In the arenium ion (sigma complex) structurally formed specifically during the intermediate step of — Haloalkanes and Haloarenes Chemistry Question

💡 Solution & Explanation

In standard benzene, there are $6$ delocalized $\pi$ -electrons shared across $6$ $sp^2$ hybridized carbon atoms in a continuous cyclic loop. During electrophilic aromatic substitution, an electrophile ($Cl^+$) attacks the ring, forming a new covalent sigma bond with one of the carbon atoms. This specific carbon atom rehybridizes from $sp^2$ to $sp^3$, breaking the continuous cyclic overlap. The remaining conjugated portion of the ring now consists of $5$ $sp^2$ hybridized carbon atoms sharing the remaining $4$ $\pi$ -electrons, accompanied by a delocalized positive charge.