Illustrated Glossary of Organic Chemistry

Nitronium cation: NO2+. A reactive intermediate in the electrophilic aromatic substitution nitration reaction mechanism.


Nitronium cation Lewis structure.


The nitronium cation is a reactive intermediate in the electrophilic aromatic substitution nitration mechanism. Nitric acid (HONO2) is protonated by H3O+ (a strong acid). Water then leaves, forming the nitronium cation (shown in red). This cation replaces a benzene ring proton via the standard electrophilic aromatic substitution mechanism.