scholarly journals Toward the Development of a Fundamentally Based Chemical Model for Cyclopentanone: High-Pressure-Limit Rate Constants for H Atom Abstraction and Fuel Radical Decomposition

2016 ◽  
Vol 120 (36) ◽  
pp. 7037-7044 ◽  
Author(s):  
Chong-Wen Zhou ◽  
John M. Simmie ◽  
William J. Pitz ◽  
Henry J. Curran
Keyword(s):  
High Pressure ◽  
Rate Constants ◽  
Chemical Model ◽  
Pressure Limit ◽  
Radical Decomposition

Die unimolekulare thermische Spaltung von Äthylchlorid-2-d3 und Äthylchlorid-2-d1 nach einem Vierzentrenmechanismus

1968 ◽  
Vol 23 (11) ◽  
pp. 1407-1411 ◽  
Author(s):  
G. W. Völker ◽  
H. Heydemann
Keyword(s):  
Thermal Decomposition ◽  
High Pressure ◽  
Rate Constants ◽  
Mass Spectrometric ◽  
Spectrometric Analysis ◽  
Static System ◽  
Pressure Limit ◽  
Reaction Complex ◽  
Elimination Mechanism ◽  
Two Temperatures

The unimolecular thermal decomposition of chloroethane-2-d3 and chloroethane-2-d1 was studied in a static system at two temperatures and at pressures between 0.1 and 10 mm Hg. The rate constants for the high pressure limit were obtained from these measurements and used to calculate the Arrhenius equations. The decomposition of chloroethane-2-d3 was also studied at high conversions and yielded almost exclusively (97%) DCl and CD2CH2 as shown by mass spectrometric analysis thus proving a molecular elimination mechanism via a four-centered reaction complex.

scholarly journals Fall-Off Curves for the Reaction ClO + NO2( + N2) ClONO2 (+N2)

1977 ◽  
Vol 32 (6) ◽  
pp. 648-651 ◽  
Author(s):  
Reinhard Zellner
Keyword(s):  
High Pressure ◽  
Rate Constants ◽  
Low Pressure ◽  
Effective Rate ◽  
Reference Points ◽  
Atmospheric Models ◽  
Chlorine Nitrate ◽  
Pressure Limit

Abstract Fall-off curves for the reaction ClO+NO2(+N2)→ClONO2(+N2) at 300 and 220 K have been calculated from Kassel integrals by use of a theoretically derived high pressure limit and the experimentally determined low pressure limit as reference points. The reaction is found to deviate considerably from the low pressure limit at pressures larger than 10 Torr. Effective rate constants for the use in atmospheric models of chlorine nitrate formation are derived.

scholarly journals Accurate Rate Constants for the Forward and Reverse H + CO ↔ HCO Reactions at the High-Pressure Limit

ACS Omega ◽  
2020 ◽  
Vol 5 (37) ◽  
pp. 23975-23982
Author(s):  
Rafael M. Vichietti ◽  
Francisco B. C. Machado ◽  
Roberto L. A. Haiduke
Keyword(s):  
High Pressure ◽  
Rate Constants ◽  
Pressure Limit

The pyrolysis of trimethylarsine

1970 ◽  
Vol 48 (20) ◽  
pp. 3209-3212 ◽  
Author(s):  
S. J. W. Price ◽  
J. P. Richard
Keyword(s):  
Activation Energy ◽  
High Pressure ◽  
Rate Constants ◽  
Flow System ◽  
Heterogeneous Reaction ◽  
Methyl Radicals ◽  
Product Analysis ◽  
First Order ◽  
Carrier Flow ◽  
Pressure Limit

The pyrolysis of trimethylarsine has been studied in a toluene carrier flow system from 764 to 858 °K using total pressures from 6.35 to 35.5 mm. Contact times varied from 0.9 to 3.7 s and the amount of decomposition, from 1.2 to 73 %. The progress of the reaction was followed by measuring the amount of methane, ethane, ethylene, and ethylbenzene formed. No heterogeneous reaction was detected and the first order rate constants appear to have been determined at approximately the high pressure limit. In seven runs the undecomposed alkyl was also measured. The quantity found was in agreement with the product analysis if three methyl radicals are released for each molecule undergoing reaction.Least squares analysis of the results gives[Formula: see text]The activation energy should be a good approximation to D[(CH3)2As—CH3]. The product analysis and the values of k4/k51/2 are consistent with the simple consecutive release of three methyl radicals but thermodynamic and kinetic considerations may preclude this possibility.

