Title: Chiral Self-Sorting of Flexible Covalent Organic Pillars forAdaptive Molecular Recognition

Authors: Shengnan Gao#, Min Zhang#, Yimin Zhang, Congsen Wang, Andrew C.-H. Sue*

Abstract: Flexible covalent organic pillars (flex-COP-n) areintroduced as a family of dual-open-ended nanotubular hostsconstructed via dynamic imine condensation between pillararene-derived macrocyclic building blocks and conformationally mobile –(CH2)n– aliphatic linkers. These discrete molecular containers featurewell-defined tubular channels capable of adaptive host–guestinteractions. The self-assembly process exhibits a pronounced odd-even effect, yielding either enantiomeric or meso duplexes throughdistinct chiral self-sorting pathways. Host-guest interactions betweenflex-COP-4 and a series of α,ω-dibromoalkanes were systematicallyinvestigated using NMR spectroscopy and single-crystal X-raycrystallography. The resulting inclusion complexes span a continuumof binding modes—from relaxed encapsulation to strained,overpacked assemblies—governed by geometric complementarityand mutual host-guest deformation. These findings highlight the roleof conformational flexibility in modulating molecular recognition undernanoscale confinement and establish flex-COP-n as a dynamicplatform for mimicking adaptive features of biological receptors.

Full-Link: https://doi.org/10.1002/anie.202509177