Rate measurements of the hydrolysis of complex organic macromolecules in cold aqueous solutions: Implications for prebiotic chemistry on the early Earth and Titan

Organic macromolecules (complex tholins) were synthesized from a 0.95 N-2/0.05 CH4 atmosphere in a high-voltage AC flow discharge reactor. When placed in liquid water, specific water soluble compounds in the macromolecules demonstrated Arrhenius type first order kinetics between 273 and 313 K and produced oxygenated organic species with activation energies in the range of similar to 60 +/- 10 kJ mol(-1). These reactions displayed half lives between 0.3 and 17 days at 273 K. Oxygen incorporation into such materials - a necessary step toward the formation of biological molecules - is therefore fast compared to processes that occur on geologic timescales, which include the freezing of impact melt pools and possible cryovolcanic sites on Saturn's organic-rich moon Titan.