Oxidation reaction mechanism and kinetics between OH radicals and alkyl-substituted aliphatic thiols: H-abstraction pathways

IF 2.1 4区 化学 Q3 CHEMISTRY, PHYSICAL
A. Tahan, A. Shiroudi
{"title":"Oxidation reaction mechanism and kinetics between OH radicals and alkyl-substituted aliphatic thiols: H-abstraction pathways","authors":"A. Tahan, A. Shiroudi","doi":"10.1177/1468678319886129","DOIUrl":null,"url":null,"abstract":"Kinetic rate constants for the oxidation reaction of the hydroxyl radical with CH3SH, C2H5SH, n-C3H7SH, and iso-C3H7SH under inert (Ar) conditions over the temperature range 252–430 K have been studied theoretically using density functional theory along with various exchange–correlation functionals as well as the benchmark CBS-QB3 quantum chemical approach. Bimolecular rate constants were estimated using transition state theory and the statistical Rice–Ramsperger–Kassel–Marcus theory. Comparison with experiment confirms that in the OH addition reaction pathways leading to the related products, the first bimolecular reaction steps have effective negative activation energy barriers. Effective rate constants have been calculated according to a steady-state analysis of a two-step model reaction mechanism. As a consequence of the negative activation energies, pressures higher than 104 bar are required to reach the high-pressure limit. Both from thermodynamic and kinetic viewpoints, the most favorable process here is the oxidation reaction of hydroxyl radicals with n-C3H7SH.","PeriodicalId":20859,"journal":{"name":"Progress in Reaction Kinetics and Mechanism","volume":null,"pages":null},"PeriodicalIF":2.1000,"publicationDate":"2019-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"2","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Progress in Reaction Kinetics and Mechanism","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1177/1468678319886129","RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 2

Abstract

Kinetic rate constants for the oxidation reaction of the hydroxyl radical with CH3SH, C2H5SH, n-C3H7SH, and iso-C3H7SH under inert (Ar) conditions over the temperature range 252–430 K have been studied theoretically using density functional theory along with various exchange–correlation functionals as well as the benchmark CBS-QB3 quantum chemical approach. Bimolecular rate constants were estimated using transition state theory and the statistical Rice–Ramsperger–Kassel–Marcus theory. Comparison with experiment confirms that in the OH addition reaction pathways leading to the related products, the first bimolecular reaction steps have effective negative activation energy barriers. Effective rate constants have been calculated according to a steady-state analysis of a two-step model reaction mechanism. As a consequence of the negative activation energies, pressures higher than 104 bar are required to reach the high-pressure limit. Both from thermodynamic and kinetic viewpoints, the most favorable process here is the oxidation reaction of hydroxyl radicals with n-C3H7SH.
羟基自由基与烷基取代脂肪族硫醇之间的氧化反应机理和动力学:吸氢途径
利用密度泛函理论和各种交换相关泛函以及基准的CBS-QB3量子化学方法,从理论上研究了在惰性(Ar)条件下羟基自由基与CH3SH、C2H5SH、n-C3H7SH和iso-C3H7SH在252-430 K温度范围内的氧化反应的动力学速率常数。利用过渡态理论和统计rice - ramspberger - kassel - marcus理论估计了双分子速率常数。与实验对比证实,在生成相关产物的OH加成反应途径中,第一双分子反应步骤具有有效的负活化能垒。根据两步模型反应机理的稳态分析,计算了反应的有效速率常数。由于活化能为负,需要高于104 bar的压力才能达到高压极限。从热力学和动力学的角度来看,最有利的过程是羟基自由基与n-C3H7SH的氧化反应。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
求助全文
约1分钟内获得全文 求助全文
来源期刊
CiteScore
2.10
自引率
0.00%
发文量
5
审稿时长
2.3 months
期刊介绍: The journal covers the fields of kinetics and mechanisms of chemical processes in the gas phase and solution of both simple and complex systems.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信