Reactions of the borate radical with para-substituted benzoic acids (photo-kolbe reaction)

Rate constants for the reactions of the borate radical B(OH)3O⨪ with various para-substituted benzoic acids were measured by flash kinetic spectrophotometry. The product analyses and kinetic studies are consistent with an electron transfer mechanism followed by decarboxylation. In the case of the p-aminobenzoate anion the —NH2 and —COO− groups react simultaneously with the borate radical providing two parallel pathways with different rate constants.