Hierarchical Assembly of an Interlocked M(8)L(16) Container

The self‐assembly of eight Pd(II) cations and sixteen phenanthrene‐derived bridging ligands with 60° bite angles yielded a novel M(8)L(16) metallosupramolecular architecture composed of two interlocked D (4h)‐symmetric barrel‐shaped containers. Mass spectrometry, NMR spectroscopy, and X‐ray analysis revealed this self‐assembled structure to be a very large “Hopf link” catenane featuring channel‐like cavities, which are occupied by NO(3) (−) anions. The importance of the anions as catenation templates became imminent when we observed the nitrate‐triggered structural rearrangement of a mixture of M(3)L(6) and M(4)L(8) assemblies formed in the presence of BF(4) (−) anions into the same interlocked molecule. Furthermore, the densely packed structure of the M(8)L(16) catenane was exploited in the preparation of a hexyloxy‐functionalized analogue, which further self‐assembled into vesicle‐like aggregates in a reversible manner.