Related Experiment Video
Updated: May 29, 2026

Exploring Protein-Glycan Interactions: Advances in Nuclear Magnetic Resonance
Published on: August 26, 2025
N22C2 versus N24: role of molecular curvature in determining isomer stability
Shanese Jasper1, Asya Hammond, Jessica Thomas
1Department of Physical Sciences, Alabama State University, Montgomery, Alabama 36101, United States.
Abstract:
Three-dimensional N(22)C(2) cages are examined by theoretical calculations to determine relative stability among various isomers. Stability as a function of cage shape and stability as a function of carbon location are calculated and discussed. The results are compared to isomers of N(24) to determine the effects of carbon substitution into the cage structure. Further, since the various cage shapes in this study vary by degree of curvature, model calculations are carried out to determine the energetic consequences of curving the local structure around nitrogen and carbon. The model calculations are compared to the actual results on the larger cages to determine how well curvature effects explain the relative stability of N(22)C(2) isomer as compared to the corresponding N(24).
Related Concept Videos
Stereoisomerism of Cyclic Compounds
Stability of Substituted Cyclohexanes
The two chair conformations of cyclohexanes undergo rapid interconversion at room temperature. Both forms have identical energies and stabilities, each comprising equal amounts of the equilibrium mixture. Replacing a hydrogen atom with a functional group makes the two conformations energetically non-equivalent.
For example, in...
¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
Disubstituted Cyclohexanes: cis-trans Isomerism
In cyclohexane, the substituents can occupy different positions generating distinct isomers.
Conformations of Cyclohexane
The chair form is the most stable and derives its name from its resemblance to the “easy chair.” In the chair conformation, two carbon atoms are arranged out-of-plane — one above and one below, minimizing the torsional strain. In the chair form, the bond angle is very close to the ideal tetrahedral value,...
Conformations of Cycloalkanes

