scholarly journals Ruthenium(III) Catalysis in Perborate Oxidation of 5-Oxoacids

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
S. Shree Devi ◽  
P. Krishnamoorthy ◽  
B. Muthukumaran
Keyword(s):  
Hydrogen Peroxide ◽  
Kinetic Data ◽  
Reaction Rate ◽  
Acidic Solution ◽  
Activation Parameters ◽  
Reactive Species ◽  
Rate Law ◽  
First Order ◽  
Catalyzed Oxidation ◽  
Electron Withdrawing Substituents

Ruthenium(III) catalyzes perborate oxidation of substituted 5-oxoacids in acidic solution. The catalyzed oxidation is first order with respect to the oxidant and catalyst. The rate of ruthenium(III) catalyzed oxidation displays the Michaelis-Menten kinetics on the reductant and is independent of [H+] of the medium. Hydrogen peroxide is the reactive species of perborate and the kinetic results reveal formation of ruthenium(III) peroxo species-5-oxoacid complex. Electron-releasing substituents accelerate the reaction rate and electron-withdrawing substituents retard it. The order of reactivity among the studied 5-oxoacids is p-methoxy ≫  p-methyl > p-phenyl > −H > p-chloro > p-bromo > m-nitro. Activation parameters are evaluated using Arrhenius and Eyring’s plots. A mechanism consistent with the observed kinetic data is proposed and discussed. A suitable rate law is derived based on the mechanism.

scholarly journals Kinetics and Mechanistic Study of Cetyltrimethylammonium Bromide Catalyzed Oxidation of Tetraethylene Glycol byN-Chlorosaccharin in Acidic Medium

2008 ◽  
Vol 5 (3) ◽  
pp. 598-606
Author(s):  
Vandana Sharma ◽  
K. V. Sharma ◽  
V. W. Bhagwat
Keyword(s):  
Cetyltrimethylammonium Bromide ◽  
Reaction Rate ◽  
Activation Parameters ◽  
Mechanistic Study ◽  
Tetraethylene Glycol ◽  
Aqueous Acetic Acid ◽  
Acetic Acid Medium ◽  
First Order ◽  
Dielectric Effect ◽  
Catalyzed Oxidation

The kinetics and mechanism of cetyltrimethylammonium bromide catalyzed oxidation of tetraethylene glycol [2,2'-(oxibis(ethylenoxy)diethanol)] byN-chlorosaccharin in aqueous acetic acid medium in presence of perchloric acid have been investigated at 323K. The reaction is first order dependence on Nchlorosaccharin. The reaction rate follows first order kinetics with respect to [tetraethylene glycol] with excess concentration of other reactants. The miceller effect due to cetyltrimethylammonium bromide, a cationic surfactant has been studied. The change in ionic strength shows negligible salt effect. The dielectric effect is found to be positive. Addition of one of the products (saccharin) retards the reaction rate. Activation parameters are calculated from the Arrhenious plot. A possible mechanism consistent with the experimental results has been proposed.

Photocatalysed Oxidation of Toxic Organics

1987 ◽  
Vol 19 (3-4) ◽  
pp. 381-390 ◽  
Author(s):  
M. Brett Borup ◽  
E. Joe Middlebrooks
Keyword(s):  
Hydrogen Peroxide ◽  
Ultraviolet Radiation ◽  
Organic Compounds ◽  
Hydroxyl Radicals ◽  
Reaction Rate ◽  
Oxidation Process ◽  
Dimethyl Phthalate ◽  
First Order ◽  
Toxic Organics ◽  
Catalyzed Oxidation

The feasibility of treating water contaminated by two toxic organic compounds with an ultraviolet light catalyzed oxidation process using hydrogen peroxide as an oxidant is investigated. In this process hydrogen peroxide is decomposed by ultraviolet radiation producing hydroxyl radicals. The hydroxyl radicals will then oxidize organic compounds via a complex chain of radical reactions. Tests showed that this photooxidation process could successfully remove isophorone and dimethyl phthalate from contaminated waters. A reaction rate expression which adequately describes the process was developed. The reaction rate was found to be first order with respect to hydrogen peroxide concentration, zero order with respect to organic concentration and a function of ultraviolet radiation intensity. The reaction did not exhibit autocatalytic characteristics.

