Synthesis, characterization, photophysical, and photochemical studies of BODIPY derivatives

Substances that change the rate of a chemical reaction when exposed to light are called photocatalysts. This work covers the development of new photocatalysts that are active under light and suitable for use in organic reactions. In this context, novel benzyl-, naphthalimide (NI)-, and carbazole (CB)-BODIPY derivatives were synthesized, and their molecular structures were characterized via spectroscopic techniques. Various photophysical/photochemical properties including molar absorption coefficients, fluorescent quantum yields, fluorescent lifetime profiles, and singlet-oxygen-production capabilities of the BODIPY derivatives (11-16) were determined by UV-Vis absorption and fluorescence spectroscopies. The novel BODIPYs exhibited strong absorption bands, moderate fluorescence characters, and good singlet-oxygen-generating abilities as expected from a good photocatalyst. These compounds were also used in the synthesis of juglone by the photooxidation of 1,5-dihydroxynaphtalene (DHN) and in the presence of the photocatalysts 11-13, whereby 77% juglone production was achieved in 20 min. The production of juglone with beneficial health effects under controlled light with a short reaction time and good yield may contribute to its use as an agent in different biological processes.