THE REACTION OF ACTIVE NITROGEN WITH ETHANOL

1965 ◽  
Vol 43 (4) ◽  
pp. 935-939 ◽  
Author(s):  
P. A. Gartaganis
Keyword(s):  
Flow System ◽  
Methyl Radicals ◽  
Kcal Mole ◽  
Hydrogen Atoms ◽  
Active Nitrogen ◽  
Condensed Discharge ◽  
Preliminary Study ◽  
Fast Flow ◽  
Ethyl Radicals ◽  
Water Hydrogen

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.

THE REACTION OF ACTIVE NITROGEN WITH METHANOL

1963 ◽  
Vol 41 (5) ◽  
pp. 1097-1103 ◽  
Author(s):  
M. J. Sole ◽  
P. A. Gartaganis
Keyword(s):  
Hydrogen Cyanide ◽  
Flow System ◽  
Main Reaction ◽  
Kcal Mole ◽  
Hydrogen Atoms ◽  
Active Nitrogen ◽  
Steric Factors ◽  
Additional Water ◽  
Fast Flow ◽  
Methane Carbon

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.

THE KINETICS OF THE REACTION OF ATOMIC HYDROGEN WITH METHANE

1964 ◽  
Vol 42 (7) ◽  
pp. 1638-1644 ◽  
Author(s):  
J. W. S. Jamieson ◽  
G. R. Brown
Keyword(s):  
Activation Energy ◽  
Electric Discharge ◽  
Atomic Hydrogen ◽  
Flow System ◽  
Steric Factor ◽  
Primary Reaction ◽  
Kcal Mole ◽  
Hydrogen Atoms ◽  
Fast Flow ◽  
Kinetics Of

Reinvestigation of the reaction of hydrogen atoms, produced by electric discharge, with methane in a fast flow system has given an activation energy of 7.4 ± 1.1 kcal/mole and a steric factor of about 10−3 for the primary reaction, H + CH4 → H2 + CH3.

THE REACTION OF NITROGEN ATOMS WITH HYDROGEN ATOMS

1962 ◽  
Vol 40 (2) ◽  
pp. 240-245 ◽  
Author(s):  
C. Mavroyannis ◽  
C. A. Winkler
Keyword(s):  
Atomic Hydrogen ◽  
Molecular Hydrogen ◽  
Pressure Range ◽  
Flow System ◽  
Hydrogen Bromide ◽  
Hydrogen Atoms ◽  
Active Nitrogen ◽  
Reaction Tube ◽  
Fast Flow ◽  
Hydrogen Stream

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.

Reactions of free radicals with aromatic compounds in the gaseous phase. I. Kinetics of the reaction of methyl radicals with toluene

1964 ◽  
Vol 17 (12) ◽  
pp. 1329 ◽  
Author(s):  
MFR Mulcahy ◽  
DJ Williams ◽  
JR Wilmshurst
Keyword(s):  
Flow System ◽  
Methyl Radicals ◽  
Methyl Radical ◽  
Hydrogen Atoms ◽  
Methyl Group ◽  
Benzyl Radical ◽  
Toluene Molecule ◽  
Benzyl Radicals ◽  
Butyl Peroxide ◽  
Kinetics Of

The kinetics of abstraction of hydrogen atoms from the methyl group of the toluene molecule by methyl radicals at 430-540�K have been determined. The methyl radicals were produced by pyrolysis of di-t-butyl peroxide in a stirred-flow system. The kinetics ,agree substantially with those obtained by previous authors using photolytic methods for generating the methyl radicals. At toluene and methyl-radical concentrations of about 5 x 10-7 and 10-11 mole cm-3 respectively the benzyl radicals resulting from the abstraction disappear almost entirely by combination with methyl radicals at the methylenic position. In this respect the benzyl radical behaves differently from the iso-electronic phenoxy radical, which previous work has shown to combine with a methyl radical mainly at ring positions. The investigation illustrates the application of stirred-flow technique to the study of the kinetics of free-radical reactions.

THE REACTION OF NITROGEN ATOMS WITH OXYGEN ATOMS IN THE ABSENCE OF OXYGEN MOLECULES

1961 ◽  
Vol 39 (8) ◽  
pp. 1601-1607 ◽  
Author(s):  
C. Mavroyannis ◽  
C. A. Winkler
Keyword(s):  
Nitric Oxide ◽  
Nitrogen Atom ◽  
Rate Constant ◽  
Rate Constants ◽  
Flow System ◽  
Titration Method ◽  
Active Nitrogen ◽  
Reaction Tube ◽  
Fast Flow ◽  
Oxygen Atoms

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.

