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 ((Dy2L2Y2)-Y-x) (1-4) based on the association of various flexible benzothiazolyl ligands and beta-diketonate ligands [(Dy(2)L(2)(x)Z(2)) (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.