SIMBAD references

Products O₃, N, NO, NO₂, N₂O, c-(NO)₂, and excited states of O₂ were detected after the photolysis of solid O₂ in icy N₂ near 4 K with radiation at 200 nm. The temporal profiles of these products enable the derivation of a mechanism for the photochemical reactions in this system: dissociation of O₂ first-generated O ³P that reacted with nearby N₂ to yield N₂O. Other products resulted from the secondary photolysis of N₂O and the reactions of O with N₂O. The reaction of O with O₂ to form O₃ was impeded by the small concentration of the latter, which requires substantial migration through the N₂ lattice. However, sufficient O₃ was eventually formed to enable detection either directly from O coming from O₂ or indirectly through N₂O. These results enhance our understanding of the evolution of the transformation of oxygen and nitrogen in irradiated ices and have possible astrophysical applications.