The design and generation of inorganic cylindrical cage architectures by metal-ion-directed multicomponent self-assembly

The inorganic cage-type architectures 1-6 and 10 of cylindrical shape and nanometric size are generated spontaneously by self-assembly from the linear ditopic ligands 7a-f and 9, the circular tritopic ligand 8 and copper(I) or silver(I) ions. The crystal structures of two such complexes have been determined. They confirm and provide a detailed description of the geometry of these species. They also indicate that the anions are contained within the central cavity. An experiment performed with a mixture of the ligands 7a, 7c, and 7d shows that self-assembly occurs with ligand selection, only the expected complexes 1a, 3, and 4 being formed. The self-assembly is also influenced by the nature of the counteranions. The results demonstrate that supramolecular architectures of well-defined shape and nanometric size are accessible by multicomponent self-assembly processes involving several ligands of different types and several metal ions. They open ways towards the spontaneous but directed generation of complex nanostructures. © WILEY-VCH Verlag GmbH, D-69451 Weinheim, 1999