Cite this publication
Conformation and Aggregation of Proline Esters and Their Aromatic Homologs: Pyramidal vs. Planar RR ' N-H in Hydrogen Bonds
Hesse, S. & Suhm, M. A. (2009)
Zeitschrift für physikalische Chemie, 223(4-5) pp. 579-604. DOI: https://doi.org/10.1524/zpch.2009.6043
Documents & Media
- Hesse, Susanne; Suhm, Martin A.
- The conformations of proline esters are investigated by infrared spectroscopy in supersonic slit jet expansions. Two easily convertible puckering variants of the pyrrolidine ring with intramolecular N-H center dot center dot center dot O contacts are shown to be particularly stable. The aggregation tendency of proline esters via intermolecular N-H center dot center dot center dot O hydrogen bonds is remarkably weak. IR differences between enantiopure and racemic dimers are difficult (L) quantify. Dehydrogenation of the pyrrolidine ring to pyrrole leads to a stable planar carboxylic ester conformation. Its aggregation tendency is pronounced due to the planar hybridization of the nitrogen atom and leads to a symmetric, beta sheet-like dimer with strongly red-shifting hydrogen bonds. The spectroscopic observations underscore the differences between intermolecular interactions of N-terminal and peptide-bound amino acids in peptide chains.
- Issue Date
- Oldenbourg Verlag
- Zeitschrift für physikalische Chemie
- Institut für Physikalische Chemie