June 20, 2022

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…

zach Uncategorized 0 25 sec read
June 20, 2022

The Radiolysis of Aqueous Ammonium Cyanide: Compounds of Interest to Chemical Evolution Studies

Authors: Z. D. Draganić, V. Niketić, S. Jovanović, I. G. Draganić Oxygen-free aqueous solutions of NH4CN (0.1 M, pH 9) were exposed to gamma rays from a60Co source, the mixture of nonvolatile products was fractionated, and the fractions were analyzed. The procedures were chosen to make effective investigations of radiolytic products, and to minimize the contributions of chemical changes which…

zach Uncategorized 0 57 sec read
June 20, 2022

Radiolysis of Pyrimidines in Aqueous Solutions

Authors: G. A. Infante, P. Jirathana, J. H. Fendler, E. J. Fendler Product yields in the reaction of e;,, .H, -OH and CI,. with thymine and those in the reaction of e^(-)aq and .OH/O-. with thymine- have been determined quantitatively in 60-co-irradiated aqueous thymine solutions in the presence of suitable scavengers. Good material balances between G(- thymine) and G(total products)…

zach Uncategorized 0 30 sec read
June 20, 2022

An efficient prebiotic synthesis of cytosine and uracil

Authors: M. P. Robertson, S. L. Miller IN contrast to the purines, the routes that have been proposed for the prebiotic synthesis of pyrimidines from simple precursors give only low yields. Cytosine can be synthesized from cyano-acetylene and cyanate; the former precursor is produced from a spark discharge in a CH4/N2 mixture and is an abundant interstellar molecule. But this…

zach Uncategorized 0 49 sec read
June 20, 2022

Polyphosphate and Trimetaphosphate Formation under Potentially Prebiotic Conditions

Authors: R. Osterberg, L. E. Orgel When ammonium dihydrogen phosphate is heated with urea to temperatures in the range 85–100°C, it polymerizes almost quantitatively to give polyphosphates containing, on the average, more than ten (PO3) residues. Similar experiments carried out at 72°C give polyphosphate in more than 60% yield. If a nucleoside (thymidine or 3′-deoxythymidine) is added to the reaction…

zach Uncategorized 0 21 sec read

Archives

Categories

Meta