Evidence for infrared absorbing electrons in alkaline aqueous glasses. A pulse-radiolysis study at temperatures down to 6 K

Abstract

The absorption spectra observed on pulse radiolysis at 6 K of glassy concentrated solutions of NaOD, KOD, RbOD and CsOD in D₂O are reported. In addition to the well established band in the visible due to e^–_vis' a second band is observed in the near-infrared in all the glasses. This band is attributed to e^–_IR, i.e. an electron trapped in a distinctly different environment from e^–_vis. From the effect of glass composition on the yields of e^–_vis it is inferred that e^–_IR is associated with the unbound water in the glass. At 76 K e^–_IR is not observed.