Unstable intermediates. Part XL. Solvated electrons: electron–cation interactions in potassium–amine solutions

Abstract

Electron spin resonance and electronic absorption spectra are described for solutions of potassium metal in ethylamine, propylamine, isopropylamine, and n-butylamine. The electron spin resonance spectra consist of a quartet, attributed to “solvated potassium atoms,” and a singlet arising from solvated electrons. The hyperfine splitting constant of the quartet is strongly dependent on solvent and temperature. The electronic absorption spectra contain bands at 14,800 and 11,500 cm.^–1. It is concluded that the electronic absorption band at 14,800 cm.^–1 does not arise from a transition of the solvated atom. A rapid equilibrium is shown to exist between solvated atoms and solvated electrons, and its dependence on solvent, temperature, and metal concentration is explored. The nature of the solvated atom is considered in the light of these results.