THE THERMAL DECOMPOSITION OF AZOMETHANE: I. EFFECT OF ADDED OLEFIN AND NITRIC OXIDE

1963 ◽  
Vol 41 (3) ◽  
pp. 562-585 ◽  
Author(s):  
W. Forst ◽  
O. K. Rice
Keyword(s):  
Nitric Oxide ◽  
Activation Energy ◽  
Thermal Decomposition ◽  
Chain Length ◽  
Rate Increase ◽  
Short Chain ◽  
Identical Result ◽  
Rate Minimum ◽  
Induced Decomposition

The addition of ethylene and propylene reduces the rate of azomethane decomposition as measured by the rate of nitrogen production, and also reduces the ratio CH4/N2 in the products, but the reduction in the value of both quantities is different for each of the two olefins. In 100% decomposition, ethylene and propylene both increase somewhat the ratio (nitrogen recovered)/(azomethane decomposed). These results are interpreted to mean that there is in fact a short chain in the pyrolysis, but that ethylene and propylene are unsuitable inhibitors.The addition of a few millimeters of NO reduces the rate to a minimum which is lower than that with added propylene or ethylene (apparent chain length 2 to 3), but further addition of NO increases the rate again. Identical result is obtained in a packed vessel. The yield of methane, ethane, and ethylene is reduced to almost zero with a sufficient amount of NO. The ratio (NO consumed)/(nitrogen produced) reaches the value of two in the neighborhood of the rate minimum. It is concluded that the net inhibited rate, i.e. rate corrected for the stimulatory effect of NO, refers to the initial unimolecular process CH3N2CH3 → 2CH3 + N2. The rate as well as the activation energy of this process is found to be pressure dependent.It is shown by the use of the isotopic nitric oxide 15NO that about one-half of the rate increase at higher NO pressures is due to nitrogen produced from NO. The remainder of the rate increase is accounted for by a NO-induced decomposition of azomethane.

THE KINETICS OF THE DECOMPOSITION REACTIONS OF THE LOWER PARAFFINS: VII. THE NITRIC OXIDE INHIBITED DECOMPOSITION OF ETHANE

1940 ◽  
Vol 18b (11) ◽  
pp. 351-357 ◽  
Author(s):  
E. W. R. Steacie ◽  
Gerald Shane
Keyword(s):  
Nitric Oxide ◽  
Activation Energy ◽  
Thermal Decomposition ◽  
Free Radical ◽  
Radical Chain ◽  
Decomposition Reactions ◽  
Rearrangement Mechanism ◽  
Chain Lengths ◽  
Kinetics Of

An investigation has been made of the nitric oxide inhibited thermal decomposition of ethane. Apparent chain lengths of 2.4 to 5 are found at temperatures from 640° to 565 °C. The activation energy of the inhibited reaction is found to be 77.3 Kcal. The results are discussed and it is concluded that the thermal decomposition of ethane proceeds mainly by a rearrangement mechanism and that free-radical chain mechanisms for the ethane decomposition are untenable.

The thermal decomposition of diethyl ether. IV. Production of cyanides and the mechanism of the nitric-oxide-induced reaction

1958 ◽  
Vol 245 (1240) ◽  
pp. 68-74 ◽  
Keyword(s):  
Nitric Oxide ◽  
Thermal Decomposition ◽  
Diethyl Ether ◽  
Chain Mechanism ◽  
Induced Decomposition ◽  
Induced Reaction

The formation of cyanides in the nitric-oxide-induced decomposition of diethyl ether has been determined as a function of nitric oxide pressure. A possible chain mechanism for nitric oxide consumption and cyanide production is considered.

Kinetics and mechanisms of the thermal decomposition of ethane - II. The reaction inhibited by nitric oxide

1961 ◽  
Vol 260 (1300) ◽  
pp. 103-113 ◽  
Keyword(s):  
Nitric Oxide ◽  
Activation Energy ◽  
Thermal Decomposition ◽  
Induction Period ◽  
Volume Ratio ◽  
Frequency Factor ◽  
Inflexion Point ◽  
Kcal Mole ◽  
First Order ◽  
Pressure Time

The pressure-time curves for the decomposition of ethane when fully inhibited by nitric oxide have initially a point of inflexion. The initial rates are proportional to the first power of the pressure at higher pressures, and to the 3/2 power at lower pressures; the rates at the inflexion point are proportional to the pressure to a power which is slightly greater than unity. The acti­vation energy corresponding to the initial rates in the first-order region was found to be 77∙5 kcal/mole, and the frequency factor 3∙12 × 10 15 s -1 . The reaction was slightly inhibited by increasing the surface: volume ratio, and the induction period disappeared on addition of ethylene. The facts are shown to be consistent with a mechanism in which initiation occurs by the reaction NO + C 2 H 6 → C 2 H 5 + HNO, which is estimated to have an activation energy of 52 kcal. At the beginning of the reaction and at lower pressures termination is con­sidered to occur by H + HNO → H 2 + NO; as ethylene accumulates the ratio [C 2 H 5 ]/[H] increases and the termination step becomes C 2 H 5 + HNO → C 2 H 6 + NO. The mechanism is shown to account for the fact that propylene and other inhibitors give rise to the same limiting rate.

