Photolysis of 3‐(1‐acyl‐5‐aryl‐3‐pyrazolinyl)coumarins—Effective Fluorescence Decay

Abstract

Photophysical characteristics of new 3‐(1‐acyl‐5‐aryl‐3‐pyrazolinyl)coumarins have been measured. These coumarin derivatives are found to be effective fluorophores and show high values of quantum yields of fluorescence both in nonpolar and in polar solvents. The 3‐(1‐acyl‐5‐aryl‐3‐pyrazolinyl)coumarins turned to be photosensitive compounds and undergo photolysis under irradiation in the range of 310–465 nm. Photolysis is suggested to include retro‐cyclization and retro‐condensation steps. The process is accompanied by a sharp drop of fluorescence that can be of interest for the creation of new media in optical recording of information.