Fast disproportionation of hexacyanomanganate(III) in acidic solution. Formation of hexacyanomanganate(IV) and kinetics of its decomposition

1986 ◽  
Vol 64 (12) ◽  
pp. 2301-2304 ◽  
Author(s):  
Guillermo López-Cueto ◽  
Carlos Ubide
Keyword(s):  
Ionic Strength ◽  
Rate Constants ◽  
Acidic Solution ◽  
Activation Parameters ◽  
Rate Law ◽  
First Order ◽  
Experimental Rate ◽  
Parallel Pathways ◽  
Solution Formation ◽  
Kinetics Of

When potassium hexacyanomanganate(III) dissolves in acidic solution it rapidly disproportionates into hexacyanomanganate(IV) and Mn(II). Hexacyanomanganate(IV) then slowly decomposes to yield Mn(II) and (CN)2. Kinetics of the latter reaction has been studied. The reaction is found to be first order with respect to [Formula: see text], H+, and Mn(II) concentrations and the experimental rate law has the form v = kobs[Mn(IV)] = (ka + kb[H+] + kc[Mn(II)])[Mn(IV)]. At 40 °C and ionic strength 2.0, ka, kb, and kc values are (1.78 ± 0.01) × 10−4 s−1, (5.97 ± 0.05) × 10−5 s−1 M−1, and (3.40 ± 0.18) × 10−3 s−1 M−1, respectively. A mechanism with three parallel pathways is proposed, the deduced rate law being similar to the experimental one. Activation parameters, ΔH≠and ΔS≠ for the rate constants ka, kb, and kc are also reported.

The kinetics of the decarboxylation of β-resorcylic acid in catechol

1976 ◽  
Vol 29 (2) ◽  
pp. 443 ◽  
Author(s):  
MA Haleem ◽  
MA Hakeem
Keyword(s):  
Rate Equation ◽  
Kinetic Data ◽  
Reaction Rate ◽  
Complex Mechanism ◽  
First Order ◽  
Absolute Reaction Rate ◽  
First Time ◽  
Kinetics Of ◽  
Absolute Reaction ◽  
Reaction Rate Equation

Kinetic data are reported for the decarboxylation of β-resorcylic acid in resorcinol and catechol for the first time. The reaction is first order. The observation supports the view that the decomposition proceeds through an intermediate complex mechanism. The parameters of the absolute reaction rate equation are calculated.

scholarly journals The alcoholysis of 1,2,2-trimethylpropyl-methylfluorophosphonate

2000 ◽  
Vol 65 (12) ◽  
pp. 857-866
Author(s):  
Mladjen Micevic ◽  
Slobodan Petrovic
Keyword(s):  
Kinetic Data ◽  
Reaction Rate ◽  
Frequency Factor ◽  
Reaction Rate Constant ◽  
Order Reaction ◽  
Activation Entropy ◽  
Second Order Reaction ◽  
Third Order ◽  
First Order ◽  
Kinetics Of

The alcoholysis of 1,2,2-trimethylpropyl-methylfluorophosphonate (soman) was examined with a series of alkoxides and in corresponding alcohols: methanol, ethanol, 1-propanol, 2-propanol, 2-methoxyethanol and 2-ethoxyethanol. Soman reacts with the used alkoxides in a second order reaction, first order in each reactant. The kinetics of the reaction between 1,2,2-trimethylpropyl-methylfluorophosphonate and ethanol in the presence of diethylenetriamine was also examined. A third order reaction rate constant was calculated, first order in each reactant. The activation energy, frequency factor and activation entropy were determined on the basis of the kinetic data.

Hydrogen Peroxide Decay in Waters with Suspended Soils: Evidence for Biologically Mediated Processes

1990 ◽  
Vol 47 (5) ◽  
pp. 888-893 ◽  
Author(s):  
William J. Cooper ◽  
Richard G. Zepp
Keyword(s):  
Hydrogen Peroxide ◽  
Natural Water ◽  
Water Samples ◽  
First Order ◽  
Natural Water Samples ◽  
Major Reaction Product ◽  
Major Reaction ◽  
Chemical Sterilization ◽  
Pseudo First Order ◽  
Catalyzed Oxidation

Hydrogen peroxide decay studies have been conducted in suspensions of several well-characterized soils and in natural water samples. Kinetic and product studies indicated that the decay was biologically-mediated, and could be described by pseudo first-order rate expressions. At an initial H2O2 concentration of 0.5 μM, the hydrogen peroxide half-life varied from 1 to 8 h. The decay was inhibited by thermal and chemical sterilization of the soils. Peroxidase activity was inferred in several natural water samples, where the suspended particles catalyzed the oxidation of p-anisidine by hydrogen peroxide. The mass spectrum of the major reaction product indicated that it was the dimer, possibly benzoquinone-4-methoxyanil, a product that also was observed from the horseradish peroxidase-catalyzed oxidation of p-anisidine by hydrogen peroxide.

scholarly journals Kinetics and mechanism of the C-S coupling reactions of aryl Grignard reagents with aryl arenesulfonates

