Rate coefficients for the gas-phase reaction of OH radicals with the L4, L5, D5, and D6 permethylsiloxanes

IF 1.5 4区 化学 Q4 CHEMISTRY, PHYSICAL
François Bernard, James B. Burkholder
{"title":"Rate coefficients for the gas-phase reaction of OH radicals with the L4, L5, D5, and D6 permethylsiloxanes","authors":"François Bernard,&nbsp;James B. Burkholder","doi":"10.1002/kin.21769","DOIUrl":null,"url":null,"abstract":"<p>Rate coefficients, <i>k</i>(T), for the gas-phase OH radical reaction with decamethyltetrasiloxane ((CH<sub>3</sub>)<sub>3</sub>SiO[Si(CH<sub>3</sub>)<sub>2</sub>O]<sub>2</sub>Si(CH<sub>3</sub>)<sub>3</sub>, L<sub>4</sub>, <i>k</i><sub>1</sub>), dodecamethylpentasiloxane ((CH<sub>3</sub>)<sub>3</sub>SiO[Si(CH<sub>3</sub>)<sub>2</sub>O]<sub>3</sub>Si(CH<sub>3</sub>)<sub>3</sub>, L<sub>5</sub>, <i>k</i><sub>2</sub>), and decamethylcyclopentasiloxane ([–Si(CH<sub>3</sub>)<sub>2</sub>O–]<sub>5</sub>, D<sub>5</sub>, <i>k</i><sub>3</sub>), and dodecamethylcyclohexasiloxane ([–Si(CH<sub>3</sub>)<sub>2</sub>O–]<sub>6</sub>, D<sub>6</sub>, <i>k</i><sub>4</sub>) were measured using a pulsed laser photolysis—laser induced fluorescence absolute method over the temperature range 270–370 K. The obtained room temperature rate coefficients, with quoted 2σ absolute uncertainties, and fitted temperature dependence are (cm<sup>−3</sup> molecule<sup>−1</sup> s<sup>−1</sup>):\n\n </p><p>The 2σ absolute rate coefficient uncertainty, for all compounds included in this study, is conservatively estimated to be ∼10% over the entire temperature range. The cyclic permethylsiloxanes were found to be less reactive than the analogous linear compound, while both linear and cyclic compounds show increasing reactivity with increasing number of CH<sub>3</sub>- groups. A structure activity relationship (SAR) parameterization for the permethylsiloxanes is presented. The estimated atmospheric lifetimes due to OH reaction for L<sub>4</sub>, L<sub>5</sub>, D<sub>5</sub>, and D<sub>6</sub> are 5.2, 4.4, 6.8, and 5.2 days, respectively.</p>","PeriodicalId":13894,"journal":{"name":"International Journal of Chemical Kinetics","volume":"57 3","pages":"199-212"},"PeriodicalIF":1.5000,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/kin.21769","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Chemical Kinetics","FirstCategoryId":"92","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/kin.21769","RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0

Abstract

Rate coefficients, k(T), for the gas-phase OH radical reaction with decamethyltetrasiloxane ((CH3)3SiO[Si(CH3)2O]2Si(CH3)3, L4, k1), dodecamethylpentasiloxane ((CH3)3SiO[Si(CH3)2O]3Si(CH3)3, L5, k2), and decamethylcyclopentasiloxane ([–Si(CH3)2O–]5, D5, k3), and dodecamethylcyclohexasiloxane ([–Si(CH3)2O–]6, D6, k4) were measured using a pulsed laser photolysis—laser induced fluorescence absolute method over the temperature range 270–370 K. The obtained room temperature rate coefficients, with quoted 2σ absolute uncertainties, and fitted temperature dependence are (cm−3 molecule−1 s−1):

The 2σ absolute rate coefficient uncertainty, for all compounds included in this study, is conservatively estimated to be ∼10% over the entire temperature range. The cyclic permethylsiloxanes were found to be less reactive than the analogous linear compound, while both linear and cyclic compounds show increasing reactivity with increasing number of CH3- groups. A structure activity relationship (SAR) parameterization for the permethylsiloxanes is presented. The estimated atmospheric lifetimes due to OH reaction for L4, L5, D5, and D6 are 5.2, 4.4, 6.8, and 5.2 days, respectively.

Abstract Image

求助全文
约1分钟内获得全文 求助全文
来源期刊
CiteScore
3.30
自引率
6.70%
发文量
74
审稿时长
3 months
期刊介绍: As the leading archival journal devoted exclusively to chemical kinetics, the International Journal of Chemical Kinetics publishes original research in gas phase, condensed phase, and polymer reaction kinetics, as well as biochemical and surface kinetics. The Journal seeks to be the primary archive for careful experimental measurements of reaction kinetics, in both simple and complex systems. The Journal also presents new developments in applied theoretical kinetics and publishes large kinetic models, and the algorithms and estimates used in these models. These include methods for handling the large reaction networks important in biochemistry, catalysis, and free radical chemistry. In addition, the Journal explores such topics as the quantitative relationships between molecular structure and chemical reactivity, organic/inorganic chemistry and reaction mechanisms, and the reactive chemistry at interfaces.
×
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