Relationship of photoacid production and fluorescence quenching of anthryl sensitizers by aryl iodonium and sulfonium salts

Abstract

While it has been recognized that sensitizers can be used to extend the wavelength range of onium salts are, it has not been established if the sensitizer participates directly in the production of photoacid nor if all photosensitizers are equally effective in quenching event. The authors have studied fluorescence quenching for a series of anthyryl derivatives and obtained the yield of H+ under conditions of equal fluorescence quenching and under conditions of equal onium salt concentration. The authors find that H+ yield per quenching event is similar for this series of molecules but under conditions of equal onium concentration significant differences are observed because of widely differing Stern-Volmer constants.