乙基过氧化物的单分子分解：从头算/Rice-Ramsperger-Kassel-Marcus 理论预测速率常数。

Unimolecular decomposition of ethyl hydroperoxide: ab initio/Rice-Ramsperger-Kassel-Marcus theoretical prediction of rate constants.

机构信息

National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui, People's Republic of China.

出版信息

J Phys Chem A. 2011 Feb 10;115(5):602-11. doi: 10.1021/jp1099305. Epub 2011 Jan 5.

DOI:10.1021/jp1099305

PMID:21207985

Abstract

Alkyl hydroperoxides are found to be important intermediates in the combustion and oxidation processes of hydrocarbons. However, studies of ethyl hydroperoxide (CH(3)CH(2)OOH) are limited. In this work, kinetics and mechanisms for unimolecular decomposition of CH(3)CH(2)OOH have been investigated. The potential energy surface of decomposition reactions have first been predicted at the CCSD(T)/6-311+G(3df,2p)//B3LYP/6-311G(d,p) level. The results show that the formation of CH(3)CH(2)O + OH via O-O direct bond dissociation is dominant, the branching ratio of which is over 99% in the whole temperature range from 300 to 1000 K, and its rate constant can be expressed as k1 = 9.26 × 10(52)T(-11.91)exp(-26879/T) s(-1) at 1 atm. The rate constants of the reaction CH(3)CH(2)OOH → CH(3)CH(2)O + OH at different temperatures and pressures have been calculated, which can help us to comprehend the reactions of CH(3)CH(2)OOH at experimental conditions.

摘要

过氧烷基氢是碳氢化合物燃烧和氧化过程中的重要中间体。然而，对于乙基过氧化物（CH(3)CH(2)OOH）的研究有限。在这项工作中，研究了 CH(3)CH(2)OOH 的单分子分解的动力学和机理。首先在 CCSD(T)/6-311+G(3df,2p)//B3LYP/6-311G(d,p)水平下预测了分解反应的势能面。结果表明，通过 O-O 直接键离解形成 CH(3)CH(2)O + OH 是主要的，在 300 到 1000 K 的整个温度范围内，其分支比超过 99%，其速率常数可以表示为 k1 = 9.26 × 10(52)T(-11.91)exp(-26879/T) s(-1)在 1 atm 下。计算了不同温度和压力下反应 CH(3)CH(2)OOH → CH(3)CH(2)O + OH 的速率常数，这有助于我们理解实验条件下 CH(3)CH(2)OOH 的反应。