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

Template-freemolecular 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.