Gas-phase oxidation of cresol isomers initiated by OH or NO3 radicals in the presence of NO2

✍ Scribed by Solvejg Jørgensen

• Publisher: John Wiley and Sons
• Year: 2012
• Tongue: English
• Weight: 239 KB
• Volume: 44
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/kin.20703

✦ Synopsis

We have studied the reaction mechanism for both the NO 3 -and OH-initiated atmospheric oxidation of three cresol isomers, p-cresol, m-cresol, and o -cresol, in the presence of high NO 2 concentration. We have focused on the reaction mechanism leading to ringretaining products. Geometries of the reactants, intermediates, transition states, and products have been optimized at DFT-BB1K level of theory with the 6-311+G(d,p) basis set. The single point energy calculations have been carried out at the CCSD(T) level of theory with the cc-pVDZ basis set. Several energetically favorable reaction pathways were revealed for the first time. In the NO 3 -initiated reaction, the NO 3 radical is added to the carbon atom with the OH group, then the NO 2 radical is added to one of the neighboring carbon atoms, and finally HNO 3 is eliminated, leading to a methylnitrophenol isomer. In the OH-initiated reaction, the OH radical is added to the carbon atom adjacent to the carbon atom with the OH group; second, the NO 2 radical is added to the carbon atom with the original OH group, and, finally, HNO 2 is eliminated, leading to a dihydroxymethylbenzene isomer. The calculated results were compared with available experimental observations.