Absolute third-order rate constants for the recombination reactions between alkali-metal and iodine atoms and the measurement for Rb + I + He

1986 ◽  
Vol 82 (6) ◽  
pp. 897 ◽  
Author(s):  
John M. C. Plane ◽  
David Husain
Keyword(s):  
Alkali Metal ◽  
Rate Constants ◽  
Third Order ◽  
Order Rate ◽  
Recombination Reactions

Third-order rate constants of atmospheric importance

1983 ◽  
Vol 15 (11) ◽  
pp. 1189-1227 ◽  
Author(s):  
Roger Patrick ◽  
David M. Golden
Keyword(s):  
Rate Constants ◽  
Third Order ◽  
Order Rate

The formation and reactions of aromatic dimer cations in a high pressure photoionization source

1980 ◽  
Vol 58 (16) ◽  
pp. 1666-1672 ◽  
Author(s):  
John A. Stone ◽  
Margaret S. Lin
Keyword(s):  
High Pressure ◽  
Charge Transfer ◽  
Ionization Potential ◽  
Rate Constants ◽  
Aromatic Compounds ◽  
Third Order ◽  
Order Rate ◽  
Lower Ionization Potential ◽  
The Difference

Aromatic dimer cations (M2+) have been generated for a series of aromatic compounds in a high pressure photoionization source. Relative third order rate constants for formation of M2+ have been obtained for benzene (1.0), benzene-d6 (2.7), toluene (0.8), o-xylene (1.5), p-xylene (0.7), fluorobenzene (0.3), m-fluorotoluene (0.5), m-chlorotoluene (0.7), p-chlorotoluene (0.5), and o-methoxytoluene (0.4). These values are consistent with and supplement previous data for such systems. Reagent ion monitoring has been used to determine the relative rates of reaction of both M2+ and the monomer ions, M+, with a series of (mainly) aromatic compounds (X). Reaction of C6H6+ is by charge transfer to compounds of lower ionization potential than C6H6. (C6H6)2+ reacts only by charge transfer, if the ionization potential of X is more than 0.5 eV lower than that of benzene. When the difference is smaller, mixed dimer cations are observed which are probably formed in a switching reaction (C6H6)2+ + X → (C6H6•X)+ + C6H6.

Rate constants for the gaseous reactions OH + C2H4 and OH + OH

1980 ◽  
Vol 33 (7) ◽  
pp. 1425 ◽  
Author(s):  
GK Farquharson ◽  
RH Smith
Keyword(s):  
Mass Spectrometer ◽  
Hydroxyl Radicals ◽  
Rate Constant ◽  
Rate Constants ◽  
Order Rate Constant ◽  
Resonance Fluorescence ◽  
Flow Tube ◽  
Third Order ◽  
Order Rate ◽  
Wall Loss

The rate of disappearance of hydroxyl radicals (generated by H+NO2 → OH+NO) along a discharge flow tube both with and without ethene present was measured by resonance fluorescence. Stoichiometry was simultaneously measured with a mass spectrometer, the leak into which was located downstream of the resonance fluorescence cell. After allowing for loss of hydroxyl by known homogeneous reactions and for wall loss (when applicable) it was found that for OH+C2H4 the low pressure limiting third-order rate constant kter was (3.1 � 0.5)x 10-29 cm6 s-1 at approximately 298 K. In addition an estimate for the second- order rate constant for OH+OH was obtained, namely (1.7 � 0.2) × 10-12 cm3 s-1. These results are discussed in relation to previous measurements.

Investigation of CO2 and ethylethanolamine reaction kinetics in aqueous solutions using the stopped-flow technique

2013 ◽  
Vol 67 (9) ◽  
Author(s):  
Hanna Kierzkowska-Pawlak ◽  
Marta Siemieniec ◽  
Andrzej Chacuk
Keyword(s):  
Aqueous Solutions ◽  
Rate Constants ◽  
Original Method ◽  
Single Step ◽  
Stopped Flow ◽  
Third Order ◽  
Order Rate ◽  
Pseudo Second Order ◽  
Kinetics Of ◽  
Single Step Reaction

AbstractKinetics of the reaction of CO2 and ethylethanolamine (EMEA) in aqueous solutions has been studied using the stopped-flow technique with conductivity detection. Measurements were performed at 288 K, 293 K, 298 K, and 303 K. Amine concentration ranged from 10 mol m−3 to 37.5 mol m−3. The termolecular mechanism was applied to interpret the kinetic data. In this mechanism, carbamate formation occurs in a single-step reaction without the formation of a zwitterion intermediate. An original method of analyzing the experimental data was proposed allowing the derivation of pseudo second order rate constants from the measured kinetic traces. Based on these values, the third order rate constants $$\left( {k_{H_2 O} } \right)$$ of the reaction of CO2, water, and EMEA were derived and correlated by the Arrhenius equation.

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.

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