Theoretical study of tautomers and photoisomers of avobenzone by DFT methods.

Organic ultraviolet (UV) filters such as cinnamates, benzophenones, p-aminobenzoic derivatives, and avobenzone (which have well-established and recognized UV-filtering efficacies) are employed in cosmetic/pharmaceutical products to minimize the harm caused by exposure of the skin to sunlight. In this study, a detailed investigation of the photostability and tautomerism mechanisms of avobenzone was performed utilizing DFT methods. The UV spectral profile of avobenzone was also simulated, and the results showed good agreement with experimental data. Furthermore, the calculations were able to distinguish tautomers and photoisomers of the studied organic filter based on their properties, thus showing the potential to develop new organic UV filters. Graphical Abstract Theoretical studies of avobenzone and its tautomers by TD-DFT.