Question

Why do tertiary alkyl halides react in an ${S_N}1$mechanism more easily than${S_N}2$?

Answer 1

Organic chemistry, hydrocarbon is an important topic. Hydrocarbons are majorly classified into three groups. There are alkane, alkene and alkyne. The alkane means carbon-carbon single bond. The alkene has a carbon-carbon double bond. The alkyne means carbon-carbon having a triple bond in the molecule. The general formula of an alkane is${{\text{C}}_{\text{n}}}{{\text{H}}_{{\text{2n + 2}}}}$. The general formula of an alkene is${{\text{C}}_{\text{n}}}{{\text{H}}_{{\text{2n}}}}$. The general formula of the alkyne is ${{\text{C}}_{\text{n}}}{{\text{H}}_{{\text{2n - 2}}}}$.

Complete answer:
The ${S_N}1$ means substitution reaction in nucleophilic on unimolecular mechanisms. That means there are two steps in the mechanism. The first step is removing the leaving group and the second step is attacking a nucleophilic agent. So, here bulkiness of the molecules is not impacted.
The ${S_N}2$ means substitution reaction in nucleophilic on bimolecular mechanism. That means there is one step in the mechanism. The single step is removing the leaving group and attacking a nucleophilic agent. So, here bulkiness of the molecules is mostly impacted and changes the nominal condition of the chemical reaction.
The tertiary alkyl halides have three alkyl bonding in the one carbon atom and it makes more steric hindrance. So, the tertiary alkyl halides react in a ${S_N}1$mechanism more easily than${S_N}2$.
According to the above discussion, the reason for tertiary alkyl halides reacts in a ${S_N}1$mechanism more easily than${S_N}2$ is the bulkiness of the substituent bonds.

Note:
Alkyl halides are classified into three types. There are primary alkyl halides, secondary alkyl halides, and tertiary alkyl halides. The full form of IUPAC is the International Union of Pure and Applied Chemistry. It is a WorldWide organization for the nomenclature of the new elements in the periodic table and chemical molecules. The IUPAC has certain rules and regulations for naming the organic compound. In that method only we named the organic molecules at the World level. The naming of any organic molecule depends on the parent saturated hydrocarbon.