Isomer effects in fragmentation of Polycyclic Aromatic Hydrocarbons

Abstract

International audienceWe have observed significant differences in the fragmentation patterns of isomeric Polycyclic Aromatic Hydrocarbon (PAH) cations following collisions with helium atoms at center-of-mass energies around 100 eV. This is in contrast to the situation at other collision energies or in photo-absorption experiments where isomeric effects are very weak and where the lowest-energy dissociation channels (H- and C2H2-loss) dominate in statistical fragmentation processes. In the 100 eV range, non-statistical fragmentation also competes and is uniquely linked to losses of single carbon atoms (CHx-losses). We find that such CHx-losses are correlated with the ionic ground state energy within a given group of isomers. We present results for three C16H10+, four C18H12+ and five C20H12+ isomers colliding with He

IR photofragmentation of the phenyl cation: spectroscopy and fragmentation pathways

“…34,35 Furthermore, many studies on the larger PAH species have shown a trend for smaller and irregular PAHs to be more likely to lose [2C,2H] than H or H 2 upon photofragmentation. [36][37][38][39][40][41][42] It would thus be of great interest to find out if phenylium follows this trend.…”

Dissociation of polycyclic aromatic hydrocarbons: molecular dynamics studies

“…Erosion by hot gas would lead, in particular, to the progressive loss of C 2 H n fragments (n = 0, 1, 2) [17]. PAH dissociation induced by collision with energetic ions has been the object of several experimental studies [20][21][22][23][24][25][26] in which the dependence of the fragmentation patterns of the PAH on its size and on the energy and nature of the colliding particle has been investigated.…”

Environmental analysis of polar and non-polar Polycyclic Aromatic Compounds in airborne particulate matter, settled dust and soot: Part II: Instrumental analysis and occurrence

“…PAHs, but they had to apply high CEs (from 18 to 40 eV for LMW PAHs and from 30 to 40 eV for HMW PAHs) to obtain fragments from CID [109]. The predominance of H and C2H2 knockouts was also observed and is explained in the work of Stockett et al [120].…”