Question

Stability of intermediates is known to be: $Ethy{l}^{(-)}<Methy{l}^{(-)}$ and $Ethy{l}^{.}>Methy{l}^{.}$
This is due to

• A. +I effect of the methyl group in ethyl anion and $\sigma \to p$ orbital conjugation in ethyl radical.
• B. - I effect of the methyl group in ethyl anion and $\sigma \to \sigma \ast$ conjugation in ethyl radical.
  
• C. Resonance effect of the methyl group in both cases
  
• D. +I effect of the methyl group in ethyl anion and $\sigma \to \sigma \ast$ conjugation in ethyl radical.
  
  
  

Answer 1

The correct option is A +I effect of the methyl group in ethyl anion and $\sigma \to p$ orbital conjugation in ethyl radical.

$C{H}_3-\overline{C}{H}_2$ is less stable than $\overline{C}{H}_3$ as the $C{H}_3$- group exerts +I effect.

C₂H₅• radical is more stable than CH₃• , this is due to $\sigma -p$ conjugation, also known as hyper conjugation.