Effects of Reaction Media on Photoinduced Electron-Transfer Reactions

Development of Highly Efficient Photoreactions and Their Synthetic Applications

Abstract

Effects of reaction media on photoinduced electron-transfer reactions are reviewed from synthetic and mechanistic viewpoints. This review deals with the following subjects : (1) The characteristics and the problems of photoinduced electron-transfer reactions in organic photochemistry. (2) The salt effects on organic photoreactions which proceed via exciplexes and radical ion species. In this section, examples are given that the efficiencies of the photoreactions are enhanced and suppressed by the addition of salts into the reaction systems. Examples are also given that the selectivities in the photoreactions are affected by the addition of salts. (3) The effects of other additives such as oxygen and aromatic hydrocarbons on photoreactions. These additives are shown to often act as redox sensitizers or co-sensitizers in electron-transfer mediated photoreactions. (4) The solvent effects on photoreactions. The change of solvents are shown to often affect the product distributions.