Thermochemistry and Kinetics of the Atmospheric Oxidation Reactions of Propanesulfinyl Chloride Initiated by OH Radicals: A Computational Approach
Thermochemistry and Kinetics of the Atmospheric Oxidation Reactions of Propanesulfinyl Chloride Initiated by OH Radicals: A Computational Approach
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OH 自由基引发的丙亚磺酰氯大气氧化反应的热化学和动力学：一种计算方法
DOI：
10.1021/acs.jpca.2c01203
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发表时间：
2022
期刊：
影响因子：
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通讯作者：
Musah, Rabi A.
中科院分区：
文献类型：
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作者：
Arathala, Parandaman;Musah, Rabi A.
采用高水平量子化学计算和多能阱反应（Mesmer）动力学Master方程求解程序，研究了丙烷亚磺酰氯（CH 3-CH 2-CH 2-S（CH 2 O）Cl; PSICl）在羟基自由基（OH）引发下的大气氧化反应机理. PSICl在OH自由基存在下的氧化机理可以通过H-提取和取代途径进行。CCSD（T）/aug-cc-pV（T+d）Z//MP2/aug-cc-pV（T+d）Z能级计算的能量显示，OH自由基与亚磺酰基（−S（CH 2 O））部分的S原子加成，随后Cl-S（CH 2 O）单键断裂，导致丙烷亚磺酸（PSIA）形成，与所有其他可能的通道相比，Cl自由基是主要途径。该反应的过渡态势垒高度相对于起始PSICl + OH自由基反应物的能量为−3.0 kcal mol-1。在200-320 K的大气相关温度范围内和在1个大气压下，计算所有可能的路径的速率系数。在298 K和1 atm下，PSICl + OH自由基反应生成PSIA + Cl自由基的速率系数为8.2 × 10- 12 cm-3 molecule-1 s-1。从支化比计算，它表明，在PSIA + Cl自由基的形成导致的反应贡献了约52%的总反应。计算了PSICl + OH反应的总速率系数，在298 K和1 atm下为1.6 × 10- 11 cm-3 molecule-1 s-1。总的来说，结果表明，PSICl的大气寿命为12-20小时，在200和320 K之间的温度范围内，这表明它对全球变暖的贡献是微不足道的。然而，其降解产物主要是通过与OH自由基的相互作用而形成的，其中SO2、Cl自由基、HO 2自由基和丙烯等对酸雨、二次有机气溶胶、臭氧层和全球气候变暖有重要影响。
The thermochemistry and kinetics of the atmospheric oxidation mechanism for propanesulfinyl chloride (CH3–CH2–CH2–S(═O)Cl; PSICl) initiated by the hydroxyl (OH) radical were investigated with high level quantum chemistry calculations and the Master equation solver for multi-energy well reaction (Mesmer) kinetic code. The mechanism for the oxidation of PSICl in the presence of OH radical can proceed via H-abstraction and substitution pathways. The CCSD(T)/aug-cc-pV(T+d)Z//MP2/aug-cc-pV(T+d)Z level calculated energies revealed addition of the OH radical to the S-atom of the sulfinyl (−S(═O)) moiety, followed by cleavage of the Cl–S(═O) single bond, leading to formation of propanesulfinic acid (PSIA) and the Cl radical to be the major pathway when compared to all other possible channels. The transition state barrier height for this reaction was found to be −3.0 kcal mol–1relative to the energy of the starting PSICl + OH radical reactants. The rate coefficients were calculated for all possible paths in the atmospherically relevant temperature range of 200–320 K and at 1 atm. The rate coefficient for the formation of the PSIA + Cl radical from the PSICl + OH radical reaction was found to be 8.2 × 10–12cm3molecule–1s–1at 298 K and a pressure of 1 atm. From branching ratio calculations, it was revealed that the reaction resulting in the formation of the PSIA + Cl radical contributed ∼52% to the total reaction. The overall rate coefficient for the PSICl + OH reaction was also calculated and found to be 1.6 × 10–11cm3molecule–1s–1at 298 K and a pressure of 1 atm. In the aggregate, the results indicate the atmospheric lifetime of PSICl to be ∼12–20 h in the temperature range between 200 and 320 K, which suggests that its contribution to global warming is negligible. However, the degradation products revealed to be formed in its interactions with the OH radical, which include that SO2, Cl radical, HO2radical, and propylene have significant effects on the formation of acid rain, secondary organic aerosols, the ozone layer, and global warming.