Related Experiment Video
Updated: Aug 15, 2026

Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates
Published on: February 15, 2016
Chiral recognition in gas-phase cyclodextrin: amino acid complexes--is the three point interaction still valid in the
S Ahn1, J Ramirez, G Grigorean
1Department of Chemistry, University of California, Davis 95616, USA.
Abstract:
The validity of the "three-point interaction" model is examined in the guest exchange reaction involving complexes of cyclodextrins and amino acids. The amino acid guest is exchanged in the gas phase in the presence of a gaseous alkyl amine. The net reaction is proton transfer between the protonated amino acid and the alkyl amine. The amino acid is lost as a neutral species. This reaction is sensitive to the chirality of the amino acid. Several amino acids are examined as well as the respective methyl esters to determine the role of the three interacting groups (ammonium, carboxylic acid, and side chain) in enantioselectivity. We find that the three-point interaction model is indeed valid in the gas phase. Enantioselectivity is optimal when two points of attraction and one repulsion is present in the gas-phase complex. The results are supported by molecular modeling calculations. A mechanism for the exchange is proposed.
Related Concept Videos
Chirality
Chiral objects exhibit a sense of handedness when they interact with another chiral object. For example, our left foot can only fit in the left shoe and not in the right shoe. Achiral objects — objects that have...
Molecules with Multiple Chiral Centers
Stereoisomerism of Cyclic Compounds
Chirality at Nitrogen, Phosphorus, and Sulfur
A consequence of chirality is the need for enantiomeric resolution. While this is theoretically possible for all...
Prochirality
Chirality in Nature

