During the last two decades, synthetic macromolecules have been successfully folded into various types of secondary structures by following biological principles. Since the pioneering work by Hamilton and co-workers in the late 90s, a large number of aromatic oligoamides based on heterocycles and benzene-derivatives have been designed and synthesized for folding studies. Among various folded structures, helix, planner-sheet, and zigzag structures are the most common secondary structures that have been observed so far. Despite significant advancement, owing to their intrinsic aggregation tendency, mimicking the β-sheet structure is relatively rare.<br/>In my presentation, I will demonstrate the design of a polymer and the underlying principles for mimicking β-sheet structure. To this objective, a pair of periodically-grafted clickable aromatic polyamides have been designed and their propensity to fold into a β-sheet-like structure has been studied experimentally and by using computational studies. Among the two polymer chains, the polymer comprises both intramolecular H-bonding as well as π-stacking motifs readily fold into a β-sheet-like secondary structure. However, the other polymer was structurally identical with the previous one except for the intramolecular H-bonding motifs, assuming random coil conformations under similar experimental conditions. In addition to demonstrating the role of H-bonding and π-stacking interactions in effecting β-sheet-like folding, the reinforcement of this secondary structure through host-guest interaction will also be demonstrated. Possible applications of these molecules as through-space electron-conducting materials and organocatalysis can be envisaged.

Folding of aromatic polyamides into a rare intrachain β-sheet type structure and further reinforcement of secondary structure through host-guest interactions

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.