Abstract
Optical absorption spectra of solvated electrons in ammonia solutions of sodium iodide at three different temperatures and
at three different salt concentrations all exhibited essentially the same identical shape as that observed in pure ammonia.
At each salt concentration, the spectra shifted to longer wavelengths as temperature was increased. At each temperature, the spectra shifted to shorter wavelengths as salt concentration was increased. The salt-effected shifts are shown to arise from the interaction of solvated electrons with the added ionic components, principally through ion pairing with sodium cations. Intrinsic shifts of the optical absorption spectra of the pertinent solvated-electron species are shown to be related to the changes produced in their standard free energies by the added salt. Theoretical estimates of the intrinsic shifts compare quite well with those obtained from the analysis of the experimental data.