Deexcitation Dynamics of Superhydrogenated Polycyclic Aromatic Hydrocarbon Cations after Soft-x-Ray Absorption

Geert Reitsma, Leon Boschman, Mart Johan Deuzeman, Olmo Gonzalez Magana, Steven Hoekstra, Stéphanie Cazaux, Ronnie Hoekstra, Thomas Schlathölter

OnderzoeksoutputAcademicpeer review

43 Citaten (Scopus)
270 Downloads (Pure)


We have investigated the response of superhydrogenated gas-phase coronene cations upon soft x-ray absorption. Carbon (1s)⟶π⋆ transitions were resonantly excited at hν =285 eV. The resulting core hole is then filled in an Auger decay process, with the excess energy being released in the form of an Auger electron. Predominantly highly excited dications are thus formed, which cool down by hydrogen emission. In superhydrogenated systems, the additional H atoms act as a buffer, quenching loss of native H atoms and molecular fragmentation. Dissociation and transition state energies for several H loss channels were computed by means of density functional theory. Using these energies as input into an Arrhenius-type cascade model, very good agreement with the experimental data is found. The results have important implications for the survival of polyaromatic hydrocarbons in the interstellar medium and reflect key aspects of graphene hydrogenation.
Originele taal-2English
TijdschriftPhysical Review Letters
StatusPublished - aug.-2014

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