OH与正丙基溴和异丙基溴气相反应的温度相关动力学研究。

Temperature-dependent kinetics study of the gas-phase reactions of OH with n- and i-propyl bromide.

作者信息

Bryukov Mikhail G, Vidrine Rebecca G, Dellinger Barry

机构信息

Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, USA.

出版信息

J Phys Chem A. 2007 Jul 19;111(28):6197-203. doi: 10.1021/jp072693c. Epub 2007 Jun 27.

DOI:10.1021/jp072693c

PMID:17595069

Abstract

An experimental, temperature-dependent kinetics study of the gas-phase reactions of hydroxyl radical with n-propyl bromide, OH+n-C3H7Br-->products (reaction 1), and i-propyl bromide, OH+i-C3H7Br-->products (reaction 2), has been performed over wide ranges of temperatures 297-725 and 297-715 K, respectively, and at pressures between 6.67 and 26.76 kPa by a pulsed laser photolysis/pulsed laser-induced fluorescence technique. Data sets of absolute bimolecular rate coefficients obtained in this study for reactions 1 and 2 demonstrate no correlation with pressure and exhibit positive temperature dependencies that can be represented with modified three-parameter Arrhenius expressions within their corresponding experimental temperature ranges: k1(T)=(1.32x10(-17))T1.95 exp(+25/T) cm3 molecule(-1) s(-1) for reaction 1 and k2(T)=(1.56x10(-24))T4.18exp(+922/T) cm3 molecule(-1) s(-1) for reaction 2. The present results, which extend the current kinetics data base of reactions 1 and 2 to high temperatures, are compared with those from previous works. On the basis of the present data and available data from previous studies, the following bimolecular rate coefficient temperature dependencies can be recommended for the purpose of kinetic modeling: k1(T)=(1.89x10(-19))T2.54exp(+301/T) cm3 molecule-1 s-1 for reaction 1 in a temperature range 210-725 K, and k2(T)=(2.83x10(-21))T3.1exp(+521/T) cm3 molecule(-1) s(-1) and k2(T)=(4.54x10(-24))T4.03exp(+860/T) cm3 molecule(-1) s(-1) for reaction 2 in temperature ranges 210-480 and 297-715 K, respectively.

摘要

采用脉冲激光光解/脉冲激光诱导荧光技术，分别在297 - 725 K和297 - 715 K的宽温度范围以及6.67至26.76 kPa的压力下，对羟基自由基与正丙基溴（反应1：OH + n-C₃H₇Br → 产物）和异丙基溴（反应2：OH + i-C₃H₇Br → 产物）的气相反应进行了实验性的、与温度相关的动力学研究。本研究中获得的反应1和反应2的绝对双分子速率系数数据集表明，其与压力无关，并呈现出正温度依赖性，在各自相应的实验温度范围内可用修正的三参数阿伦尼乌斯表达式表示：反应1的k1(T) = (1.32×10⁻¹⁷)T¹.⁹⁵ exp( + 25/T) cm³ molecule⁻¹ s⁻¹，反应2的k2(T) = (1.56×10⁻²⁴)T⁴.¹⁸ exp( + 922/T) cm³ molecule⁻¹ s⁻¹。将本研究结果（其将反应1和反应2的当前动力学数据库扩展到了高温）与先前研究的结果进行了比较。基于本研究数据和先前研究的可用数据，为动力学建模目的，可推荐以下双分子速率系数温度依赖性：反应1在210 - 725 K温度范围内的k1(T) = (1.89×10⁻¹⁹)T².⁵⁴ exp( + 301/T) cm³ molecule⁻¹ s⁻¹，反应2在210 - 480 K和297 - 715 K温度范围内的k2(T) = (2.83×10⁻²¹)T³.¹ exp( + 521/T) cm³ molecule⁻¹ s⁻¹和k2(T) = (4.54×10⁻²⁴)T⁴.⁰³ exp( + 860/T) cm³ molecule⁻¹ s⁻¹。