KINETICS AND MECHANISMS OF THE THERMAL DECOMPOSITION OF PROPIONALDEHYDE: PART II. THE REACTION IN THE PRESENCE OF NITRIC OXIDE

1965 ◽  
Vol 43 (1) ◽  
pp. 278-289 ◽  
Author(s):  
K. J. Laidler ◽  
M. Eusuf
Keyword(s):  
Nitric Oxide ◽  
Thermal Decomposition ◽  
Relative Rate ◽  
Temperature Range ◽  
Presence And Absence

The decomposition of propionaldehyde in the presence of various amounts of nitric oxide has been studied in the temperature range 520–560 °C and at propionaldehyde pressures from 30 to 300 mm Hg. The reaction is inhibited by small amounts of nitric oxide, and larger amounts give rise to strong catalysis. The order of the maximally inhibited reaction is 1.5 and the degree of inhibition decreases with an increase of propionaldehyde pressure. In the catalytic region the order of the overall reaction is 1.25 with respect to propionaldehyde, and the relative rate (the ratio of rates in the presence and absence of nitric oxide) is independent of propionaldehyde pressure. The overall rate in the catalytic region can be expressed as[Formula: see text]the unit of concentration being mole per cc. A mechanism in which nitric oxide initiates chains by the reaction C2H5CHO + NO → C2H5CO + HNO, propagates them by C2H5NO + C2H5CHO → C2H6 + C2H5CO + NO, and terminates them by C2H5 + C2H5NO → C4H10 + NO and C2H6 + C2H4 + NO and C2H5NO + C2H5NO → C4H10 + 2NO or C2H6 + C2H4 + 2NO is proposed and is shown to be consistent with the results.

THE KINETICS OF THE THERMAL DECOMPOSITIONS OF THE LOWER PARAFFINS: V. THE NITRIC OXIDE INHIBITED DECOMPOSITION OF n-BUTANE

1940 ◽  
Vol 18b (1) ◽  
pp. 1-11 ◽  
Author(s):  
E. W. R. Steacie ◽  
H. O. Folkins
Keyword(s):  
Nitric Oxide ◽  
Thermal Decomposition ◽  
Free Radical ◽  
High Pressures ◽  
Free Radical Processes ◽  
Temperature Range ◽  
Radical Recombination ◽  
Radical Processes ◽  
Kinetics Of ◽  
Good Agreement

A detailed investigation of the inhibition by nitric oxide of the thermal decomposition of n-butane has been carried out over the temperature range 500° to 550 °C.In all cases it was found that inhibition decreased with increasing butane concentration. This suggests that radical recombination occurs in the normal decomposition by ternary collisions with butane molecules acting as third bodies.The activation energies of the normal and inhibited reactions have been determined. For high pressures the two values are in good agreement, viz., 58,200 and 57,200 cal. per mole respectively. The products of the inhibited reaction were also found to be the same as those of the normal reaction.It is concluded that free radical processes predominate, involving comparatively short chains.

KINETICS AND MECHANISMS OF THE PYROLYSIS OF DIMETHYL ETHER: II. THE REACTION INHIBITED BY NITRIC OXIDE AND PROPYLENE

1963 ◽  
Vol 41 (8) ◽  
pp. 1993-2008 ◽  
Author(s):  
D. J. McKenney ◽  
B. W. Wojciechowski ◽  
K. J. Laidler
Keyword(s):  
Nitric Oxide ◽  
Thermal Decomposition ◽  
Dimethyl Ether ◽  
Chain Process ◽  
Maximal Inhibition ◽  
First Order ◽  
Temperature Range ◽  
Maximum Inhibition ◽  
A Chain

The thermal decomposition of dimethyl ether, inhibited by nitric oxide and by propylene, was studied in the temperature range of 500 to 600 °C. About 1.5 mm of nitric oxide gave maximal inhibition, the rate then being approximately 8% of the uninhibited rate. With propylene, approximately 70 mm gave maximal inhibition, the rate being slightly higher than that using nitric oxide (~12.5% of the uninhibited rate). In both cases the degree of inhibition was independent of the ether pressure. In the maximally inhibited regions both reactions are three-halves order with respect to ether pressure. As the pressure of nitric oxide was increased beyond 10–15 mm, the overall rate increased, and in this region the reaction is first order with respect to both nitric oxide and ether. A 50:50 mixture of CH3OCH3 and CD3OCD3, with enough NO to ensure maximum inhibition, was pyrolyzed. Even at very low percentage decomposition the CD3H/CD4 ratio was approximately the same as that in the uninhibited decomposition, proving that the inhibited reaction is largely a chain process. Detailed inhibition mechanisms are proposed in which the inhibitor is involved both in initiation and termination reactions.

Consecutive reactions in the thermal decomposition of phenylalkyldiazirines

1977 ◽  
Vol 55 (20) ◽  
pp. 3596-3601 ◽  
Author(s):  
Michael T. H. Liu ◽  
Barry M. Jennings
Keyword(s):  
Thermal Decomposition ◽  
Kinetic Parameters ◽  
Diazo Compounds ◽  
First Order ◽  
Temperature Range ◽  
Decomposition Reactions ◽  
Consecutive Reactions ◽  
Rate Processes ◽  
Subsequent Decomposition

The thermal decomposition of phenyl-n-butyldiazirine and of phenylmethyldiazirine in DMSO and in HOAc have been investigated over the temperature range 80–130 °C. The intermediate diazo compounds, 1-phenyl-1-diazopentane and 1-phenyldiazoethane respectively have been detected and isolated. The decomposition of phenyl-n-butyldiazirine and the subsequent decomposition of its product, 1-phenyl-1-diazopentane, are an illustration of consecutive reactions. The kinetic parameters for the isomerization and decomposition reactions have been determined. The isomerization of phenylmethyldiazirine to 1-phenyldiazoethane is first order and probably unimolecular but the kinetics for the subsequent reactions of 1-phenyldiazoethane are complicated by several competing rate processes.

A Shock Tube Study of the Thermal Decomposition of Nitric Oxide

1975 ◽  
Vol 10 (3-4) ◽  
pp. 155-162 ◽  
Author(s):  
QUAC LE TRUNG ◽  
DONALD MACKAY ◽  
AKIRA HIRATA ◽  
OLEV TRASS
Keyword(s):  
Nitric Oxide ◽  
Thermal Decomposition ◽  
Shock Tube ◽  
Tube Study

Influence of Nitric Oxide on the Thermal Decomposition of Dimethyl Ether. Gaseous Catalysis

Nature ◽  
1936 ◽  
Vol 138 (3491) ◽  
pp. 546-547 ◽  
Author(s):  
P. F. GAY ◽  
MORRIS W. TRAVERS
Keyword(s):  
Nitric Oxide ◽  
Thermal Decomposition ◽  
Dimethyl Ether
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