Wu Jianfeng, Cador Olivier, Li Xiao-Lei, Zhao Lang, Le Guennic Boris, Tang Jinkui
State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun 130022, People's Republic of China.
Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS-Université de Rennes 1 , 263 Avenue du General Leclerc, 35042 Rennes Cedex, France.
Inorg Chem. 2017 Sep 18;56(18):11211-11219. doi: 10.1021/acs.inorgchem.7b01582. Epub 2017 Aug 30.
A series of mononuclear Dy complexes with the general formula [DyLz(salicylaldehyde)]·X·solvent (Lz = 6-pyridin-2-yl[1,3,5]triazine-2,4-diamine; X = OH (1·OH), Cl (2·Cl), Br (3·Br)) have been synthesized using mixed salicylaldehyde/pyridinyl-triazine ligands and discriminative counteranions. The Dy ion in these three complexes resides in a similar D coordination geometry with counteranions perturbing the coordination environment and bond lengths and angles in the lattice. Magnetostructural studies reveal that the asymmetric distribution of salicylaldehyde/pyridinyl-triazine ligands and the presence of discriminative counteranions result in the coexistence of large anisotropy and quantum tunneling of magnetization. The magnetic anisotropy is dominated by the axial ligand field with short Dy-O distances and large ∠O-Dy-O angles, while the quantum tunneling relaxation is probably dictated by the π-π stacking of the Lz ligands, which induces an axial constriction of the coordinating plane. Ab initio calculations substantiate the diversity of the magnetic behaviors in these complexes and highlight the importance of axial ligand field with short Dy-O distances, large ∠O-Dy-O angles and less ligand stacking in these pseudo-D-symmetrical single-molecule magnets.
