Magnetic refrigeration property and single-molecule magnetic behavior of three asymmetric Ln2 (LnIII = Gd, TB and Dy) compounds

Three new dinuclear Ln(III)-based compounds formulated as {Ln2(dbm)5L}& sdot;nMeOH (Ln = Gd (1), Tb (2), and Dy (3), Hdbm = dibenzoylmethane, HL = 2-hydroxyimino-propionic acid (6-methoxy-pyridin-2-ylmethylene)-hydrazide, MeOH = methanol) have been successfully synthesized under solvothermal conditions. The structures and magnetic properties of 1-3 have been systematically studied. The single-crystal X-ray diffraction analysis shows that compounds 1-3 are dinuclear structures with two asymmetric LnIII ion centres. The magnetic properties study suggests that compound 1 displays cryogenic magnetic refrigeration property, while compound 3 exhibits single-molecule magnetic behavior with an energy barrier (Delta E/kB) of 62.3 K and pre-exponential factor tau 0 = 2.93 x 10-8 s under a zero direct-current field.