Abstract
Donor–acceptor chromophores were synthesized by Knoevenagel condensation and characterized by using spectroscopic measurements (FT-IR, 1H NMR, 13C NMR, and mass) and elemental analyses. UV–Vis and fluorescence spectroscopic studies provided that these dyes are good absorbent and fluorescent. The results of photostability study showed that photobleaching of Dyes 2 and 4 was more significant than that of Dyes 1 and 3, providing that Dyes 1 and 3 are more photostable than Dyes 2 and 4. In addition, all dyes included in this study are found to be sensitive to the polarity of the microenvironment provided by different solvents based on the results of fluorescence polarity studies.