Some heterocyclic azo dyes derived from thiazolyl derivatives; Synthesis; substituent effects and solvatochromic studies

摘要

A series of azo disperse dyes were synthesized by coupling reaction of N,N-diethylaniline, 2-anilinoethanol and N-phenyl-2,2′-iminodiethanol with diazotized aminothiazolyl derivatives as diazo components. These dyes have been prepared in good yields, and were characterized by UV-Vis, FT-IR and ~1H NMR spectroscopic techniques. The effects of solvent polarity and various pH on dyes in the visible absorption spectra were evaluated. All dyes exhibit an excellent correlation coefficient (r > 0.92) for the linear solvation energy relationship with π* values calculated by Kamlet et al. The influence of the pH on the dyes with electron-donating group implied that these dyes exist in acid-base equilibrium in acidic environment. The effect of substituents of both coupler and diazo component on the color of dyes was investigated as well.