Université de Lille Nord de France, F-59000, Lille, France.
J Phys Chem A. 2011 Aug 25;115(33):9160-8. doi: 10.1021/jp205595c. Epub 2011 Aug 4.
The kinetics of the overall reaction between OH radicals and 2,3-pentanedione (1) were studied using both direct and relative kinetic methods at laboratory temperature. The low pressure fast discharge flow experiments coupled with resonance fluorescence detection of OH provided the direct rate coefficient of (2.25 ± 0.44) × 10(-12) cm(3) molecule(-1) s(-1). The relative-rate experiments were carried out both in a collapsible Teflon chamber and a Pyrex reactor in two laboratories using different reference reactions to provide the rate coefficients of 1.95 ± 0.27, 1.95 ± 0.34, and 2.06 ± 0.34, all given in 10(-12) cm(3) molecule(-1) s(-1). The recommended value is the nonweighted average of the four determinations: k(1) (300 K) = (2.09 ± 0.38) × 10(-12) cm(3) molecule(-1) s(-1), given with 2σ accuracy. Absorption cross sections for 2,3-pentanedione were determined: the spectrum is characterized by two wide absorption bands between 220 and 450 nm. Pulsed laser photolysis at 351 nm was used and the depletion of 2,3-pentanedione (2) was measured by GC to determine the photolysis quantum yield of Φ(2) = 0.11 ± 0.02(2σ) at 300 K and 1000 mbar synthetic air. An upper limit was estimated for the effective quantum yield of 2,3-pentanedione applying fluorescent lamps with peak wavelength of 312 nm. Relationships between molecular structure and OH reactivity, as well as the atmospheric fate of 2,3-pentanedione, have been discussed.
研究了 OH 自由基与 2,3-戊二酮（1）之间的总反应动力学，使用直接和相对动力学方法在实验室温度下进行。低压快速放电流动实验与 OH 的共振荧光检测相结合，提供了直接的（2.25 ± 0.44）×10(-12) cm(3) 分子(-1) s(-1)的速率系数。相对速率实验在两个实验室的可折叠聚四氟乙烯室和 Pyrex 反应器中进行，使用不同的参考反应来提供 1.95 ± 0.27、1.95 ± 0.34 和 2.06 ± 0.34 的速率系数，所有这些都以 10(-12) cm(3) 分子(-1) s(-1)给出。推荐值是四个测定值的非加权平均值：k(1)（300 K）=（2.09 ± 0.38）×10(-12) cm(3) 分子(-1) s(-1)，给出了 2σ 精度。确定了 2,3-戊二酮的吸收截面：该光谱的特征是在 220 至 450nm 之间有两个宽吸收带。使用 351nm 的脉冲激光光解，通过 GC 测量 2,3-戊二酮（2）的消耗来确定在 300 K 和 1000 mbar 合成空气中的光解量子产率 Φ(2) = 0.11 ± 0.02（2σ）。应用峰值波长为 312nm 的荧光灯，估计了 2,3-戊二酮的有效量子产率的上限。讨论了分子结构与 OH 反应性之间的关系，以及 2,3-戊二酮在大气中的命运。
