ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

OH-initiated oxidation mechanism and kinetics of organic sunscreen benzophenone-3: A theoretical study

Ming-Guo Peng, Hua-Jie Li, Er-Deng Du, Hong-Qi Feng, Juan-Lin Wang, Dong-Dong Li, and Jing Zhou

^aSchool of Environmental and Safety Engineering, Changzhou University, Changzhou 213164, China

E-mail: duerdeng@cczu.edu.cn

Abstract: Benzophenone-3 (BP-3), as an important organic UV filter, is widely used in the sunscreen, cosmetic, and personal care products. The chemical reaction mechanism and kinetics of BP-3 degradation initiated by hydroxyl (OH) radical was investigated in the atmosphere based on the density functional theory (DFT). The results showed that the OH radical is more easily added to the C3 position of the aromatic ring (pathway 3), while the H atom abstraction from the OH group on the aromatic ring (pathway 23) is an energetically favorable reaction pathway. At ambient temperature, 298 K, the overall rate constant for the primary reaction is about 1.50 × 10⁻¹⁰ cm³ mol ⁻¹ s⁻¹ with the lifetime of 1.92 h. OH addition reactions play the key role in the OH-initiated reaction of BP-3. The study is helpful for better understanding of the removal, transformation, and fate of BP-3 in the atmosphere.

Keywords: OH radical – benzophenone-3 (BP-3) – mechanism and kinetics – organic sunscreen – quantum calculation

Full paper is available at www.springerlink.com.

DOI: 10.1515/chempap-2016-0003

Chemical Papers 70 (6) 856–868 (2016)