Inductive Effects On Carbocations Analysis
When the bond between carbon and an atom having greater electronegativity undergoes heterolytic fission, a carbon atom bearing positive charge is produced. The atom with higher electronegativity takes the bonding pair of electrons and leaves as a negative ion. The carbocation generated should have a triagonal planar structure with a bond angle of 120^\circ120
∘
. The central carbon atom is {\rm{s}}{{\rm{p}}^2}sp
2
hybridized. One s orbital and two p orbitals are used by the carbon to form bonds with other three groups. The remaining unhybridized {\rm{p}}p orbital is empty. It lies perpendicular to the plane of the carbocation. Carbocations are species with only six electrons in its valance shell. They need two more electrons to complete the octet. Thus, they are electron deficient in nature. This electron deficiency makes them highly reactive, unstable and electrophilic in nature. Carbocations are important reaction intermediates in many reactions including {{\rm{S}}_{\rm{N}}}1S
N
​
1 reaction. The Hammond postulate suggests that the activation energy of the rate determining step will be inversely proportional to the stability of the carbocation intermediate. Thus, anything that can stabilize the carbocation will speed up the reaction. Therefore, the stability of intermediate carbocations plays an important role in the reaction. Carbocations are electron deficient species and the factors which can increase the electron density on the carbon atom can stabilize the carbocation and the factors which decrease the electron density on the carbon atom can destabilize the carbocation. One of the main effects which can influence the stability of carbocations is inductive effect.
