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Ferris, J. P.

Publications and source records attributed to Ferris, J. P..

51 records · Page 3
All sourcesNASA NTRSDOE OSTI
NASA NTRS1981

Irradiation of NH3-CH4 mixtures as a model of photochemical processes in the Jovian planets and Titan

The reactions occurring upon the ultraviolet irradiation of ammonia-methane mixtures are investigated in a simulation of the atmospheric chemistry of the Jovian planets and Titan. Gas mixtures were irradiated at 185 nm at temperatures from 156-298 K, and product and reactant concentrations were determined by means of gas chromatography. The ratio of the moles of CH4 lost per mole of NH3 decomposed is found to be 0.25, with the extent of CH4 decomposition independent of temperature. The absence of a temperature effect suggests that nonthermal atoms, probably hydrogen, initiate CH4 decomposition by the extraction of a hydrogen atom. A decrease in CH4 loss with increasing pressure or the addition of other gases to the photolysis mixture, and the lack of an increase in NH3 photolysis with CH4 pressure support this mechanism. Major reaction products obtained include C2H2, C3H8 or CH3NH2, and C4H10. Considerations of atmospheric concentrations of H2 and He indicate that NH3 photolysis does not contribute to CH4 decomposition on Jupiter, Saturn, Uranus, and Neptune, although it may have had a role in the formation of the Titan atmosphere.

Ferris, J. P.↗
NASA NTRS1981

Structural studies on HCN oligomers

NMR spectral studies on the HCN oligomers suggest the presence of carboxamide and urea groupings. The release of CO2, H2O, HCN, CH3CN, HCONH2 and pyridine on pyrolysis is consistent with the presence of these groupings as well as carboxylic acid groups. No basic primary amine groupings could be detected with fluorescamine. Hydrazinolysis of the HCN oligomers releases 10% of the amino acids normally released by acid hydrolysis. The oligomers give a positive biuret test but this is not due to the presence of peptide bonds. There is no conclusive evidence for the presence of peptide bonds in the HCN oligomers. No diglycine was detected on partial hydrolysis of the HCN oligomers at pH 8.5 suggesting that HCN oligomers were not a source of prebiotic peptides.

Ferris, J. P.↗
NASA NTRS1981

Photolysis of CH4-NH3 mixtures and PH3 as models for the photochemical transformations on the primitive earth and Jupiter

Methane, ammonia and phosphine are some of the possible constituents of the atmospheres of the Jovian planets and their satellites. Photolysis of NH3 in the presence of CH4 at 185 nm in the temperature range of 25 C to -100 C results in the decomposition of CH4. The reaction is inhibited by added H2 or SF6. These findings are consistent with the reaction of hot hydrogen atoms with CH4 to give the CH3 radical. P2H4 is the initial product formed by the photolysis of PH3 at 206 nm. Kinetic studies established that it is the intermediate in the formation of P4 from PH3. The potential significance of these reactions to the atmospheric photochemistry of the Jovian planets and moons is discussed.

Ferris, J. P.↗
NASA NTRS1981

Clay-mediated reactions of HCN oligomers - The effect of the oxidation state of the clay

Montmorillonite clays which contain Fe(III) inhibit the oligomerization of aqueous solutions of HCN. The inhibitory effect is due to the rapid oxidation of diaminomaleonitrile, a key intermediate in HCN oligomerization, by the Fe(III) incorporated into the aluminosilicate lattice of the clay. The Fe(III) oxidizes diaminomaleonitrile to diiminosuccinonitrile, a compound which is rapidly hydrolyzed to HCN and oxalic acid derivatives. Diaminomaleonitrile is not oxidized when Fe(III) in the montmorillonite is reduced with hydrazine. The oxidation state of the clay is an important variable in experiments designed to simulate clay catalysis on the primitive earth.

Ferris, J. P.↗
NASA NTRS1980

Diphosphine is an intermediate in the photolysis of phosphine to phosphorus and hydrogen

The photolysis of phosphine to red phosphorus (P4) and hydrogen is investigated in light of the potential significance of the reaction in the atmospheric chemistry of Jupiter. It is reported that the photolysis of PH3 at room temperature by a 206.2-nm light source gave rise to a product identified by its UV and IR spectra and gas chromatographic retention time as P2H4, the yield of which is found to increase to a maximum and then decrease to 20% of the maximum value with illumination time. A mechanism for phosphine photolysis including diphosphine formation as an intermediate step is proposed, and it is concluded that P2H4 is a likely constituent of the atmospheres of the Jovian planets.

