Classical trajectory and statistical adiabatic channel study of the dynamics of capture and unimolecular bond fission. VI. Properties of transitional modes and specific rate constants k(E,J)

2002 ◽  
Vol 117 (9) ◽  
pp. 4201-4213 ◽  
Author(s):  
A. I. Maergoiz ◽  
E. E. Nikitin ◽  
J. Troe ◽  
V. G. Ushakov
Keyword(s):  
Rate Constants ◽  
Classical Trajectory ◽  
Specific Rate

scholarly journals Kinetic analysis of chemical reactions coupled to an enzymic step. Application to acid phosphatase assay with Fast Red

1984 ◽  
Vol 223 (3) ◽  
pp. 633-638 ◽  
Author(s):  
J Escribano ◽  
F García-Carmona ◽  
F García-Cánovas ◽  
J L Iborra ◽  
J A Lozano
Keyword(s):  
Acid Phosphatase ◽  
Chemical Reactions ◽  
Rate Constants ◽  
Diazonium Salt ◽  
Specific Rate ◽  
Fast Red ◽  
Temperature Ranges ◽  
Lag Period ◽  
Ph Range ◽  
Phosphatase Assay

Acid phosphatase assay with alpha-naphthyl phosphate as substrate and the use of diazonium salt (Fast Red TR) for chromophore formation was kinetically analysed as a system of two chemical reactions coupled to an enzymic reaction. This system follows a mechanism defined as enzymic-chemical-chemical (EzCC). The accumulation of chromophore with reaction time presented a marked lag period, which was only dependent on the rate constants of the chemical reactions and was independent of the enzymic step. The specific rate constants of each chemical step were determined in 3.8-5.0 pH and 10-35 degrees C temperature ranges. Thermodynamic parameters of the chemical steps were also obtained. Measurement of acid phosphatase activity can be carried out in the pH range 3.8-5.0 (4.8 was optimal pH) without the need to eliminate the lag period.

Channel specific rate constants for reactions of O(1D) with HCl and HBr

1986 ◽  
Vol 84 (3) ◽  
pp. 1349-1354 ◽  
Author(s):  
P. H. Wine ◽  
J. R Wells ◽  
A. R. Ravishankara
Keyword(s):  
Rate Constants ◽  
Specific Rate

Ligand substitution reactions of pentacyanoferrate(II) complexes with N-heterocyclic cations in aqueous solution

1989 ◽  
Vol 67 (11) ◽  
pp. 1774-1779 ◽  
Author(s):  
Donal Hugh Macartney ◽  
Lauren Jean Warrack
Keyword(s):  
Aqueous Solution ◽  
Rate Constants ◽  
Dissociation Constants ◽  
Formation Rate ◽  
Spectroscopic Studies ◽  
Ligand Substitution ◽  
Acid Dissociation ◽  
Specific Rate ◽  
Dissociative Mechanism ◽  
Heterocyclic Cations

Kinetic and spectroscopic studies have been carried out in aqueous solution on the formation (from Fe(CN)5OH23−) and dissociation of pentacyanoferrate(II) complexes containing 1-(4-pyridyl)pyridinium and the neutral, protonated, and N-methylated forms of 4,4′-bipyridine (BPY), 1,2-bis(4-pyridyl)ethane (BPA), and trans-1,2-bis(4-pyridyl)ethylene (BPE). The pH dependences of the formation kinetics have been analyzed in terms of the specific rate and acid dissociation constants for these ligands. The rate constants (25.0 °C, I = 0.10 M) for the formation of the dinuclear complexes (NC)5FeLFe(CN)56− have been determined for BPY (50 M−1 s−1), BPA (66 M−1 s−1), BPE (95 M−1 s−1), and pyrazine (10 M−1 s−1), and are compared with the respective rate constants for the formation of (NC)5FeLCo(NH3)5. The relationships between the formation rate constants and the size of the ligand, the number of donor sites, and the magnitude and position of charges on the ligand are discussed in terms of an ion-pair dissociative mechanism. Keywords: pentacyanoferrate(II) complexes, N-heterocycles, ligand substitution, kinetics.

COMPARATIVE STUDY OF REACTION RATE CONSTANTS FOR THE NH3 + H → NH2 + H2 REACTION WITH GLOBE DYNAMICS AND TRANSITION STATE THEORIES

2009 ◽  
Vol 08 (06) ◽  
pp. 1227-1233 ◽  
Author(s):  
JU LIPING ◽  
LU RUIFENG
Keyword(s):  
Transition State ◽  
Cross Sections ◽  
Rate Constants ◽  
Quantum Dynamics ◽  
Classical Trajectory ◽  
State Theory ◽  
Title Reaction ◽  
Reaction Rate Constants ◽  
Barrier Type ◽  
Good Agreement

The nine-dimension quasi-classical trajectory (QCT) calculations have been carried out for the title reaction with a global potential energy surface (PES) constructed by Corchado and Espinosa-García (J Chem Phys106:4013, 1997). The detailed dynamics calculations cover the specific collision energies falling in the range of 0.62–3.04 eV, which are sufficient to fit the calculated reactive cross-sections into a barrier-type excitation function and to obtain the thermal rate constants. The present QCT rate constants are in good agreement with the recent quantum dynamics (QD) results, both of which are much lower than that of the previous variational transition state theory (VTST).

scholarly journals Features of Hydrogen Reduction of Fe(CN)63− Ions in Aqueous Solutions: Effect of Hydrogen Dissolved in Palladium Nanoparticles

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2587
Author(s):  
Roman Solovov ◽  
Boris Ershov
Keyword(s):  
Aqueous Solution ◽  
Catalytic Activity ◽  
Catalytic Reaction ◽  
Rate Constants ◽  
Palladium Nanoparticles ◽  
Hydrogen Reduction ◽  
Specific Rate ◽  
Hydrogen Saturation ◽  
Palladium Catalyzed ◽  
Catalyzed Reactions

Preliminary saturation of 2.6 nm palladium nanoparticles with hydrogen accelerates the reduction of Fe(CN)63− ions in aqueous solution three to four-fold. An analytical equation was derived describing the hydrogen saturation of palladium nanoparticles and the dependence of their catalytic activity on the hydrogen content in the metal. The specific rate constants of reduction do not depend on the content of palladium nanoparticles in the solution. A change in the temperature and pH or stirring of the solution do not affect the rate of catalytic reaction. Approaches to optimization of palladium-catalyzed reactions involving hydrogen are substantiated.

Sign in / Sign up

Export Citation Format

Share Document