Organic synthesis from reducing models of the atmosphere of the primitive earth with UV light and electric discharges

Abstract

The purpose of this paper is to compare the role of UV light and of electric discharges, the two most important sources of energy on the primitive earth, in the synthesis of organic compounds out of a reducing model of that atmosphere. Since Miller's experiments in 1953, most of the experimental simulations have been performed with electric discharges, and it has been assumed that UV radiations would give similar results. In order to check this assumption we have performed both experimental simulations in our laboratory. Experimental results indicate that this assumption was wrong in a large extent. Our four main conclusions are: 1. Unlike electric discharges, UV light is not an efficient source for producing unsaturated carbon chains. 2. UV light is efficient for producing nitriles in CH4--NH3 mixtures when the mole fraction of NH3 is very low while electric discharges need a higher mole fraction of NH3. 3. UV light is not able to produce nitriles from CH4--N2 mixtures while electric discharges produce important quantities of diversified nitriles from these mixtures. 4. UV light is not very efficient for producing aldehydes from CH4--H2O model atmosphere, electric discharges seem to be able to produce them more efficiently.