what is ortho effect?

how and why does it change acidity and basicity? or what is the effect of ortho effect on acidity & basicity

please explain in simple words

eagerly waiting 4 reply

TEJASWI

Dear student,

The ortho effect if based on the premise that an ortho-substituted acid (take benzoic acid as an example) is more acidic than the meta or para-substituted form. This effect is not dependent on the nature of the substituent (e- donating or e- withdrawing). The reason for this is that the steric hinderance between the substituent and the neighboring carboxylate forces the carboxylate to bend out of the plane of the aromatic ring. This conformational shift alters the delocalization of the charge into the benzene ring, making it easier for the negative charge to be delocalized throughout the pi-system.