Laboratory photo-chemistry of pyrene clusters: an efficient way to form large PAHs

Junfeng Zhen, Tao Chen, Alexander G. G. M. Tielens

(Submitted on 26 Sep 2018)

In this work, we study the photodissociation processes of small PAH clusters (e.g., pyrene clusters). The experiments are carried out using a quadrupole ion trap in combination with time-of-flight (QIT-TOF) mass spectrometry. The results show that pyrene clusters are converted into larger PAHs under the influence of a strong radiation field. Specifically, pyrene dimer cations (e.g., [C16H10−C16H9]+ or C32H19+), will photo-dehydrogenate and photo-isomerize to fully aromatic cations (PAHs) (e.g., C32H16+) with laser irradiation. The structure of new formed PAHs and the dissociation energy for these reaction pathways are investigated with quantum chemical calculations. These studies provide a novel efficient evolution routes for the formation of large PAHs in the interstellar medium (ISM) in a bottom-up process that will counteract the top-down conversion of large PAHs into rings and chains, and provide a reservoir of large PAHs that can be converted into C60 and other fullerenes and large carbon cages.

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Astrophysics of Galaxies (astro-ph.GA)

Journal reference: The Astrophysical Journal, 863:128 (6pp), 2018 August 20

DOI: 10.3847/1538-4357/aad240

Cite as: arXiv:1809.09770 [astro-ph.IM] (or arXiv:1809.09770v1 [astro-ph.IM] for this version)

Submission history

From: Junfeng Zhen  

[v1] Wed, 26 Sep 2018 00:44:34 GMT (12503kb,D)

https://arxiv.org/abs/1809.09770

Astrobiology, Astrochemistry