Self‐Templating and In Situ Assembly of a Cubic Cluster‐of‐Clusters Architecture Based on a {Mo(24)Fe(12)} Inorganic Macrocycle

Engineering self‐templating inorganic architectures is critical for the development of bottom‐up approaches to nanoscience, but systems with a hierarchy of templates are elusive. Herein we describe that the cluster‐anion‐templated (CAT) assembly of a {CAT}⊂{Mo(24)Fe(12)} macrocycle forms a giant ca. 220 nm(3) unit cell containing 16 macrocycles clustered into eight face‐shared tetrahedral cluster‐of‐clusters assemblies. We show that {CAT}⊂{Mo(24)Fe(12)} with different CATs gives the compounds 1–4 for CAT=Anderson {FeMo(6)} (1), Keggin {PMo(12)} (2), Dawson {P(2)W(18)} (3), and {Mo(12)O(36)(HPO(3))(2)} (4) polyoxometalates. “Template‐free” assembly can be achieved, whereby the macrocycle components can also form a template in situ allowing template to macrocycle to superstructure formation and the ability to exchange the templates. Furthermore, the transformation of template clusters within the inorganic macrocycle {Mo(24)Fe(12)} allows the self‐generation of an uncapped {Mo(12)O(36)(HPO(3))(2)} in compound 4.