What Will Photo-Processing of Large, Ionized Amino-Substituted Polycyclic Aromatic Hydrocarbons Produce in the Interstellar Medium?
Jake BurnerBrandi J WestPaul M MayerPublished in: The journal of physical chemistry. A (2019)
Collision-energy resolved tandem mass spectrometry was used to probe the trends in unimolecular fragmentation in a series of ionized amino-substituted polycyclic aromatic hydrocarbons ranging from naphthalene to pyrene. As the ring system expands, the dominant dissociation process changes from HNC loss (aniline) to H loss for 1-aminopyrene. Imaging photoelectron photoion coincidence spectroscopy of 1-aminopyrene yielded threshold photon-energy resolved breakdown curves, the Rice-Ramsperger-Kassel-Marcus modeling of which gave a 0 K activation energy, E0, for H loss of 3.8 ± 0.4 eV. Calculations at the CCSD/6-31G(d)//B3LYP/6-31G(d) level of theory were used to explore the possible reaction mechanisms for H, HNC, and C,N,H2 losses, and details of the reaction pathways are presented. The H atom loss was found to be due both to direct N-H bond cleavage and isomerization to form an azepine derivative.
Keyphrases
- polycyclic aromatic hydrocarbons
- tandem mass spectrometry
- electron transfer
- high resolution
- ultra high performance liquid chromatography
- high performance liquid chromatography
- molecular dynamics
- living cells
- ms ms
- solid phase extraction
- single molecule
- photodynamic therapy
- transcription factor
- dna binding
- fluorescence imaging