Early-Earth small molecule reactions : an experimental survey of submarine alkaline hydrothermal vent chemistry

Abstract

Alkaline hydrothermal vents provide a variety of chemical reagents and conditions that may provide insight as to how life emerged on Earth. This study examined small molecule chemistry under conditions found at these vents. Two major experiments were preformed using small molecules that are generated and available at hydrothermal vents. CO[subscript 2]-switchable ionic liquids were the medium for small molecule reactions to occur. Reactions between cyanamide (CH[subscript 2]N[subscript 2]) and glycolaldehyde (C[subscript 2]H[subscript 4]O[subscript 2]) produced 2-aminooxazole (C[subscript 3]H[subscript 4]N[subscript 2]O) were set up in water, but failed to produce a result in CO[subscript 2]-switchable ionic liquids. Exploration of the reaction of CS[subscript 2] with acetate (CH[subscript 3]COO[superscript -]) in acetonitrile with CO[subscript 2] passing over resulted in a product that could not be identified. Interestingly, CO[subscript 2] and CS[subscript 2] exchanged oxygen and sulfur in the presence of acetate. Thus, suggested that a metal catalyst is not necessary for CO[subscript 2]/CS[subscript 2] scrambling. Observations of this phenomenon demonstrated that CO[subscript 2] and CS[subscript 2] are more dynamic at low temperature and pressure conditions than previously thought. The Finding of this study show that there is still much to understand about small molecule under pre-biotic conditions.