Laser-induced fragmentation of coronene cations

• Published in: Physical chemistry chemical physics : PCCP 2024-07, Vol.26 (27), p.18557-1857
• Main Authors: Panchagnula, Sanjana, Kamer, Jerry, Candian, Alessandra, Hrodmarsson, Helgi R, Linnartz, Harold, Bouwman, Jordy, Tielens, Alexander G. G. M
• Format: Article
• Language: English
• Subjects: Carbon; Cations; Clusters; Density functional theory; Fragmentation; Galactic evolution; Galaxies; Interstellar matter; Isomerization; Mass spectrometry; Molecular chains; Photochemistry; Photodissociation; Polycyclic aromatic hydrocarbons; Sciences of the Universe
• ISSN: 1463-9076; 1463-9084; 1463-9084
• DOI: 10.1039/d4cp01301h

Polycyclic aromatic hydrocarbons are an important component of the interstellar medium of galaxies and photochemistry plays a key role in the evolution of these species in space. Here, we explore the photofragmentation behaviour of the coronene cation (C 24 H 12 &z.rad; + ) using time-of-flight mass spectrometry. The experiments show photodissociation fragmentation channels including the formation of bare carbon clusters (C n &z.rad; + ) and hydrocarbon chains (C n H x + ). The mass spectrum of coronene is dominated by peaks from C 11 &z.rad; + and C 7 H + . Density functional theory was used to calculate relative energies, potential dissociation pathways, and possible structures for relevant species. We identify 6-6 → 5-7 ring isomerisation as a key step in the formation of both the bare carbon clusters and the hydrocarbon chains observed in this study. We present the dissociation mechanism outlined here as a potential formation route for C 60 and other astrochemically relevant species. Polycyclic aromatic hydrocarbons are an important component of the interstellar medium of galaxies and photochemistry plays a key role in the evolution of these species in space.