Self-assembly of a large, closed capsule reminiscent of protein-cage formation

In this issue of Chem, Nitschke and co-workers report on a new type of tetrahedral cage where, unlike in conventional metal-organic capsules (in which individual ligands define the faces or edges of a polyhedron), each face of the capsule is spanned by three ligand panels, reminiscent of ferritin capsule formation. They achieve this concept through the self-assembly of a simple twisted tetramine subcomponent. Moreover, the resulting large, enclosed cavity is able to accommodate multiple equivalents of large dianions.