Ferris, J. P.↗
NASA NTRS1978

Chemical evolution. XXIX - Pyrimidines from hydrogen cyanide

Compounds obtained by hydrolysis of HCN oligomers formed by allowing pH 9.2, 0.1 M cyanide to stand at room temperature for 4 to 12 months were analyzed. Hydrolysis of HCN oligomers yielded 4,5-dihydroxypyrimidine and 5-hydroxyuracil; orotic acid was detected after hydrolysis at pH 8.5. A unified pathway from diaminofumaronitrile to the pyrimidines observed is suggested. As purines, pyrimidines and amino acids are released by hydrolysis of HCN oligomers in either acidic or mildly basic aqueous solutions, they could have been formed on the primitive earth in spite of fluctuations in pH. 4,5-dihydroxypyrimidines appear to be likely candidates for incorporation into primitive nucleic acids, as they should undergo Watson-Crick hydrogen bonding with adenine.

Ferris, J. P.↗
NASA NTRS1975

Photosynthesis of organic compounds in the atmosphere of Jupiter

An efficient conversion of CH4 to hydrocarbons and HCN takes place when NH3 is photolysed in the presence of CH4, H2, and He using a 184.9 nm light source. The extent of NH3 decomposition after a 1 hr exposure was determined spectrophotometrically; CH4, N2, and C2 and C3 hydrocarbons were detected and analyzed by mass spectrometry. Photolysis of one molar equivalent of NH3 results in the loss of 0.84 molar equivalent of CH4, which apparently reacts with hot hydrogen atoms produced by photolysis. The 8% of the NH3 which is not converted to N2 probably is converted to organic amines and nitrile derivatives. The results indicate that NH3 photolysis is a highly probable mechanism for the conversion of methane to more complex hydrocarbons in the upper atmosphere of Jupiter, and predict the occurrence of HCN, NH2NH2, and higher hydrocarbons in the Jovian atmosphere above the NH3 clouds.

Ferris, J. P.↗
NASA NTRS1975

Ultraviolet-gas phase and -photocatalytic synthesis from CO and NH3

Ammonium cyanate is identified as the major product of the photolysis of gaseous NH3-CO mixtures at 206.2 or 184.9 nm. Lesser amounts of urea, biurea, biuret semicarbazide, formamide and cyanide are observed. A series of 18 reactions underlying the formation of photolysis products is presented and discussed. Photocatalytic syntheses of C-14-urea, -formamide, and -formaldehyde are carried out through irradiation of (C-14)O and NH3 in the presence of Vycor, silica gel, or volcanic ash shale surfaces. The possible contributions of the relevant reactions to the abiotic synthesis of organic nitrogen compounds on Mars, the primitive earth, and in interstellar space are examined.

Hubbard, J. S.↗
NASA NTRS1974

Photolysis of CO-NH3 mixtures and the Martian atmosphere

It has already been noted (Ferris and Nicodem, 1972) that although neither CO2 nor H2O affected the rate of NH3 photolysis, CO accelerated the photodecomposition of ammonia, with the formation of a solid product. The photolysis of NH3 in the presence of CO is investigated in greater detail not only because of the potential significance to atmospheric photochemistry on Mars, but also because of the possibility of photocatalytic reactions of NH3 and CO on the Martian surface and in the interstellar medium. These photoreactions may also have occurred on the primitive earth.

Ferris, J. P.↗
NASA NTRS1974

Biomolecules from HCN

It has been suggested by Sanchez et al. (1967) that HCN might have been one of the more important precursors of biological molecules on the primitive earth. Studies were conducted to determine the mechanisms involved in HCN oligomerizations in dilute aqueous solutions and to identify the compounds which are produced in these oligomerization mixtures. Indirect evidence for the formation of cyanate was obtained along with direct evidence for the formation of citrulline, aspartic acid, and orotic acid.

Ferris, J. P.↗
NASA NTRS1974

Chemical evolution. XXI - The amino acids released on hydrolysis of HCN oligomers

Major amino acids released by hydrolysis of acidic and basic HCN oligomers are identified by chromatography as Gly, Asp, and diaminosuccinic acid. Smaller amounts of Ala, Ile and alpha-aminoisobutyric acid are also detected. The amino acids released did not change appreciably when the hydrolysis medium was changed from neutral to acidic or basic. The presence of both meso and d, l-diaminosuccinic acids was established by paper chromatography and on an amino acid analyzer.

Ferris, J. P.↗
NASA NTRS1974

Ammonia - Did it have a role in chemical evolution

The significance of ammonia in the chemical evolution related to the origin of life is evaluated. A computer program was employed to calculate the time needed for the decomposition of ammonia by means of a photochemical reaction. Various possible protection mechanisms for ammonia are discussed, giving attention to hydrogen sulfide, hydrogen, ozone, and CO. It is concluded that in the absence of a sufficiently high pressure of hydrogen, any ammonia present in the primitive atmosphere would have been decomposed by photolysis in a million years.

Ferris, J. P.↗
NASA NTRS1973

Ammonia photolysis on Jupiter.

Ammonia photolysis under simulated Jovian conditions indicates that the photochemical reaction would rapidly convert all the ammonia of Jupiter to nitrogen even in a large excess of hydrogen. It is suggested that ammonia is observed because the planet's atmosphere is deep and hot and/or because electrical discharge phenomena are important.

Nicodem, D. E.↗