Abstract
We report here the synthesis, structure, magnetic and photoluminescence properties of three new bifunctional Schiff-base complexes [Dy(L1)2(py)2][B(Ph)4]•py (1), [Dy(L1)2Cl(DME)]•0.5DME (2) and [Dy(L2)2Cl]•2.5(C7H8) (3) (HL1 = Phenol, 2,4-bis(1,1dimethylethyl)-6-[[(2-methoxy-5-methylphenyl)imino]methyl]; HL2 = Phenol, 2,4-bis(1,1-dimethylethyl)-6-[[(2-methoxyphenyl)imino] methyl]). The coordination environment of the Dy 3+ ion and the direction of the anisotropic axis may be controlled by the combination of the substituent groups of the Schiff bases, the nature of the counter-ions (Cl vs. BPh4 ) and the coordinative solvent molecules. A zero-field slow relaxation of the magnetization is evidenced for all complexes but strong differences in the relaxation dynamics are observed depending on the Dy 3+ site geometry. In this sense, complex 1 exhibits an anisotropic barrier of 472 cm 1 , which may be favourably compared to other related examples due to the shortening of the Dy-O bond in the axial direction. Besides, the three complexes exhibit a ligand-based luminescence making them as bifunctional magneto-luminescent systems.