Seven new azo disperse dyes based on N-benzyl–N-ethyl–aniline were synthesized and characterized by UV–Vis, FT-IR and 1H NMR spectroscopic techniques. The UV–visible studies and solvatochromic behavior of all dyes in 15 solvents with different polarity were examined and a meaningful correlation was observed. In the optical characterization of dyes using Z-Scan experiment, thin films of polymethyl metacrylate doped with guest ...