Clusters of PAHs: Laboratory Proxies for Astrochemical and Atmospherical Processes

Polycyclic aromatic hydrocarbons (PAHs) are abundant species in the interstellar medium (ISM) as well as in the Earth’s atmosphere. In both these environments PAHs can form clusters and nanoparticles, which play an important role in heterogeneous chemistry. We propose to investigate the formation of PAH clusters, uptake of different molecules on them, their subsequent coagulation and finally reactions triggered by electrons or photons using molecular beam experiments accompanied by molecular simulations. The clusters will be generated in a unique and versatile cluster beam apparatus CLUB incorporating various methods of mass spectrometry (electron ionization, photoionization, electron attachment), and UV and IR spectroscopies. Obtained results will bring new insight into mechanisms of chemical reactions occurring in the ISM and they will be also relevant in atmospheric chemistry.