Peculiarities in the photochemical behavior of 1-bromo-2-hydroxynaphthalene in cetylpyridinium chloride micellar solution

Unlike the case of aqueous solution, two products are formed in the photolysis of 1-bromo-2-hydroxynaphthalene in a cetylpyridinium chloride micellar solution in the presence of sodium sulfite. These products are formed as a result of competitive steps of the primary photochemical process, the C–Br bond photodissociation and the heterolytic dissociation with elimination of the bromide anion. The bond photodissociation results in the product of bromine replacement by the sulfo group. The heterolytic dissociation affords the dimerization product. In the micellar solution, the iodide ions increase the quantum yield of the photosubstitution product due to the heavy atom effect and do not affect the quantum yield of the dimerization product. The halogenated derivatives of hydroxynaphthalene in micelles do not fluoresce in a neutral or alkaline medium.