2008 ◽  
Vol 6 (2) ◽  
pp. 237-244 ◽  
Author(s):  
Ender Erdik ◽  
Fatma Eroğlu
Keyword(s):  
Nucleophilic Addition ◽  
Kinetic Data ◽  
Grignard Reagent ◽  
Activation Parameters ◽  
Grignard Reagents ◽  
Coupling Reactions ◽  
Sulfonyl Group ◽  
First Order ◽  
Kinetics Of ◽  
Hammett Relationship

AbstractThe kinetics of the C-S coupling of arylmagnesium bromides with phenyl tosylate has been studied in THF: toluene at 90°C. The reaction is first order in Grignard reagent and first order in phenyl tosylate. Kinetic data, Hammett relationship and activation parameters are consistent with a nucleophilic addition mechanism involving rate determining attack of carbanion to sulfonyl group followed by a fast phenoxide group leaving.

Kinetics of the Substitution of Norbornadiene in Tetracarbonyl(norbomadiene)molybdenum(0) by 2,2'-Bipyridine

2001 ◽  
Vol 56 (3) ◽  
pp. 281-286 ◽  
Author(s):  
Ceyhan Kayran ◽  
Eser Okan
Keyword(s):  
Reaction Rate ◽  
Activation Parameters ◽  
Bipy Ligand ◽  
First Order ◽  
Rate Determining Step ◽  
Vis Spectroscopy ◽  
Different Temperatures ◽  
Ft Ir ◽  
Thermal Substitution ◽  
Kinetics Of

Abstract The kinetics of the thermal substitution of norbornadiene (nbd) by 2,2'-bipyridine (2,2'-bipy) in (CO)4Mo(C7H9) was studied by quantitative FT-IR and UV-VIS spectroscopy. The reaction rate exhibits first-order dependence on the concentration of the starting complex, and the observed rate constant depends on the concentration of both leaving nbd and entering 2,2'-bipy ligand. The mechanism was found to be consistent with the previously proposed one, where the rate determining step is the cleavage of one of the two Mo-olefin bonds. The reaction was performed at four different temperatures (35 -50 °C) and the evaluation of the kinetic data gives the activation parameters which now support states.

scholarly journals Kinetics and mechanism of the oxidation of some cis-Alpha- Phenylcinnamic acids by Pyridinium Chlorochromate

2017 ◽  
Vol 12 (5) ◽  
pp. 4434-4441
Author(s):  
S. Nalini ◽  
R. Udhayakumar ◽  
K. Anbarasu ◽  
P. Manivannan ◽  
K. Raghu
Keyword(s):  
Reaction Rate ◽  
Activation Parameters ◽  
Sodium Chlorate ◽  
Dipole Interaction ◽  
Slow Step ◽  
Pyridinium Chlorochromate ◽  
Cinnamic Acids ◽  
Acetic Acid Medium ◽  
First Order ◽  
Rate Of Reaction

Oxidation of cis α-phenyl cinnamic acids by pyridinium chlorochromate (PCC) was studied in acetic acid–water mixturecontaining perchloric acid. The reaction rate is first order in [PCC] and fractional order in [H+] and has aldehyde as aproduct. The rate of reaction increases with increase in the percentage of acetic acid medium. The reactions exhibit kineticisotope effect. The activation parameters have been evaluated. The added Mn (II) decreases the rate of reaction. Theadded sodium chlorate has no effect on the reaction rate and indicates the absence of ion-ion (or) ion- dipole interaction inthe slow step. The deviation of Hammett plot is noted and a “V” shaped curve is obtained.

scholarly journals OXIDATION OF BENZALDEHYDE BY QUINOXALINIUM DICHROMATE

2016 ◽  
Vol 12 (9) ◽  
pp. 4396-4403 ◽  
Author(s):  
K Anbarasu ◽  
N. GEETHA
Keyword(s):  
Acetic Acid ◽  
Perchloric Acid ◽  
Reaction Rate ◽  
Sodium Perchlorate ◽  
Activation Parameters ◽  
Probable Mechanism ◽  
Water Medium ◽  
First Order ◽  
Rate Of Reaction ◽  
Acetic Acid Water

The kinetics and mechanism of oxidation of benzaldehyde by quinoxalinium dichromate has been studied in the presence of perchloric acid in 70 % acetic acid - water medium. The reaction follows first order with respect to benzaldehyde, quinoxalinium dichromate and fractional order with respect to perchloric acid. There is no effect on the reaction rate with increase in ionic strength of the medium by adding sodium perchlorate. The rate of reaction increases with increase in the percentage of acetic acid. The reaction does not induce the polymerization with acrylonitrile. The rate of reaction decreases with increase in the concentration of manganoussulphate. The thermodynamic and activation parameters have been calculated and a probable mechanism has been proposed.

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