Static studies of absorption and emission spectra of acid yellow 17-An azo dye

In the present paper, the absorption and emission spectra of acid yellow 17 (C₁₆H₁₀C_l2N₄Na₂O₇S₂), a fluorescent azo dye, have been recorded in water at concentrations between 10^-3 M and 10^-6 M. This dye is used in many scientific and industrial applications. This has led to the determination of optimum concentrations to record the absorption and emission spectra of the molecule. The absorption spectrum shows three peaks at 224, 254 and 400 nm, recorded in the spectral region 200-600 nm, which have been assigned to (π* ← π ) ¹La* ←¹A (primary), (π*←n)¹ 1L_b ←¹A (secondary) and (π* ← n)¹ W ←¹A transitions, respectively. Emission spectra of the compound show four peaks at 295, 306, 412 and 437 nm corresponding to absorption peaks at 224, 254 and 400 nm. Their corresponding Stokes shifts have also been determined.