One-step heterogeneous assembly of terbium(III) and silver(I) with thiacalix[4]arene ligands to form a cage including terbium(III) in an octa-oxygen cube

A heterogeneous one-step self-assembly of Ag+, Tb3+, and thiacalix[4]arene (TCAS), of which the donor atoms S and O showed high selectivity toward Ag+ and Tb3+ ions, respectively, afforded a supramolecular cage compound, Ag-4(+)center dot Tb3+center dot TCAS(2), at the center of which an octa-oxygen cube encapsulated the Tb3+ center to completely shield it from solvent molecules.