Photophysical Responses of Benzimidazolic and Benzoxazolic Hydroxy Coumarin Dyes

Four novel benzoxazolic and benzimidazolic derivatives of 6-hydroxycoumarin were synthesized and their photophysical properties were studied as well. the products with brilliant yellow color shades revealed green fluorescence. the emission peaks of the products appeared at 456–474 nm. the important characteristics of fluorescent compounds, including the stokes shift (νa-νf), oscillator strength (f), and fluorescence quantum yield (φf) were measured. furthermore, their photophysical and electronic properties have been theoretically investigated using density functional theory. dyeing of nylon fabrics was also carried out by the synthesized fluorescent dyes. the build-up curves of the synthesized dyes generally flatten off at dye concentrations of 2-3 % owf.