Question

Give a brief description about the ortho effect with an example?

Answer 1

The ortho effect is a collection of steric effects, certain bonding interactions, and polar effects induced by the different substituents in a given molecule, which change its chemical and physical characteristics. In general, substituted benzene molecules are linked with the ortho effect.

Complete answer:
The Ortho effect is a phenomenon in which benzoic acids found in ortho are much stronger than benzoic acid. Whether the replacement is electron-withdrawing or electron-releasing makes no difference. In basic terms, an aromatic acid's acid strength is continually boosted by a group in the ortho position. Ortho compound will be the most powerful acid in ortho meta and para substitution. The presence of a group in the ortho position in relation to the carboxyl group creates steric barriers, causing the carboxyl group to spin and retreat away from the benzene ring. Because a carboxyl group can no longer participate in the ring resonance after delocalization, the acidity rises.
The ortho effect is linked to benzene molecules that have been replaced. It refers to a collection of bonding interactions and steric effects with polar effects imposed on a given molecule by numerous substituents, altering its physical and chemical characteristics.
In substituted benzene, there are three primary ortho effects.
In substituted benzoic acid, there is an ortho effect.
In aniline, there is an ortho effect.
Electrophilic aromatic substitution of disubstituted benzene compounds has an ortho effect.
When a group is substituted for benzoic acid in the ortho position to the carboxyl group, the acidic property of that molecule is greater than benzoic acid. Ortho-substituted benzoic acid is usually more potent than para and meta isomers.
When a group is present in the ortho position to $N{{H}_{2}}$ in aniline, the compound's basic nature is also less than aniline.

Note:
Aniline and benzoic acids are the only ones that have the Ortho effect. It specifies that ortho-substituted benzoic acids and anilines are more acidic than benzoic acid and aniline, respectively. Because it is well recognised that conjugating carboxylic acid to aryl rings raises its acidity, bending out the plane lowers it.