Reaction pathways leading to HPALD intermediates in the OH-initiated oxidation of isoprene
| dc.contributor.author | Szabó, P. | |
| dc.contributor.author | Liu, Z. | |
| dc.contributor.author | Müller, J.-F. | |
| dc.contributor.author | Harvey, J.N. | |
| dc.contributor.author | Peeters, J. | |
| dc.date | 2024 | |
| dc.date.accessioned | 2024-10-18T12:21:31Z | |
| dc.date.available | 2024-10-18T12:21:31Z | |
| dc.identifier.uri | https://orfeo.belnet.be/handle/internal/13480 | |
| dc.description | In this study, we revisited the mechanism of isoprene oxidation by OH radicals, focusing on the formation of hydroperoxyaldehydes (HPALDs) in the reactions following O2-addition at the α-position to Z,Z′-OH-allyl radical products of the 1,6-H shift of the 1st-generation Z-δ-OH-isoprenylperoxy radicals. Utilizing high-level ab initio quantum chemical calculations and a master equation approach, we provide theoretical confirmation that the formation of δ-HPALDs dominates by far and show that production of β-HPALDs by the mechanism proposed by Wennberg et al. (Chem. Rev., 2018, 118, 3337–3390) is negligible. Besides the dominance of the δ-HPALD formation channel, our investigation also reveals a novel though minor reaction channel resulting in the formation of an allylic δ-hydroperoxy acid and OH radical. Of primary importance for the assessment of the respective channels is the identification of a chemically activated mechanism driving the δ-HPALD formation process under atmospheric conditions. Different from traditional thermally activated pathways, we found that the rovibrationally hot peroxy radicals resulting from O2 addition to Z,Z′-OH-allyl radicals undergo prompt rearrangement and decomposition at a rate faster than their collisional relaxation, predominantly yielding δ-HPALDs in a chemically activated manner with high efficiency under atmospheric conditions. | |
| dc.language | eng | |
| dc.title | Reaction pathways leading to HPALD intermediates in the OH-initiated oxidation of isoprene | |
| dc.type | Article | |
| dc.subject.frascati | Physical sciences | |
| dc.audience | Scientific | |
| dc.source.title | Physical Chemistry Chemical Physics | |
| dc.source.volume | 26 | |
| dc.source.issue | 40 | |
| dc.source.page | 26129-26137 | |
| Orfeo.peerreviewed | Yes | |
| dc.identifier.doi | 10.1039/D4CP02106A | |
| dc.identifier.url |