Synthesis, Characterization, and Optical Properties of Novel Heterocyclic Azo Dyes and Evaluation of Their Antioxidant Activity as an Active Sunscreen Agent.

We synthesized some novel isoxazole azo derivatives using conventional methods and studied their linear, non‐linear optical properties and antioxidant activity. UV‐Vis spectroscopy revealed absorption bands ranging from 310–470 nm for the obtained compounds. Compounds 3 c and 3 b, for example, showed a large redshift and solvatochromic behavior. NLO analysis results show that compounds exhibit a greater NLO response than the magnitude of urea done by the DFT method. The electrochemical properties of compounds are studied using cyclic voltammetry and results are used for calculation of HOMO and LUMO experimentally. The antioxidant activity of the synthesized azo dyes displayed that 3 c has excellent antioxidant activity with the highest percentage (71.54605 %) of radical inhibition as compared to reference standard Vit‐C. Molecular docking analysis shows that compounds have a strong binding affinity in the range of −7.0 to −4.6 kcal/mol compared to Vit‐C, which has a binding affinity of −3.6 kcal/mol. The sun protection factor performance was determined by UV‐Vis spectroscopy, and results show that compounds are most effective, exhibit a remarkable SPF value, and offer superior sun protection by absorbing UV rays. [ABSTRACT FROM AUTHOR]