Reactions of hydrocarbons with mixtures of active nitrogen and hydrogen atoms. III. Reactions of methylacetylene and allene

1968 ◽  
Vol 72 (9) ◽  
pp. 3323-3326 ◽  
Author(s):  
David R. Safrany ◽  
Walter Jaster

1965 ◽  
Vol 43 (4) ◽  
pp. 935-939 ◽  
Author(s):  
P. A. Gartaganis

The reaction of active nitrogen with ethanol has been investigated in the range 300 to 593 °K using a modified condensed-discharge Wood–Bonhoeffer fast-flow system. The only condensable products found in appreciable amounts were hydrogen cyanide and water. Hydrogen was the main noncondensable product. A very small amount of acetaldehyde was also formed along with traces of ethane, ethylene, methane, acetonitrile, cyanogen, and probably carbon monoxide. The overall activation energy is 3.4 kcal/mole. It is postulated that the mechanism consists of the formation of two fragments NC2H5 and OH, from which the condensable products result as follows:[Formula: see text]A number of products found in trace quantities are produced by concomitant reactions of the hydrogen atoms with methyl radicals, and with ethanol as well as by disproportionation of ethyl radicals to produce ethane and ethylene. A preliminary study of the reaction of active nitrogen with isopropanol indicated that the energy of activation is in line with the energies of activation of methanol and ethanol.



1964 ◽  
Vol 42 (8) ◽  
pp. 1948-1956 ◽  
Author(s):  
W. E. Jones ◽  
C. A. Winkler

The reactions of active nitrogen with ethane, propane, and neopentane have been studied over the temperature range 0 to 450 °C. A cobalt probe technique was used to stop the reactions after various reaction times. Second order rate constants have been calculated on the assumption that nitrogen atoms are the only reactive species in active nitrogen. Broken Arrhenius lines were obtained for both the ethane and neopentane reactions but this behavior was not observed with the propane reaction. The dual activation energies have been attributed to a mechanism involving initiation by both excited molecules and either nitrogen or hydrogen atoms. Methods are outlined by which an estimate has been made of the concentration of excited species assumed to be involved in the ethane reaction.



1955 ◽  
Vol 33 (4) ◽  
pp. 692-698 ◽  
Author(s):  
G. R. Freeman ◽  
C. A. Winkler

Hydrazine was completely destroyed by active nitrogen, at both 150 °C. and 480 °C., up to a hydrazine flow rate of about 22 × 10−6 mole per sec., whereas ammonia production was small at hydrazine flow rates below about 12 × 10−6 mole per sec. Thus it appears that ammonia is formed in secondary reactions only. The results indicate that NH2 radicals rather than hydrogen atoms may be prominent in secondary reactions. Comparison of the rate of hydrazine destruction with the rate of production of hydrogen cyanide from ethylene indicates that excited nitrogen molecules do not make a large contribution to the chemical reactivity of active nitrogen.



1963 ◽  
Vol 41 (5) ◽  
pp. 1097-1103 ◽  
Author(s):  
M. J. Sole ◽  
P. A. Gartaganis

The reaction of active nitrogen with methanol has been investigated at several temperatures in the range 30 to 480 °C using a fast-flow system. The only condensable products found in appreciable amounts were water and hydrogen cyanide. The overall activation energy is 3.0 and 3.2 kcal/mole and the steric factors 1.3 × 10−3 and 2.1 × 10−3 for streamline and turbulent flow respectively.It is postulated that the mechanism consists of the initial formation of a collision complex, [NCH3OH], which breaks down to two fragments, NCH3 and OH, from which the two condensable products are formed,[Formula: see text]Attack of the methanol molecules by hydrogen atoms resulting from the main reaction occurs to a lesser extent and is responsible for the production of small quantities of methane, carbon monoxide, and additional water.





1962 ◽  
Vol 40 (2) ◽  
pp. 240-245 ◽  
Author(s):  
C. Mavroyannis ◽  
C. A. Winkler

The reaction has been studied in a fast-flow system by the addition of atomic hydrogen to active nitrogen. Hydrogen atom concentrations were estimated from the maximum destruction of hydrogen bromide in the atomic hydrogen stream. The nitrogen atom consumption, in the reaction mixture, was determined by addition of nitric oxide at different positions along the reaction tube. A lower limit of 4.87 ± 0.8 × 1014 cc2mole−2sec−1 was derived for the rate constant of the reaction of nitrogen atoms with hydrogen atoms, over the pressure range 2.5 to 4.5 mm, in an unheated reaction tube, poisoned with phosphoric acid. No reaction between nitrogen atoms and molecular hydrogen was observed, even at 350 °C.



1957 ◽  
Vol 35 (11) ◽  
pp. 1298-1303 ◽  
Author(s):  
D. M. Wiles ◽  
C. A. Winkler

Hydrogen chloride was apparently destroyed by catalyzing the recombination of nitrogen atoms, the maximum observed rate of destruction being less than one sixth of the active nitrogen flow rate. The effects on the hydrogen chloride – active nitrogen reaction of added chlorine and added hydrogen indicated the reaction between hydrogen atoms and molecular chlorine to be the most important secondary reaction.



1956 ◽  
Vol 34 (10) ◽  
pp. 1457-1463 ◽  
Author(s):  
P. A. Gartaganis ◽  
C. A. Winkler

Reinvestigation of the active nitrogen – methane reaction in the temperature range 45° to 500 °C. has confirmed hydrogen cyanide as the only product, other than hydrogen, formed in measurable amounts. An “induction” effect in the hydrogen cyanide production was observed with increase of methane flow rate. This induction decreased with increase of temperature and was shown to be due to concomitant hydrogen atom reactions, since it could be eliminated by addition of hydrogen atoms to the reaction mixture. Reinvestigation of the active nitrogen – ethane reaction over the temperature range −100° to 475 °C. also confirmed hydrogen cyanide to be the only measurable product, other than hydrogen, of that reaction. There was some indication that an induction effect was present with ethane, as with methane, and it may be concluded tentatively that both reactions are carried substantially by hydrogen atom reactions.



1967 ◽  
Vol 31 ◽  
pp. 91-93 ◽  
Author(s):  
G. Herzberg

It is suggested that the diffuse interstellar lines are produced in the interstellar gas by molecules consisting of a few hydrogen atoms and one other atom, such as CH4+ or NH4. Diffuseness of the lines is assumed to result from predissociation of these molecules.



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