Chrysene, a four-ring polycyclic aromatic hydrocarbon (PAH), is recalcitrant to biodegradation and persistent in the environment due to its low water solubility. Here, we investigated the atmospheric degradation process of chrysene initiated by OH radical in the presence of O₂ and NO_X using quantum chemical calculations. The reaction mechanisms were elucidated by density functional theory (DFT) at M06–2X/6–311++G(3df,2p)//M06–2X/6-311+G(d,p) level, and the kinetics calculations were conducted with Rice-Ramsperger-Kassel-Marcus (RRKM) theory. The results show that the oxidation products of atmospheric chrysene are oxygenated PAHs (OPAHs) and nitro-PAHs (NPAHs), including nitro-chrysene, hydroxychrysene, hydroxychrysenone, 11-benzo[a]fluorenone and dialdehydes. Most of the products have deleterious effects on the environment and human beings due to their acute toxicity, carcinogenicity and mutagenicity. The overall rate constant for the reaction of chrysene with OH radical is 4.48 × 10⁻¹¹ cm³ molecule⁻¹ s⁻¹ and the atmospheric lifetime of chrysene determined by OH radical is 6.4 h. The present work provided a comprehensive understanding on the degradation mechanisms and kinetics of chrysene, which could help to clarify its atmospheric fate and environmental risks.

四环多环芳烃（PAH）苯由于其水溶性低而难以生物降解并在环境中持久存在。在这里，我们使用量子化学计算研究了在O ₂和NO _X存在下由OH自由基引发的丙烯在大气中的降解过程。在M06–2X / 6–311 ++ G（3df，2p）// M06–2X / 6-311 + G（d，p）水平上通过密度泛函理论（DFT）阐明了反应机理。使用Rice-Ramsperger-Kassel-Marcus（RRKM）理论进行。结果表明，大气中的氧化产物为氧化型多环芳烃（OPAHs）和硝基多环芳烃（NPAHs），包括硝基苯，羟基苯，羟基苯二酚，11-苯并[ a]。芴酮和二醛。大多数产品由于其急性毒性，致癌性和致突变性，对环境和人类具有有害作用。丙烯与OH自由基反应的总速率常数为4.48×10 ^-11  cm ³分子^-1 s ^-1，由OH自由基测定的丙烯的大气寿命为6.4 h。目前的工作提供了对降解机理和动力学的全面了解，可以帮助阐明其大气命运和环境风险。