hz, the out-of-phase component first reaches a maximum at 13 K and then steadily increases rather than declining to zero while decreasing the temperature. This indicates a transition from a thermally activated to a temperature-independent regime in the relaxation process [36,50–51]. Shape and frequency dependence of the out-of-phase component in ac susceptibilities suggests that 1 might be a SMM.…”

Two Dysprosium(III)‐Based Single‐Molecule Magnets Derived from 1,10‐Phenanthroline Ligands and Different Anions as Bridging Groups

“…The magnetization values of both 1 and 2 at 2 K reached 11.41 and 4.91 µ B at 70 kOe, respectively, and are clearly lower than the expected theoretical saturation values for two uncorrelated Dy III ions (20 µ B ) or one independent Dy III ion (10 µ B ); therefore, the magnetization values suggest the presence of magnetic anisotropy, low‐lying excited states, or both. In addition, the non‐superimposition of the M versus H/T data for 1 and 2 at 2.0–8.0 K confirm the presence of anisotropy, low‐lying excited states, or both …”

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]. …”