Design, Synthesis, and Evaluation of Dyeing Properties of 7-Hydroxy-4-Substituted Coumarin Dyes

The study focuses on the synthesis, characterization, and performance evaluation of a series of coumarin-based dyes, specifically 3-(thiazole/benzothiazole/naphthalene/anthracene)-7-hydroxy-4-substituted-2H-chromen-2-one derivatives (1, 3, 2a-d, 4a-d). These compounds were synthesized and thoroughly characterized using 1H NMR, 13C NMR, IR spectroscopy, and HRMS. The synthesized dyes were tested for their ability to dye various fabrics, including cotton, polyester, and wool. The dyes demonstrated a range of color strengths on polyester fabric, with some showing exceptional dyeing performance. The color values for the dyes on polyester were found on dyes (1, 2a-d) 1.00, 1.02, 3.55, 2.01, 1.55, and dyes (3, 4a-d) 1.59, 2.02, 2.25, 5.55. These results indicate that the synthesized dyes generally provided good to excellent dyeing performance on polyester, outperforming methyl orange, a common reference dye. The dyes were also evaluated for light fastness, sublimation resistance, and perspiration resistance on the fabrics. The results showed that the dyes exhibited moderate to excellent performance in durability and color retention under various conditions. These dyes were further evaluated for their antibacterial and water-testing properties. These results were compared for the dye solutions before and after the dyeing process, helping to evaluate the environmental consequences of using these dyes.