Control of the fluorescence of laser dyes by photooxidation of dihydrohetarenes

Abstract We consider new procedures for the photocontrol of fluorescence of laser dyes that can be used in optical information recording systems and sensing technologies. These procedures are based on photooxidation reactions of dihydrohetarenes with the use of perchloroalkanes or benzoquinone as the photooxidants. Photooxidation of dihydrohetarenes in the presence of perchloroalkanes generates an H + -acid that opens the lactone ring in Rhodamine laser dyes and thus initiates strong fluorescence. Photooxidation of dihydrohetarenes in the presence of benzoquinone does not generate acidity but increases the rate of radical photooxidation of the Coumarin 6 dihydro form, thus providing a strong fluorescence response of the laser dye.