Related Experiment Video
Updated: Jul 2, 2025

Self-assembling Morphologies Obtained from Helical Polycarbodiimide Copolymers and Their Triazole Derivatives
Published on: February 7, 2017
Quantifying macrocyclization-induced strain utilizing N-phenylimides as conformational reporters.
Bright U Emenike1, David W Shinn2, Ronald A Spinelle1
1Department of Chemistry & Physics, State University of New York, 223 Store Hill Road, Old Westbury, NY 11568, USA. emenikeb@oldwestbury.edu.
Macrocyclization strain was measured using N-phenylimide units. Smaller macrocycles showed strain, while larger ones had negligible effects, highlighting N-phenylimides as reporters of conformational strain.
Area of Science:
- Organic Chemistry
- Supramolecular Chemistry
- Physical Chemistry
Background:
- Macrocycles are cyclic molecules with diverse applications.
- Quantifying macrocyclization strain is crucial for understanding molecular behavior.
- N-phenylimide units offer potential as molecular probes.
Purpose of the Study:
- To develop a method for measuring macrocyclization strain.
- To investigate the relationship between macrocycle size and strain.
- To validate N-phenylimide as a conformational reporter.
Main Methods:
- Synthesis of macrocycles and linear-chain controls containing N-phenylimide units.
- Spectroscopic analysis to monitor conformational changes of the N-phenylimide unit.
- Comparison of conformational data between macrocyclic and linear systems.
Main Results:
- N-phenylimide units effectively reported conformational changes.
- Smaller macrocycles exhibited significant macrocyclization strain.
- Larger macrocycles showed minimal to negligible macrocyclization strain.
- Strain was found to be inversely proportional to macrocycle size.
Conclusions:
- N-phenylimide is a reliable conformational reporter for macrocyclization strain.
- Macrocyclization strain is size-dependent, decreasing with increasing ring size.
- This method provides a quantitative approach to study strain in cyclic systems.
More Related Videos
06:55Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level
Published on: September 26, 2016
16:27Biophysical Assays to Probe the Mechanical Properties of the Interphase Cell Nucleus: Substrate Strain Application and Microneedle Manipulation
Published on: September 14, 2011
Related Concept Videos
¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
Conformations of Cycloalkanes
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...
¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR
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...
Stereoisomerism of Cyclic Compounds