Synthesis of Benzene and Phenol From the Irradiation of Benzonitrile: Water Ices by (<10 eV) Electrons: Application to the Planets and Meteorites Surface Chemistry

Aromatic compounds are present in the interstellar space and on carbonaceous meteorites where they intriguingly represent the most important constituents along with the water ice. Exposed to the cosmic radiation, more complex species are generated via processes that are still far from being understood. The present study aims at studying the chemistry of benzonitrile in water ice environment when exposed to the ballistic low energy free electrons produced abundantly along the radiation tracks. Here we show that phenol and benzene are synthetized at the electron energy above but also below 6 eV via different routes, which can be selectively activated by tuning the electron energy. The reactivity presented in this work may contribute to a better understanding of the time evolution, via models and simulations, of species present in interstellar space ices and meteorites. Plain Language Summary Water and benzonitrile have both been found on meteorites as ices, which may be exposed to solar and cosmic radiation. The high energy primary particles from such radiation penetrate into the ice producing large numbers of ballistic secondary electrons. Here, we show that these electrons can induce reactions in water‐benzonitrile ice to synthesize phenol and benzene, which have also been identified in cometary ice. The presented results therefore contribute to a better understanding of the evolution of chemistry in meteorites and, more generally, in extra‐terrestrial space. Key Points Water ice, benzonitrile benzene and phenol are found in interstellar media Radiation plays a crucial role in the astrochemical synthesis and low energy electrons are abundantly produced from the energetic particles We explore the chemistry induced by low energy electrons in benzonitrile: water ices