The Gamma Irradiation of Aqueous Solutions of Urea. Implications for Chemical Evolution

Authors: R. Navarro-González, A. Negrón-Mendoza, E. Chacón 0.05moledm-3,Oz-free aqueous solutions of urea were studies after receiving various doses of 6°Co gamma rays(0.14-600kGy). Urea was found to be relatively stable under radiation; its radiation chemical yield of decomposition was 0.47. Hydrogen (G=0.50), carbon dioxide (G=0.44), ammonia (G=0.22), oxalic acid (G=0.0054), malonic acid (G=0.000064)and three unidentified oligomers were found to be the…

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…

Nitrile gas chemistry in Titan’s atmosphere

Authors: T. Gautier, N. Carrasco, A. Buch, C. Szopa, E. Sciamma-O’Brien, G. Cernogora, This work presents the first study of the gaseous products resulting from the partial dissociation of meth- ane and nitrogen in the PAMPRE experimental setup simulating Titan’s atmospheric chemistry. Using cryogenic trapping, the gaseous products generated from the chemical reactions occurring in the reactor have been trapped….

High Energy Radical Chemistry Formation of HCN-rich Atmospheres on early Earth

Authors: M. Ferus, P. Kubelík, A. Knízek, A. Pastorek, J. Sutherland, S. Civiš Recent results in prebiotic chemistry implicate hydrogen cyanide (HCN) as the source of carbon and nitrogen for the synthesis of nucleotide, amino acid and lipid building blocks. HCN can be produced during impact events by reprocessing of carbonaceous and nitrogenous materials from both the impactor and the…

The Radiolysis of Aqueous Acetonitrile: Compounds of Interest to Chemical Evolution Studies

Authors: I.G. Draganić, S. Jovanić, V. Niketić, Z.D. Draganić, Oxygen-free aqueous solutions of CH3CN (0.1 M, pH 6) were ex- posed to gamma rays from a 60Co source,the mixture of non volatile radiolytic products was fractionated and the fractions were analysed. Succinic,maleic, fumaric, malonic andpyruvic acids were identified. Glycol aldehyde,glucose and probably ribose were observed in the hydrolysate of fractionated…

Spectroscopic investigations of high-energy-density plasma transformations in a simulated early reducing atmosphere containing methane,

Authors: M. Civiš, M. Ferus, A. Knížek, P. Kubelik, M. Kamas, P. Španel, K. Drahina, V. Shestivska, L. Juha, P. Skrehot, V. Laitl, S. Civiš Large-scale plasma was created in gas mixtures containing methane using high-power laser-induced dielectric breakdown (LIDB). The composition of the mixtures corresponded to a cometary and/or meteoritic impact into the early atmosphere of either Titan or…

Cyanomethylene Formation from the Reaction of Excited Nitrogen Atoms with Acetylene: A Crossed Beam and ab Initio Study

Authors: N. Balucani, M. Alagia, L. Cartechini, P. Casavecchia, G. G. Volpi, K. Sato, T. Takayanagi, Y. Kurosaki The reaction of excited nitrogen atoms, N(2D), with the simplest alkyne, C2H2, was investigated for the first time under single-collision conditions in crossed beam experiments with mass spectrometric detection. The experimental results combined with electronic structure calculations and RRKM predictions allow us…