THE REACTION OF ACTIVE NITROGEN WITH PROPANE

1954 ◽  
Vol 32 (4) ◽  
pp. 351-355 ◽  
Author(s):  
M. Onyszchuk ◽  
L. Breitman ◽  
C. A. Winkler
Keyword(s):  
Activation Energy ◽  
Flow Rate ◽  
Rate Constants ◽  
Hydrogen Cyanide ◽  
Main Product ◽  
Second Order ◽  
Steric Factor ◽  
Active Nitrogen ◽  
Flow Rates ◽  
Order Rate

The reaction of nitrogen atoms with propane has been found to produce hydrogen cyanide as the main product, together with smaller amounts of acetylene, ethylene, and ethane, which were recovered at all propane flow rates. Complete consumption of nitrogen atoms was not attained at any propane flow rate used at 63 °C, but was attained at 250 °C for ratios of propane to nitrogen atoms greater than 1.3. An activation energy of 5.6 ± 0.6 kcal. and a steric factor between 10−2 and 10−3 was estimated from second order rate constants.

THE REACTIONS OF ACTIVE NITROGEN WITH THE BUTANES

1954 ◽  
Vol 32 (7) ◽  
pp. 718-724 ◽  
Author(s):  
R. A. Back ◽  
C. A. Winkler
Keyword(s):  
Nitrogen Atom ◽  
Rate Constants ◽  
Hydrogen Cyanide ◽  
Main Product ◽  
Activation Energies ◽  
Reactive Species ◽  
Atomic Nitrogen ◽  
Initial Attack ◽  
Active Nitrogen ◽  
Rate Controlling Step

The main product of the reactions of active nitrogen with n- and iso-butanes at 75 °C. and 250 °C. was hydrogen cyanide. Small amounts of C2 hydrocarbons, mainly ethylene and acetylene, were produced in both reactions. Second order rate constants were calculated on the assumption that the reactive species in active nitrogen is atomic nitrogen, and that the initial attack of a nitrogen atom is the rate-controlling step. The activation energies were then estimated to be 3.6 kcal. and 3.1 kcal. and the probability factors 4.5 × 10−4 and 4.4 × 10−4, for the n-butane and isobutane reactions respectively.

scholarly journals THE REACTION OF NITROGEN ATOMS WITH METHANE AND ETHANE

1951 ◽  
Vol 29 (11) ◽  
pp. 1010-1021 ◽  
Author(s):  
H. Blades ◽  
C. A. Winkler
Keyword(s):  
Activation Energy ◽  
Nitrogen Atom ◽  
High Temperatures ◽  
Hydrogen Cyanide ◽  
Active Species ◽  
Second Order ◽  
Steric Factor ◽  
Atomic Nitrogen ◽  
Atom Concentration ◽  
Nitrogen Stream

Methane reacted with nitrogen atoms at temperatures above 300°C. to produce hydrogen cyanide. An activation energy of 11 kcal. and a steric factor of 5 × 10−3 were obtained. The reaction of ethane with nitrogen atoms was studied up to 295°C., with hydrogen cyanide the only product found in measurable amounts. At high temperatures, nitrogen atom consumption was complete in excess ethane, and the hydrogen cyanide production under these conditions, compared with the atom concentration determined by a Wrede gauge, indicated the active species in the nitrogen stream to be only atomic nitrogen. The ethane – nitrogen atom reaction was second order, with an activation energy of 7 ± 1 kcal. and a steric factor between 10−1 and 10−3.

scholarly journals THE REACTIONS OF ACTIVE NITROGEN WITH ACETYLENE, METHYLACETYLENE, AND DIMETHYLACETYLENE

1959 ◽  
Vol 37 (4) ◽  
pp. 655-659 ◽  
Author(s):  
A. Schavo ◽  
C. A. Winkler
Keyword(s):  
Flow Rate ◽  
Hydrogen Cyanide ◽  
Linear Increase ◽  
Low Flow ◽  
Active Nitrogen ◽  
Flow Rates ◽  
Polymer Formation

Hydrogen cyanide was the main nitrogen-containing product of all three reactions, but whereas only about one-half the available active nitrogen was converted to product in the acetylene reaction, the conversion by methyl- and dimethyl-acetylene was substantially complete. A faster-than-linear increase of HCN production with acetylene flow rate was observed at low flow rates. Similar behavior was just perceptible in the corresponding curve for methylacetylene, while no observable inflection was present with dimethylacetylene. Polymer formation was pronounced with acetylene, less so with methylacetylene, and practically absent with dimethylacetylene. Small amounts of cyanogen resulted from all three reactions, while condensable hydrocarbons were obtained in significant yields from the methyl- and dimethyl-acetylene reactions only at higher flow rates of the alkynes.

