End‐Group‐Dependent Host–Guest Complexation of Poly(2‐ethyl‐2‐oxazoline) with β‐Cyclodextrin

ABSTRACT Poly(2‐ethyl‐2‐oxazoline) (PEtOx) represents a versatile platform for developing supramolecular polymer systems. In this study, propargyl‐terminated PEtOx was synthesized via cationic ring‐opening polymerization and subsequently functionalized at the γ‐chain end with either adamantane or phenyl groups using thiol–yne click chemistry. Monoazide‐functionalized β‐cyclodextrin (β‐CD‐N 3 ) was then covalently conjugated to these polymers through Cu(I)‐catalyzed azide–alkyne cycloaddition. Comprehensive characterization by 1H NMR, NOESY NMR, FTIR, GPC, and MALDI‐TOF MS confirmed successful synthesis and precise end‐group modifications. Notably, 2D NOESY NMR spectroscopy provided direct evidence of supramolecular host–guest interactions between the adamantane moiety and the β‐CD cavity in the P1/CD conjugate, while no significant inclusion complexation was observed for the phenyl‐terminated counterpart (P2/CD), highlighting the critical influence of end‐group identity on supramolecular complexation behavior in PEtOx‐based systems. Overall, this work introduces a versatile strategy for designing supramolecular polymer architectures through end‐group engineering and cyclodextrin conjugation, offering new perspectives for advanced functional materials with tunable self‐assembly properties.