PHOTOINDUCED ELECTRON-TRANSFER REACTION O F AZO-COMPOUNDS

Recently, photoinduced electron transfer (PET) reactions have been foc used on the behavior of radical-ion species. Here, we review the PET r eactions of azo compounds, especially azoalkanes. Ground state interac tions between azoalkanes and cationic salts have been investigated. On the basis of these results, studies of CT band excitation and PET rea ctions are developed. There are two types of the PET reactions. One is the electron transfer from the excited molecules of azoalkanes to the ground stale electron acceptor molecules, and the other is the electr on transfer from the ground stale molecules of azoalkanes to the excit ed electron acceptor molecules. Products via cation intermediates are given from the reactions of acyclic azoalkanes and rearranged products are produced from the reaction of cyclic azo compounds. In many cases , it is known the back electron transfer plays very important role in the PET reaction.