Air Pollution Research Center and Department of Environmental Sciences, University of California Riverside, California 92521, USA.
J Phys Chem A. 2010 May 13;114(18):5810-6. doi: 10.1021/jp101893g.
Using a relative rate method, rate constants have been measured for the reactions of OH radicals with 4,4-dimethyl-1-pentene [(CH(3))(3)CCH(2)CH=CH(2)] and its major reaction product, 3,3-dimethylbutanal [(CH(3))(3)CCH(2)CHO], at 296 +/- 2 K and atmospheric pressure of air. The rate constants obtained were 2.41 x 10(-11) and 2.73 x 10(-11) cm(3) molecule(-1) s(-1), respectively, with estimated uncertainties of +/-10%. The products identified and quantified by gas chromatography with mass spectrometry and/or flame ionization detection from the 4,4-dimethyl-1-pentene reaction were acrolein [CH(2)=CHCHO], 3,3-dimethylbutanal, and a molecular weight 112 carbonyl attributed to 4,4-dimethyl-2-pentenal [(CH(3))(3)CCH=CHCHO], with formation yields of 2.7 +/- 0.5%, 59 +/- 6%, and 3.4 +/- 0.6%, respectively. Using direct air sampling atmospheric pressure ionization mass spectrometry, additional products of molecular weight 146, 177, and 193 were observed, and on the basis of expected reaction schemes these are attributed to the dihydroxycarbonyl HOCH(2)C(CH(3))(2)CH(2)C(O)CH(2)OH, the hydroxynitrates (CH(3))(3)CCH(2)CH(OH)CH(2)ONO(2) and/or (CH(3))(3)CCH(2)CH(ONO(2))CH(2)OH, and the dihydroxynitrate O(2)NOCH(2)C(CH(3))(2)CH(2)CH(OH)CH(2)OH, respectively. The hydroxynitrates were also tentatively identified by gas chromatography, with a summed yield of approximately 15%. Acrolein and 4,4-dimethyl-2-pentenal arise from H-atom abstraction from the three equivalent CH(3) groups and the 3-position CH(2) group, and the sum of their formation yields (6.1 +/- 0.8%) is expected to be very close to the fraction of the overall reaction proceeding by H-atom abstraction.
使用相对速率法，在 296 ± 2 K 和大气压力下测量了 OH 自由基与 4,4-二甲基-1-戊烯[(CH(3))(3)CCH(2)CH=CH(2)]及其主要反应产物 3,3-二甲基丁醛[(CH(3))(3)CCH(2)CHO]的反应速率常数。得到的速率常数分别为 2.41 x 10(-11) 和 2.73 x 10(-11) cm(3) molecule(-1) s(-1)，不确定度约为 10%。通过气相色谱法结合质谱和/或火焰离子化检测，从 4,4-二甲基-1-戊烯反应中鉴定和定量的产物为丙烯醛[CH(2)=CHCHO]、3,3-二甲基丁醛和分子量为 112 的羰基，归因于 4,4-二甲基-2-戊烯醛[(CH(3))(3)CCH=CHCHO]，其生成产率分别为 2.7 ± 0.5%、59 ± 6%和 3.4 ± 0.6%。使用直接空气采样大气压电离质谱法，观察到分子量为 146、177 和 193 的其他产物，根据预期的反应方案，这些产物归因于二羟基羰基 HOCH(2)C(CH(3))(2)CH(2)C(O)CH(2)OH、羟基硝酸盐(CH(3))(3)CCH(2)CH(OH)CH(2)ONO(2)和/或(CH(3))(3)CCH(2)CH(ONO(2))CH(2)OH 和二羟基硝酸盐 O(2)NOCH(2)C(CH(3))(2)CH(2)CH(OH)CH(2)OH。羟基硝酸盐也通过气相色谱法进行了初步鉴定，总生成率约为 15%。丙烯醛和 4,4-二甲基-2-戊烯醛是从三个等效的 CH(3)基团和 3 位 CH(2)基团的 H 原子提取形成的，它们的生成产率之和(6.1 ± 0.8%)预计非常接近通过 H 原子提取进行的总反应分数。