The kinetics of the thermal decomposition of branched-chain paraffin hydrocarbons - II. The isomeric hexanes

1952 ◽  
Vol 214 (1118) ◽  
pp. 339-343 ◽  
Keyword(s):  
Nitric Oxide ◽  
Activation Energy ◽  
Thermal Decomposition ◽  
Order Transition ◽  
First Order ◽  
Single Transition ◽  
Branched Chain ◽  
Kinetics Of ◽  
Constant Activation Energy ◽  
Methyl Pentane

In the study of the thermal decomposition of paraffins the contrast of iso -butane with n -butane and of the branched pentanes with normal pentane has led to the investigation of the isomeric hexanes. The nitric oxide-inhibited reaction of neo -hexane possesses a constant, activation energy at different initial pressures and shows a single transition from second to first order with increasing pressure. The reactions of 2:3-dimethyl-butane, 2-methyl-pentane and 3-methyl-pentane show a double-order transition and a rise in activation energy at lower initial pressures, as previously found for the higher normal paraffins.

scholarly journals Reaction chains in the thermal decomposition of hydrocarbons. A comparison of methane, ethane, propane and hexane

1938 ◽  
Vol 167 (931) ◽  
pp. 447-455 ◽  
Author(s):  
J. E. Hobbs ◽  
Cyril Norman Hinshelwood
Keyword(s):  
Nitric Oxide ◽  
Thermal Decomposition ◽  
Chain Length ◽  
Homologous Series ◽  
Normal Rate ◽  
Chain Mechanism ◽  
Reaction Proceeds ◽  
Decomposition Of Hydrocarbons ◽  
A Chain

The inhibition by nitric oxide of the thermal decomposition of ethane at 600° shows that the reaction proceeds partly by a chain mechanism, the apparent chain length, as measured by the ratio of the normal rate to that of the chain-free reaction, being of the order 5-15 over the range of pressure 50-500 mm., and falling with increasing pressure (Staveley 1937; Hobbs and Hinshelwood 1938). In passing up a homologous series of compounds the chain length may rise or fall. With the series of ethers, for examples, it decreases rapidly, whereas with the aldehydes it increases (Staveley and Hinshelwood 1937).

scholarly journals The mechanism of chain breaking in the thermal decomposition of ethane

1938 ◽  
Vol 167 (931) ◽  
pp. 439-446 ◽  
Author(s):  
J. E. Hobbs ◽  
Cyril Norman Hinshelwood
Keyword(s):  
Nitric Oxide ◽  
Thermal Decomposition ◽  
Free Radicals ◽  
Chain Length ◽  
Chain Mechanism ◽  
Collision Process ◽  
Ethane Molecule ◽  
Chain Breaking ◽  
The Mean ◽  
A Chain

The decomposition of ethane in the neighbourhood of 600° occurs largely by a chain mechanism in which free radicals are formed. In the course of experiments on the inhibition of the reaction by nitric oxide, Staveley (1937) found that the mean chain length diminished with increasing ethane pressure. From this he reached the conclusion that the chains were broken predominantly by a ternary collision process involving two radicles and an ethane molecule. The important question whether chains are ended by binary or by ternary collisions can be approached in another way, the exploration of which is described in the following pages.

Induction of inflammatory cytokines and nitric oxide in J774.2 cells and murine macrophages by lipoteichoic acid and related cell wall antigens from Staphylococcus epidermidis

2005 ◽  
Vol 54 (4) ◽  
pp. 315-321 ◽  
Author(s):  
Karen J Jones ◽  
Alan D Perris ◽  
Ann B Vernallis ◽  
Tony Worthington ◽  
Peter A Lambert ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Chain Length ◽  
Inflammatory Cytokines ◽  
Staphylococcus Epidermidis ◽  
Teichoic Acid ◽  
Lipoteichoic Acid ◽  
Short Chain ◽  
Wall Teichoic Acid ◽  
Gram Positive ◽  
Short Chain Length

Staphylococcus epidermidis causes infections associated with medical devices including central venous catheters, orthopaedic prosthetic joints and artificial heart valves. This coagulase-negative staphylococcus produces a conventional cellular lipoteichoic acid (LTA) and also releases a short-glycerophosphate-chain-length form of LTA (previously termed lipid S) into the medium during growth. The relative pro-inflammatory activities of cellular and short-chain-length exocellular LTA were investigated in comparison with peptidoglycan and wall teichoic acid from S. epidermidis and LPS from Escherichia coli O111. The ability of these components to stimulate the production of pro-inflammatory cytokines [interleukin (IL)-1β, IL-6 and tumour necrosis factor (TNF)-α] and nitric oxide was investigated in a murine macrophage-like cell line (J774.2), and in peritoneal and splenic macrophages. On a weight-for-weight basis the short-chain-length exocellular LTA was the most active of the S. epidermidis products, stimulating significant amounts of each of the inflammatory cytokines and nitric oxide, although it was approximately 100-fold less active than LPS from E. coli. By comparison the full-chain-length cellular LTA and peptidoglycan were less active and the wall teichoic acid had no activity. As an exocellular product potentially released from S. epidermidis biofilms, the short-chain-length exocellular LTA may act as the prime mediator of the host inflammatory response to device-related infection by this organism and act as the Gram-positive equivalent of LPS in Gram-negative sepsis. The understanding of the role of short-chain-length exocellular LTA in Gram-positive sepsis may lead to improved treatment strategies.

scholarly journals Nitric oxide formation during light-induced decomposition of phenyl N-tert-butylnitrone

1993 ◽  
Vol 268 (16) ◽  
pp. 11520-11527
Author(s):  
W. Chamulitrat ◽  
S.J. Jordan ◽  
R.P. Mason ◽  
K. Saito ◽  
R.G. Cutler
Keyword(s):  
Nitric Oxide ◽  
Oxide Formation ◽  
Nitric Oxide Formation ◽  
Induced Decomposition
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