Kinetic Studies of the Reactions of Cyanide Ion and 1,3,5-Trinitrobenzene in Ethanol, n-Propanol, Isopropanol, and t-Butanol at 25.0 °C

1974 ◽  
Vol 52 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Leong Huat Gan ◽  
Albert Richard Norris
Keyword(s):  
Rate Constants ◽  
Kinetic Studies ◽  
Specific Rate ◽  
Cyanide Ion ◽  
Solvent Parameter ◽  
Kinetics Of

The specific rate constants for the formation of the 1:1 1,3,5-trinitrobenzene – cyanide ion σ-complex in ethanol, n-propanol, isopropanol, and t-butanol are 442 ± 14,932 ± 30, 2.45 ± 0.10 × 103 and 1.06 ± 0.05 × 105 M−1 s−1, respectively. A plot of log kvs. Dimroth's solvent parameter Et is linear with slope −0.25. The kinetics of the reactions of cyanide ion and 1,3,5-trinitrobenzene in ethanol and n-propanol are complicated by alcoholysis of cyanide ion which yields the corresponding alkoxide ion and the 1:1 1,3,5-trinitrobenzene–alkoxide ion σ-complex.

Kinetic studies of the reactions of 4-nitrobenzofuroxan with cyanide ion and isopropoxide ion in isopropanol

1980 ◽  
Vol 58 (16) ◽  
pp. 1691-1696 ◽  
Author(s):  
Michael E. Moir ◽  
Albert R. Norris
Keyword(s):  
Rate Constants ◽  
Activation Parameters ◽  
Kinetic Studies ◽  
Specific Rate ◽  
Stopped Flow ◽  
Cyanide Ion ◽  
Temperature Range ◽  
Flow Reaction

Kinetic studies of the reactions in isopropanol of 4-nitrobenzofuroxan with cyanide ion and isopropoxide ion have been carried out over the temperature range 15.0 to 35.0 °C. For both bases, the first species identifiable using stopped-flow reaction techniques is postulated to be a C-7 σ-complex of 4-nitrobenzofuroxan and base. Specific rate constants and activation parameters for the formation of these σ-complexes are compared to corresponding data relating to the formation of cyanide ion and isopropoxide ion—σ-complexes of 1,3,5-trinitrobenzene in isopropanol.

Kinetics of the Ozonation of Tetrabromobisphenol-A in Wastewater

2011 ◽  
Vol 383-390 ◽  
pp. 2945-2950 ◽  
Author(s):  
Jie Zhang ◽  
Shi Long He ◽  
Mei Feng Hou ◽  
Li Ping Wang ◽  
Li Jiang Tian
Keyword(s):  
Rate Constants ◽  
Apparent Rate Constant ◽  
Reaction Rate ◽  
Batch Reactor ◽  
Kinetic Studies ◽  
Tetrabromobisphenol A ◽  
First Order ◽  
Reaction Rate Constants ◽  
Pseudo First Order ◽  
Kinetics Of

The kinetics of TBBPA degradation by ozonation in semi-batch reactor was studied. The reaction rate constants of TBBPA with O3 and •OH were measured by means of direct ozone attack and competition kinetics, and the values of which were 6.10 l/(mol•s), 4.8×109 l/(mol•s), respectively. Results of kinetic studies showed that TBBPA degradation by ozonation under the different conditions tested followed the pseudo-first-order. The values of apparent rate constant of TBBPA degradation increased with the increase of ozone dosage and pH, but decreased with the increase of initial TBBPA concentration.

