C₂O₄^2--templated cage-shaped Ln₂₈ (Ln = Gd, Eu) nanoclusters with magnetocaloric effect and luminescence

The assembly of high-nuclearity lanthanide nanoclusters with favourable magnetocaloric effects suffers from a significant challenge. Herein, two outstanding examples of cage-shaped nanoclusters, namely, [Ln(28)(IN)(25)(C2O4)(6)(HCOO)(mu(3)-OH)(36)(mu(2)-OH)(2)(H2O)(36)]center dot 8Br center dot xH(2)O (Ln = Gd and Eu; x = 21, abbreviated as Gd-28; x = 17, abbreviated as Eu-28, HIN = isonicotinic acid; H2C2O4 = oxalic acid) have been triumphantly designed and constructed under hydrothermal conditions. The crystallographic study revealed that the aesthetically pleasing triangle-shaped Gd-12 subunit and Gd-16 subunit built separately from four Gd-3 units and four Gd-4 units, respectively, are shaped into an unprecedented cage-shaped configuration. Prominently, six small and simple C2O42- anions generated via the in situ reaction of HIN are faultlessly anchored in the cage-shaped framework. Furthermore, the existence of abundant Gd-III ions impart Gd-28 with a captivating magnetic entropy change (-Delta S-m(max) = 37.5 J kg(-1) K-1) at 2.0 K for Delta H = 7.0 T.