Two Windmill-Shaped Ln₁₈ Nanoclusters Exhibiting High Magnetocaloric Effect and Luminescence

The self-assembly of the high-nuclearity Ln-exclusive nanoclusters is challenging but of significance due to its aesthetically pleasing architectures and far-reaching latent applications in magnetic cooling technologies. Herein, two novel high-nuclearity lanthanide nanoclusters were successfully synthesized under solvothermal conditions, formulated as {[Gd18(IN)20(HCOO)8(μ6-O)(μ3-OH)24(H2O)4]·4H2O}n and {[Eu18(IN)16(HCOO)8(CH3COO)4(μ6-O)(μ3-OH)24(H2O)4]·5H2O}n (abbreviated as Gd18 and Eu18, HIN = isonicotinic acid). Both of them possess novel and exquisite windmill-shaped cationic cores in the family of high-nuclearity Ln-exclusive nanoclusters. Remarkably, the adjacent second building units are interconnected into a three-dimensional (3D) metal–organic framework by IN– ligands. As expected, the abundant existence of GdIII ions endows Gd18 with a favorable magnetic entropy change at 2.0 K for ΔH = 7.0 T (−ΔSmmax = 40.0 J kg–1 K–1), and Eu18 displays the typical luminescence of EuIII ions