Mesolysis Processes with Benzylic Carbon-Oxygen. Bond Cleavage in Radical Anions of Aryl Benzyl Ethers Studied by Electron Pulse Radiolysis in DMF

摘要

Based on transient absorption measurements obtained upon electron-pulse radiolysis of aromatic ethers in N,N-dimethylformamide (DMF), mesolysis processes of the radical anions were investigated. We observed transient absorption spectral change due to the formation of the radical anions in the temperature range (220-295 K). The transient absorption of the radical anions decreased with first-order kinetics along with the growth of the absorption spectrum of the corresponding benzylic radical. Arrhenius analysis of the decay rates of the radical anions provided the activation energies and the frequency factors for the mesolysis. These observations indicated that the mesolysis of the radical anions occurs via a stepwise mechanism, resulting in the formation of benzylic radical and phenolate anion due to the C-O bond cleavage.