Classify the radicals into the appropriate categories

Classify the radicals into the appropriate categories.

Primary, Secondary, Tertiary, Allyic

The Correct Answer and Explanation is :

In organic chemistry, radicals—also known as free radicals—are highly reactive species characterized by an unpaired electron. Their stability and reactivity are influenced by their structure and the nature of the atoms to which they are attached. Classifying radicals into categories such as primary, secondary, tertiary, and allylic helps in understanding their behavior in chemical reactions.

Primary Radicals:
A primary radical is a species where the unpaired electron resides on a carbon atom that is attached to only one other carbon atom. This configuration is less stable due to minimal electron-donating effects from neighboring groups. For example, the methyl radical (CH₃·) is a primary radical.

Secondary Radicals:
Secondary radicals have the unpaired electron on a carbon atom attached to two other carbon atoms. This structure allows for greater stabilization through hyperconjugation and inductive effects from adjacent alkyl groups, making them more stable than primary radicals.

Tertiary Radicals:
Tertiary radicals feature the unpaired electron on a carbon atom bonded to three other carbon atoms. The increased number of electron-donating alkyl groups provides significant stabilization, making tertiary radicals the most stable among alkyl radicals. This trend parallels the stability of carbocations, where tertiary carbocations are more stable than secondary, which are more stable than primary. citeturn0search0

Allylic Radicals:
Allylic radicals are those where the unpaired electron is located on a carbon atom adjacent to a double bond. This positioning allows for resonance stabilization, as the unpaired electron can be delocalized over the conjugated π system, distributing the electron density and enhancing stability. Allylic radicals are more stable than tertiary alkyl radicals due to this resonance effect. citeturn0search2

Understanding these classifications is crucial for predicting the reactivity and stability of radicals in various chemical reactions. For instance, the stability of a radical influences the rate and outcome of reactions such as halogenation, polymerization, and other radical-mediated processes.

For a visual explanation and further insights into classifying radicals and determining their stability, you might find the following video helpful:

videoClassifying Radicals and Determining the Most Stableturn0search6