Efficient Self-assembly of Isoquinoline-Based Triply Interlocked Cages

Abstract

Triple interlocked systems represent highly intricate topological structures, formed by entwining two mechanically interlocked cages. Achieving controlled and straightforward construction of these aesthetic topologies continues to pose an enduring challenge. Herein, we employ a coordination-driven self-assembly strategy, capitalizing on non-covalent interactions in conjunction with half-sandwich metal units and meticulously designed isoquinoline-based ligands, to achieve the effective construction of organometallic interlocked cages 1 and 2. The resulting triple interlocked system's formation and architecture were validated by single-crystal X-ray diffraction, electrospray ionization mass spectroscopy, and comprehensive NMR tests. The Independent Gradient Model (IGM) more intuitively demonstrates the multiple stacking interactions within cage compounds, while planarity analysis elucidates the self-adaptability of the ligands and their tunable conformations.