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Formation of Carbon Centered Free Radical

Learning Objective: To learn about different ways by which the formation of a carbon-centred free radical occurs.

Skill Level - Intermediate

 

Prerequisites: 

 

Chapter: Reactive Intermediates

Sub-topic: Free Radicals

 

Author's Note: A free radical can form by the homolytic cleavage of the single bond. However, there are three different ways by which a homolytic bond cleavage can occur. This section covers those methods by which a free radical, especially carbon-centered, can be obtained. Also, in scenarios that require external assistance, the role of radical initiators is also discussed.

Formation of Carbon Centered Free Radical

A covalent bond can cleave in two ways- heterolytically and homolytically.

In heterolytic bond cleavage, one of the two atoms of the bond, the more electronegative one, takes away both the bond electrons and gets a negative charge (forming an anion). In contrast, the other atom receives a positive charge (forming a cation). 

The bond breaking and the movement of two electrons are shown using a double-headed curly arrow.

 

 

In homolytic bond cleavage, the two-electron bond cleaves in half so that each atom holding the bond receives one electron and forms a radical.

Each free radical atom has an unpaired electron.

In homolytic bond cleavage, the bond breaking is shown using a ‘fish-hook’ arrow representing the movement of one electron.

 

 

Homolytic bond cleavages are seen in molecules where the electronegativity difference ....

 

Types of homolytic bond cleavages forming radicals

Suppose the energy to break the covalent bond homolytically is provided using...

 

Role of Radical Initiators

Sometimes, radical initiators are used for inducing homolytic bond cleavage in otherwise unreactive ....

 

Subscribe to learn about different ways by which the formation of a carbon-centered free radical occurs.

Reactive Intermediates
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