ISSN:
1432-1432
Keywords:
Ammonia Photolysis
;
Photocatalytic Synthesis
;
Abiotic Synthesis
;
Carbon Monoxide
;
Mars
;
Primitive Earth
;
Interstellar Space
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary The major photoproduct obtained on irradiation of gaseous NH3 and CO mixtures is ammonium cyanate; lesser amounts of urea, biurea, biuret semi-carbazide, formamide and cyanide were observed. The formation of the major gas phase photolysis product may be rationalized by the following reaction sequence: Urea is probably formed from NH4NCO in a thermal reaction while formamide may result from the disproportionation of NH2CO. Photocatalytic syntheses of14C-urea, -formamide, and -formaldehyde are effected by irradiation of14CO and NH3 in the presence of Vycor, silica gel, or volcanic ash shale surfaces. These syntheses are catalyzed by ultraviolet wavelengths longer than those absorbed by the gaseous reactants. The syntheses are also effected when the surface material is first irradiated in the presence of CO followed by a dark incubation with NH3. Apparently, the initiating step is a light dependent formation of a reactive form of CO on the surface. A discussion is given on the possible contribution of these reactions to the abiotic synthesis of organic nitrogen compounds on Mars, on the primitive Earth and in interstellar space.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01741243
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