A class of aromatic oligoamides composed of pyridine and quinoline units have experimentally been shown to form helical capsules and encapsulate small polar ligands. Applications of encapsulation can be found in molecular recognition, catalysis and drug delivery. Despite this, several molecular level factors determining capsule-ligand stability are missing, such as ligand binding interactions and ligand entering and leaving mechanisms. Therefore, we address these issues by use molecular dynamics (MD) simulations with re-parametrized aryl-amide torsional parameters that provide a more accurate description of the conformations of these helical capsules. We find that ligand's size, its binding position within the capsule, and the solvent interactions with the capsule are factors of consideration in the stability of capsule-ligand complexes. We demonstrate that the mechanisms of ligand binding and leaving are a consequence of an oligoamide's flexible nature and its interactions with the solvent molecules. This study helps in understanding the crucial details in the dynamics in capsule-ligand complexes.

Computational investigation of ligand encapsulation in helical foldamers

247th National Meeting (2014)

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