D. Meisel

On the existence of dielectrons in aqueous solutions

Abstract Alkaline aqueous solutions under high H 2 pressures when pulse radiolysed should favor the formation of dielectrons through the reaction e aq − + e aq − → (e 2 −2 )aq → H 2 + 2OH − . In our pulse radiolysis investigation of such solutions, no U.V. absorption, which can be attributed to the decay of e aq − , remains after the decay of e aq − . We conclude that either dielectrons scarcely absorb any light in the region where e aq − absorbs or else the dielectron is quite short-lived as compared to the lifetime of e aq − under these conditions.

On the use of the electron spin resonance–flow technique in the study of short-lived radicals

The use of double mixing in the study of a mixture of alcohol radicals by means of H2O2+ TiIII redox system is shown to be superfluous. The ratio of the concentrations of two such radicals is found to be independent of the order of introduction of the parent alcohols to the system. The ratio of radical concentrations is determined by simple competition of the alcohols for the primary OH radicals but side reactions and differences in recombination rates are shown to influence considerably the ratio of the observed radical concentrations. Limitations on mechanistic conclusions and kinetic studies of such systems are discussed.

The role of the reaction of eaq - with FeIII in the radiation chemistry of acid aqueous solutions

Abstract The reaction Eaq-+Fe2 Fe2+ was investigated by competition with the reaction Eaq-+H+ H. In acid solutions of alcohol, G(H2) was reduced very efficiently by FeIII. K 1 k 2 was determineed in HClO4 and H2SO4 and it was found to depend on the form of FeIII ion in solution. At pH 1·8, k 1 k 2 ≈2 in both HClO4 and H2SO4. Inclusion of this reaction in the mechanism of oxidation of Fe2+ in acid solutions (which has been generally neglected) confirms, as suggested by Schwarz(2), that Geaq - seems to be almost pH independent. It also removes the necessity of assuming the existence of H2O2+ which was proposed(4) (Pucheault et. al., Int. J. Radiat. Phys. Chem. 1969. 1, 209) in order to interpret the variation of G(FeIII) in acid air-saturated FeIII/Fe2+ solutions.