KINETIC STUDIES OF METHYL-BIS-β-CHLOROETHYLAMINE: III. THE KINETICS OF THE DIMERIZATION IN METHANOL

1948 ◽  
Vol 26b (2) ◽  
pp. 175-180 ◽  
Author(s):  
C. A. Winkler ◽  
A. W. Hay ◽  
A. L. Thompson
Keyword(s):  
Rate Constants ◽  
Initial Rate ◽  
Kinetic Studies ◽  
First Order ◽  
Rate Expression ◽  
Principal Reaction ◽  
Kinetics Of ◽  
Rate Controlling Step

The principal reaction of methyl-bis-β-chloroethylamine in methanol is dimerization, which results in one chlorine from each molecule becoming ionic, but this is accompanied by slight alcoholysis. The rate-controlling step is believed to be the first order formation of an ethylenimonium ion which reacts rapidly with one of its kind to form dimer. The rate expression as calculated from initial rate constants is k (initial) = 4.0 × 1013e−19600/RThr.−1.

scholarly journals Nitrogenase of Klebsiella pneumoniae. Kinetic studies on the Fe protein involving reduction by sodium dithionite, the binding of MgADP and a conformation change that alters the reactivity of the 4Fe-4S centre

1987 ◽  
Vol 246 (2) ◽  
pp. 455-465 ◽  
Author(s):  
G A Ashby ◽  
R N F Thorneley
Keyword(s):  
Klebsiella Pneumoniae ◽  
Rate Constants ◽  
Protein Conformation ◽  
Kinetic Studies ◽  
Sodium Dithionite ◽  
Conformation Change ◽  
Fe Protein ◽  
Redox Active ◽  
Dithionite Ion ◽  
Kinetics Of

The kinetics of reduction of indigocarmine-dye-oxidized Fe protein of nitrogenase from Klebsiella pneumoniae (Kp2ox) by sodium dithionite in the presence and absence of MgADP were studied by stopped-flow spectrophotometry at 23 degrees C and at pH 7.4. Highly co-operative binding of 2MgADP (composite K greater than 4 × 10(10) M-2) to Kp2ox induced a rapid conformation change which caused the redox-active 4Fe-4S centre to be reduced by SO2-.(formed by the predissociation of dithionite ion) with k = 3 × 10(6) M-1.s-1. This rate constant is at least 30 times lower than that for the reduction of free Kp2ox (k greater than 10(8) M-1.s-1). Two mechanisms have been considered and limits obtained for the rate constants for MgADP binding/dissociation and a protein conformation change. Both mechanisms give rate constants (e.g. MgADP binding 3 × 10(5) less than k less than 3 × 10(6) M-1.s-1 and protein conformation change 6 × 10(2) less than k less than 6 × 10(3) s-1) that are similar to those reported for creatine kinase (EC 2.7.3.2). The kinetics also show that in the catalytic cycle of nitrogenase with sodium dithionite as reductant replacement of 2MgADP by 2MgATP occurs on reduced and not oxidized Kp2. Although the Kp2ox was reduced stoichiometrically by SO2-. and bound two equivalents of MgADP with complete conversion into the less-reactive conformation, it was only 45% active with respect to its ability to effect MgATP-dependent electron transfer to the MoFe protein.

scholarly journals THE PHOTOINITIATED ADDITION OF MERCAPTANS TO OLEFINS: III. THE KINETICS OF THE ADDITION OF THIOPHENOL TO STYRENE AND TO 1-OCTENE

1957 ◽  
Vol 35 (7) ◽  
pp. 723-733 ◽  
Author(s):  
R. H. Pallen ◽  
C. Sivertz
Keyword(s):  
Free Radical ◽  
Rate Constants ◽  
Chain Transfer ◽  
Kinetic Studies ◽  
Activation Energies ◽  
Reverse Reaction ◽  
Kinetics Of

Kinetic studies were made of the free radical photoinitiated addition of thiophenol to 1-octene and to styrene in the absence of oxygen. In addition to the usual attack, chain transfer, and termination steps, it is found that a reverse reaction accompanies the attack step, [Formula: see text] The rate constants for the thiophenol–styrene reaction were calculated to be [Formula: see text]kt = 2 × 107 liters.moles−1sec.−1. The over-all activation energies for the two reactions were found to be E (1-octene) = 1.2 kcal., E (styrene) = 2.4 kcal.; suggestions are submitted as to why these activation energies are so low. These reactions are compared with n-butyl mercaptan – olefin reactions.

