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In this study, a series of H‐bonded arylamide foldamers bearing benzoselenadiazole ends with solvent‐responsive properties have been synthesized. In dichloromethane or dimethyl sulfoxide solvents, the molecules exhibit meniscus or linear structures, respectively, which can be attributed to the unique intramolecular hydrogen bonding behavior evidenced by 1D 1H NMR and 2D NOESY spectra. UV‐vis spectroscopy experiments show that the absorption wavelength of H‐bonded arylamide foldamers are significantly red‐shifted due to the presence of benzoselenadiazole group. In addition, the crystal structures reveal that effective intermolecular dual Se ⋅ ⋅ ⋅ N interactions between benzoselenadiazole groups induce further assembly of the monomers. Remarkably, supramolecular linear and double helices structures are constructed under the synergistic induction of intramolecular hydrogen bonding and intermolecular chalcogen bonding. Additionally, 2D DOSY diffusion spectra and theoretical modelling based on density functional theory (DFT) are performed to explore the persistence of intermolecular Se ⋅ ⋅ ⋅ N interactions beyond the crystalline state. [ABSTRACT FROM AUTHOR]

Folding-induced folding for the construction of artificial hybrid helices from two different kinds of aromatic sequences is described. Linear compounds 1a, 1b, and 2, containing one aromatic amide trimer or pentamer and one or two aromatic 1,2,3-triazole tetramers, have been designed and synthesized. The trimeric and pentameric amide segments are driven by intramolecluar N—H···F hydrogen bonding to adopt a folded or helical conformation, whereas the triazole segment is intrinsically disordered. In organic solvents of low polarity, the amide foldamer segment induces the attached triazole segment(s) to fold through intramolecular stacking, leading to the formation of hybrid helices. The helical conformation of these hybrid sequences has been confirmed by 1H and 19F NMR spectroscopy, UV/Vis spectroscopy, circular dichroism (CD) experiments, and theoretical calculations. It was found that the amide pentamer exhibits a stronger ability to induce the folding of the attached triazole segment(s) compared with that of the shorter trimer. Enantiomers (R)-3 and (S)-3, which contain an R- or S-(1-naphthyl)ethylamino group at the end of a tetraamide segment, have also been synthesized. CD experiments showed that introduction of a chiral group caused the whole framework to produce a strong helicity bias. Densityfunctional- theory calculations on (S)-3 suggested that this compound exists as a right-handed (P) helix. [ABSTRACT FROM AUTHOR]