Laboratory formation of large molecules in the gas phase

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)nC$_{48}^+$, n = 0, 1, 2, 3 and (C14H10)mC$_{62}^+$, 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