Effect of intramolecular H-bonding and πstacking on the folding of periodicallygrafted amphiphilic polyamides

Abstract

The study of natural biological systems where covalent and non-covalent molecular interactions between unique units in their sequence aid folding into a well-defined three-dimensional structure inspired the field of foldamer chemistry. In this work, two different aromatic oligoamide foldamers were synthesized and characterized by 1H NMR, UV-Visible spectroscopy. The plan was to synthesize π-electron rich foldamers in which conformational preferences can be induced through different covalent and non-covalent interactions (for example, hydrogen bonding). The target polymer POLY 11 consists of donor group 1, 5-diaminonapthalene, and monomer hydroxyl substituted chelidamic acid, i.e., a potential candidate to facilitate intramolecular hydrogen bonding; predicted that this would induce a random coil structure into a well-organized foldameric system. All of the backbone's structural features are designed to aid in the folding process. The primary outcome of work is after post-polymerization modification that helps in solubility of the polymer in different organic solvents. Conclusions regarding stable folded conformations along the polymer chain were inferred from NMR and UV-Vis spectroscopy.