The key difference between electrofuge and nucleofuge is that an electrofuge is a leaving group that does not retain the bonding pair of electrons from its previous bond with another species whereas a nucleofuge is a leaving group that retains the lone pair from its previous bond with another species.
The terms electrofuge and nucleofuge are used in organic chemistry as names for leaving groups. These two groups differ from each other according to the retaining process of the bonding electron pairs on the molecule. However, these terms were used mainly in older literature, and these terms are uncommon in modern literature of chemistry.
CONTENTS
1. Overview and Key Difference
2. What is Electrofuge
3. What is Nucleofuge
4. Side by Side Comparison – Electrofuge vs Nucleofuge in Tabular Form
5. Summary
What is Electrofuge?
Electrofuge compounds can be described as leaving groups that do not retain the bonding pair of electrons from its former bond with another species. This type of leaving groups form from the heterolytic breaking of covalent bonds. After performing the corresponding reaction, electrofuge groups tend to possess either a positive or a neutral charge, which is governed by the nature of the specific reaction. An example of an electrofuge involving reaction is the loss of H+ ion from a molecule of benzene during the nitration process. In this context, the word electrofuge commonly refers to the leaving group that is found in older literature, but its use in modern organic chemistry is uncommon now.
What is Nucleofuge
Nucleofuge compounds can be described as leaving groups that can retain the lone electron pair from its previous bond with another species. As an example, in the SN2 reaction, a nucleophile attacks the organic compound containing the nucleofuge, simultaneously breaking the bond with nucleofuge.
Figure 01: An Example of a Reaction involving a Nucleofuge
After the completion of the reaction involving nucleofuge, the nucleofuge may contain a negative or a neutral charge. This is controlled by the nature of the specific reaction. It’s also important to know that the word nucleofuge was used in older literature of chemistry, but its use is less common in modern literature.
What is the Difference Between Electrofuge and Nucleofuge?
The terms electrofuge and nucleofuge are used in organic chemistry as names for leaving groups. The key difference between electrofuge and nucleofuge is that an electrofuge does not retain the bonding pair of electrons from its previous bond with another species whereas the nucleofuge retains the lone pair from its previous bond with another species. Furthermore, after the completion of the particular reaction involving the electrofuge, the electrofuge tends to possess either a positive charge or a neutral charge while the nucleofuge, in the same context, tends to have either a negative charge or a neutral charge.
An example of the use of electrofuge is the loss of H+ ion from a molecule of benzene during nitration. An example of the use of word nucleofuge is in the SN2 mechanism where a nucleophile attacks an organic compound containing the nucleofuge, simultaneously breaking the bond with the nucleofuge.
Below infographic summarizes the differences between electrofuge and nucleofuge in tabular form.
Summary – Electrofuge vs Nucleofuge
The terms electrofuge and nucleofuge are used in organic chemistry as names for leaving groups. The key difference between electrofuge and nucleofuge is that an electrofuge does not retain the bonding pair of electrons from its previous bond with another species whereas a nucleofuge retains the lone pair from its previous bond with another species. Therefore, these two groups differ from each other according to the retaining process of the bonding electron pairs on the molecule.
Reference:
1. “Nucleofuge.” Wikipedia, Wikimedia Foundation, 9 June 2019, Available here.
Image Courtesy:
1. “BromoethaneSN2reaction-small” By en:User:Benjah-bmm27 – https://secure.wikimedia.org/wikipedia/en/wiki/Image:BromoethaneSN2reaction-small.png (Public Domain) via Commons Wikimedia