Mechanism and rate constant of the reaction of oxygen atoms with acetylene

1965 ◽  
Vol 14 (3) ◽  
pp. 396-399 ◽  
Author(s):  
L. I. Avramenko ◽  
R. V. Kolesnikova ◽  
G. I. Savinova
Keyword(s):  
Rate Constant ◽  
Oxygen Atoms

Reaction of oxygen atoms with ethanol

1967 ◽  
Vol 45 (16) ◽  
pp. 1845-1861 ◽  
Author(s):  
A. Kato ◽  
R. J. Cvetanović
Keyword(s):  
Rate Constant ◽  
Vapor Phase ◽  
Room Temperature ◽  
Initial Reaction ◽  
Reaction Products ◽  
Absolute Value ◽  
Oxygen Atoms

Reaction of O(3P) atoms with ethanol in the vapor phase has been studied at room temperature. The principal initial reaction products are water, acetaldehyde, and 2,3-butanediol. The data are consistent with abstraction of an α-hydrogen from ethanol as the primary step in the reaction. Ethanol is found to react with O(3P) atoms about 3.5 times less rapidly than acetaldehyde. The approximate absolute value of the rate constant of the ethanol reaction at 25 °C is 6.2 × 1010 cm3 mole−1 s−1.As a corollary to the investigation of the reaction of oxygen atoms with ethanol, a brief study has been made of the mercury Hg 6(3P1) photosensitized decomposition of ethanol at room temperature.

Kinetics of reactions involving CN emission IV. Study of the reactions of CN by electronic absorption spectroscopy

1968 ◽  
Vol 305 (1480) ◽  
pp. 107-123 ◽  
Keyword(s):  
Absorption Spectroscopy ◽  
Rate Constant ◽  
Electronic Absorption ◽  
Flow Reactor ◽  
Initial Step ◽  
Electronic Absorption Spectroscopy ◽  
Kinetics Of ◽  
Cn Radicals ◽  
Limiting Values ◽  
Oxygen Atoms

The kinetics of the reaction between oxygen atoms and cyanogen have been studied in a capacity flow reactor at temperatures between 570 and 687 °K. The concentration of CN radicals was measured by electronic absorption spectroscopy. This work confirms the previously proposed mechanism (part II). The initial step has a rate constant of k 1 = 2∙5 (± 0∙3) x 10 13 exp ( – 11000±2000/ RT ) cm 3 mole –1 s –1 . CN radicals are removed mainly by reactions (4) and (2) for which k 4 = 6∙3 (±3∙5) x 10 13 exp (–2400±700/ RT ) cm 3 mole –1 s –1 and k 2 = 4∙4 (±2∙0) x 10 12 cm 3 mole –1 s –1 . CN+O = CO+N, (4) CN+O 2 = NCO+O. (2) The rates of reaction of CN with NO and NH 3 were also measured; for CH 4 and H 2 limiting values were obtained.

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.

Rates of elementary processes in the chain reaction between hydrogen and oxygen I. Reactions of oxygen atoms

1963 ◽  
Vol 275 (1363) ◽  
pp. 544-558 ◽  
Keyword(s):  
Rate Constant ◽  
Atomic Oxygen ◽  
Elevated Temperatures ◽  
Collision Frequency ◽  
Flow System ◽  
Chain Reaction ◽  
Elementary Processes ◽  
A Value ◽  
Good Agreement ◽  
Oxygen Atoms

The rates of reaction of 3 P oxygen atoms with hydroxyl and hydrogen have been measured in a flow system at pressures around 2 mmHg. The former reaction, O + OH -> H + O 2 , ( — 4) occurred in the products of the rapid reaction between H and NO 2 , and was followed by measurements of atomic oxygen concentrations. k -4 was found to be 5±2 x 10 -11 cm 3 molecule -1 s -1 at 265 and 293 °K. This result, when combined with data on the reverse reaction at elevated temperatures, gives a value of k -4 which is virtually independent of temperature and equal to about 1/20 of the bimolecular collision frequency. The reaction O + H 2 -> OH + H (3) was studied in the absence of molecular oxygen and found to have a rate constant of 6 x 10 -13 exp (-8900/ RT ) cm 3 molecule -1 s -1 in the range 409 to 733 °K. This is in good agreement with values obtained at higher temperatures. The rate constant for O + D 2 was significantly less than that for O + H 2 at temperatures between 491 and 671 °K.

