Cl--Templated Assembly of Novel Peanut-like Ln40Ni44 Heterometallic Clusters Exhibiting a Large Magnetocaloric Effect.

Two novel and fascinating high-nuclearity lanthanide-transition (4f-3d) heterometallic clusters were obtained based on an anion-template (Cl-) and ligand-controlled approach, formulated as [Gd40Ni44(CO3)12(CH3COO)4(IDA)44(C2O4)(μ2-O)4(μ3-OH)60(μ3-O)6(H2O)12]·Cl10·20H2O (abbreviated as Gd40Ni44, 1) and [Eu40Ni44(CO3)12(CH3COO)6(IDA)44(C2O4)(μ2-O)4(μ3-OH)62(μ3-O)4(H2O)12]·Cl10·23H2O (abbreviated as Eu40Ni44, 2), where H2IDA = iminodiacetic acid and H2C2O4 = oxalic acid. Structural analysis exhibits that the compounds 1 and 2 were both constructed by two enticing bowl-like anion units Ln20Ni22, featuring peanut-like structures. Besides, the assembly of Ln20Ni22 was templated by five Cl- ions. Magnetically, compound 1 shows a significant magnetocaloric effect, with -ΔSm = 36.05 J kg-1 K-1 at 3 K for ΔH = 7 T.