scholarly journals Association of Cl with C2H2by unified variable-reaction-coordinate and reaction-path variational transition-state theory

2020 ◽  
Vol 117 (11) ◽  
pp. 5610-5616
Author(s):  
Linyao Zhang ◽  
Donald G. Truhlar ◽  
Shaozeng Sun
Keyword(s):  
High Pressure ◽  
Transition State ◽  
Transition State Theory ◽  
Reaction Path ◽  
State Theory ◽  
Reaction Coordinate ◽  
Acetylene Molecule ◽  
Variational Transition State Theory ◽  
Pressure Limit ◽  
Variational Transition State

Barrierless unimolecular association reactions are prominent in atmospheric and combustion mechanisms but are challenging for both experiment and kinetics theory. A key datum for understanding the pressure dependence of association and dissociation reactions is the high-pressure limit, but this is often available experimentally only by extrapolation. Here we calculate the high-pressure limit for the addition of a chlorine atom to acetylene molecule (Cl + C2H2→C2H2Cl). This reaction has outer and inner transition states in series; the outer transition state is barrierless, and it is necessary to use different theoretical frameworks to treat the two kinds of transition state. Here we study the reaction in the high-pressure limit using multifaceted variable-reaction-coordinate variational transition-state theory (VRC-VTST) at the outer transition state and reaction-path variational transition state theory (RP-VTST) at the inner turning point; then we combine the results with the canonical unified statistical (CUS) theory. The calculations are based on a density functional validated against the W3X-L method, which is based on coupled cluster theory with single, double, and triple excitations and a quasiperturbative treatment of connected quadruple excitations [CCSDT(Q)], and the computed rate constants are in good agreement with some of the experimental results. The chlorovinyl (C2H2Cl) adduct has two isomers that are equilibrium structures of a double-well C≡C–H bending potential. Two procedures are used to calculate the vibrational partition function of chlorovinyl; one treats the two isomers separately and the other solves the anharmonic energy levels of the double well. We use these results to calculate the standard-state free energy and equilibrium constant of the reaction.

scholarly journals High-Pressure Limit of Equilibrium in Axisymmetric Open Traps

2019 ◽  
Vol 14 (0) ◽  
pp. 2403007-2403007 ◽  
Author(s):  
Mikhail S. KHRISTO ◽  
Alexey D. BEKLEMISHEV
Keyword(s):  
High Pressure ◽  
Pressure Limit

scholarly journals Kinetic Study of Photocatalytic Degradation of Tolonium Chloride Under High Pressure Irradiation in Aquatic Buffer Systems

2011 ◽  
Vol 8 (s1) ◽  
pp. S19-S26 ◽  
Author(s):  
M. Montazerozohori ◽  
S. Nezami ◽  
S. Mojahedi
Keyword(s):  
High Pressure ◽  
Photocatalytic Degradation ◽  
Kinetic Study ◽  
Rate Constants ◽  
Order Kinetic ◽  
Optimum Conditions ◽  
First Order ◽  
Reactor Cell ◽  
Order Kinetic Model ◽  
Tolonium Chloride

Anatase titanium dioxide catalyzed photodegradation of tolonium chloride at various bufferic pH of 2, 7, 9 and 12 in aqueous solution is presented. The effect of some physicochemical parameters such as initial concentration of dye, catalyst amount and reaction time on photocatalytic degradation has been investigated in a photo-reactor cell containing high pressure mercury lamp to obtain the optimum conditions in each bufferic pH at constant temperature. A complete spectrophotometric kinetic study of tolonium chloride under high pressure irradiation at buffer media was performed. The photocatalytic degradation observed rate constants (kobs) were found to be 2.90×10-3, 3.30×10-3, 3.20×10-3and 5.20×10-3min-1for buffer pH of 2-12 respectively. It was found that a pseudo-first-order kinetic model based on Langmuir-Hinshelwood one is usable to photodegradation of this compound at all considered buffer pH. In addition to these, the Langmuir-Hinshelwood rate constants, krfor the titled compound at various pH are reported.

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