Magnetic refrigeration and single-molecule magnet behavior of two rhombus-shaped Ln(III)4 (Ln = Gd, Dy) clusters

Two tetranuclear lanthanide(III) clusters, [Gd-4(mu(3)-OH)(2)L-6(dbm)(4)].solvent, (1, Ln = Gd-III, solvent = 2CH(3)CN center dot 2CH(2)Cl(2) and 2, Ln = Dy-III, solvent = 6CH(3)CN; HL = 5-(4-o-hydroxybenzylidene)-8-hydroxylquinoline; dbm = 1,3-diphenyl-1,3-propanedione), were characterized in terms of structure and magnetism. The X-ray structural analysis exhibit that clusters 1 and 2 contain one Ln4 center with rhombus-shaped arrangement, and each Ln(III) ion of them is located in a distorted square-antiprismatic coordination sphere. Magnetic measurements indicate that 1 show magnetic refrigeration (-Delta S-m = 13.91 J kg(-1) K-1 for Delta H = 7.0 T at 3.0 K) and 2 display single molecule magnets behaviors with energy barrier (Delta E/k(B)) of 52.65 K and tau(0) = 7.01 x 10(-7) s. (C) 2018 Elsevier Ltd. All rights reserved.