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Division of Science, Mathematics, and Computing presents

Intramolecular H-bonding in Aromatic Oligoamide Foldamers

Friday, March 22, 2013

A lecture by
Jessica Geer
Candidate for the position in Chemistry
Aromatic oligoamide foldamers are synthetic oligomers that adopt stable secondary structures in solution and can be designed to have therapeutic applications. The design process draws on the principles that govern biopolymer shapes and thus leads to structures that mimic motifs found in biochemical systems. Among many strategies used in foldamer design, hydrogen bonding (H-bonding) has served as a very effective designing tool due to the strength and directional characteristics. We investigate various intramolecular H-bond patterns, with a focus on the influence that one H-bond has on the strength of another, shared one.

A comprehensive ab initio study followed by a Natural Bond Orbital (NBO) analysis has been performed on diarylamide model compounds.  Our analysis demonstrates to what extent cooperativity between shared H-bonds exist in these types of foldamer units. Using our torsional profile and NBO analysis, we will discuss cooperativity of the shared H-bonds. In addition, a realistic assessment of the torsional distributions is necessary to accurately describe the behavior of the model compounds in various environments.

Therefore, following quantum mechanic analysis, molecular dynamic simulations were performed in the gas phase, methanol, chloroform and water solvent systems.  Torsional parameters obtained from ab initio calculations were applied to the general AMBER force field (GAFF).

Location: RKC 115