OH自由基对丙烷和正丁烷进行一级和二级氢及氘提取的位点特异性速率常数测量
Site-specific rate constant measurements for primary and secondary H- and D-abstraction by OH radicals: propane and n-butane.
作者信息
Badra Jihad, Nasir Ehson F, Farooq Aamir
机构信息
Clean Combustion Research Center, Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology (KAUST) , Thuwal 23955, Saudi Arabia.
出版信息
J Phys Chem A. 2014 Jul 3;118(26):4652-60. doi: 10.1021/jp503849b. Epub 2014 Jun 19.
Site-specific rate constants for hydrogen (H) and deuterium (D) abstraction by hydroxyl (OH) radicals were determined experimentally by monitoring the reaction of OH with two normal and six deuterated alkanes. The studied alkanes include propane (C3H8), propane 2,2 D2 (CH3CD2CH3), propane 1,1,1-3,3,3 D6 (CD3CH2CD3), propane D8 (C3D8), n-butane (n-C4H10), butane 2,2-3,3 D4 (CH3CD2CD2CH3), butane 1,1,1-4,4,4 D6 (CD3CH2CH2CD3), and butane D10 (C4D10). Rate constant measurements were carried out over 840-1470 K and 1.2-2.1 atm using a shock tube and OH laser absorption. Previous low-temperature data were combined with the current high-temperature measurements to generate three-parameter fits which were then used to determine the site-specific rate constants. Two primary (P1,H and P1,D) and four secondary (S00,H, S00,D, S01,H, and S01,D) H- and D-abstraction rate constants, in which the subscripts refer to the number of C atoms connected to the next-nearest-neighbor C atom, are obtained. The modified Arrhenius expressions for the six site-specific abstractions by OH radicals are P1,H = 1.90 × 10(-18)T(2.00) exp(-340.87 K/T) cm(3) molecule(-1) s(-1) (210-1294 K); P1,D = 2.72 × 10(-17) T(1.60) exp(-895.57 K/T) cm(3) molecule(-1) s(-1) (295-1317 K); S00,H = 4.40 × 10(-18) T(1.93) exp(121.50 K/T) cm(3) molecule(-1) s(-1) (210-1294 K); S00,D = 1.45 × 10(-20) T(2.69) exp(282.36 K/T) cm(3) molecule(-1) s(-1) (295-1341 K); S01,H = 4.65 × 10(-17) T(1.60) exp(-236.98 K/T) cm(3) molecule(-1) s(-1) (235-1407 K); S01,D = 1.26 × 10(-18) T(2.07) exp(-77.00 K/T) cm(3) molecule(-1) s(-1) (294-1412 K).
通过监测羟基（OH）自由基与两种普通烷烃和六种氘代烷烃的反应，实验测定了羟基（OH）自由基夺取氢（H）和氘（D）的位点特异性速率常数。所研究的烷烃包括丙烷（C₃H₈）、丙烷-2,2-D₂（CH₃CD₂CH₃）、丙烷-1,1,1-3,3,3-D₆（CD₃CH₂CD₃）、丙烷-D₈（C₃D₈）、正丁烷（n-C₄H₁₀）、丁烷-2,2-3,3-D₄（CH₃CD₂CD₂CH₃）、丁烷-1,1,1-4,4,4-D₆（CD₃CH₂CH₂CD₃）和丁烷-D₁₀（C₄D₁₀）。使用激波管和OH激光吸收在840 - 1470 K和1.2 - 2.1 atm的条件下进行速率常数测量。将先前的低温数据与当前的高温测量数据相结合，生成三参数拟合，然后用于确定位点特异性速率常数。获得了两个一级（P1,H和P1,D）和四个二级（S00,H、S00,D、S01,H和S01,D）H和D夺取速率常数，其中下标表示与次近邻碳原子相连的碳原子数。OH自由基进行的六个位点特异性夺取反应的修正阿伦尼乌斯表达式为：P1,H = 1.90×10⁻¹⁸T².⁰⁰ exp(-340.87 K/T) cm³ molecule⁻¹ s⁻¹（210 - 1294 K）；P1,D = 2.72×10⁻¹⁷ T¹.⁶⁰ exp(-895.57 K/T) cm³ molecule⁻¹ s⁻¹（295 - 1317 K）；S00,H = 4.40×10⁻¹⁸ T¹.⁹³ exp(121.50 K/T) cm³ molecule⁻¹ s⁻¹（210 - 1294 K）；S00,D = 1.45×10⁻²⁰ T².⁶⁹ exp(282.36 K/T) cm³ molecule⁻¹ s⁻¹（295 - 1341 K）；S01,H = 4.65×10⁻¹⁷ T¹.⁶⁰ exp(-236.98 K/T) cm³ molecule⁻¹ s⁻¹（235 - 1407 K）；S01,D = 1.26×10⁻¹⁸ T².⁰⁷ exp(-77.00 K/T) cm³ molecule⁻¹ s⁻¹（294 - 1412 K）。
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