Studies of the reaction processes of atmospheric minor constituents related to the global warming

采用绝对速率法和相对速率法研究了295 2K下6 Torr氩气或800-950 Torr氮气中Cl原子与环己酮的反应性。绝对速率法测得k（Cl+环己酮）=（1.88 ± 0.38）×10^<-10>，相对速率法测得k（Cl+环己酮）=（1.66±026）×10^<-10>cm ^3·<-1>s <-1>^。环己酮具有宽的紫外吸收带，在285 nm附近的最大吸收截面为（4.0±03）×10^-20 cm ^2分子<-1>。本文用绝对（PLP-LIF）和相对速率技术研究了295± 2K，8 Ton氩气或800-950 Ton氮气中Cl + CH_3（CH_2）_3CHO反应的动力学和机理。在8 Ton氩气中，绝对速率实验测得k（Cl + CH_3（CH_2）_3CHO）=（2.31±0.35）×10^<-10>，在800-950 Ton氮气中，相对速率实验测得k（Cl + CH_3（CH_2）_3CHO）=（2.24±0.20）×10^<-10>cm ^3 molecule·<-1>s^<-1>。额外的相对速率实验给出了 关于我们 在700 Ton N_2中，k（Cl+CH_3（CH_2）_3C（O）Cl）=（8.74± 1.38）×10^<-11>cm ^3 molecule^<-1>s^<-1>。烟雾室傅里叶变换红外光谱（F-IR）分析表明，酰基生成通道占反应总能量的42 ± 3%。结果进行了讨论与文献数据和重要性的远程（= 2个碳原子沿沿着脂肪链）在决定有机分子对氯原子的反应性方面的作用。氯原子与丙酮、丁酮、2-戊酮、3-戊酮、2-己酮、3-己酮、用脉冲激光光解真空紫外激光诱导荧光（PLP-LIF）技术研究了295±2 K时环戊酮和环戊酮的光解产物。Cl（^2P_3/_2）原子是由Cl_2在351 nm处光解产生的，并由LIF光谱在134.72 nm处监测（3p^52P_3/^2- 3p^44s^2_3/2跃迁）。氯原子与丙酮、丁酮、2-戊酮、3-戊酮、2-己酮、3-己酮和环戊酮反应的速率系数分别为：（2.30±0.12）×10 -12、（4.08±0.21）×10 - 12<-11>、（1.23± 0.13）× 10 - 12<-10>、（8.87 s-0.92）40 - <-1>12、（2.08±0.32）×10 - 12<-10>、（1.43±0.19）×10 - 12<-10>和（1.16±0.12）×10 - 13 <-10>cm-3 molecule·<-1>s-1<-1>。丙酮和丁酮的结果与以前的研究一致。2-戊酮、3-戊酮、2-己酮和3-己酮的结果比先前绝对速率研究的结果高约2-3倍。这些差异可能的解释进行了讨论。对流层的酮与氯原子反应的寿命进行了估计和讨论。少

Absolute and relative rate techniques were used to study the reactivity of Cl atoms with cyclohexanone in 6 Torr of argon or 800-950 Torr of N2 at 295 2 K The absolute rate experiments gave k(Cl+cyclohexanone) = (1.88 0.38)×10^<-10> while the relative rate experiments gave k(Cl+cyclohexanone) = (1.66±026)×10^<-10> cm^3 molecule^<-1> s^<-1> methods. Cyclohexanone has a broad UV absorption band with a maximum cross section of (4.0±03)×10^-20 cm^2 molecule^<-1> near 285 nm The results are discussed with respect to the literature data.The kinetics and mechanism of the reaction Cl + CH_3 (CH_2)_3CHO was investigated using absolute (PLP-LIF) and relative rate techniques in 8 Ton of argon or 800-950 Ton of N_2 at 295± 2K. The absolute rate experiments gave k(C1 + CH_3(CH_2)_3CHO) = (2.31±0.35)×10^<-10> in 8 Ton of argon while relative rate experiments gave k(CI + CH_3(CH_2)_3CHO) = (2.24±0.20)×10^<-10> cm^3 molecule^<-1> s^<-1> in 800-950 Ton of N_2. Additional relative rate experiments gave … More k(Cl+CH_3(CH_2)_3C(O)CI) = (8.74± 1.38)×10^<-11> cm^3 molecule^<-1> s^<-1> in 700 Ton of N_2. Smog chamber Fourier transform infrared (F IR) techniques indicated that the acyl-forming channel accounts for 42 ± 3% of the reaction. The results are discussed with respect to the literature data and the importance of long range (= 2 carbon atoms along the aliphatic chain) effects in determining the reactivity of organic molecules towards chlorine atoms.The gas-phase reactions of Cl atoms with acetone, butanone, 2-pentanone, 3-pentanone, 2-hexanone, 3-hexanone, and cyclopentanone at 295±2 K were studied using pulsed laser photolysis vacuum UV laser-induced fluorescence (PLP-LIF) techniques. Cl(^2P_3/_2) atoms were produced by photolysis of Cl_2 at 351 nm and monitored by LIF spectroscopy at 134.72 nm (3p^5 2P_3/^2-3p^44s ^2_3/2 transition). Rate coefficients for reactions of Cl atoms with acetone, butanone, 2-pentanone, 3-pentanone, 2-hexanone, 3-hexanone, and cyclopentanone are : (2.30±0.12)×10_-12, (4.08±0.21)×10^<-11>, (1.23±013)-〜10^<-10>, (8.87s-0.92)40^<-1>1, (2.08±0.32)×10^<-10>, (1.43±0.19)×10^<-10> and (1.16±0.12)×10^<-10> cm^3 molecule^<-1>s^<-1>, respectively. The results for acetone and butanone are consistent with previous studies. The results for 2-pentanone, 3-pentanone, 2-hexanone, and 3-hexanone are approximately a factor of 2-3 higher than those from previous absolute rate studies. Likely explanations for these discrepancies are discussed. Tropospheric lifetimes of ketones with respect to reaction with Cl atoms are estimated and discussed. Less