School of Public and Environmental Affairs, Indiana University, Bloomington, Indiana 47405, USA.
J Phys Chem A. 2011 Feb 3;115(4):500-6. doi: 10.1021/jp111173s. Epub 2010 Dec 17.
The rate constants for the gas-phase reactions of hydroxyl radicals and ozone with the biogenic hydrocarbons β-ocimene, β-myrcene, and α- and β-farnesene were measured using the relative rate technique over the temperature ranges 313-423 (for OH) and 298-318 K (for O₃) at about 1 atm total pressure. The OH radicals were generated by photolysis of H₂O₂, and O₃ was produced from the electrolysis of O₂. Helium was used as the diluent gas. The reactants were detected by online mass spectrometry, which resulted in high time resolution, allowing large amounts of data to be collected and used in the determination of the Arrhenius parameters. The following Arrhenius expressions have been determined for these reactions (in units of cm³ molecules⁻¹ s⁻¹): for β-ocimene + OH, k = (4.35(-0.66)(+0.78)) × 10⁻¹¹ exp[(579 ± 59)/T]; for β-ocimene + O₃, k = (3.15(-0.95)(+1.36)) × 10⁻¹⁵ exp[-(626 ± 110)/T]; for β-myrcene + O₃, k = (2.21(-0.66)(+0.94)) × 10⁻¹⁵ exp[-(520 ± 109)/T]; for α-farnesene + OH, k(OH) = (2.19 ± 0.11) × 10⁻¹⁰ for 23-413 K; for α-farnesene + O₃, k = (3.52(-2.54)(+9.09)) × 10⁻¹² exp[-(2589 ± 393)/T]; for β-farnesene + OH, k(OH) = (2.88 ± 0.15) × 10⁻¹⁰ for 323-423 K; for β-farnesene + O₃, k = (1.81(-1.19)(+3.46)) × 10⁻¹² exp[-(2347 ± 329)/T]. The Arrhenius parameters here are the first to be reported. The reactions of α- and β-farnesene with OH showed no significant temperature dependence. Atmospheric residence times due to reactions with OH and O₃ were also presented.
用相对速率法在 313-423 K（用于 OH）和 298-318 K（用于 O₃）的温度范围内，在约 1 个大气压的总压力下，测量了羟基自由基和臭氧与生物源碳氢化合物β-罗勒烯、β-松油烯和α-和β-法呢烯在气相中的反应速率常数。羟基自由基由 H₂O₂的光解产生，O₃由 O₂的电解产生。氦气用作稀释气体。反应物通过在线质谱法检测，这导致了高时间分辨率，允许收集大量数据并用于确定阿仑尼乌斯参数。已经为这些反应确定了以下阿仑尼乌斯表达式（单位为 cm³分子⁻¹ s⁻¹）：对于β-罗勒烯+OH，k =（4.35（-0.66）（+0.78））×10⁻¹¹ exp[(579 ± 59)/T]；对于β-罗勒烯+O₃，k =（3.15（-0.95）（+1.36））×10⁻¹⁵ exp[-(626 ± 110)/T]；对于β-松油烯+O₃，k =（2.21（-0.66）（+0.94））×10⁻¹⁵ exp[-(520 ± 109)/T]；对于α-法呢烯+OH，k（OH）=（2.19 ± 0.11）×10⁻¹⁰ 用于 23-413 K；对于α-法呢烯+O₃，k =（3.52（-2.54）（+9.09））×10⁻¹² exp[-(2589 ± 393)/T]；对于β-法呢烯+OH，k（OH）=（2.88 ± 0.15）×10⁻¹⁰ 用于 323-423 K；对于β-法呢烯+O₃，k =（1.81（-1.19）（+3.46））×10⁻¹² exp[-(2347 ± 329)/T]。这里报告的是第一个阿仑尼乌斯参数。α-和β-法呢烯与 OH 的反应没有明显的温度依赖性。还提出了由于与 OH 和 O₃ 的反应而导致的大气停留时间。
