Identification of the fragment of the 1-methylpyrene cation by mid-IR spectroscopy

Pavol Jusko (1, 2) , Aude Simon (3) , Gabi Wenzel (1) , Sandra Brünken (2, 4) , Stephan Schlemmer (2) , Christine Joblin (1)

1 IRAP - Institut de recherche en astrophysique et planétologie
2 I. Physikalisches Institut [Köln]
3 MAD - Modélisation, Agrégats, Dynamique (LCPQ)
4 Radboud University, Institute for Molecules and Materials, FELIX Laboratory

The fragment of the 1-methylpyrene cation, C17H11+, is expected to exist in two isomeric forms, 1-pyrenemethylium PyrCH2+ and the tropylium containing species PyrC7+ . We measured the infrared (IR) action spectrum of cold C17H11+ tagged with Ne using a cryogenic ion trap instrument coupled to the FELIX laser. Comparison of the experimental data with density functional theory calculations allows us to identify the PyrCH2+ isomer in our experiments. The IR Multi-Photon Dissociation spectrum was also recorded following the C2H2 loss channel. Its analysis suggests combined effects of anharmonicity and isomerisation while heating the trapped ions, as shown by molecular dynamics simulations.

Mots clés: 22 pole cryogenic ion trap; PAH; Ne tagging spectroscopy; molecular dynamics simulations

Domaines: Chimie-Physique [physics.chem-ph]

Pavol Jusko, Aude Simon, Gabi Wenzel, Sandra Brünken, Stephan Schlemmer, et al.. Identification of the fragment of the 1-methylpyrene cation by mid-IR spectroscopy. Chemical Physics Letters, 2018, 698, pp.206-210. ⟨10.1016/j.cplett.2018.03.028⟩. ⟨hal-01675239v2⟩