Oxidation of naphthalene by radiolytically produced [rad]OH radicals

Abstract

Radiolytically produced OH radicals react with naphthalene in aqueous solution in the presence of ferricyanide mainly to yield 1- and 2-naphthol in a ratio of 2.1:1. Reaction takes place via addition of OH to the naphthalene with a rate constant of 1.2 x 10 10M -1S -1. Because of the low solubility of naphthalene (∼ 2 x 10 -4M) γ-radiolysis studies were carried out at doses of ∼ 10 3 rad, where the naphthols were produced at micromolar concentrations. Analysis was by high-performance liquid chromatography. The initial yields of naphthols from solutions saturated with N 2O and naphthalene total 4.7 molec/100 eV, indicating near to quantitative conversion of the OH adducts to the naphthols by the ferricyanide. The observed product ratio is taken to reflect a two-fold preference for attack of OH at the 1-position as compared with that at the 2-position of naphthalene with only little (<10%) reaction at the 9-position.