Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
β-Ionone reactions with ozone and OH radical: Rate constants and gas-phase products
AbstractThe bimolecular rate constants, kOH+β-ionone (118±30)×10−12cm3molecule−1s−1 and , (0.19±0.05)×10−16cm3molecule−1s−1, were measured using the relative rate technique for the reaction of the hydroxyl radical (OH) and ozone (O3) with 4-(2,6,6-trimethyl-1-cyclohexen-1-yl)-3-buten-2-one (β-ionone) at 297±3K and 1atm total pressure. To more clearly define part of β-ionone's indoor environment degradation mechanism, the products of the β-ionone+OH and β-ionone+O3 reactions were also investigated. The identified β-ionone+OH reaction products were: glyoxal (ethanedial, HC(=O)C(=O)H), and methylglyoxal (2-oxopropanal, CH3C(=O)C(=O)H) and the identified β-ionone+O3 reaction product was 2-oxopropanal. The derivatizing agents O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine (PFBHA) and N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) were used to propose 2,6,6-trimethylcyclohex-1-ene-1-carbaldehyde as the other major β-ionone+OH and β-ionone+O3 reaction product. The elucidation of this other reaction product was facilitated by mass spectrometry of the derivatized reaction products coupled with plausible β-ionone+OH and β-ionone+O3 reaction mechanisms based on previously published volatile organic compound+OH and volatile organic compound+O3 gas-phase reaction mechanisms. The additional gas-phase products observed from the β-ionone+OH reaction are proposed to be the result of cyclization through a radical intermediate.
β-Ionone reactions with ozone and OH radical: Rate constants and gas-phase products
AbstractThe bimolecular rate constants, kOH+β-ionone (118±30)×10−12cm3molecule−1s−1 and , (0.19±0.05)×10−16cm3molecule−1s−1, were measured using the relative rate technique for the reaction of the hydroxyl radical (OH) and ozone (O3) with 4-(2,6,6-trimethyl-1-cyclohexen-1-yl)-3-buten-2-one (β-ionone) at 297±3K and 1atm total pressure. To more clearly define part of β-ionone's indoor environment degradation mechanism, the products of the β-ionone+OH and β-ionone+O3 reactions were also investigated. The identified β-ionone+OH reaction products were: glyoxal (ethanedial, HC(=O)C(=O)H), and methylglyoxal (2-oxopropanal, CH3C(=O)C(=O)H) and the identified β-ionone+O3 reaction product was 2-oxopropanal. The derivatizing agents O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine (PFBHA) and N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) were used to propose 2,6,6-trimethylcyclohex-1-ene-1-carbaldehyde as the other major β-ionone+OH and β-ionone+O3 reaction product. The elucidation of this other reaction product was facilitated by mass spectrometry of the derivatized reaction products coupled with plausible β-ionone+OH and β-ionone+O3 reaction mechanisms based on previously published volatile organic compound+OH and volatile organic compound+O3 gas-phase reaction mechanisms. The additional gas-phase products observed from the β-ionone+OH reaction are proposed to be the result of cyclization through a radical intermediate.
β-Ionone reactions with ozone and OH radical: Rate constants and gas-phase products
Forester, Crystal D. (Autor:in) / Ham, Jason E. (Autor:in) / Wells, J. Raymond (Autor:in)
Atmospheric Environment ; 41 ; 8758-8771
22.07.2007
14 pages
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch