Tertiary alkyl halides are practically inert to substitution by SN2 me...
In SN2 mechanism, tha attack of nucleophile takes place from behind on ABMO of leaving group. if the surrounding atoms or molecules provide steric hinderance then, attack is not possible because already the ABMO is very small in siza and also it makes it very very difficult or impossible to form a 5 membered transition state and thus, SN2 mechanism fails.
Tertiary alkyl halides are practically inert to substitution by SN2 me...
Explanation:
Tertiary alkyl halides have a hindered structure due to the presence of three alkyl groups attached to the carbon atom bonded to the halogen atom. This structure leads to steric hindrance, which makes the molecule practically inert to substitution by SN2 mechanism.
Steric Hindrance:
Steric hindrance occurs when bulky groups attached to the carbon atom prevent the attack of nucleophiles. In the case of tertiary alkyl halides, the three alkyl groups attached to the carbon atom create a bulky structure, which hinders the approach of nucleophiles. As a result, the SN2 reaction mechanism becomes less favorable.
SN2 Mechanism:
The SN2 reaction mechanism involves the attack of a nucleophile on the carbon atom of the alkyl halide, leading to the displacement of the halogen atom. In the case of tertiary alkyl halides, the steric hindrance caused by the three alkyl groups attached to the carbon atom makes it difficult for the nucleophile to attack the carbon atom and displace the halogen atom. Therefore, the SN2 mechanism becomes less favorable.
Conclusion:
Tertiary alkyl halides are practically inert to substitution by SN2 mechanism because of steric hindrance caused by the presence of three alkyl groups attached to the carbon atom. This steric hindrance makes it difficult for the nucleophile to approach the carbon atom and displace the halogen atom, leading to the inhibition of the SN2 reaction mechanism.
To make sure you are not studying endlessly, EduRev has designed JEE study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in JEE.