The Cl/OH initiated temperature dependent photo-oxidative reaction kinetics of methyl butyrate (MB) were examined using a relative rate (RR) technique. Gas chromatography with flame ionization and mass spectrometric detection were used to monitor the concentration of the reactants and to identify the products. The temperature dependent kinetics of MB with Cl atoms were measured with respect to the reaction of Cl with C₂H ₆ and C₂H₄. The temperature dependent kinetics for the reaction of MB with OH radicals were measured using n- propanol and iso -propanol as references. The obtained rate coefficients for the Cl and OH reactions with MB are, k Cl(Expt) (T) = [(7.76 ± 0.47) × 10 ⁻¹¹] exp [(10.31 ± 0.20)/T] cm³ molecule⁻¹ s⁻¹ and k OH(Expt) (T) = [(4.32 ± 0.21) × 10 ⁻¹²] exp [-(25.26 ± 0.39)/T] cm³ molecule⁻¹ s⁻¹ respectively. Dual level direct dynamics were used to perform the computational calculations to further elucidate the mechanisms over the studied temperature range. The rate coefficients for H-abstraction reactions were computed using Canonical Variational Transition State Theory with Small Curvature Tunneling (CVT/SCT) with Interpolated Single Point Energies (ISPE) method. The rate coefficients over the studied temperature range yielded the Arrhenius equations: k Cl(Theory) (200–400 K) = [(4.05 ± 0.54) × 10^–11] exp [-(2.80 ± 0.11)/T] cm³ molecule⁻¹ s⁻¹ and k OH(Theory) (200–400 K) = [(1.96 ± 0.68) × 10 -11] exp [-(384 ± 38)/T] cm³ molecule ⁻¹ s ⁻¹. Possible degradation mechanisms for the reactions are proposed based on the observed products. Thermo-chemical parameters, ozone formation potential, branching ratios, and the atmospheric lifetime of MB are calculated to understand the fate of MB in the atmosphere.

使用相对速率 (RR) 技术检查了 Cl/OH 引发的丁酸甲酯 (MB) 的温度依赖性光氧化反应动力学。使用带有火焰离子化和质谱检测的气相色谱来监测反应物的浓度并鉴定产物。MB与Cl原子的温度相关动力学是根据Cl与C ₂ H ₆和C ₂ H ₄的反应测量的。MB与OH自由基反应的温度依赖性动力学使用正丙醇和异丙醇作为参考进行测量。获得的 Cl 和 OH 与 MB 反应的速率系数为 k Cl(Expt) (T) = [(7.76 ± 0.47) × 10 ^-11 ] exp [(10.31 ± 0.20)/T] cm³分子^-1  s ^-1和 k OH(Expt) (T) = [(4.32 ± 0.21) × 10 ^-12 ] exp [-(25.26 ± 0.39)/T] cm ³分子^-1  s ^-1。使用双能级直接动力学进行计算计算，以进一步阐明研究温度范围内的机制。H-抽象反应的速率系数使用具有小曲率隧道的典型变分过渡态理论 (CVT/SCT) 和内插单点能量 (ISPE) 方法计算。所研究温度范围内的速率系数产生了 Arrhenius 方程： k Cl(Theory) (200–400 K) = [(4.05 ± 0.54) × 10 ^–11 ] exp [-(2.80 ± 0.11)/T] cm³分子^-1  s ^-1和 k OH(理论) (200–400 K) = [(1.96 ± 0.68) × 10 -11] exp [-(384 ± 38)/T] cm ³分子^-1  s ^-1 . 基于观察到的产物提出了反应的可能降解机制。计算热化学参数、臭氧形成潜力、支化率和 MB 在大气中的寿命，以了解 MB 在大气中的命运。