KINETIC STUDIES OF PROTEIN–DYE AND ANTIBODY–HAPTEN INTERACTIONS WITH THE TEMPERATURE-JUMP METHOD

1962 ◽  
Vol 40 (9) ◽  
pp. 1786-1797 ◽  
Author(s):  
A. Froese ◽  
A. H. Sehon ◽  
M. Eigen
Keyword(s):  
Relaxation Time ◽  
Bovine Serum Albumin ◽  
Rate Constants ◽  
Temperature Jump ◽  
Relaxation Times ◽  
Kinetic Studies ◽  
Single Relaxation Time ◽  
Effects Of Temperature ◽  
Arsonic Acid ◽  
Kinetics Of

The kinetics of protein–dye and antibody–hapten reactions were studied with the temperature-jump method. The systems used consisted of (i) bovine serum albumin (BSA) and the dye 1-naphthol-4-[4-(4′-azobenzene azo)phenyl arsonic acid], referred to as N—R′, (ii) BSA and the dye 1-naphthol-2-sulphonic acid-4-[4-(4′-azobenzene azo)phenyl arsonic acid], referred to as NS—R′, and (iii) rabbit antibodies to phenyl arsonic acid [Ab] and the hapten N—R′.Each of the systems exhibited a single relaxation time. From the analysis of the concentration dependence of the relaxation times, it was concluded that each system could be represented by the reactions[Formula: see text]where P refers to BSA or Ab, and D to N—R′ or NS—R′. The following rate constants were calculated for the three systems at 25 °C:[Formula: see text]The effects of temperature and pH on the rate constants of the system BSA – N—R′ are discussed.

IDENTIFICATION OF RATE CONSTANTS AND NONOBSERVABLE ABSORPTION SPECTRA IN NONLINEAR BIOCHEMICAL REACTION DYNAMICS

2004 ◽  
Vol 14 (06) ◽  
pp. 2081-2092 ◽  
Author(s):  
D. MARAUN ◽  
W. HORBELT ◽  
H. RUST ◽  
J. TIMMER ◽  
H. P. HAPPERSBERGER ◽  
...  
Keyword(s):  
Absorption Spectra ◽  
Rate Constants ◽  
Reaction Dynamics ◽  
Biochemical Reaction ◽  
Multiple Shooting ◽  
Specific Rate ◽  
Time Resolved ◽  
Time Courses ◽  
Kinetics Of ◽  
Shooting Algorithm

On analyzing data of biochemical reaction dynamics monitored by time-resolved spectroscopy, one faces the problem that the concentration time courses of the involved components are not directly observed, but the superposition of their absorption spectra. Furthermore the single spectra are often unknown, because the corresponding reagents cannot be isolated. We propose a method based on Bock's multiple shooting algorithm to estimate the rate constants and individual spectra simultaneously. Applying this procedure to a biochemical reaction we identify the specific rate constants characterizing the reaction dynamics as well as the nonobservable absorption spectra. The results lead to a better understanding of the kinetics of a novel modification reaction which was used as trapping reaction in disulfide bond mediated protein folding reactions.

Kinetics of Acid-Catalysed Hydrolysis of Diethylsuccinate in Dioxane-Water Mixtures

1982 ◽  
Vol 37 (4) ◽  
pp. 390-394
Author(s):  
Fayez Y . Khalil ◽  
F. M. Abdel-Halim ◽  
Adel N. Asaad
Keyword(s):  
Dielectric Constant ◽  
Thermodynamic Parameters ◽  
Rate Constants ◽  
Solvent Composition ◽  
Specific Rate ◽  
Molecular Dipole ◽  
First Order ◽  
Kinetics Of ◽  
Hydrolysis Of ◽  
Activated Complex

