An assessment of the tropospherically accessible photo-initiated ground state chemistry of organic carbonyls
-
Published:2022-01-20
Issue:2
Volume:22
Page:929-949
-
ISSN:1680-7324
-
Container-title:Atmospheric Chemistry and Physics
-
language:en
-
Short-container-title:Atmos. Chem. Phys.
Author:
Rowell Keiran N., Kable Scott H., Jordan Meredith J. T.ORCID
Abstract
Abstract. Carbonyls are among the most abundant volatile organic compounds in the
atmosphere. They are central to atmospheric photochemistry as absorption of
near-UV radiation by the C=O chromophore can lead to photolysis. If
photolysis does not occur on electronic excited states, non-radiative
relaxation to the ground state will form carbonyls with extremely high
internal energy. These “hot” molecules can access a range of ground state
reactions. Up to nine potential ground state reactions are investigated
at the B2GP-PLYP-D3/def2-TZVP level of theory for a test set of 20
representative carbonyls. Almost all are energetically accessible under
tropospheric conditions. Comparison with experiment suggests the most
significant ground state dissociation pathways will be concerted triple
fragmentation in saturated aldehydes, Norrish type III dissociation to
form another carbonyl, and H2 loss involving the formyl H atom
in aldehydes. Tautomerisation, leading to more reactive unsaturated
species, is also predicted to be energetically accessible and is likely to
be important when there is no low-energy ground state dissociation pathway,
for example in α,β-unsaturated carbonyls and some ketones. The
concerted triple fragmentation and H2-loss pathways have immediate
atmospheric implications for global H2 production, and tautomerisation has
implications for the atmospheric production of organic acids.
Funder
Australian Research Council Australian Space Research Program
Publisher
Copernicus GmbH
Subject
Atmospheric Science
Reference131 articles.
1. Ahn, D. H., Choi, T., Kim, J., Park, S. S., Lee, Y. G., Kim, S.-J., and Koo,
J.-H.: Southern Hemisphere mid- and high-latitudinal AOD, CO, NO2, and
HCHO: Spatiotemporal patterns revealed by satellite observations, Prog.
Earth Planet. Sci., 6, 34, https://doi.org/10.1186/s40645-019-0277-y, 2019. a 2. Amaral, G. A., Arregui, A., Rubio-Lago, L., Rodríguez, J. D., and Baares,
L.: Imaging the radical channel in acetaldehyde photodissociation: Competing
mechanisms at energies close to the triplet exit barrier, J. Chem. Phys.,
133, 064 303, https://doi.org/10.1063/1.3474993, 2010. a, b, c 3. Anderson, D. C., Nicely, J. M., Wolfe, G. M., Hanisco, T. F., Salawitch, R. J.,
Canty, T. P., Dickerson, R. R., Apel, E. C., Baidar, S., Bannan, T. J.,
Blake, N. J., Chen, D., Dix, B., Fernandez, R. P., Hall, S. R., Hornbrook,
R. S., Gregory Huey, L., Josse, B., Jöckel, P., Kinnison, D. E., Koenig,
T. K., Le Breton, M., Marécal, V., Morgenstern, O., Oman, L. D., Pan, L. L.,
Percival, C., Plummer, D., Revell, L. E., Rozanov, E., Saiz-Lopez, A.,
Stenke, A., Sudo, K., Tilmes, S., Ullmann, K., Volkamer, R., Weinheimer,
A. J., and Zeng, G.: Formaldehyde in the tropical Western Pacific: Chemical
sources and sinks, convective transport, and representation in CAM-Chem and
the CCMI models, J. Geophys. Res.-Atmos., 122, 11201–11226,
https://doi.org/10.1002/2016JD026121, 2017. a 4. Andrews, D. U., Heazlewood, B. R., Maccarone, A. T., Conroy, T., <span id="page945"/>Payne, R. J.,
Jordan, M. J. T., and Kable, S. H.: Photo-Tautomerization of acetaldehyde to
vinyl alcohol: A potential route to tropospheric acids, Science, 337,
1203–1206, https://doi.org/10.1126/science.1220712, 2012. a, b, c, d 5. Andrews, D. U., Kable, S. H., and Jordan, M. J.: A phase space theory for
roaming reactions, J. Phys. Chem. A, 117, 7631–7642,
https://doi.org/10.1021/jp405582z, 2013. a
Cited by
6 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献
|
|