Hierarchical Assembly of an Interlocked M8L16 Container

• Published in: Angewandte Chemie International Edition Vol. 57; no. 19; pp. 5534 - 5538
• Main Authors: Bloch, Witold M., Holstein, Julian J., Dittrich, Birger, Hiller, Wolf, Clever, Guido H.
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 04.05.2018; John Wiley and Sons Inc
• Edition: International ed. in English
• Subjects: Anions; Assembly; catenanes; Catenation; Cations; Communication; Communications; Containers; interlocked structures; Magnetic resonance spectroscopy; Mass spectrometry; Mass spectroscopy; Molecular structure; NMR; NMR spectroscopy; Nuclear magnetic resonance; Phenanthrene; self-assembly; structural transformations; supramolecular chemistry
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201800490

The self‐assembly of eight PdII cations and sixteen phenanthrene‐derived bridging ligands with 60° bite angles yielded a novel M8L16 metallosupramolecular architecture composed of two interlocked D4h‐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 NO3− anions. The importance of the anions as catenation templates became imminent when we observed the nitrate‐triggered structural rearrangement of a mixture of M3L6 and M4L8 assemblies formed in the presence of BF4− anions into the same interlocked molecule. Furthermore, the densely packed structure of the M8L16 catenane was exploited in the preparation of a hexyloxy‐functionalized analogue, which further self‐assembled into vesicle‐like aggregates in a reversible manner. The missing link: A 24‐component Pd8L16 catenane composed of two interlocked Pd4L8 barrel‐shaped containers has been synthesized. NO3− anions act as templates and can also trigger the transformation of Pd4L8 monomers into the same interlocked molecule. When functionalized with hexyloxy chains, the densely packed catenane further self‐assembles into vesicle‐like structures in a reversible manner.