Manipulating the Relaxation of Quasi- D4 d Dysprosium Compounds through Alternation of the O-Donor Ligands

Mei Guo; Jianfeng Wu; Olivier Cador; Jingjing Lu; Bing Yin; Boris Le Guennic; Jinkui Tang

doi:10.1021/acs.inorgchem.8b00294

Manipulating the Relaxation of Quasi- D_{4 d} Dysprosium Compounds through Alternation of the O-Donor Ligands

Inorg Chem. 2018 Apr 16;57(8):4534-4542. doi: 10.1021/acs.inorgchem.8b00294. Epub 2018 Apr 3.

Authors

Mei Guo^{1

2}, Jianfeng Wu^{1

3}, Olivier Cador⁴, Jingjing Lu¹, Bing Yin⁵, Boris Le Guennic⁴, Jinkui Tang¹

Affiliations

¹ State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry , Chinese Academy of Sciences , Changchun 130022 , P. R. China.
² University of Chinese Academy of Sciences , Beijing , 100049 , P. R. China.
³ Sino-German Joint Research Lab for Space Biomaterials and Translational Technology, School of Life Sciences , Northwestern Polytechnical University , Xi'an , 710072 , P. R. China.
⁴ Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes)-UMR 6226 , F-35000 Rennes , France.
⁵ Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science , Northwest University , Xi'an , 710069 , P. R. China.

PMID: 29613778
DOI: 10.1021/acs.inorgchem.8b00294

Abstract

Three mononuclear Dy^III complexes with the same auxiliary ligand Lz (2,4-diamino-6-pyridyl-1,3,5-triazine), [Dy(TTA)₃Lz] (1Dy) (TTA = 4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedionate), [Dy(acac)₃Lz]·CH₃OH·0.5H₂O (2Dy) (acac = acetylacetonate), and [Dy(MQ)₂Lz₂]Br·CH₃OH (3Dy) (HMQ = 2-methyl-8-quinolinol), have been synthesized through alteration of the ligands containing O donors. In all three complexes, the Dy^III ions are eight-coordinate and submitted to pseudo- D_{4 d} symmetry in the first coordination sphere. It is noteworthy that the TTA ligands in 1Dy are easily substituted by other bidentate capping ligands with O donors, leading to distinct magnetic properties, which were studied experimentally and via ab initio calculations. All three complexes were found to exhibit single-molecule magnet behavior with U_eff of 22 cm^-1 (1Dy), 112 cm^-1 (2Dy), and 56 cm^-1 (3Dy) under zero applied dc field. Complex 1Dy demonstrates inferior SIM properties compared with 2Dy and 3Dy, which can be attributed to the strong electron-withdrawing effects of TTA ligands, as confirmed by theoretical calculations. However, butterfly-shaped magnetic hysteresis in 1Dy and 3Dy was observed at 1.9 K, while not in 2Dy.