Inhibition in Purified Systems and in Human Plasma of Chimaeric Plasminogen Activators Consisting of the NH2-Terminal Region of Tissue-Type Plasminogen Activator and the COOH-Terminal Region of UrokinaseType Plasminogen Activator

1988 ◽  
Vol 60 (02) ◽  
pp. 247-250 ◽  
Author(s):  
H R Lijnen ◽  
L Nelles ◽  
B Van Hoef ◽  
F De Cock ◽  
D Collen
Keyword(s):  
Plasminogen Activator ◽  
Rate Constants ◽  
Plasminogen Activators ◽  
Second Order ◽  
Tissue Type ◽  
Single Chain ◽  
Chain Molecules ◽  
Order Rate ◽  
Type Plasminogen Activator ◽  
Urokinase Type Plasminogen Activator

SummaryRecombinant chimaeric molecules between tissue-type plasminogen activator (t-PA) and single chain urokinase-type plasminogen activator (scu-PA) or two chain urokinase-type plasminogen activator (tcu-PA) have intact enzymatic properties of scu-PA or tcu-PA towards natural and synthetic substrates (Nelles et al., J Biol Chem 1987; 262: 10855-10862). In the present study, we have compared the reactivity with inhibitors of both the single chain and two chain variants of recombinant u-PA and two recombinant chimaeric molecules between t-PA and scu-PA (t-PA/u-PA-s: amino acids 1-263 of t-PA and 144-411 of u-PA; t-PA/u-PA-e: amino acids 1-274 of t-PA and 138-411 of u-PA). Incubation with human plasma in the absence of a fibrin clot for 3 h at 37° C at equipotent concentrations (50% clot lysis in 2 h), resulted in significant fibrinogen breakdown (to about 40% of the normal value) for all two chain molecules, but not for their single chain counterparts. Preincubation of the plasminogen activators with plasma for 3 h at 37° C, resulted in complete inhibition of the fibrinolytic potency of the two chain molecules but did not alter the potency of the single chain molecules. Inhibition of the two chain molecules occurred with a t½ of approximately 45 min. The two chain variants were inhibited by the synthetic urokinase inhibitor Glu-Gly-Arg-CH2CCl with apparent second-order rate constants of 8,000-10,000 M−1s−1, by purified α2-antiplasmin with second-order rate constants of about 300 M−1s−1, and by plasminogen activator inhibitor-1 (PAI-1) with second-order rate constants of approximately 2 × 107 M−1s−1.It is concluded that the reactivity of single chain and two chain forms of t-PA/u-PA chimaers with inhibitors is very similar to that of the single and two chain forms of intact u-PA.

Determination of the Nucleophilicity of Tricarbonyliron Coordinated Cyclohepta-1,3,5-triene

1999 ◽  
Vol 64 (11) ◽  
pp. 1770-1779 ◽  
Author(s):  
Herbert Mayr ◽  
Karl-Heinz Müller
Keyword(s):  
Gibbs Energy ◽  
Ambient Temperature ◽  
Rate Constants ◽  
Second Order ◽  
Order Rate ◽  
Electrophilic Additions ◽  
Kinetics Of

The kinetics of the electrophilic additions of four diarylcarbenium ions (4a-4d) to tricarbonyl(η4-cyclohepta-1,3,5-triene)iron (1) have been studied photometrically. The second-order rate constants match the linear Gibbs energy relationship log k20 °C = s(E + N) and yield the nucleophilicity parameter N(1) = 3.69. It is concluded that electrophiles with E ≥ -9 will react with complex 1 at ambient temperature.