THE PYROLYSIS OF TRIMETHYLTHALLIUM

1965 ◽  
Vol 43 (7) ◽  
pp. 1961-1967 ◽  
Author(s):  
M. G. Jacko ◽  
S. J. W. Price
Keyword(s):  
Activation Energy ◽  
Rate Constant ◽  
Total Pressure ◽  
Flow System ◽  
Total Darkness ◽  
Methyl Radicals ◽  
Kcal Mole ◽  
Homogeneous Process ◽  
Carrier Flow ◽  
Reaction Proceeds

The pyrolysis of trimethylthallium has been studied in a toluene carrier flow system from 458 to 591 °K using total pressures from 5.6 to 33.0 mm. The progress of the reaction was followed by measuring the amount of methane, ethane, ethylene, and ethylbenzene formed and, in 21 runs, by direct thallium analysis. All preparative and kinetic work was carried out in total darkness where possible. A shielded 10 W lamp was used when some illumination was necessary.The decomposition is approximately 80% heterogeneous in an unconditioned vessel and 14–27% heterogeneous in a vessel pretreated with hot 50% HF for 10 min. The reaction proceeds by the simple consecutive release of three methyl radicals. The rate constant depends only slightly on the total pressure in the system so that the activation energy of the homogeneous process, 27.4 kcal/mole, may be equated to D[(CH3)2Tl—CH3].

THE REACTION OF HYDROGEN ATOMS WITH KETENE

1964 ◽  
Vol 42 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Nick Demchuk ◽  
H. Gesser
Keyword(s):  
Carbon Monoxide ◽  
Gas Phase ◽  
Surface Reaction ◽  
Flow System ◽  
Minor Amount ◽  
Phase Reaction ◽  
Hydrogen Atoms ◽  
A Chain ◽  
Fast Flow ◽  
A Minor

The gas-phase reaction of atomic hydrogen with ketene has been investigated over a temperature range of −130° to 232 °C using a low-pressure, fast-flow system. In most cases methane, carbon monoxide, and ethane were the major products, but trace amounts of glyoxal were also detected. Above −96 °C. considerable evidence exists for the occurrence of a chain reaction carried by HCO radicals. The surface reaction at −196 °C produced methane and glyoxal predominantly with only a minor amount of carbon monoxide.

Abstraction of hydrogen atoms from bicyclo[2.1.1]hexane by methyl radicals and chlorine atoms: photochlorination of 1-methylbicyclo[2.1.1]hexane

1969 ◽  
Vol 47 (10) ◽  
pp. 1627-1631 ◽  
Author(s):  
R. Srinivasan ◽  
F. I. Sonntag
Keyword(s):  
Activation Energy ◽  
Room Temperature ◽  
Methyl Radicals ◽  
Absolute Rate ◽  
Methyl Radical ◽  
Kcal Mole ◽  
Hydrogen Atoms ◽  
Chlorine Atoms ◽  
Exponential Factor ◽  
Highly Strained

Photolysis of acetone has been used as a source of methyl radicals to study the abstraction of hydrogen atoms from bicyclo[2.1.1]hexane by methyl radicals. The reaction was found to have an activation energy of 10.3 kcal/mole and a pre-exponential factor that is typical of other abstraction reactions. The absolute rate of abstraction of hydrogen atoms from bicyclo[2.1.1]hexane by chlorine atoms at room temperature was measured to be 8.1 × 1010 l mole−1 s−1. The photochlorination of 1-methylbicyclo-[2.1.1]hexane in solution gave both the 1-chloromethyl and 2- or 3-chloro-1-methylbicyclohexanes. The relative rates of attack at the methyl and the 2- or 3- position were determined to be 1:2.1. It is pointed out that the rate parameters for the abstraction of an H atom from bicyclo[2.1.1]hexane by a methyl radical are slower than for cyclopentane, as would be expected for a highly strained hydrocarbon, whereas the abstraction by chlorine is slightly faster than the rate for cyclopentane.

An electron spin resonance study of the reactions of hydrogen atoms with halocarbons

1986 ◽  
Vol 64 (11) ◽  
pp. 2192-2195 ◽  
Author(s):  
William E. Jones ◽  
Joseph L. Ma
Keyword(s):  
Rate Constants ◽  
Gas Flow ◽  
Esr Spectroscopy ◽  
Flow System ◽  
Electron Spin Resonance Study ◽  
Absolute Rate ◽  
Hydrogen Atoms ◽  
Vinyl Halides ◽  
Spin Resonance ◽  
Spin Resonance Study

The absolute rate constants for the reaction of H atoms with methyl- and vinyl-halides have been determined using esr spectroscopy and a conventional gas flow system. The rate constants determined at 298 ± 2 K at a pressure of 0.55 Torr are methane, (1.7 ± 0.3) × 10−17; ethane, (2.3 ± 0.5) × 10−17; methylfluoride, (4 ± 3) × 10−15; methylchloride, (8 ± 2) × 10−16; methylbromide, (2.1 ± 0.6) × 10−14; vinylfluoride, (1.47 ± 0.02) × 10−13; vinylchloride, (1.66 ± 0.08) × 10−13; and vinylbromide (4.07 ± 0.73) × 10−13 in units of cm3 molecule−1 s−1.

The reaction of active nitrogen with fluoroethylenes

1982 ◽  
Vol 60 (20) ◽  
pp. 2629-2633 ◽  
Author(s):  
William E. Jones ◽  
Mahmooda G. Ahmed
Keyword(s):  
Mass Spectrometer ◽  
Reaction Mechanisms ◽  
Flow System ◽  
Intermediate Species ◽  
Active Nitrogen ◽  
Reacting Mixtures

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.

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