W. Paplawsky

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The sources and speciation of reduced carbon and nitrogen inferred for the early Archean are reviewed in terms of current observations and models, and known chemical reactions. Within this framework hydrogen cyanide and cyanide ion in significant concentration would have been eliminated by reaction with excess formaldehyde to form cyanohydrin(More)
A range of naturally occurring divalent-trivalent metal cation hydroxides and modified artifical analogs have been synthesized and characterized. Structural and chemical properties of these minerals, determining their capability to selectively concentrate, order and alter molecules of prebiotic interest, include their anion exchange capacity and(More)
The crystal structures of synthetic 7 angstrom and 10 angstrom manganates, synthetic birnessite and buserite, substituted by mono- and divalent cations were investigated by X-ray and electron diffractions. The monoclinic unit cell parameters of the subcell of lithium 7 angstrom manganate, which is one of the best ordered manganates, were obtained by(More)
Photoemission and solvation of electrons from iron (II) ion in aqueous solution has been shown to lead to reduction of water to hydrogen (Cairns-Smith, 1981; Braterman et al., 1983). In the presence of dissolved carbon dioxide the photochemical reduction yields formate, oxalate and aldehydes, (Getoff 1963; ~kermark et al., 1980). These species are formed in(More)
The concentration of ammonia from dilute aqueous solution could have facilitated many prebiotic reactions. This may be especially true if this concentration involves incorporation into an organized medium. We have shown that (unlike iron(III) ferrocy anide) zinc ferrocyanide, Zn2 Fe (CN)6·xH2O, preferentially takes up ammonium ions from 0.01 M NH4Cl to give(More)
Synthesis and investigation of such minerals show common representatives to be efficient concentrators of cyanide and ferrocyanide, phosphate and diphosphate (pyrophosphate), carbonate and bicarbonate; the latter have, in solution, or in surface reactions, been shown to be photoreducable_ precursors of formate and formaldehyde (Garrison et al., 1951;(More)
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