Lanthanide-directed fabrication of three phenoxo-O bridged dinuclear compounds showing magnetic refrigeration and single-molecule magnet behavior

A series of lanthanide based dinuclear compounds, namely, [Ln(bfa)(2)L](2) (Ln = Gd (1), Tb (2), and Dy (3), bfa = benzoyltrifluoroacetone and HL = 2-[5-methyl-1,2-oxazol-imino]methyl]-8-hydroxyquinoline), were synthesized by employing a multidentate 8-hydroxyquinoline Schiff base derivative ligands (HL) and a bidentate beta-diketonate coligand (bfa). The elemental analysis (EA), powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), single-crystal X-ray diffraction and magnetic properties of the three Ln(2) compounds were completely characterized. Structures of 1-3 are similar to each other with a parallelogram Ln(2)O(2) core. Magnetic properties study indicates that 1 exhibits antiferromagnetic exchange interaction between two nearby GdIII centers and shows magnetic refrigeration (-Delta S-m = 17.78 J kg(-1) K-1 for Delta H = 7 T at 2.0 K). Ac magnetic susceptibility measurements of 3 demonstrate that slow relaxation behavior is observed in 3, with effective energy barrier U-eff = 24.3 K and pre-exponential factor tau(0) = 1.71 x 10(-6) s. (C) 2017 Elsevier Ltd. All rights reserved.