Studies of the antenna effect in polymer molecules. 28. Photo-Fries rearrangement of 1-naphthyl acetate in aqueous solutions of poly(sodium styrenesulfonate-co-2-vinylfluorene)

Abstract

The photo-Fries rearrangement of 1-naphthyl acetate (NA) in aqueous solutions of the novel antenna polyelectrolyte, poly(sodium styrenesulfonate-co-2-vinylfluorene) (PSSS-VF), was studied. Three copolymers with different fluorene (Fl) chromophore contents were synthesized. The solubilizing abilities of the PSSS-VF copolymers in aqueous solution were tested using perylene as a probe. The polarity of the polymeric medium was shown to be lower than that of the interior of typical surfactant micelles. It was demonstrated that electronic excitation energy can migrate along the polymer chain before being transferred to the solubilized probe molecule. The reaction of NA is sensitized efficiently by light absorbed by the polymeric fluorene chromophores. It was found that the product distribution of the reaction strongly depends on the content of fluorene in the copolymer. The reaction in aqueous solutions of PSSS-VF rich in Fl chromophores occurs with high selectivity to form the cage product, 2-acetonaphthol (2-AN) in 95% yield. Polymeric sensitizers with low fluorene content (∽5%) gave 90% yields of the non-cage product 1-naphthol. Both are more selective than when the Fries reaction is carried out in methanol solution.