Laser-induced fragmentation of coronene cations

Abstract

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 (C24H12+) using time of flight mass spectrometry. The experiments show photodissociation fragmentation channels including the formation of bare carbon clusters (Cn+) and hydrocarbon chains (CnHx+). The mass spectrum of coronene is dominated by peaks from C11+ and C7H+. Density functional theory was used to calculate relative energies, potential dissociation pathways, and possible structures for relevant species. We identify 6-6 to 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 C60 and other astrochemically relevant species.

17 pages, 12 figure. Version submitted after referee report to PCCP. Supplementary information available at https://www.rsc.org/suppdata/d4/cp/d4cp01301h/d4cp01301h1.pdf

References in corpus (11)

• Detection of Two Interstellar Polycyclic Aromatic Hydrocarbons via Spectral Matched Filtering
• The Diffuse Interstellar Bands: A Major Problem in Astronomical Spectroscopy
• Discovery of the Pure Polycyclic Aromatic Hydrocarbon Indene ($c$-C${}_9$H${}_8$) with GOTHAM Observations of TMC-1
• Laboratory formation of fullerenes from PAHs: Top-down interstellar chemistry
• VLT/X-shooter survey of near-infrared diffuse interstellar bands
• Laboratory Photo-chemistry of PAHs: Ionization versus Fragmentation
• C${}_{60}^{+}$ and the Diffuse Interstellar Bands: An Independent Laboratory Check
• Astrochemical relevance of VUV ionization of large PAH cations
• Characterizing the infrared spectra of small, neutral, fully dehydrogenated PAHs
• Stability of Polycyclic Aromatic Hydrocarbon Clusters in Protoplanetary Disks
• IR photofragmentation of the Phenyl Cation: Spectroscopy and Fragmentation Pathways

Cited by in corpus (3)

• Discovery of the 7-ring PAH Cyanocoronene (C${}_{24}$H${}_{11}$CN) in GOTHAM Observations of TMC-1
• Photofragmentation of Corannulene (C20H10) and Sumanene (C21H12) cations in gas phase and its Astrophysical implications
• Aromatic Species in the Molecular Universe