Sulfur Dioxide Sensitized Photochemical Oxidation of Hydrocarbons

Near-ultraviolet sunlight is absorbed by sulfur dioxide to produce electronically excited molecules, which react with n-butane in the presence of wet or dry air to produce an aerosol and eventually a liquid precipitate. The product is a heavily oxidized, sulfur-containing, organic strong acid. The possible role of these reactions in photochemical air pollution is discussed.