Abstract: The photo-retro-aldol type reactions of several nitroaromatic compounds have been studied in aqueous solution over the pH 1-14 range. These reactions are observed only in aqueous or in predominantly aqueous solution. Catalysis of reaction due to hydroxide ion is observed for several derivatives. Quantum yields of reaction and product ratios (of nitrotoluene vs dinitrobibenzyl) are reported as a function of pH. The proposed ...