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Abstract: Hydrogen bonded arylamide foldamers have been introduced in switchable pseudo[2]rotaxanes and [2]rotaxanes, which also include a cyclobisparaquat(p-phenylene) (CBPQT4+) ring and a ‘dumbbell’ containing tetrathiafulvalene (TTF) and 1,5-dioxynaphthalene (DNP, for rotaxanes). The foldamer size changes through folding and unfolding serve as a steric handle to modulate the mechanical movement of the CBPQT4+ ring along the dumbbell of the pseudo[2]rotaxanes and [2]rotaxanes. By varying the number of the repeating units in the foldamer, the kinetics of the solvent-dependent slippage/deslippage of pseudo[2]rotaxanes and the switching of the ring between TTF and DNP of the [2]rotoxanes can be tuned remarkably, with the time scope ranging from several minutes to several days, in twelve solvents of varying polarity, which have been confirmed by the 1H NMR, UV–vis spectroscopy, and cyclic voltammogram experiments. [Copyright &y& Elsevier]

Abstract: In this paper, we report the synthesis and self-assembling behavior of an F⋯H–N hydrogen bonding-induced arylamide-based dipodal foldamer. SEM, AFM, TEM, and XRD studies reveal that this preorganized oligomer stacks to form vesicles in methanol–chloroform (10–70%) binary solvents due to the strong stacking interaction of the folded segments and the supramolecular polymeric feature of the dipodal molecule in the stacked state. In contrast, a simple folded molecule can give rise to vesicles only when the chloroform content is 45–55%. [Copyright &y& Elsevier]

Abstract: Four porphyrin-bridge-C60 dyads have been synthesized by covalently linking the chromophores at the opposite ends of a hydrogen bonded arylamide-derived foldamer bridge. For comparison, four C60-free porphyrin derivatives of the same frameworks have also been prepared. The fully hydrogen bonded bridges enable the appended porphyrin and C60 moieties to contact in a face-to-face manner. 1H NMR, UV–vis and fluorescent investigations in chloroform indicate that such a structural matching remarkably facilitates the intramolecular energy and electron transfer and charge separation between the two chromophores and also retards the recombination of the charge-separated state. Removing one hydrogen bond considerably reduces the energy and electron transfer. Further removing another one leads to no important interaction between the chromophores to occur. [Copyright &y& Elsevier]

Abstract: The self-assembly of a novel series of intramolecular hydrogen bonding-driven foldamers have been described. Five linear aromatic amide oligomers 1–5 , which bear two to six repeating benzoyl amide subunits, respectively, have been prepared by continuous amide-coupling reactions. The existence of three-centered hydrogen bonds in the oligomers and consequently, the folding conformation of the oligomers in the solid state and solution have been proved by the X-ray analysis (for 2 ) and the 1H NMR and IR experiments. Molecular modeling reveals a planar and rigid conformation for the oligomers and a cavity of 0.86nm in diameter for 6-mer 5 . Fluorescent and 1H NMR experiments have demonstrated that the new aromatic oligo-amide foldamers can bind primary and secondary alkyl ammonium ions in chloroform and the associated binding constants have been determined. It is revealed that 5-mer 4 exhibits the largest binding ability. A face-to-face binding mode has been proposed for the complexes. [Copyright &y& Elsevier]