Reaction of Hypochlorous Acid with Hydrogen Peroxide and tert-Butyl Hydroperoxide. 1H NMR Spectroscopy and Chemiluminescence Analyses
Abstract In contrast to the well-known reaction of hypochlorous acid with hydrogen peroxide, no singlet oxygen is formed as the result of reaction between hypochlorous acid and tert -butyl hydroperoxide. The reaction with hydrogen peroxide yielded a quadratic dependence of light intensity on reactant concentration, a drastic enhancement of luminescence yield using D2O as solvent and only an emission of red light, that are typical characteristics of emission resulting from two molecules of delta singlet oxygen. Other chemiluminescence properties were observed using tert-butyl hydroperoxide. There was a linear dependence of light intensity on reactant concentration using rm-butyl hydroperoxide in excess with a decline of emission at higher concentrations. 1H-NMR spectroscopic analysis revealed di-tert-butyl peroxide, tert -butanol and also tert-butyl hypochlorite, acetone and acetate as products of the reaction between hypochlorous acid and tert -butyl hydroperoxide. The formation of di-tert-butyl peroxide is only possible assuming a tert-butyloxy radical as primary intermediate product of this reaction. Our results demonstrate that alkoxy radicals derived from organic hydroperoxides can participate in lipid peroxidation induced by hypochlorous acid. On the other hand, singlet oxygen did not influence the yield of peroxidation products. Changing H2O for D2O in suspension of egg yolk phosphaditylcholine no differences in accumulation of thiobarbituric acid reactive products were observed.