The photo-oxidation reaction of ethyl methacrylate (EMA) initiated by Cl atoms were explored in the Earth’s tropospheric conditions using experimental as well as computational methodologies. The experiments were performed to measure the rate coefficients of the title reaction over the temperature range of 268−363 K by the relative rate method. The rate coefficients for the title reaction were measured relative to 1, 3 butadiene and trans-2-butene. The rate coefficient for the title reaction at 298 K was experimentally measured to be k_EMA+Cl^{Exp − 298 K} = (2.80 ± 0.80) × 10⁻¹⁰ cm³ molecule⁻¹ s⁻¹. The derived Arrhenius expression for the title reaction is k_TFEA+Cl^{Exp − (268−363K)}= (2.32 ± 0.20) × 10⁻¹¹ exp [(696 ± 54)/T] cm³ molecule⁻¹ s⁻¹. Computational calculations were performed at CCSD(T)//MP2/6-31+G(d, p) level of theory using canonical variational transition state theory (CVT) with small curvature tunneling (SCT) in the temperatures between 200 and 400 K. The degradation mechanism initiated by Cl atoms was proposed for the title reaction based on the qualitative analysis of the products. The important atmospheric parameters such as atmospheric lifetimes, global warming potentials, and photochemical ozone creation potentials, thermochemistry and branching ratios of the test reaction are presented in the manuscript.

中文翻译：

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Cl原子在气相中引发的甲基丙烯酸乙酯的对流层光氧化：动力学和机理研究

在地球的对流层条件下，使用实验和计算方法研究了由Cl原子引发的甲基丙烯酸乙酯（EMA）的光氧化反应。进行了实验，通过相对速率法测量了在268-363 K温度范围内标题反应的速率系数。相对于1、3丁二烯和反式-2-丁烯测量标题反应的速率系数。通过实验测量在298 K下标题反应的速率系数为k _{EMA + Cl} ^{Exp -298 K} =（2.80±0.80）×10 ^-10 cm ³分子^-1 s ^-1。导出的标题反应的Arrhenius表达式为k_{TFEA +氯}^{精通- （268-363K）} =（2.32±0.20）×10 ^-11 EXP [（696±54）/ Ť ]厘米³分子^-1小号^-1。在200至400 K的温度下，使用具有小曲率隧穿（SCT）的规范变分过渡状态理论（CVT），以CCSD（T）// MP2 / 6-31 + G（d，p）的理论水平进行了计算计算。在对产物进行定性分析的基础上，提出了由Cl原子引发的降解机理。手稿中介绍了重要的大气参数，例如大气寿命，全球变暖潜势和光化学臭氧生成潜势，热化学和测试反应的支化比。