Metal-driven self assembly of C-3 symmetry molecular cages

A series of tris(2-aminoethyl)amine (TREN) derivatives functionalized on the arms with pyridine or methylimidazole ligands bind very strongly to a trisporphyrin derivative via apical coordination, with formation of molecular cages; the strength of the binding (K-b up to 10(8.8) mol(-1) dm(3)) depends on the structure of the TREN derivative as well as on its coordination to Zn(II).