Giant Hollow Heterometallic Polyoxoniobates with Sodalite-Type Lanthanide-Tungsten-Oxide Cages: Discrete Nanoclusters and Extended Frameworks

The first series of niobium-tungsten-lanthanide (Nb-W-Ln) heterometallic polyoxometalates {Ln(12)W(12)O(36)(H2O)(24)(Nb6O19)(12)} (Ln= Y, La, Sm, Eu, Yb) have been obtained, which are comprised of giant cluster-in-cluster-like ({Ln(12)W(12)}-in-{Nb-72}) structures built from 12 hexaniobate {Nb6O19} clusters gathered together by a rare 24-nuclearity sodalite-type heterometal-oxide cage {Ln(12)W(12)O(36)(H2O)(24)}. The Nb-W-Ln clusters present the largest multi-metal polyoxoniobates and a series of rare high-nuclearity 4d-5d-4f multicomponent clusters. Furthermore, the giant Nb-W-Ln clusters may be isolated as discrete inorganic alkali salts and can be used as building blocks to form high-dimensional inorganic-organic hybrid frameworks.