Fig. 6.

Photodegradation profiles (approximated with monoexponential decay) of 1–3 in aqueous buffer solution (100 mM; pH=7.5) when illuminated with a 525 nm high-power LED (3 W). The solutions (3 ml) were placed in a glass cuvette and irradiated in a fixed position with respect to the light source. The photodegradation profiles were obtained by monitoring the absorption spectra in the absorption maximum of each dye. Dye concentration was adjusted so that A₅₂₅=0.4 for all dyes.