Reactions of OH with Butene Isomers: Measurements of the Overall Rates and a Theoretical Study

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• 作者：Subith S. Vasu ; Lam K. Huynh ; David F. Davidson ; Ronald K. Hanson ; David M. Golden
• 刊名：Journal of Physical Chemistry A
• 出版年：2011
• 出版时间：March 31, 2011
• 年：2011
• 卷：115
• 期：12
• 页码：2549-2556
• 全文大小：915K
• 年卷期：v.115,no.12(March 31, 2011)
• ISSN：1520-5215

文摘

Reactions of hydroxyl (OH) radicals with 1-butene (k₁), trans-2-butene (k₂), and cis-2-butene (k₃) were studied behind reflected shock waves over the temperature range 880鈭?341 K and at pressures near 2.2 atm. OH radicals were produced by shock-heating tert-butyl hydroperoxide, (CH₃)₃鈭扖O鈭扥H, and monitored by narrow-line width ring dye laser absorption of the well-characterized R₁(5) line of the OH A鈭扻 (0, 0) band near 306.7 nm. OH time histories were modeled using a comprehensive C₅ oxidation mechanism, and rate constants for the reaction of OH with butene isomers were extracted by matching modeled and measured OH concentration time histories. We present the first high-temperature measurement of OH + cis-2-butene and extend the temperature range of the only previous high-temperature study for both 1-butene and trans-2-butene. With the potential energy surface calculated using CCSD(T)/6-311++G(d,p)//QCISD/6-31G(d), the rate constants and branching fractions for the H-abstraction channels of the reaction of OH with 1-butene were calculated in the temperature range 300鈭?500 K. Corrections for variational and tunneling effects as well as hindered-rotation treatments were included. The calculations are in good agreement with current and previous experimental data and with a recent theoretical study.