High-energy chemistry of formamide: a simpler way for nucleobase formation.

The formation of nucleobases from formamide during a high-energy density event, i.e., the impact of an extraterrestrial body into the planetary atmosphere, was studied by irradiation of formamide ice and liquid samples with a high-power laser in the presence of potential catalysts. FTIR spectroscopy, time-resolved emission spectroscopy, and GC-MS were subsequently used to monitor the dissociation of this molecule into stable molecular fragments (HCN, H2O, HNCO, H2, CO, and NH3) and unstable species (HNC, •CN, and •NH). The kinetic and thermodynamic models of the high-energy density event molecular dynamics have been suggested together with the reaction routes leading from the dissociation products to the nucleobases. In addition, using theoretical calculations, we propose a simple new reaction pathway for the formation of both pyrimidine and purine nucleobases involving •CN radical chemistry.