A solvated electron is a free electron held in (solvated in) a solution. It can occur in both water and liquid ammonia and turns the solute blue. While it is stable in anhydrous liquid ammonia for days, it is very short lived when in water. A solution of metal ions and solvated electrons in ammonia can be made by dissolving an alkali metal such as sodium in liquid ammonia. A common use of sodium dissolved in liquid ammonia is the Birch reduction.
The solvated electron is a reactive species which is responsible for a great deal of radiation chemistry. One possible industrial application of radiation generated solvated electrons is the treatment of PCBs, the polychlorobiphenyls are converted to biphenyl and inorganic chloride.
The solvated electron can react with dissolved oxygen to form a superoxide radical (O2.-), which is a potent oxidant; also the solvated electron can react with nitrous oxide to form hydroxyl radicals (HO.). The solvated electrons can be scavenged from both aqueous and organic systems by adding nitrobenzene or sulfur hexafluoride.