Sequential Electron−Proton−Electron Transfer in the Radiolytic and Photochemical Oxidation of Thioxanthene and Xanthene

Radical cations generated from thioxanthene and xanthene undergo structural relaxation in low-temperature hydrocarbon glasses upon warming. Under conditions of unrestricted diffusion, deprotonation of the radical cations occurs and results in the formation of the thioxanthyl and xanthyl radicals. Subsequent electron loss leads ultimately to the closed-shell thioxanthyl and xanthyl cations. Using combined steady-state and time-resolved radiolytic and photochemical methods, the radical cations, radicals, and cations of interest were spectroscopically and kinetically characterized.