Zero-Field Single-Molecule Magnet Behavior in a Series of Dinuclear Dysprosium(III) Complexes Based on Benzothiazolyl-Based Ligands and β‑Diketonates

We report the synthesis and crystal structures of four dinuclear dysprosium(III) complexes with the general formula (Dy₂L₂^xY₂) (1–4) based on the association of various flexible benzothiazolyl ligands and β-diketonate ligands [(Dy₂L₂^xZ₂) (x = 1, 3 with Z = 1,3-diphenyl-1,3-propanedionate (dphac); x = 2, 4 with Z = hexafluoroacetylacetonate (hfac)]. While these complexes share similar dinuclear cores, magnetic investigations, in line with theoretical calculations, reveal a zero-field slow relaxation of the magnetization for all complexes, albeit different relaxation dynamics. Although the Dy³⁺ single-ion anisotropy is mainly driving the relaxation, the observed intramolecular ferromagnetic interactions shortcut the quantum tunneling of the magnetization.