Radiolysis of pyridine in solid water

Prudence C. J. Ada Bibang (1) , Aditya N Agnihotri (1) , Philippe Boduch (1) , Alicja Domaracka (1) , Zuzana Kanuchova (2) , Hermann Rothard (1)

1 CIMAP - UMR 6252 - Centre de recherche sur les Ions, les MAtériaux et la Photonique
2 Astronomical Institute of the Slovak Academy of Sciences

We irradiated the complex organic molecule pyridine and mixtures of pyridine and water in solid phase (thin icy films) at 12K at different beam lines of the GANIL facility (ARIBE: 90 keV O 6+ , SME: 650 MeV Zn 26+). The destruction of the initial molecule and the appearance of radiolytic products were followed by in-situ infrared absorption spectroscopy as a function of the projectile fluence with the CASIMIR experimental setup of CIMAP. We measured the destruction cross section as a function of pyridine concentration. A clear dependence on the percentage of pyridine in H2O was found: the destruction cross sections are significantly higher for small concentration, i.e. pure pyridine is more radioresistant than pyridine diluted in water ice at 12 K. Thus, the presence of water environment significantly modifies the radiation resistance of the initial complex organic molecules: it enhances radiosensitivity and destruction of pyridine, with implications for radiobiology and astrochemistry.

Domaines: Radiochimie

Prudence C. J. Ada Bibang, Aditya N Agnihotri, Philippe Boduch, Alicja Domaracka, Zuzana Kanuchova, et al.. Radiolysis of pyridine in solid water. The European Physical Journal D : Atomic, molecular, optical and plasma physics, 2021, 75 (2), pp.57. ⟨10.1140/epjd/s10053-021-00058-y⟩. ⟨hal-03143008⟩