Design and Synthesis of Macrocycles with Tuneable Diameters and Helical Foldamers with Customizable Peripheral Side Chains

Tubular structures with nanosized pores have shown remarkable applications in areas such as ion transport and water filtration, but their development is often hindered by challenges including low yields, limited functionalization, and poor uniformity. Herein, we present a new series of macrocycles with tuneable diameters and helical foldamers featuring customizable peripheral side chains. The macrocycles, with diameters ranging from 0.8 to 1.4 nm, were synthesized in moderate to good yields using a one-pot method. Solid-state analysis revealed that these macrocycles form nanochannels, highlighting their potential applications in areas such as molecular recognition and artificial water channels (AWCs). Additionally, we synthesized helical aromatic amide polymers with narrow dispersities via a living chain-growth process. Our strategy enables the incorporation of diverse functional groups, including ethers, esters, acids, and amides, on the outer surfaces of the macrocycles or synthetic nanotubes. Circular dichroism (CD) spectroscopy confirmed the helical conformations of the polymers in solution. These macrocycles and foldamers present exciting opportunities for designing bioinspired membrane channels and functional nanotubes with tuneable hydrophobicity and cavity sizes, paving the way for innovative applications in nanotechnology and materials science.