Reaction of Oxygen Atoms, O(3P), with Ethylene in Liquid Nitrogen Solution

1973 ◽  
Vol 51 (3) ◽  
pp. 373-381 ◽  
Author(s):  
Shun-Ichi Hirokami ◽  
R. J. Cvetanović
Keyword(s):  
Quantum Yield ◽  
Ethylene Oxide ◽  
Molecular Oxygen ◽  
Liquid Nitrogen ◽  
Rate Constant ◽  
Ground State ◽  
Relative Rate ◽  
Quantum Yields ◽  
Relative Rate Constant ◽  
Oxygen Atoms

The reaction of ground-state oxygen atoms, O(3P), with ethylene and ethylene-d4 in liquid nitrogen solution at 77° K has been studied. The major and perhaps the exclusive products are ethylene oxide and acetaldehyde. The ratio of acetaldehyde to ethylene oxide is 1.2 ± 0.1 for ethylene and 0.91 ± 0.09 for ethylene-d4. Much smaller amounts of formaldehyde and trace quantities of cyclopropane are also observed.The effect of the concentration of ethylene on the quantum yields of addition products was measured. A limiting quantum yield of oxygen atoms scavenged by ethylene to form the addition products was 0.12 + 0.01. The low quantum yield suggests an appreciable cage recombination of the ground-state oxygen atoms with the trace amounts of molecular oxygen present. The effect of the concentration of added oxygen on the product yields and the relative rate constant for the addition of O(3P) to molecular oxygen and to ethylene were determined. The ratio [Formula: see text] is 6.0 ± 1.0 and the relative rate constant for the addition of O(3P) to ethylene and to ethylene-d4, [Formula: see text], is 2.0 ± 0.1.The type of products formed and the isotope effects observed are discussed in terms of the mechanism of addition of O(3P) atoms to ethylene.

Rate constant for the reaction between oxygen atoms and ammonia

1962 ◽  
Vol 11 (6) ◽  
pp. 918-923 ◽  
Author(s):  
L. I. Avramenko ◽  
R. V. Kolesnikova ◽  
N. L. Kuznetsova
Keyword(s):  
Rate Constant ◽  
Oxygen Atoms

The kinetics and mechanism of the reaction of atomic oxygen with acetylene

1973 ◽  
Vol 335 (1603) ◽  
pp. 547-562 ◽  
Keyword(s):  
Triplet State ◽  
Rate Constant ◽  
Ground State ◽  
Excited Molecule ◽  
Secondary Process ◽  
Experimental Conditions ◽  
Electronically Excited ◽  
Stable Product ◽  
State Concentration ◽  
Oxygen Atoms

A photoionization mass spectrometer has been used to study the reaction of ground-state oxygen atoms with acetylene. The oxygen atoms were produced in the absence of molecular oxygen in a discharge-flow system with nitrogen as the principal carrier gas. Several of the free radicals and stable product molecules that were observed previously have been studied in more detail. Experiments with added gases have shown that the methylene radicals observed are probably in their ground, triplet state. The ratio of rate constants for the reactions of CH 2 with O 2 and O respectively was found to be approximately 1:10. The dependence of the C 3 H 3 radical concentration on the experimental conditions showed that C 3 H 3 was formed in a secondary reaction, probably involving an excited molecule or radical. The rate constant for the reaction of the HCCO radical with O 2 was measured as 2.2 ± 1.2х10 7 1 mol -1 s -1 . The product observed at mass 42 appears to be ground-state ketene formed in the primary step, perhaps via a triplet state. However, the possibility that the ketene might be formed in a secondary process cannot be dismissed. The rate constant for the reaction of ground-state oxygen atoms with ketene was measured, with a result significantly lower than a previous study. The diacetylene concentration showed a complex dependence on reaction conditions. Analysis of the approach of [C 4 H 2 ] to its steady-state concentration gave a rate constant for the reaction of oxygen atoms with diacetylene of 1.6 ± 0.5 х10 9 1 mol -1 s -1 . The relation of these results to previous studies is discussed briefly. It is suggested that a reaction of one or more of the energetic primary products, such as electronically excited CH 2 , HCCO or ketene, could be responsible for the chemiluminescence of CH, OH and CHO.

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