{"title":"氨基NH和乙基C2H5自由基之间反应的理论研究:星际和行星乙胺的可能气相形成途径","authors":"Nadia Balucani , Dimitrios Skouteris , Cecilia Ceccarelli , Claudio Codella , Stefano Falcinelli , Marzio Rosi","doi":"10.1016/j.molap.2018.10.001","DOIUrl":null,"url":null,"abstract":"<div><p><span>The reaction between the amidogen, NH, radical and the ethyl, C</span><sub>2</sub>H<sub>5</sub><span><span>, radical has been investigated by performing electronic structure calculations of the underlying doublet potential energy surface. Rate coefficients and product branching ratios have also been estimated by combining capture and RRKM calculations. According to our results, the reaction is very fast, close to the gas-kinetics limit. However, the main product channel, with a yield of ca. 86–88% in the range of temperatures investigated, is the one leading to </span>methanimine and the methyl radical. The channels leading to the two </span><em>E-, Z</em><span>- stereoisomers of ethanimine account only for ca. 5–7% each. The resulting ratio [</span><em>E</em>-CH<sub>3</sub>CHNH]/[<em>Z</em>-CH<sub>3</sub><span>CHNH] is ca. 1.2, that is a value rather lower than that determined in the Green Bank Telescope PRIMOS radio astronomy survey spectra of Sagittarius B2 North (ca</span><em>.</em><span> 3). Considering that ice chemistry would produce essentially only the most stable isomer, a possible conclusion is that the observed [</span><em>E</em>-CH<sub>3</sub>CHNH]/[<em>Z</em>-CH<sub>3</sub>CHNH] ratio is compatible with a combination of gas-phase and grain chemistry. More observational and laboratory data are needed to definitely address this issue.</p></div>","PeriodicalId":44164,"journal":{"name":"Molecular Astrophysics","volume":"13 ","pages":"Pages 30-37"},"PeriodicalIF":0.0000,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.molap.2018.10.001","citationCount":"18","resultStr":"{\"title\":\"A theoretical investigation of the reaction between the amidogen, NH, and the ethyl, C2H5, radicals: a possible gas-phase formation route of interstellar and planetary ethanimine\",\"authors\":\"Nadia Balucani , Dimitrios Skouteris , Cecilia Ceccarelli , Claudio Codella , Stefano Falcinelli , Marzio Rosi\",\"doi\":\"10.1016/j.molap.2018.10.001\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p><span>The reaction between the amidogen, NH, radical and the ethyl, C</span><sub>2</sub>H<sub>5</sub><span><span>, radical has been investigated by performing electronic structure calculations of the underlying doublet potential energy surface. Rate coefficients and product branching ratios have also been estimated by combining capture and RRKM calculations. According to our results, the reaction is very fast, close to the gas-kinetics limit. However, the main product channel, with a yield of ca. 86–88% in the range of temperatures investigated, is the one leading to </span>methanimine and the methyl radical. The channels leading to the two </span><em>E-, Z</em><span>- stereoisomers of ethanimine account only for ca. 5–7% each. The resulting ratio [</span><em>E</em>-CH<sub>3</sub>CHNH]/[<em>Z</em>-CH<sub>3</sub><span>CHNH] is ca. 1.2, that is a value rather lower than that determined in the Green Bank Telescope PRIMOS radio astronomy survey spectra of Sagittarius B2 North (ca</span><em>.</em><span> 3). Considering that ice chemistry would produce essentially only the most stable isomer, a possible conclusion is that the observed [</span><em>E</em>-CH<sub>3</sub>CHNH]/[<em>Z</em>-CH<sub>3</sub>CHNH] ratio is compatible with a combination of gas-phase and grain chemistry. More observational and laboratory data are needed to definitely address this issue.</p></div>\",\"PeriodicalId\":44164,\"journal\":{\"name\":\"Molecular Astrophysics\",\"volume\":\"13 \",\"pages\":\"Pages 30-37\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2018-11-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://sci-hub-pdf.com/10.1016/j.molap.2018.10.001\",\"citationCount\":\"18\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Molecular Astrophysics\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S240567581830023X\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"Physics and Astronomy\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Molecular Astrophysics","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S240567581830023X","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"Physics and Astronomy","Score":null,"Total":0}
A theoretical investigation of the reaction between the amidogen, NH, and the ethyl, C2H5, radicals: a possible gas-phase formation route of interstellar and planetary ethanimine
The reaction between the amidogen, NH, radical and the ethyl, C2H5, radical has been investigated by performing electronic structure calculations of the underlying doublet potential energy surface. Rate coefficients and product branching ratios have also been estimated by combining capture and RRKM calculations. According to our results, the reaction is very fast, close to the gas-kinetics limit. However, the main product channel, with a yield of ca. 86–88% in the range of temperatures investigated, is the one leading to methanimine and the methyl radical. The channels leading to the two E-, Z- stereoisomers of ethanimine account only for ca. 5–7% each. The resulting ratio [E-CH3CHNH]/[Z-CH3CHNH] is ca. 1.2, that is a value rather lower than that determined in the Green Bank Telescope PRIMOS radio astronomy survey spectra of Sagittarius B2 North (ca. 3). Considering that ice chemistry would produce essentially only the most stable isomer, a possible conclusion is that the observed [E-CH3CHNH]/[Z-CH3CHNH] ratio is compatible with a combination of gas-phase and grain chemistry. More observational and laboratory data are needed to definitely address this issue.
期刊介绍：
Molecular Astrophysics is a peer-reviewed journal containing full research articles, selected review articles, and thematic issues. Molecular Astrophysics is a new journal where researchers working in planetary and exoplanetary science, astrochemistry, astrobiology, spectroscopy, physical chemistry and chemical physics can meet and exchange their ideas. Understanding the origin and evolution of interstellar and circumstellar molecules is key to understanding the Universe around us and our place in it and has become a fundamental goal of modern astrophysics. Molecular Astrophysics aims to provide a platform for scientists studying the chemical processes that form and dissociate molecules, and control chemical abundances in the universe, particularly in Solar System objects including planets, moons, and comets, in the atmospheres of exoplanets, as well as in regions of star and planet formation in the interstellar medium of galaxies. Observational studies of the molecular universe are driven by a range of new space missions and large-scale scale observatories opening up. With the Spitzer Space Telescope, the Herschel Space Observatory, the Atacama Large Millimeter/submillimeter Array (ALMA), NASA''s Kepler mission, the Rosetta mission, and more major future facilities such as NASA''s James Webb Space Telescope and various missions to Mars, the journal taps into the expected new insights and the need to bring the various communities together on one platform. The journal aims to cover observational, laboratory as well as computational results in the galactic, extragalactic and intergalactic areas of our universe.
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