key term - Deactivating groups

Definition

In the context of electrophilic aromatic substitution reactions, deactivating groups are substituents attached to a benzene ring that decrease the reactivity of the ring towards an electrophile. They accomplish this by either withdrawing electron density from the ring or by being meta-directing in orientation.

Related terms

Electrophilic Aromatic Substitution:

A reaction in which an electrophile replaces a hydrogen atom on an aromatic ring.

Electron Withdrawing Group: A substituent that pulls electron density away from the rest of the molecule, often making a site less reactive towards electrophiles.

Meta:

Directing Groups - Substituents on a benzene ring that direct incoming substituents to attach at the meta position relative to themselves during an electrophilic aromatic substitution reaction