DYE-SENSITIZED PHOTOLYSTS OF DISODIUM PHENYL PHOSPHATE IN AQUEOUS SOLUTION UNDER OXYGEN: INVOLVEMENT OF SINGLET OXYGEN

Abstract— The release of orthophosphate from oxygen-saturated aqueous solutions of disodium phenyl phosphate by near-UV and visible light was enhanced in the presence of the sensitizing dyes methylene blue, rose bengal and thionine. The reaction was accompanied by the bleaching of these dyes. In the absence of oxygen, under nitrogen, the photodecomposition was very much slower. In deuterium oxide as the solvent, the dye-sensitized photodecomposition was 9 times faster than in normal water. This result suggests that singlet oxygen is probably the reactive species in the dye-sensitized reaction.