Controlling the Reactivity of the [P8W48O184]40- Inorganic Ring and Its Assembly into POMZite Inorganic Frameworks with Silver Ions

The construction of pure-inorganic framework materials with well-defined design rules and building blocks is challenging. In this work, we show how a polyoxometalate cluster with an integrated pore, based on [P8W48O184](40-) (abbreviated as {P8W48}), can be self-assembled into inorganic frameworks using silver ions, which both enable reactions on the cluster as well as link them together. The {P8W48} was found to be highly reactive with silver ions resulting in the in situ generation of fragments, forming {P9W63O235} and {P10W66O251} in compound (1) where these two clusters co-crystallize and are connected into a POMZite framework with 11 Ag+ ions as linkers located inside clusters and 10 Ag+ linking ions situated between clusters. Decreasing both the concentration of Ag+ ions, and the reaction temperature compared to the synthesis of compound (1), leads to {P8W51O196} in compound 2 where the {P8W48} clusters are linked to form a new POMZite framework with 9 Ag+ ions per formula unit. Further tuning of the reaction conditions yields a cubic porous network compound (3) where {P8W48} clusters as cubic sides are joined by 4 Ag+ ions to give a cubic array and no Ag+ ions were found inside the clusters.