Halving the Barrier to Gas-Phase Oxidation of Bromide by Ozone
| dc.contributor.author | Brydon, S.C. | |
| dc.contributor.author | Szabó, P. | |
| dc.contributor.author | Wongsomboon, P. | |
| dc.contributor.author | Poad, B.L.J. | |
| dc.contributor.author | Marshall, D.L. | |
| dc.contributor.author | Miljevic, B. | |
| dc.contributor.author | Trevitt, A.J. | |
| dc.contributor.author | Bieske, E.J. | |
| dc.contributor.author | Harvey, J.N. | |
| dc.contributor.author | Blanksby, S.J. | |
| dc.date | 2025 | |
| dc.date.accessioned | 2025-11-13T11:52:56Z | |
| dc.date.available | 2025-11-13T11:52:56Z | |
| dc.identifier.uri | https://orfeo.belnet.be/handle/internal/14410 | |
| dc.description | Recent atmospheric measurements indicate that bromine and iodine may be responsible for up to 72% of halogen-induced ozone loss near the tropopause, yet there is ongoing uncertainty regarding the multiphase chemistry of bromide and iodide anions in ozone depletion. Here, we demonstrate the unequivocal ozone-dependence of the archetype 1Br– + 1O3 reaction, which proceeds with an experimental rate constant of 8.9 (±4.4) × 10–15 cm3 molecule–1 s–1. The reaction mechanism is revised to proceed via a singlet transition state with a rate-limiting barrier of +22.1 kJ mol–1 −half that of prior estimates −prior to facile spin-crossing to yield 1BrO– + 3O2. Statistical rate modeling using this new barrier height predicts a rate constant of 5.7 × 10–15 cm3 molecule–1 s–1, which is in excellent agreement with the experiment. This reconciliation of the kinetics for the intrinsic gas-phase reaction will enable systematic evaluation of temperature, pressure, and solvation effects on this ion–molecule chemistry and thus inform the impact of halide anion chemistry on atmospheric ozone. | |
| dc.language | eng | |
| dc.title | Halving the Barrier to Gas-Phase Oxidation of Bromide by Ozone | |
| dc.type | Article | |
| dc.subject.frascati | Physical sciences | |
| dc.audience | Scientific | |
| dc.subject.free | Anions | |
| dc.subject.free | Basis sets | |
| dc.subject.free | Bromine | |
| dc.subject.free | Ions | |
| dc.subject.free | Thermodynamic properties | |
| dc.source.title | The Journal of Physical Chemistry Letters | |
| dc.source.volume | 16 | |
| dc.source.issue | 45 | |
| dc.source.page | 11770-11776 | |
| Orfeo.peerreviewed | Yes | |
| dc.identifier.doi | 10.1021/acs.jpclett.5c02949 | |
| dc.identifier.url |