Topological Isomerism of Möbius‐Shaped Aramide Macrocycles Induced by Host‐Guest Interactions

ABSTRACT In contrast to traditional Möbius molecules characterized by fully conjugated backbones, synthetic amide‐linked Möbius‐shaped macrocycles represent a hitherto‐unreported class of topological architectures. Here we report the rational design of the first hydrogen‐bonded Möbius‐shaped aramide macrocycles. Central to this design are intramolecular hydrogen bonds within a para ‐linked aromatic segment, which critically stabilize the conformation and lock the macrocyclic ring into a single‐twist topology. Crystallographic analyses unambiguously confirm their single‐twisted Möbius‐shaped architectures, while LOL‐π calculations support sustained electronic delocalization across the macrocyclic backbones. Notably, a reversible topological switching between a single‐twisted Möbius‐shaped and a planar Hückel‐shaped conformation occurs upon the introduction of water clusters, which occupy the central cavity and competitively disrupt the para ‐linker hydrogen bonds. Furthermore, complexation with chiral amino acids induces characteristic circular dichroism responses, successfully translating host–guest recognition into distinct chiroptical outputs. This work establishes a fully amide‐linked macrocyclic platform that enables stimuli‐responsive interconversion between Möbius‐ and Hückel‐shaped conformations.