Affiliation:
1. Department of Geosciences, Pennsylvania State University, 116 Deike Building, University Park, PA 16802, USA
Abstract
Hydrothermal systems are areas in which heated fluids and organic molecules rush through basaltic material rich in metals and minerals. By studying malononitrile and acetonitrile, we examine the effects of metal and mineral nanoparticles on nitrile compounds in anoxic, hydrothermal conditions representing a prebiotic environment of early Earth. Polymerization, reduction, cyclization, and a phenomenon colloquially known as ‘chemical gardening’ (structure building via reprecipitation of metal compounds or complexing with organics) are all potential outcomes with the addition of metals and minerals. Reduction occurs with the addition of rhodium (Rh) or iron (II) sulfide (FeS), with positive identification of ethanol and ethylamine forming from acetonitrile reduction. We find that polymerization and insoluble product formation were associated with oxide minerals, metallic nickel (Ni), and metallic cobalt (Co) acting as catalysts. Oxide minerals strongly promoted polymerization into insoluble, tar-like products of nitriles. FeS, iron-nickel alloy (FeNi), and rhodium are unique cases that appear to act as reagents by actively participating in chemical gardening without returning to their initial state. Further, FeS tentatively had a phase change into the mineral parabutlerite. This research aims to identify metals and metal minerals that could best serve nitrile catalysis and reactions on early Earth.
Subject
Paleontology,Space and Planetary Science,General Biochemistry, Genetics and Molecular Biology,Ecology, Evolution, Behavior and Systematics
Reference59 articles.
1. Shock, E.L. (1996). Novartis Foundation Symposium, Wiley.
2. Hydrothermal serpentinization of peridotite within the oceanic crust: Experimental investigations of mineralogy and major element chemistry;Janecky;Geochim. Cosmochim. Acta,1986
3. Kobayashi, K., and Yanagawa, H. (2002). Biological Systems Under Extreme Conditions: Structure and Function, Springer.
4. An off-axis hydrothermal vent field near the Mid-Atlantic Ridge at 30° N;Kelley;Nature,2001
5. Organic synthesis during fluid mixing in hydrothermal systems;Shock;J. Geophys. Res.,1998