Related Experiment Video
Updated: Jun 7, 2026

Preparation of a Corannulene-functionalized Hexahelicene by Copper(I)-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units
Published on: September 18, 2016
Consistent aromaticity evaluations of methylenecyclopropene analogues.
Yan Wang1, Israel Fernández, Matthew Duvall
1School of Science, Beijing Institute of Technology, Beijing 100081, China.
This study quantifies aromaticity in cyclopropenes using computational methods. Electronegative substituents enhance aromaticity, while electropositive ones decrease it, impacting ring stability.
Area of Science:
- Computational Chemistry
- Organic Chemistry
- Quantum Chemistry
Background:
- Cyclopropenes are strained cyclic systems.
- Understanding aromaticity is key to predicting chemical stability and reactivity.
- Exocyclic substituents significantly influence electronic properties.
Purpose of the Study:
- To quantitatively evaluate the aromaticity and antiaromaticity of neutral exocyclic substituted cyclopropenes.
- To correlate energetic measures of aromaticity with magnetic indices.
- To investigate the effect of substituent electronegativity on cyclopropene aromaticity.
Main Methods:
- Block-localized wave function (BLW) method for computing extra cyclic resonance energies (ECRE).
- Energy decomposition analyses (EDA) for calculating aromatic stabilization energies (ASEs).
- Nucleus-independent chemical shift (NICS) calculations and anisotropy of the induced current density (AICD) plots.
Main Results:
- Strong correlation (R² = 0.974) found between ECRE and ASE.
- Electronegative substituents (e.g., oxygen) increase aromaticity, while electropositive substituents (e.g., indium) increase antiaromaticity.
- NICS(0)(πzz) values showed excellent agreement with ECRE (R² = 0.968) and ASE (R² = 0.974).
Conclusions:
- Computational energetic and magnetic indices provide reliable measures of aromaticity in substituted cyclopropenes.
- Substituent effects on aromaticity are predictable based on electronegativity.
- The study establishes a quantitative framework for assessing aromaticity in these systems.
More Related Videos
10:17Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones
Published on: February 7, 2019
11:45Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles
Published on: August 22, 2018
Related Concept Videos
Aromatic Hydrocarbon Anions: Structural Overview
Due to the absence of continuous overlap of p...
Criteria for Aromaticity and the Hückel 4n + 2 Rule
For the first time, Eric Hückel, a German chemical physicist, derived a set of structural features for a compound to be classified as aromatic. This is now known as Hückel’s rule or the 4n + 2 rule.
Aromatic Hydrocarbon Cations: Structural Overview
Removing one hydrogen from the intervening CH2 group with both...
Frost Circles for Different Conjugated Systems
Conformations of Cycloalkanes
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...