We report on the synthesis and self-assembly study of novel supramolecular monomers encompassing quadruple hydrogen-bonding motifs and metal coordinating 2,2'-bipyridine units. When mixed with metal ions such as Fe 2+ or Zn 2+ , the tetrahedron cage complexes are formed in quantitative yields and full diastereoselectivity, even in highly polar acetonitrile or methanol solvents. The symmetry of the complexes obtained has been shown to depend critically on the flexibility of the ligand. Restriction of the rotation of the hydrogen-bonding unit with respect to the metal coordinating site results in a T-symmetric cage, whereas by introducing flexibility either through a methylene linker or rotating benzene ring allows the formation of S 4-symmetric cages with selffilled interior. In addition, the possibility to select between tetrahedral cages or helicates, and to control the dimensions of the aggregate, has been demonstrated with three component assembly using external hydrogen-bonding molecular inserts or by varying the radius of the metal ion (Hg 2+ vs Fe 2+). Self-sorting studies of individual Fe 2+ complexes of with ligands of different sizes revealed their inertness toward ligand scrambling.

A novel design of highly preorganized bicyclic monomers, based on quadruple hydrogen bonding motifs, is proposed to access noncovalent cavitands with large internal volumes and interesting shapes.

We report on the binding properties of deep cavitand for various industrial pollutants in water. Depending on the guest type, monomeric cavitands, dimeric capsules or both acted as receptors and...