Name: Polyhalogen Compounds - I
Uploaded: 2019-07-19
Duration: 6 min 52 s
Description: There are several polyhalogen compounds such as dichloromethane, carbon tetrachloride and DDT that have industrial applications. Let’s study their properties!

Question

Explain

S_{N}^{1}

and

S_{N}^{2}

reactions. Discuss the two mechanisms by taking suitable examples.

Accepted Answer

$S_{N}^{1}$ reaction: It is called as Unimolecular Nucleophilic Substitution reaction. Feasibility of the reaction is given in the order tertiary alkyl halide> secondary alkyl halide> primary alkyl halide. Thus is due to stable carbocation of alkyl halide.

Step 1: The Carbon-halogen bond breaks heterolytically to form an intermediate carbocation. This is a slow step and rate determining step.

${KOH}_{(aq)} \to K^{+} + {OH}^{-}$

Step 2: This is a fast step. The hydroxyl (nucleophile) attacks the alkyl carbocation to yield an alcohol

$S_{N}^{2}$ reaction: It is called as bimolecular Nucleophilic Substitution reaction. This is a single step reaction. In this step, attack of the nucleophile and the breaking of carbon-halogen bond takes place simultaneously.

The nucleophile attacks the carbon attached to halogen takes place from the opposite side to that of halogen. This is because of steric hindrance caused due to negatively charged halogen atom and nucleophile. Feasibility of the reaction is given in the order primary alkyl halide> secondary alkyl halide> tertiary alkyl halide.

Explain $S_{N}^{1}$ and $S_{N}^{2}$ reactions. Discuss the two mechanisms by taking suitable examples.

Important Questions on Haloalkanes and Haloarenes

Learn and Prepare for any exam you want !

Explain SN1 and SN2 reactions. Discuss the two mechanisms by taking suitable examples.

Important Questions on Haloalkanes and Haloarenes

Learn and Prepare for any exam you want !

Explain $S_{N}^{1}$ and $S_{N}^{2}$ reactions. Discuss the two mechanisms by taking suitable examples.