Carboxylic Acids and Derivatives
5.0 Ortho Effect
5.0 Ortho Effect
The ortho substituted benzoic acid (whether the substituent is electron withdrawing or releasing is comparatively stronger acid than the para and meta isomers. This effect is called ortho effect. It occurs due to the joint operation of steric and intra molecular $H-$bonding where ever it takes chance to stabilize the carboxylate anion due to nearness of the substituent. Groups like $ - OH,{\text{ - }}Cl,N{O_2}$ will cause more stabilization to anion due to direct interaction through intra molecular $H-$bonding.
Order of acidic character
Reaction due to cleavage of $—O—H$ bond as acid
(i) Reaction with active metals [alkali and alkaline metal]
(ii) Reaction with $CaO$
(iii) Reaction with Bicarbonates and Carbonates
Carboxylic acid reacts with carbonates and bicarbonates to liberate $C{O_2}$ gas
