Self-Assembled Amphiphilic Janus Double Metallacycle.

A double metallacycle was prepared via the size-selective integrative self-sorting of four different building blocks driven by a reversible metal-ligand coordination interaction. A hydrophobic dendron was placed on a metallacycle and a hydrophilic dendron was attached to the other metallacycle, producing a two-faced Janus-type supramolecule with two distinct functionalities. In aqueous media, hierarchical self-assembly of the supramolecular system was induced by the combination of coordination interactions and hydrophobic-hydrophilic interactions resulting in the formation of micrometer-sized fiber-like structures, a morphology distinct from metallacycles bearing only one type of functionality. This study provides a versatile approach for the construction of Janus-type molecules and demonstrates that integrative self-sorting of a supramolecular coordination system can be utilized for the preparation of complex supramolecular systems with predesigned functionalities and morphologies.