OH和NO3自由基以及O3与1,4-噻烷和1,4-二噻烷的气相反应动力学
Kinetics of the gas-phase reactions of OH and NO3 radicals and O3 with 1,4-thioxane and 1,4-dithiane.
作者信息
Aschmann Sara M, Long William D, Atkinson Roger
机构信息
Air Pollution Research Center, University of California, Riverside, California 92521, USA.
出版信息
J Phys Chem A. 2008 Dec 25;112(51):13556-65. doi: 10.1021/jp8074018.
Rate constants for the gas-phase reactions of the cyclic organosulfur compounds 1,4-thioxane and 1,4-dithiane with NO(3) radicals and O(3) have been measured at 296 +/- 2 K, and rate constants for their reactions with OH radicals have been measured over the temperature range 278-350 K. Relative rate methods were used to measure rate constants for the OH radical and NO(3) radical reactions. The OH radical reaction in the presence of NO(x) and, to a lesser extent, the NO(3) radical reaction were subject to secondary reactions leading to additional removal of 1,4-thioxane and/or 1,4-dithiane. The rate constants obtained for the NO(3) radical and O(3) reactions at 296 +/- 2 K were (5.1 +/- 1.1) x 10(-14) cm(3) molecule(-1) s(-1) and <2 x 10(-19) cm(3) molecule(-1) s(-1), respectively, for 1,4-thioxane and (5.9 +/- 1.8) x 10(-14) cm(3) molecule(-1) s(-1) and <2.5 x 10(-19) cm(3) molecule(-1) s(-1), respectively, for 1,4-dithiane. For the OH radical reactions, the temperature-dependent rate expressions obtained were k(OH + 1,4-thioxane) = 2.54 x 10(-12) e((619+/-51)/T) cm(3) molecule(-1) s(-1) (278-349 K) and k(OH + 1,4-dithiane) = 3.71 x 10(-12) e((621+/-163)/T) cm(3) molecule(-1) s(-1) (278-350 K), with 298 K rate constants of (2.03 +/- 0.41) x 10(-11) cm(3) molecule(-1) s(-1) for 1,4-thioxane and (2.98 +/- 0.75) x 10(-11) cm(3) molecule(-1) s(-1) for 1,4-dithiane. For the experimental conditions employed, aerosol formation from the OH radical-initiated reactions of both 1,4-thioxane and 1,4-dithiane was important, accounting for approximately 60% of the organosulfur compounds reacted in both the presence and absence of NO(x). The data obtained here for 1,4-thioxane and 1,4-dithiane are compared with literature data for the corresponding reactions of simple acyclic alkyl sulfides and ethers.
已在296±2 K下测量了环状有机硫化合物1,4 - 噻烷和1,4 - 二噻烷与NO₃自由基及O₃的气相反应速率常数，并在278 - 350 K温度范围内测量了它们与OH自由基的反应速率常数。采用相对速率法测量OH自由基和NO₃自由基反应的速率常数。在有NOₓ存在时的OH自由基反应，以及在较小程度上NO₃自由基反应，会发生副反应，导致1,4 - 噻烷和/或1,4 - 二噻烷进一步去除。在296±2 K下，1,4 - 噻烷与NO₃自由基和O₃反应的速率常数分别为(5.1±1.1)×10⁻¹⁴ cm³·分子⁻¹·s⁻¹和<2×10⁻¹⁹ cm³·分子⁻¹·s⁻¹，1,4 - 二噻烷与NO₃自由基和O₃反应的速率常数分别为(5.9±1.8)×10⁻¹⁴ cm³·分子⁻¹·s⁻¹和<2.5×10⁻¹⁹ cm³·分子⁻¹·s⁻¹。对于OH自由基反应，得到的温度依赖速率表达式为k(OH + 1,4 - 噻烷)= 2.54×10⁻¹² e((619±51)/T) cm³·分子⁻¹·s⁻¹(278 - 349 K)和k(OH + 1,4 - 二噻烷)= 3.71×10⁻¹² e((621±163)/T) cm³·分子⁻¹·s⁻¹(278 - 350 K)，1,4 - 噻烷在298 K时的速率常数为(2.03±0.41)×10⁻¹¹ cm³·分子⁻¹·s⁻¹，1,4 - 二噻烷在298 K时的速率常数为(2.98±0.75)×10⁻¹¹ cm³·分子⁻¹·s⁻¹。在所采用的实验条件下，1,4 - 噻烷和1,4 - 二噻烷由OH自由基引发反应形成气溶胶很重要，在有和没有NOₓ存在的情况下，这两种有机硫化合物反应中约60%是由此导致的。将此处得到的1,4 - 噻烷和1,4 - 二噻烷的数据与文献中简单无环烷基硫化物和醚相应反应的数据进行了比较。
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