Subpicosecond pulse radiolysis study of solvated electron in alcohols

Since hydrated electrons were first observed by Boag, many researches on the solvated electrons in water and alcohols have been carried out especially with pulse radiolysis and laser photolysis. However, the radiation chemistry of solvated electrons within 30 ps has been still unknown because the highest time resolution of pulse radiolysis had remained 30 ps since the first picosecond pulse radiolysis experiment was carried out in the late 1960's. Recently, a subpicosecond pulse radiolysis system was developed at Osaka University. The subpicosecond pulse radiolysis system consists of a femtosecond electron linear accelerator, a femtosecond laser and a jitter compensation system. This system enabled the investigation on radiation chemistry of solvated electrons within 30 ps after irradiation. The objective of this study is to make clear the formation processes of solvated electrons in alcohols. Also, we aimed at the elucidation of the reactions of solvated electrons with solutes in the formation processes. Subpicosecond pulse radiolysis of several kinds of alcohols such as methanol were carried out at the wavelength of 790 nm at room temperature. Two components which have different lifetimes were clearly observed in the results. It has been reported that presolvated electrons and solvated electrons are formed in alcohols on the exposure of electron beam. Assuming a strictly stepwise model, the experimental data were analyzed. The experimental data were fitted well by this procedure. Adding dichloromethane as an electron scavenger, the rate constants of reactions with solvated electrons and presolvated electrons were estimated