Luminescence Quenching of Rhodamines by Cyclooctatetraene

1987 ◽  
Vol 42 (9) ◽  
pp. 1009-1013 ◽  
Author(s):  
P. Targowski ◽  
B. Ziętek ◽  
A. Bączyński
Keyword(s):  
Rhodamine B ◽  
Rate Constants ◽  
Internal Conversion ◽  
Rhodamine 6G ◽  
Second Order ◽  
Luminescence Quenching ◽  
Intersystem Crossing ◽  
Order Rate ◽  
Quenching Process

Cyclooctatetraene (COT) as a quencher of fluorescence of a series of Rhodamine solutions was studied. The second order rate constants for the quenching process of Rhodamine 110, Rhodamine 19 pchl., Rhodamine 6G pchl., Rhodamine 6G, Tetramethylrhodamine, Rhodamine B and Rhodamine 3B pchl. are given. It was found that COT enhances rather intersystem crossing than internal conversion.

A Study on the β-Elimination Reaction from N-[2-(p-nitrophenyl)ethyl]quinuclidinium and 2-(p-nitrophenyl)ethyl bromide induced by amines in dimethylsulfoxide with formation of p-nitrostyrene

2000 ◽  
Vol 2000 (2) ◽  
pp. 62-63
Author(s):  
Sergio Alunni ◽  
Arianna Rocchi
Keyword(s):  
Rate Constants ◽  
Second Order ◽  
Ethyl Bromide ◽  
Elimination Reaction ◽  
Order Rate

Second order rate constants kE M−1 s−1 for the β-elimination reaction from N-[2-( p-nitrophenyl)ethyl]quinuclidinium and 2-( p-nitrophenyl)ethyl bromide induced by amines of different structure in dimethylsulfoxide at 50 °C have been measured. Application of the Brønsted equation shows a similar behaviour of the two substrates, with values of β = 0.649 and 0.584 respectively.

THE REACTION OF ACTIVE NITROGEN WITH ETHYLENE

1953 ◽  
Vol 31 (1) ◽  
pp. 1-3 ◽  
Author(s):  
J. Versteeg ◽  
C. A. Winkler
Keyword(s):  
Polymeric Material ◽  
Flow Rate ◽  
Hydrogen Cyanide ◽  
Active Nitrogen ◽  
Principal Product

Reinvestigation of the active nitrogen–ethylene reaction has confirmed hydrogen cyanide as the principal product. Smaller quantities of ethane, cyanogen, acetylene, and methane have also been found and the variations in amounts of these products with ethylene flow rate have been established. No significant amount of polymeric material was found.

KINETICS OF THE AQUEOUS ALKALINE HOMOGENOUS HYDROLYSIS OF HIGH EXPLOSIVE 1, 3,5,7-TETRAAZA- 1, 3,5,7-TETRANITROCYCLOOCTANE (HMX)

1994 ◽  
Vol 30 (3) ◽  
pp. 53-61 ◽  
Author(s):  
Harro M. Heilmann ◽  
Michael K. Stenstrom ◽  
Rolf P. X. Hesselmann ◽  
Udo Wiesmann
Keyword(s):  
Temperature Dependence ◽  
Alkaline Hydrolysis ◽  
Rate Constants ◽  
Elevated Temperatures ◽  
Second Order ◽  
Order Rate ◽  
Subsequent Calculation ◽  
Kinetics Of ◽  
Hydrolysis Of ◽  
Order Rate Equation

In order to get basic data for the design of a novel treatment scheme for high explosives we investigated the kinetics for the aqueous alkaline hydrolysis of 1,3,5,7-tetraaza-1,3,5,7-tetranitrocyclooctane (HMX) and the temperature dependence of the rate constants. We used an HPLC procedure for the analysis of HMX. All experimental data could be fit accurately to a pseudo first-order rate equation and subsequent calculation of second-order rate constants was also precise. Temperature dependence could be modeled with the Arrhenius equation. An increase of 10°C led to an average increase in the second-order rate constants by the 3.16 fold. The activation energy of the second-order reaction was determined to be 111.9 ±0.76 kJ·moJ‒1. We found the alkaline hydrolysis to be rapid (less than 2.5% of the initial HMX-concentration left after 100 minutes) at base concentrations of 23 mmol oH‒/L and elevated temperatures between 60 and 80°C.

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