Pentacosaple-CO32- bridged hexacontaoctanuclear lanthanide-alkali barrels derived from octacosanuclear discs

Phosphonate lanthanide carbonate cages are highly sought after in the development of multifunctional molecular-based materials due to their rigid framework and the inherited properties of metal ions. However, the synergistic coordination of phosphonates and carbonates with lanthanide ions limits their systematic exploration. Here, we developed an efficient method to synthesize the necessary phosphonate lanthanide carbonate compound with a three-shell topology through a stepwise procedure that employs a strategy involving the assembly of several multicomponent systems, aimed at the distinctive C2-symmetric double hydrazone-based co-ligands. The resulting an octacosanuclear disc [Dy16K12(μ4-O3PC10H7)2 (μ5-O3PC10H7)12(μ6-O3PC10H7)2(L1)4(μ4-COO)4(μ2-COO)2(μ3-O)4(DMF)6(MeOH)2(H2O)4]·8DMF·4MeCN∙8H2O (Dy16K12), and an hexacontaoctanuclear barrel [Dy24Na44(μ4-O3PC11H9)8(μ7-O3PC11H9)8(μ7-CO3)12(μ8-CO3)13(L2)8(μ6-Cl)2(μ2-OH)8(DMF)8(H2O)8] ·2DMF·6MeOH∙9H2O (Dy24Na44), were achieved by leveraging the benefits of incorporating mixed chloride and carbonate templating anions along with the replacement of alkali metal ions. Notably, although compound Dy24Na44 contains 25 carbonate anions, making it the second largest among reported clusters, it has 17 fewer than the largest, which has 42. However, the proportion of carbonate anions in Dy24Na44 is 10.31%, which is 69.87% higher than the 6.07% found in the latter. Furthermore, the drastic changes in supramolecular structures directly affect magnetic dynamics phenomena, from field-induced complex relaxation phenomenon to zero-field single relaxation phenomenon. This work represents an efficient approach for synthesizing phosphonate lanthanide carbonate cages, thereby broadening the pathway for the ultimate customization of functions.