The reaction of active nitrogen with fluoroethylenes

1982 ◽  
Vol 60 (20) ◽  
pp. 2629-2633 ◽  
Author(s):  
William E. Jones ◽  
Mahmooda G. Ahmed

The reactions of active nitrogen with the fluoroethylenes C2H3F, 1,1-C2H2F2, C2HF3, and C2F4 have been investigated in a conventional flow system using a mass spectrometer to detect products and intermediate species. Addition of various gases (H, H2, NH3, CH4, N2O, [Formula: see text], and F) to the reacting mixtures provides evidence that both Hand F atoms play significant roles in the reaction mechanisms, while [Formula: see text] does not. A brief discussion of possible mechanisms is presented.


1959 ◽  
Vol 37 (3) ◽  
pp. 579-582 ◽  
Author(s):  
John T. Herron ◽  
J. L. Franklin ◽  
Paul Bradt

The reactions of active nitrogen with acetylene, ethylene, and propylene have been studied in a flow system using a mass spectrometer to analyze the products continuously. Certain features of the mass spectra of the products can be explained on the basis of cyano radical replacement reactions.



The reaction of nitrogen atoms, produced by an electric discharge, with acetaldehyde has been studied in a flow system, a mass spectrometer being used to follow the course of the reaction. Sampling was carried out through a small hole in a gold diaphragm. The main stable products were HCN, H 2 and CO; a small amount of glyoxal was also formed. In addition appreciable amounts of a substance yielding ions of m/e = 43 were obtained. Arguments are presented for identifying this with the radical CH 2 CHO. Small amounts of a product giving ions of m/e = 86 were also produced. The nature of this material is discussed. No evidence was obtained for any hydrogen abstraction by nitrogen atoms. Experiments were also carried out with CH 3 CDO to clarify certain aspects of the proposed reaction mechanism . A few experimental results obtained with propionaldehyde can be understood in similar terms. The rate constant of the reaction N + CH 3 CHO → HCN + H 2 + HCO was deduced to be 1.20 ± 0.15 x 10 10 mole -1 cm 3 s -1 at 296°K.



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.





1961 ◽  
Vol 39 (8) ◽  
pp. 1601-1607 ◽  
Author(s):  
C. Mavroyannis ◽  
C. A. Winkler

The reaction has been studied in a fast-flow system by introducing nitric oxide in the gas stream with excess active nitrogen. The nitrogen atom consumption was determined by titrating active nitrogen with nitric oxide at different positions along the reaction tube. The rate constant is found to be k1 = 1.83(± 0.2) × 1015 cc2 mole−2 sec−1 at pressures of 3, 3.5, and 4 mm, and with an unheated reaction tube.The homogeneous and surface decay of nitrogen atoms involved in the above system were studied using the nitric oxide titration method, and the rate constants were found to be k3 = 1.04 ± 0.17 × 1016 cc2 mole−2 sec−1, and k4 = 2.5 ± 0.2 sec−1 (γ = 7.5 ± 0.6 × 10–5), respectively, over the range of pressures from 0.5 to 4 mm with an unheated reaction tube.





2000 ◽  
Vol 6 (1) ◽  
pp. 65-77 ◽  
Author(s):  
Hui-Fen Wu ◽  
Ya-Ping Lin

Study of the reaction mechanisms for ion–molecule reactions and for collisionally-activated dissociations (CAD) of dopamine and adrenaline has been performed using an external chemical ionization source quadrupole ion trap mass spectrometer. This work demonstrates the possibility of applying an external source ion trap instrument to perform selective ion–molecule reactions in the gas phase, due to its high sensitivity and low detection limits in mass spectrometry/mass spectrometry (MS/MS) mode. CAD experiments on ions with relative intensity as low as 0–2%, formed as ion–molecule products of dopamine and adrenaline, have been successfully performed. Study of some fragment ions of M+• and [M + H]+, observed in the chemical ionization (CI) spectra, by CAD techniques, permits elucidation of a series of mechanisms for the sequential dissociations of the M+• and [M + H]+ ions. Thus, the structural information obtained from this method is similar to that which would have been obtained if MS n had been performed for M+• and [M + H]+ ions. From the proposed CAD reaction mechanisms and the semi-empirical calculations, the favored reactive sites for formation of the adduct ions could be determined. The reactive site for protonation of dopamine is on the amino group, but for adrenaline, it is on the benzylic hydroxyl group. As to the reactive site for the CH3O=C2H+ ion addition, dopamine is either on the amino group or on the phenyl ring. However, adrenaline is only on the benzylic hydroxyl group. Temperature effects on the formation of the ion–molecule products were also investigated. It was shown that the best source temperature for formation of [M + H]+ and [M + 13]+ ions of dopamine is 200°C. Information about use of dimethyl ether (DME) as the reagent gas in the external chemical ionization of an ion trap mass spectrometer is provided.



1968 ◽  
Vol 46 (22) ◽  
pp. 3483-3489 ◽  
Author(s):  
N. Madhavan ◽  
W. E. Jones

The reactions of the fluorocarbon olefins, C2F4, C3F6, and C4F8-2, with active nitrogen were studied in a flow system. The active nitrogen was produced by a microwave discharge at a concentration of 2.1 × 10−6 mole/s. The major gaseous products of the reactions are fluorocarbons and their production was studied quantitatively at the temperatures 25, 250, and 400 °C and at a large number of reactant flow rates to a maximum of approximately 3 × 10−6 mole/s.Three nitrogen-containing compounds, FCN, N2O, and a polymer of composition (C3F5N)n were detected as products in all three reactions; FCN and N2O are found only in very small amounts.Mechanisms for each of the reactions are discussed.



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.



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