---
title: "Directing Effects in Electrophilic Aromatic Substitution"
description: "A substituted ring does not react evenly. The group already present decides both where the next one goes and how fast, and both effects come from the stability of the intermediate cation."
canonical: https://lightmysky.com/learn/science/directing-effects-in-electrophilic-aromatic-substitution-mt_KMRxS6s06f
source: https://lightmysky.com/learn/science/directing-effects-in-electrophilic-aromatic-substitution-mt_KMRxS6s06f.md
retrieved: 2026-09-12
---

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# Directing Effects in Electrophilic Aromatic Substitution

A substituted ring does not react evenly. The group already present decides both where the next one goes and how fast, and both effects come from the stability of the intermediate cation.

Subject: Science · Area: Chemistry · Ages 20 to 22
Page: https://lightmysky.com/learn/science/directing-effects-in-electrophilic-aromatic-substitution-mt_KMRxS6s06f

## Ready when they can

- Classifies a substituent as activating or deactivating and as ortho and para or meta directing
- Draws the resonance forms of the intermediate to justify the directing outcome rather than reciting it
- Explains why the halogens deactivate but still direct to ortho and para
- Orders two substitutions correctly in a synthesis so that the second lands where it is wanted

## Lesson: Who steers the next group on a benzene ring

A group already on the ring decides where the next one lands and how fast it arrives. Groups such as OH, NH2, and alkyl push electrons toward the ring, speed it up, and send newcomers to the ortho and para spots. Groups such as NO2 and carbonyl pull electrons away, slow the ring down, and send newcomers to the meta spot.

**Example.** The halogens break the pattern and you must learn them as the exception. They slow the ring by pulling electrons through single bonds, yet they still direct ortho and para. Their lone pairs pour back into the intermediate by resonance and steady it, which outweighs the pulling.

Never recite a directing outcome without drawing the intermediate behind it. The electrophile adds first to give a carbocation called the arenium ion, and you draw its resonance forms for each attack site. For phenol, ortho and para attack give one form with the positive charge next to the oxygen lone pair, which steadies it, while meta attack gives no such form.

**Tip.** When two new groups are needed, plan the order so each group steers the next one into the wanted spot, since swapping the steps can give a different isomer. Also note that an amino group often needs protection before nitration, and Friedel Crafts reactions fail on strongly deactivated rings.

**Recap.** The group in place shapes the intermediate, the intermediate picks the landing spot, and the order of steps decides the final isomer.

## Practice

8 questions on this page, each with its working shown.

## Needs first

- [Aromaticity: Huckel's Rule and Antiaromatic Systems](https://lightmysky.com/learn/science/aromaticity-huckels-rule-and-antiaromatic-systems-mt_2UmZKQozyN)

## Opens up

- [Nucleophilic Aromatic Substitution, Diazonium Salts and Heterocycles](https://lightmysky.com/learn/science/nucleophilic-aromatic-substitution-diazonium-salts-and-heterocycles-mt_I4EtpYcrEq)
- [Functionalising a Carbon-Hydrogen Bond Without a Handle](https://lightmysky.com/learn/science/functionalising-a-carbon-hydrogen-bond-without-a-handle-mt_j0LaIeS2VP)