Mononuclear Lanthanide Complexes in Triangular Dodecahedron Geometry: Manifestation of Single Ion Magnet Behavior for Dy^III Analogue

Abstract

In this work, a tridentate N,N,O ligand [(E)-4-nitro-2-((pyridine-2ylmethylene)amino)phenol] (L NO2 H) is employed for the synthesis of neutral structurally similar complexes [Dy IIIBoth complexes are characterized by single-crystal X-ray diffraction studies. Ln III ion in complexes 1 and 2 is eight coordinated and possesses triangular dodecahedron geometry as confirmed by the SHAPE analysis. The Hirshfeld surface calculation emphasizes the importance of hydrogen bond interaction that controls the overall crystal packing. The magnetic studies reveal that complex 1 shows single ion magnet (SIM) behavior with an effective energy barrier of 34.16 K and pre-exponential parameter 6.51 × 10 −6 s. The CASSCF based ab initio calculations were performed on complexes 1 and 2 to extract SH parameters and the plausible magnetic relaxation dynamics.

Crystal engineering of monometallic lanthanide(iii) supramolecular systems within the N3-tridentate hydrazone Schiff-base ligand

“…When a phenol moiety, potentially a donor of an oxygen atom from a hydroxy group, is introduced into the ligand molecule, reactions in the presence of nitrate or chloride lanthanide salts consistently lead to obtaining 1 : 2 metal : ligand species. 60,61 On the other hand, when the ligand scaffold contains a carboxyl group involved in the coordination of the Ln( iii ) center, assemblies formed with nitrate anions maintain a molar ratio of the metal to ligand of 1 : 1, 30 as exactly observed in the synthesis of lanthanide nitrate complexes here. Moreover, with this type of N , N , O -hydrazone Schiff-base ligand, we also observe anion-driven self-assembly (utilization of chloride salts leads to formation of 1 : 2 metal : ligand complexes) and fine-tuning solvent characteristics are noted, showing structure-dependent magnetic properties.…”