Question

How do you Rank Radicals in order of stability?

Answer 1

Hint: To answer this question, we first need to understand what is stability in chemistry. Chemical stability is the thermodynamic stability of a chemical system in chemistry. When a system is in its lowest energy state, or in chemical equilibrium with its environment, it is said to be thermodynamically stable.

Complete answer:
Radicals - A radical is an atom, molecule, or ion with an unpaired valence electron in chemistry. These unpaired electrons make radicals very chemically reactive, with a few exceptions. Many radicals dimerize on their own. The majority of organic radicals have a brief life span.
The hydroxyl radical, which possesses one unpaired electron on the oxygen atom, is a well-known example of a radical. Triplet oxygen and triplet carbene, both of which have two unpaired electrons, are two examples.
Radicals in order of stability –
This method can be used to determine the stability of any intermediate, such as a carbocation, carbanion, or carbon free radical.
Consider the carbon atom as a person who is neither happy with more nor less electron density. It only needs the correct number of electrons. A free radical is an atom with one less electron than a carbon atom. As a result, it must account for the loss of one electron.
The majority of the time, we rank radicals in order of stability based on two key variables.
They are-
1.resonance-based stability.
2.Adjacent atoms with lone pairs provide stability.
However, the improvement in stability is dependent on the atom's electronegativity. As the electronegativity of an atom declines, radicals will become more stable.
 As a result, stability rises in the order of \[methyl{\text{ }}primary > {\text{ }}secondary > {\text{ }}tertiary\].
So, the final answer is \[methyl{\text{ }}primary > {\text{ }}secondary > {\text{ }}tertiary\] .

Note:
Neutral radicals and charged radicals are the two types of radicals. Furthermore, sigma radicals and pi radicals are two different types of radicals. The sigma-radical has an unpaired electron in the sigma orbital, while the pi radical has an unpaired electron in the pi orbital.