Mairean Ciprian-Paul, Roman Claudiu, Arsene Cecilia, Bejan Iustinian-Gabriel, Olariu Romeo-Iulian
Department of Chemistry, Faculty of Chemistry, "Alexandru Ioan Cuza" University of Iasi, 11 Carol I, 700506 Iasi, Romania.
Integrated Centre of Environmental Science Studies in the North Eastern Region (CERNESIM), "Alexandru Ioan Cuza" University of Iasi, 11 Carol I, 700506 Iasi, Romania.
J Phys Chem A. 2025 Apr 24;129(16):3696-3708. doi: 10.1021/acs.jpca.5c01004. Epub 2025 Apr 9.
This relative kinetic study presents the experimental results obtained from the investigation of the gas-phase ozonolysis of seven biogenic unsaturated hexenyl esters under atmospheric relevant conditions at a temperature of (298 ± 2) K and a total air pressure of (1000 ± 10) mbar. Various -3-hexenyl esters were selected for the present study since these are ubiquitous biogenic atmospheric constituents emitted by green leaf plants. The series consists of -3-hexenyl formate (3HF), -3-hexenyl acetate (3HAc), -3-hexenyl isobutyrate (3HiB), -3-hexenyl 3-methylbutanoate (3H3MeB), -3-hexenyl hexanoate (3HH), -3-hexenyl -3-hexenoate (3HZ3H), and -3-hexenyl benzoate (3HBz). The obtained experimental gas-phase reaction rate coefficients are as follows (in 10 cm molecule s): (4.5 ± 0.5) for 3HF, (5.5 ± 0.6) for 3HAc, (7.9 ± 0.9) for 3HiB, (11.9 ± 1.3) for 3H3MeB, (15.3 ± 1.7) for 3HH, (22.5 ± 2.5) for 3HZ3H, and (29.1 ± 3.2) for 3HBz, respectively. This study provides the first determination of the gas-phase rate coefficients of ozone with -3-hexenyl isobutyrate, -3-hexenyl 3-methylbutanoate, -3-hexenyl hexanoate, -3-hexenyl -3-hexenoate, and -3-hexenyl benzoate. A comparison of the results with available literature data and structure-activity relationship estimates was performed with emphasis placed on the structural features. The reactivity trend is discussed within this series, and estimates for the photochemical ozone creation potential (POCP) index are provided. Also, the atmospheric average lifetime of the investigated -3-hexenyl esters, with respect to O reaction, and for comparison purposes also to the OH, NO, and Cl driven processes, were evaluated and provided within this study.
这项相对动力学研究展示了在温度为(298±2)K、总气压为(1000±10)毫巴的大气相关条件下，对七种生物源不饱和己烯基酯进行气相臭氧分解研究所得的实验结果。本研究选择了各种-3-己烯基酯，因为它们是绿叶植物排放的普遍存在的生物源大气成分。该系列包括甲酸-3-己烯酯(3HF)、乙酸-3-己烯酯(3HAc)、异丁酸-3-己烯酯(3HiB)、3-甲基丁酸-3-己烯酯(3H3MeB)、己酸-3-己烯酯(3HH)、-3-己烯酸-3-己烯酯(3HZ3H)和苯甲酸-3-己烯酯(3HBz)。所获得的实验气相反应速率系数如下(单位为10⁻¹⁹cm³·molecule⁻¹·s⁻¹)：3HF为(4.5±0.5)，3HAc为(5.5±0.6)，3HiB为(7.9±0.9)，3H3MeB为(11.9±1.3)，3HH为(15.3±1.7)，3HZ3H为(22.5±2.5)，3HBz为(29.1±3.2)。本研究首次测定了臭氧与异丁酸-3-己烯酯、3-甲基丁酸-3-己烯酯、己酸-3-己烯酯、-3-己烯酸-3-己烯酯和苯甲酸-3-己烯酯的气相速率系数。将结果与现有文献数据以及结构-活性关系估算值进行了比较，重点关注结构特征。讨论了该系列中的反应活性趋势，并提供了光化学臭氧生成潜力(POCP)指数的估算值。此外，本研究还评估并给出了所研究的-3-己烯基酯相对于O反应以及为作比较相对于OH、NO和Cl驱动过程的大气平均寿命。
