density functional theory study of benzoic acid decarboxylation

Mechanism of decarboxylation reaction includes, metal catalyst with ag+, a radical path and oxidative decarboxylation have been investigated. the calculations have been done in two different b3lyp/lanl2dz, and wb97xd/dgdzvp/ def2dtzv levels. four structures have been proposed for oxidized benzoic acid. among four possible oxidative structures only one structure with 62.99 kcal.mol-1 activation energy could lead to the decarboxylative product. silver catalyzed decarboxylation leads to products in one step. the activation energy for this path have been determined to be 43.31 kcal.mol^-1. the radical path for decarboxylation needs 16.93 kcal.mol-1 although for radical creation it needs at least 100.12 kcal.mol^-1 energy.