Simultaneous formation of mono- and dications of free-base tetraphenylporphin during photo-oxidation probed by resonance Raman and absorption techniques

We report the simultaneous formation of mono- and dication (known as diacid ) radicals during the photo-oxidation of free-base tetraphenylporphin by se lective laser excitations using resonance Raman and optical absorption tech niques. During the process of photo-oxidation of free-base tetraphenylporph in in carbon tetrachloride, the addition of even a small quantity of tetrah ydrofuran leads to the formation of dication along with the monocation radi cal. A mechanism of simultaneous formation of di- and monocation radicals i s proposed. (C) 2000 Elsevier Science B.V. All rights reserved.