Exploiting single-molecule magnets of β-diketone dysprosium complexes with C3v symmetry: suppression of quantum tunneling of magnetization

Abstract

A series of four β-diketone mononuclear dysprosium complexes, namely, Dy(EIFD)₃(H₂O)·CH₂Cl₂ (1), Dy(EIFD)₃(DMF)·CH₂Cl₂ (2), Dy(EIFD)₃(DMSO) (3), and Dy(EIFD)₃(TPPO) (4) (EIFD: 1-(1-ethyl-1H-indol-3-yl)-4,4,4-trifluorobutane-1,3-dione, TPPO: triphenylphosphine oxide), have been isolated by the reactions of a newly designed β-diketone EIFD, DyCl₃·6H₂O and DMF, DMSO, TPPO, respectively. X-ray crystallographic analysis reveals that complexes 1–4 are isomorphic mononuclear structures in which the Dy(III) ion is rarely seven-coordinated with C_3v geometry. Magnetic studies indicate that all complexes 1–4 are single-molecule magnets. The correlations between magnetism and the distortion of the coordination symmetry around the Dy(III) ions have been investigated. Notably, the quantum tunneling of magnetization (QTM), which universally exists in the lanthanide complexes, has been effectively suppressed in this system more related to the less deviation from the ideal C_3v symmetry.