Metallo-Supramolecular Self-Assembly of a Multicomponent Ditrigon Based on Complementary Terpyridine Ligand Pairing

Predesigned complementary complexation of two 2,2':6',2 ''-terpyridine-based ligands was established by installing 2,6-dimethoxyphenyl substituents at the terpyridyl 6,6 ''-positions, which provided ancillary ion-dipole interactions in the coordination process and extra pi-stacking stabilization in the resultant heteroleptic complex. The high-fidelity self-recognition ligation afforded facile access to the quantitative self-assembly of multicomponent triangle [(Cd6L3L34)-L-3] and ditrigon [(Cd15L6L35)-L-3] (that is, a hexagon with six 120 degrees angles and two alternating edge lengths). It was found that the linear 6,6 ''-substituted ditopic motif (L-3) would be directed by the ligand geometry of L-5 to selectively incorporate into the parallel homoleptic connections in the bilayered framework.