Laboratory formation of large molecules in the gas phase

¹ CAS Key Laboratory for Research in Galaxies and Cosmology, Department of Astronomy, University of Science and Technology of China, Hefei 230026, PR China
² School of Astronomy and Space Science, University of Science and Technology of China, Hefei 230026, PR China
e-mail: jfzhen@ustc.edu.cn

Received: 13 December 2018
Accepted: 25 January 2019

Abstract

We report the experimental study on the formation process of large molecules (e.g. a family group of molecular clusters and graphene) in the gas phase. The experiment was carried out using a quadrupole ion trap in combination with time-of-flight mass spectrometry. As the initial molecular precursor, dicoronylene (DC, C₄₈H₂₀)/anthracene (C₁₄H₁₀) cluster cations, the results show that large PAH cluster cations (e.g., (C₁₄H₁₀)C₄₈H_n⁺, n = [1–19] and (C₁₄H₁₀)C₆₂H_m⁺, m = [1–25]) and PAH-graphene cluster cations (e.g., (C₁₄H₁₀)_nC₄₈⁺, n = 0, 1, 2, 3 and (C₁₄H₁₀)_mC₆₂⁺, m = 0, 1, 2) are formed by gas-phase condensation under laser irradiation conditions. We infer that these results present in here provide a formation route for interstellar large molecules under the influence of a strong radiation field in the ISM. The relevance of newly formed species to the nanometer-sized dust grain in space is briefly discussed.