Dodecanuclear [CuII6GdIII6] Nanoclusters as Magnetic Refrigerants

A novel dodecanuclear complex, [{(HL)(L)(DMF)CuIIGdIII(DMF)(H2O)}6]·6DMF (1; DMF = N,N-dimethylformamide), has been obtained using the ligand resulting from the condensation of 3-formylsalicylic acid with hydroxylamine (H3L). The exchange interaction between the phenoxo-bridged CuII and GdIII ions is weak ferromagnetic (J = +1.01 cm–1). The combination of a high-spin ground state with small anisotropy leads to a significant magnetocaloric effect [−ΔSm(0–7 T) = 23.5 J K g–1 K–1 at ∼2 K].