Abstract The specific rate constants k1 and k2 of the consecutive first-order acid-catalysed hydrolysis steps of diethylsuccinate in dioxane-water mixtures covering the range 0-95% (w/w) of dioxane are determined at 25-55 °C. As the concentration of dioxane increases, the rate of the reaction decreases to a minimum at about 90% (w/w) dioxane, after which it increases again. The ratio k1/k2 was found to be almost constant at the value 2.0. The activation energies of the reaction are independent of solvent composition. Available electrostatic theories regarding the effect of the dielectric constant on the rate are presented, from which the reaction is shown to be an ion-molecular dipole type of interaction. The thermodynamic parameters and the radii of the activated complex at different solvent compositions are calculated and discussed.

scholarly journals Aquation reaction of iminodiacetate complex of oxidovanadium(IV) with 2,2’-bipyridine induced by Fe(III) ions: Kinetic studies

2019 ◽  
Vol 44 (4) ◽  
pp. 300-306
Author(s):  
Joanna Drzeżdżon ◽  
Agnieszka Piotrowska-Kirschling ◽  
Lech Chmurzyński ◽  
Dagmara Jacewicz
Keyword(s):  
Aqueous Solutions ◽  
Computer Program ◽  
Rate Constants ◽  
Reaction Rate ◽  
Kinetic Studies ◽  
Reaction Rate Constants ◽  
Different Temperatures ◽  
Kinetics Of

The kinetics of the aquation reaction of the [VO(ida)(bipy)]·2H2O (VO(ida)(bipy)) complex (where ida = iminodiacetate anion and bipy = 2,2’-bipyridine) promoted by [Fe(H2O)6]3+ ions were investigated in aqueous solutions. Spectrophotometric studies were carried out at different temperatures in the range of 293.15–313.15 K. The concentration of the [Fe(H2O)6]3+ (Fe3+) ions was kept within the range of 2 × 10–4 to 8 × 10–4 mol L–1, and the concentration of VO(ida)(bipy) was 1 × 10–3 mol L–1. The values of the observable reaction rate constants were calculated based on the Glint computer program. Furthermore, the mechanism for the aquation of VO(ida)(bipy), induced by Fe(III) ions, has been proposed.

scholarly journals HYDROLYSIS AND DEUTERATION OF GLYCYLGLYCINE CATALYZED BY DINUCLEAR [BMXDCu 2]4+ COMPLEX

2007 ◽  
Vol 15 (15) ◽  
pp. 15-27
Author(s):  
Ana Cristina Franzoi ◽  
Gledir T. Stein Martins ◽  
Sérgio Duvoisin Jr. ◽  
Bruno Szpoganicz
Keyword(s):  
Rate Constants ◽  
Kinetic Studies ◽  
Peptide Bond ◽  
Reaction Rates ◽  
Active Species ◽  
Individual Species ◽  
Specific Rate ◽  
First Order ◽  
Parallel Reactions ◽  
Semi Empirical

Kinetic studies of hydrolysis and deuteration of glycylglycine by dinuclear [BMXDCu 2]4+ complexes were following by NMR1H. Two parallel reactions were observed for the ternary system BMXD-Cu 2-Glycylglycine: peptide bond hydrolysis and NCH2 deuteration reactions. The reaction rates show the first-order behavior to the concentration of the ternary [BMXDCu2Glycylglycine] complex. The specific rate constants for the hydrolysis reaction are: KLCu2HGG4+ (L = BMXD and GG = glycylglycine) = 1,8 x 10-6 s-1; KLCu 2GG3+ = 2,3 x 10-6 s-1; KLCu2H-1GG2+, KLCu 2(OH)H-1GG+ and KLCu 2(OH) 2H-1GG = 0, and the specific deuteration rate constants for individual species are: KLCu 2HGG4+ = 3,9 x 10-6 s-1; KLCu 2GG3+ = 4,3 x 10-6 s-1; KLCu2H-1GG2+, KLCu2(OH)H-1GG+ and KLCu2(OH)2H-1GG = 0. The results show that the most active species toward hydrolysis and deuteration reactions are the protonated and non-protonated species, the former being the most reactive species. Semi-empirical calculations for energy minimization showed that the binuclear [BMXDCu 2]4+) complexes adopt the boat-type conformation, in order to accommodate the dipeptide glycylglycine.

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