Dissociation and multiple ionization energies for five polycyclic aromatic hydrocarbon molecules
2011 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 134, no 4, 044301- p.Article in journal (Refereed) Published
We have performed density functional theory calculations for a range of neutral, singly, and multiply charged polycyclic aromatic hydrocarbons (PAHs), and their fragmentation products for H-, H+-, C2H2-, and C2H2+-emissions. The adiabatic and vertical ionization energies follow linear dependencies as functions of charge state for all five intact PAHs (naphthalene, biphenylene, anthracene, pyrene, and coronene). First estimates of the total ionization and fragmentation cross sections in ion-PAH collisions display markedly different size dependencies for pericondensed and catacondensed PAH species, reflecting differences in their first ionization energies. The dissociation energies show that the PAHq+-molecules are thermodynamically stable for q <= 2 (naphthalene, biphenylene, and anthracene), q <= 3 (pyrene), and q <= 4 (coronene). PAHs in charge states above these limits may also survive experimental time scales due to the presence of reaction barriers as deduced from explorations of the potential energy surface regions for H+-emissions from all five PAHs and for C2H2+-emission from naphthalene - the smallest PAH.
Place, publisher, year, edition, pages
2011. Vol. 134, no 4, 044301- p.
Research subject Physics
IdentifiersURN: urn:nbn:se:su:diva-63728DOI: 10.1063/1.3541252ISI: 000286897600044OAI: oai:DiVA.org:su-63728DiVA: diva2:452015