Intermediates Produced in the Flash Photolysis of Acetone and Amides in Aqueous Solution

Authors: M. Nakashima, E. Hayon The flash photolysis of air-free aqueous acetone solutions was shown to produce CH2COCH3 and (CHg^COH radicals. The acetonyl CH2COCH3 radical has an absorption maximum at 295 nm and an extinction coef- ficient 6295 = 800 ± 150 M-1 cm-1. No intermediates could be observed in the flash photolysis of air-free aqueous amide solutions. In presence…

Galactic Cosmic Rays and N2 Disassociation on Titan

Authors: L.A. Capone, J. Dubach, S.S. Prasad, R.C. Whitten The electromagnetic and particle cascade resulting from the absorption of galactic cosmic rays in the atmosphere of Titan is shown to be an important mechanism for driving the photochemistry at pressures of 1 to 50 mbar in the atmosphere. In particular, the cosmic ray cascade dissociates N2, a process necessary for…

Photochemistry of Methane and the Formation of Hydrocyanic Acid (HCN) in the Earth’s Early Atmosphere

The photochemistries of methane and HCN are discussed in the context of the primitive terrestrial atmosphere,using a detailed numerical model. In the absenceof abundant O2, absorption of solar EUV (λ < 1023Å) by N2 provides a large thermosphersic source of atomic nitrogen. Methane is oxidized cleanly and efficiently,provided CO2 is more abundant than CH,•. Otherwise,a large fraction of the methane…