Photochemical reactions of water and carbon monoxide in Earth's primitive atmosphere

The gas‐phase photolysis of H 2 O at 1849 Å in the presence of CO yields mainly CO 2 and H 2 and a variety of organic compounds, including C 1 −C 3 hydrocarbons, alcohols, aldehydes, acetone, and acetic acid. The overall quantum yield for conversion of CO to organic compounds varies between 0.23 and 0.03 as a function of the CO abundance. These results indicate that even if primitive earth's atmosphere initially contained no molecular hydrogen and contained carbon only in the form of CO or a mixture of CO and CO 2 , the prebiotic environment would have become enriched with a variety of organic compounds produced by photochemical processes.