Laura N. Olive, Alexandra D. Heide, Justin M. Turney and Henry F. Schaefer III*,
{"title":"利用高层理论研究乙炔基自由基析氢能量学和动力学","authors":"Laura N. Olive, Alexandra D. Heide, Justin M. Turney and Henry F. Schaefer III*, ","doi":"10.1021/acsearthspacechem.4c00040","DOIUrl":null,"url":null,"abstract":"<p >The ethynyl radical, C<sub>2</sub>H, is found in a variety of different environments ranging from interstellar space and planetary atmospheres to playing an important role in the combustion of various alkynes under fuel-rich conditions. Hydrogen-atom abstraction reactions are common for the ethynyl radical in these contrasting environments. In this study, the C<sub>2</sub>H + HX → C<sub>2</sub>H<sub>2</sub> + X, where HX = HNCO, <i>trans</i>-HONO, <i>cis</i>-HONO, C<sub>2</sub>H<sub>4</sub>, and CH<sub>3</sub>OH, reactions have been investigated at rigorously high levels of theory, including CCSD(T)-F12a/cc-pVTZ-F12. For the stationary points thus located, much higher levels of theory have been used, with basis sets as large as aug-cc-pV5Z and methods up to CCSDT(Q), and core correlation was also included. These molecules were chosen because they can be found in either interstellar or combustion environments. Various additive energy corrections have been included to converge the relative enthalpies of the stationary points to subchemical accuracy (≤0.5 kcal mol<sup>–1</sup>). Barriers predicted here (2.19 kcal mol<sup>–1</sup> for the HNCO reaction and 0.47 kcal mol<sup>–1</sup> for C<sub>2</sub>H<sub>4</sub>) are significantly lower than previous predictions. Reliable kinetics were acquired over a wide range of temperatures (50–5000 K), which may be useful for future experimental studies of these reactions.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":null,"pages":null},"PeriodicalIF":2.9000,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsearthspacechem.4c00040","citationCount":"0","resultStr":"{\"title\":\"Ethynyl Radical Hydrogen Abstraction Energetics and Kinetics Utilizing High-Level Theory\",\"authors\":\"Laura N. Olive, Alexandra D. Heide, Justin M. Turney and Henry F. Schaefer III*, \",\"doi\":\"10.1021/acsearthspacechem.4c00040\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p >The ethynyl radical, C<sub>2</sub>H, is found in a variety of different environments ranging from interstellar space and planetary atmospheres to playing an important role in the combustion of various alkynes under fuel-rich conditions. Hydrogen-atom abstraction reactions are common for the ethynyl radical in these contrasting environments. In this study, the C<sub>2</sub>H + HX → C<sub>2</sub>H<sub>2</sub> + X, where HX = HNCO, <i>trans</i>-HONO, <i>cis</i>-HONO, C<sub>2</sub>H<sub>4</sub>, and CH<sub>3</sub>OH, reactions have been investigated at rigorously high levels of theory, including CCSD(T)-F12a/cc-pVTZ-F12. For the stationary points thus located, much higher levels of theory have been used, with basis sets as large as aug-cc-pV5Z and methods up to CCSDT(Q), and core correlation was also included. These molecules were chosen because they can be found in either interstellar or combustion environments. Various additive energy corrections have been included to converge the relative enthalpies of the stationary points to subchemical accuracy (≤0.5 kcal mol<sup>–1</sup>). Barriers predicted here (2.19 kcal mol<sup>–1</sup> for the HNCO reaction and 0.47 kcal mol<sup>–1</sup> for C<sub>2</sub>H<sub>4</sub>) are significantly lower than previous predictions. Reliable kinetics were acquired over a wide range of temperatures (50–5000 K), which may be useful for future experimental studies of these reactions.</p>\",\"PeriodicalId\":15,\"journal\":{\"name\":\"ACS Earth and Space Chemistry\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":2.9000,\"publicationDate\":\"2024-07-03\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://pubs.acs.org/doi/epdf/10.1021/acsearthspacechem.4c00040\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"ACS Earth and Space Chemistry\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://pubs.acs.org/doi/10.1021/acsearthspacechem.4c00040\",\"RegionNum\":3,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"CHEMISTRY, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"ACS Earth and Space Chemistry","FirstCategoryId":"92","ListUrlMain":"https://pubs.acs.org/doi/10.1021/acsearthspacechem.4c00040","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
Ethynyl Radical Hydrogen Abstraction Energetics and Kinetics Utilizing High-Level Theory
The ethynyl radical, C2H, is found in a variety of different environments ranging from interstellar space and planetary atmospheres to playing an important role in the combustion of various alkynes under fuel-rich conditions. Hydrogen-atom abstraction reactions are common for the ethynyl radical in these contrasting environments. In this study, the C2H + HX → C2H2 + X, where HX = HNCO, trans-HONO, cis-HONO, C2H4, and CH3OH, reactions have been investigated at rigorously high levels of theory, including CCSD(T)-F12a/cc-pVTZ-F12. For the stationary points thus located, much higher levels of theory have been used, with basis sets as large as aug-cc-pV5Z and methods up to CCSDT(Q), and core correlation was also included. These molecules were chosen because they can be found in either interstellar or combustion environments. Various additive energy corrections have been included to converge the relative enthalpies of the stationary points to subchemical accuracy (≤0.5 kcal mol–1). Barriers predicted here (2.19 kcal mol–1 for the HNCO reaction and 0.47 kcal mol–1 for C2H4) are significantly lower than previous predictions. Reliable kinetics were acquired over a wide range of temperatures (50–5000 K), which may be useful for future experimental studies of these reactions.
期刊介绍:
The scope of ACS Earth and Space Chemistry includes the application of analytical, experimental and theoretical chemistry to investigate research questions relevant to the Earth and Space. The journal encompasses the highly interdisciplinary nature of research in this area, while emphasizing chemistry and chemical research tools as the unifying theme. The journal publishes broadly in the domains of high- and low-temperature geochemistry, atmospheric chemistry, marine chemistry, planetary chemistry, astrochemistry, and analytical geochemistry. ACS Earth and Space Chemistry publishes Articles, Letters, Reviews, and Features to provide flexible formats to readily communicate all aspects of research in these fields.