The Formation of Solvated Electrons in the Photochemistry of the Phenolate Ion in Aqueous Solutions

Evidence for the photochemical formation of solvated electrons in aqueous solutions of the phenolate ion is obtained. N₂O and acetone are employed as specific scavengers for the solvated electrons produced from the thermal dissociation of the excited state. The dependence of the quantum yield of N₂ on [N₂O] is found to agree with cage scavenging kinetics. The solvated electron-phenoxyl radical pair in the solvent cage is formed in a secondary process from the spectroscopic excited state of the ion. Spectroscopic data indicate that this excited state arises from an internal π-π* excitation and does not involve a c.t.t.s. (charge transfer to the solvent) state as in the case of solvated electron formation in the photochemistry of the halide ions in solution.