The reactions of the sulfate radical ion with phenylacetic and 4-phenylbutanoic acids

Abstract

The reactions of the sulfate radical ion (SO₄^-) were studied by pulse radiolysis of aqueous solutions of aromatic acid and peroxydisulfate ions. With phenylacetic acid, the major reaction is decarboxylation; the resulting ultra-violet absorption spectrum shows that the main product is the benzyl radical, Ph^-·CH₂, and that only minor amounts of hydroxylation products are formed. However, decarboxylation is unimportant with 4-phenylbutanoic acid and the spectrum has been assigned to the benzylic Ph-^·CH-CH₂-CH₂-COO^- radical ion. The same spectrum is obtained if the hydrogen abstraction reaction of the O^-· radical ion is used with 4-phenylbutanoic acid to form the latter radical.