Stacking-interaction-induced host-guest chemistry and Borromean rings based on a polypyridyl ligand

Template-free molecular Borromean rings (BRs) and open-ended molecular capsules were realized by strategic selection of the polypyridyl ligand tetrapyrido[3,2- a :2′,3′- c :3′′,2′′- h :2′′′,3′′′- j ] phenazine ( TPPHZ ) with a large surface area and specific geometry. The topology of these intricate architectures was constructed via precisely controlled stacking interactions, as evidenced from single-crystal X-ray analysis. Template-free molecular Borromean rings and open-ended molecular capsules were constructed via precisely controlled stacking interactions.