Balaganesh M, Dash Manas Ranjan, Rajakumar B
Department of Chemistry, Indian Institute of Technology Madras , Chennai 600036, India.
J Phys Chem A. 2014 Jul 17;118(28):5272-8. doi: 10.1021/jp502963w. Epub 2014 Jul 2.
The rate coefficient for the gas-phase reaction of Cl atoms with ethyl formate was measured over the temperature range of 268-343 K using relative rate methods, with ethyl chloride as a reference compound. The temperature dependent relative rate coefficients for the ethyl formate + Cl reaction were measured, and the modified Arrhenius expression kethyl formate(268-343) = (2.54 ± 0.57) × 10(-23) T(4.1) exp {-(981 ± 102)/T} cm(3) molecule(-1) s(-1) was obtained with 2σ error limits. The room temperature rate coefficient for the title reaction is (9.84 ± 0.79) × 10(-12) cm(3) molecule(-1) s(-1), which is in good agreement with reported values. To complement the experimental measurement, computational methods were used to calculate the rate coefficient for the ethyl formate + Cl reaction atoms using canonical variational transition state theory (CVT) with small curvature tunneling (SCT) and the CCSD (T)/cc-pVDZ//M062X/6-31+g(d,p) level of theory. The temperature dependent Arrhenius expression was obtained to be 2.97 × 10(-18) T(2.4) exp[-(390/T)] cm(3) molecule(-1) s(-1) over the temperature range of 200-400 K. The thermodynamic parameters and branching ratio were calculated. Also, the atmospheric lifetime and global warming potentials (GWPs) were calculated for ethyl formate.
采用相对速率法，以氯乙烷作为参比化合物，在268 - 343 K的温度范围内测量了氯原子与甲酸乙酯气相反应的速率系数。测定了甲酸乙酯 + Cl反应的温度相关相对速率系数，得到修正的阿伦尼乌斯表达式k甲酸乙酯(268 - 343) = (2.54 ± 0.57) × 10(-23) T(4.1) exp {-(981 ± 102)/T} cm(3) molecule(-1) s(-1)，误差限为2σ。本反应的室温速率系数为(9.84 ± 0.79) × 10(-12) cm(3) molecule(-1) s(-1)，与报道值吻合良好。为补充实验测量，采用计算方法，运用正则变分过渡态理论（CVT）结合小曲率隧道效应（SCT）以及CCSD (T)/cc-pVDZ//M062X/6-31+g(d,p)理论水平，计算了甲酸乙酯 + Cl反应原子的速率系数。在200 - 400 K的温度范围内，得到温度相关的阿伦尼乌斯表达式为2.97 × 10(-18) T(2.4) exp[-(390/T)] cm(3) molecule(-1) s(-1)。计算了热力学参数和分支比。此外，还计算了甲酸乙酯的大气寿命和全球变暖潜能值（GWPs）。
