Effect of Nitrate Ions on the Chain Photochemical Reaction of Sulfo Group Substitution for Bromine in 1-Bromo-2-Hydroxynaphthalene upon Sensitized and Direct Photolysis

The influence of nitrate ion admixtures on the proceeding of the radical-ion chain reaction of sulfo group substitution for halogen in halogenated hydroxynaphthalenes in an aqueous sodium sulfite solution was studied upon both direct and tris(2,2-bipyridyl)ruthenium(II)-sensitized photolysis. It was found that nitrate ions increase the quantum yields of the photosensitized substitution reaction and decrease the quantum yields of the reaction in the direct photolysis. Based on an analysis of kinetic schemes of the reaction, it was shown that nitrate ions affect the photoinitiation step in sensitized photolysis or the termination step in the direct photolysis.