Resolution of the Absorption Spectrum of Solvated Electrons

The abosprtion spectrum of solvated electrons is resolved by superposition of one or several Gaussian‐shaped bound‐bound (bb) bands and one bound‐continuum (bc) band. A previously derived equation is applied for the bc band. Energy levels, band amplitudes, widths, and contributions are given for tetrahydrofuran, ethylenediamine, hexamethylphosphoric triamide, water (all at room temperature), ammonia $\text{(−65°}\mathrm{C})$ , and 3‐methylpentane (77°K). Resolution is tentative for ethylenediamine because of insufficient experimental data and for ammonia and water because of inadequancy of the equation for the bc band. Experimental evidence supports this equation for all solvents except ammonia and water. A theoretical limitation is indicated. Energy levels are correlated with the nature of the solvent as characterized by the difference β between the reciprocals of the optical and static dielectric constants. Spectra of solvated electrons in solvents with low β's show a major contribution from the bc transition and only one bb transition. Conversely, a high β results in a more complex spectrum with a relatively minor bc contribution.