Why do haloalkanes undergo nucleophilic substitution?

Question

Madison Anderson · Accepted Answer

Haloalkanes undergo nucleophilic substitution because their electronegativity puts a partial positive charge on the α carbon atom.

All the halogens except iodine are more electronegative than carbon. Iodine has the same electronegativity as carbon.

That means that every carbon-halogen bond (except C-I) will have a δ⁺ charge on the carbon.

The positive charge makes that carbon susceptible to attack by a nucleophile.

Although the C-I bond is nonpolar, it is highly polarizable.

Imagine a negative ion approaching the bond from the back side of the carbon atom:

The approaching negative ion repels the electrons of the C-I bind and induces a δ⁺ charge on the carbon.

So alkyl iodides also undergo nucleophilic substitution.

Jacob Anderson · Answer

undefined Haloalkanes undergo nucleophilic substitution due to the electrophilic nature of the carbon-halogen bond, where a nucleophile displaces the halogen, forming a new bond with carbon. This reaction is influenced by factors such as nucleophile strength, leaving group ability, and steric hindrance.