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 theligand resulting from the condensation of 3-formylsalicylicacid with hydroxylamine (H3L). The exchange interactionbetween the phenoxo-bridged CuII and GdIII ions is weakferromagnetic (J = +1.01 cm−1). The combination of ahigh-spin ground state with small anisotropy leads to asignificant magnetocaloric effect [−ΔSm(0−7 T) = 23.5 JK g−1 K−1 at ∼2 K].