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

Abstract Two tetranuclear lanthanide(III) clusters, [Gd 4 ( μ 3 -OH) 2 L 6 (dbm) 4 ]·solvent, ( 1 , Ln = Gd III , solvent = 2CH 3 CN·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 Ln 4 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 (−Δ S m  = 13.91 J kg −1  K −1 for Δ H  = 7.0 T at 3.0 K) and 2 display single molecule magnets behaviors with energy barrier (Δ E / k B ) of 52.65 K and τ 0  = 7.01 × 10 −7  s.