The diethyl carbonate, DEC, is an ester that is used as a solvent in Li-ion batteries, but its behavior under ionizing radiation was unknown. The transient optical absorption spectra, the decay kinetics, and the influence of various scavengers have been studied by using the picosecond laser-triggered electron accelerator ELYSE. In neat DEC, the intense near-IR (NIR) absorption spectrum is assigned to the solvated electron. It is overlapped in the visible range by another transient but longer-lived and less intense band that is assigned to the oxidized radical DEC(-H). The solvated electron molar absorption coefficients and radiolytic yield evolution from 25 ps, the geminate recombination kinetics, and the rate constants of electron transfer reactions to scavengers are determined. The radiolytic mechanism, indicating a certain radioresistance of DEC, is compared with that for other solvents.

The knowledge of the absorption spectrum of hydrated electron is of importance in numerous pulse radiolysis studies because it is often used for dosimetry or for second-order rate constant determination. We present a direct method for the evaluation of the molar absorption coefficient of the hydrated electron. It is based on the wavelength measurement of isosbestic points during the reaction of e(-)aq with the methylviologen MV(2+) cations which leads to the formation of MV(+•). The molar absorption coefficient of hydrated electron is obtained using the value of the molar absorption coefficient of MV(+•) at the isosbestic point at 600 nm, i.e., ε600nm,(MV(+•)) = 13500 ± 300 L mol(-1) cm(-1). Therefore, at the maximum of the absorption spectrum of e(-)aq at 715 nm, the value is ε715nm,(e(-)aq) = 19700 ± 400 L mol(-1) cm(-1). The absorption spectrum of the hydrated electron has been re-evaluated and completed from 260 to 850 nm.