Relative Rate Constants of Contaminant Candidate List Pesticides with Hydroxyl Radicals

2006 ◽  
Vol 40 (14) ◽  
pp. 4460-4466 ◽  
Author(s):  
Hilla Shemer ◽  
Charles M. Sharpless ◽  
Michael S. Elovitz ◽  
Karl G. Linden
Keyword(s):  
Hydroxyl Radicals ◽  
Rate Constants ◽  
Relative Rate ◽  
Candidate List ◽  
Relative Rate Constants

Relative rate constants for reactions of hydroxyl radicals from the reaction of Fe(II) or Ti(III) with H2O2

1969 ◽  
Vol 47 (20) ◽  
pp. 3737-3744 ◽  
Author(s):  
W. A. Armstrong
Keyword(s):  
Hydrogen Peroxide ◽  
Hydroxyl Radicals ◽  
Rate Constants ◽  
Relative Rate ◽  
Chloride Ion ◽  
Strong Electron ◽  
Spin Resonance ◽  
Relative Rate Constants ◽  
Novel Method ◽  
Hydroxyl Radical Scavengers

In an attempt to clarify the reactions of ferrous sulfate and titanous sulfate with hydrogen peroxide, a novel method has been developed to determine the relative rate constants for reactions of the oxidizing species generated in these systems. These species react with hydrogen peroxide to give perhydroxyl radicals which combine with titanium(IV) ions to form the relatively stable TiOO•3+ radical. This radical gives a strong electron spin resonance signal and the competition between hydrogen peroxide and a scavenger for the oxidizing species can be followed by measuring the amplitude of this signal in the presence of various concentrations of scavenger. The relative rate constants calculated in this way for both the Fe(II)–H2O2 and Ti(III)–H2O2 systems at pH 1.0 agree with those reported for the reactions of hydroxyl radicals in γ-irradiated thymine solutions. This supports the view that hydroxyl radicals are formed in these cases.Under conditions of acidity favoring the hydrolysis of Fe(II) to FeOH+ ions, hydroxyl radical scavengers do not compete with hydrogen peroxide for the precursors of the TiOO•3+ radical. It is suggested that the FeOH+ ions react with hydrogen peroxide to give a different oxidizing species, possibly the ferryl ion.Scavengers investigated were thymine, methanol, ethanol, formic acid, acetic acid, chloride ion, and several amino acids.

Kinetics of the successive chlorination of 1,2-dichloroethane in the liquid phase

1969 ◽  
Vol 22 (6) ◽  
pp. 1177 ◽  
Author(s):  
DS Caines ◽  
RB Paton ◽  
DA Williams ◽  
PR Wilkinson
Keyword(s):  
Liquid Phase ◽  
Rate Constants ◽  
Relative Rate ◽  
Stirred Tank ◽  
Continuous Stirred Tank Reactor ◽  
Alternative Pathways ◽  
Tank Reactor ◽  
Relative Rate Constants ◽  
Continuous Stirred Tank ◽  
Kinetics Of

Liquid 1,2-dichloroethane has been chlorinated by dissolved chlorine to a succession of chloroethanes up to the ultimate hexachloroethane. The results of both batch and continuous stirred tank reactor systems have been analysed by computer techniques to give a set of relative rate constants from which one can predict the product composition for a given chlorine uptake, the aim in this work being to optimize the production of tetrachloroethanes. An unusual feature of the kinetics is that 1,1,1,2- and 1,1,2,2-tetrachloroethanes provide alternative pathways between 1,1,2-trichloroethane and pentachloroethane.

RECOMBINATION OF OPPOSITELY CHARGED AQUEOUS CLUSTER IONS USING ELECTROSTATICALLY MERGED ION BEAMS

1996 ◽  
Vol 03 (01) ◽  
pp. 655-660 ◽  
Author(s):  
B. PLASTRIDGE ◽  
K.A. COWEN ◽  
D.A. WOOD ◽  
M.H. COHEN ◽  
J.V. COE
Keyword(s):  
Rate Constants ◽  
Cluster Size ◽  
Collision Energy ◽  
Relative Rate ◽  
Center Of Mass ◽  
Cluster Ions ◽  
Charged Cluster ◽  
Relative Rate Constants ◽  
Oppositely Charged ◽  
Electrostatic Quadrupole

A new method for studying cluster-cluster interactions is introduced which involves merging mass-selected beams of oppositely charged cluster ions with an electrostatic quadrupole deflector. Recombination is monitored by measuring the rate of fast neutral production. Relative rate constants have been measured for the reaction of H 3O+( H 2 O )n+ OH −( H 2 O )m as a function of cluster size (m=n=0–3), which display a pronounced enhancement with clustering. Relative rate constants have also been measured as a function of center-of-mass collision energy for a heavily clustered reaction (n=3, m=3) and a lightly clustered reaction (n=1, m=0) revealing that clustering produces a dramatic change in the reaction mechanism.

REACTION OF OXYGEN ATOMS WITH BUTADIENE

1960 ◽  
Vol 38 (11) ◽  
pp. 2187-2195 ◽  
Author(s):  
R. J. Cvetanović ◽  
L. C. Doyle
Keyword(s):  
Pressure Dependence ◽  
Rate Constants ◽  
Room Temperature ◽  
Relative Rate ◽  
Excess Energy ◽  
General Mechanism ◽  
Arrhenius Parameters ◽  
Heats Of Reaction ◽  
Relative Rate Constants ◽  
Oxygen Atoms

Reaction of oxygen atoms with 1,3-butadiene has been investigated at room temperature. It is found that it conforms to the general mechanism established previously for the analogous reactions of monoolefins. Only 1,2-addition occurs, and the addition products, butadiene monoxide and 3-butenal, possess excess energy when formed as a result of high heats of reaction. The pressure dependence of the formation of the addition products yields the values of the "lifetimes" of the initially produced "hot" molecules. The relative rate constants have been determined at 25 and 127 °C and from these the relative values of the Arrhenius parameters have been calculated.

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