A novel sandwich-type tungstoarsenate containing a cagelike {Ca6} cluster with a water molecule enwrapped

A cage-like {[Ca(H2O)]6(H2O)}12+ cluster with a water molecule enwrapped, sandwiched by two novel [As4W6O34]12− fragments, has been obtained, and the extension of these clusters from molecules into a 2-D layer occurs through [Ca(H2O)5]2+ linkers, which represents the first heteropolyoxoanion (HPA) constituted by [As4W6O34]12− and the unprecedented high nuclearity {[Ca(H2O)]6(H2O)}12+ cluster.