Hydrazines and carbohydrazides produced from oxidized carbon in Earth's primitive environment

Abstract

Our ideas of the possible composition of the atmosphere of the primitive Earth have broadened markedly since Oparin's¹ and Urey's² postulates of a highly reducing atmosphere containing hydrogen, ammonia, hydrocarbons and water. Since then, various geochemical models of the primordial atmosphere have been proposed^3–6. Of importance is whether abiological organic compounds can be formed from the interactions of energy sources with nitrogen, oxidized carbon and water. Experiments involving electrical discharge^5,7 and bombardment with beams of He ions⁶ of various mixtures of CO, CO₂, N₂, H₂ and H₂O suggested that formic acid was the major organic product. We now report experiments using quenched spark discharges through molecular nitrogen on aqueous suspensions of CaCO₃ and other reactants to simulate the atmosphere/hydrosphere interface. Hydrazine and carbohydrazide are recovered in significant but low yields. Their reactions in primitive aquatic environments could have supplied a pathway for chemical evolution and the origin of life on a primitive Earth in which carbon in the fully oxidized states was available for the primary synthesis of organic matter.