Unusual fluorescent properties of novel fluorophores, 6-aryl-3,4-diphenyl-α-pyrone derivatives

Novel fluorophores, 6-aryl-3,4-diphenyl-alpha -pyrones, were synthesized and their spectroscopic properties investigated in the form of evaporated films on plain glass slides, as well as in the solid and solution states. An electron-donating aryl group on the 6-position of the pyrones causes a red-shift in the absorption and fluorescent maxima. In the solid states, they show intense blue-to-orange fluorescence, but not in solution. This unusual fluorescent property is caused by fixing the 6-aryl group of the pyrones, and is the result of molecular packing. These interactions induce a pathway for radiative decay, which is associated with intense fluorescence emission only in the solid state.