Chapter 8, Problem 12CTQ

Interpretation Introduction

Interpretation: Type of carbocation formed in reaction below should be determined.

  

Concept introduction: The carbon-carbon double bond in alkene consists of a strong $\sigma$ bond (formed by overlap of $s{p}^2$ hybridized orbital on each carbon) and a weak $\pi$ bond (formed by overlap of pure $p$ orbital on each carbon). Due to unsaturation, alkene shows addition reaction where the double bond provides loosely held $\pi$ electrons and is readily attacked by any electron deficient group like ${\text{H}}^{+}$ ions released from acids. The loosely held $\pi$ electrons is present, therefore, behave as base though weak one.

Carbocation is a general term employed for a postively charged carbon irrespective of valency of carbon. In carbocation, carbon is bonded to 3 atoms or groups and has only sextet of electrons so it behaves as an electron deficient species. It is $s{p}^2$ hybridized with a vacant $p$ orbital has a planar geometry.