English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Open

Presents the pdf analysis as premium feature

PDF Analysis

Insights

Presents the summarisation as premium feature

Summarisation

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

We present a detailed study of the main dehydrogenation processes of twodibenzopyrene cation (C24H14+) isomers, namely dibenzo(a,e)pyrene (AE+) anddibenzo(a,l)pyrene (AL+). First, action spectroscopy under VUV photons wasperformed using synchrotron radiation in the 8-20 eV range. We observed lowerdissociation thresholds for the non-planar molecule (AL+) than for the planarone (AE+) for the main dissociation pathways: H and 2H/H2 loss. In order torationalize the experimental results, dissociation paths were investigated bymeans of density functional theory calculations. In the case of H loss, whichis the dominant channel at the lowest energies, the observed difference betweenthe two isomers can be explained by the presence in AL+ of two C-H bonds withconsiderably lower adiabatic dissociation energies. In both isomers the 2H/H2loss channels are observed only at about 1 eV higher than H loss. We suggestthat this is due to the propensity of bay H atoms to easily form H2. Inaddition, in the case of AL+, we cannot exclude a competition between 2H and H2channels. In particular, the formation of a stable dissociation product with afive-membered ring could account for the low energy sequential loss of 2hydrogens. This work shows the potential role of non-compact PAHs containingbay regions in the production of H2 in space.

Investigating the importance of edge-structure in the loss of H/H2 of PAH cations: the case of dibenzopyrene isomers