An experimental and theoretical study of the kinetics of the reaction between 3-hydroxy-3-methyl-2-butanone and OH radicals

RSC Advances ◽  
2015 ◽  
Vol 5 (34) ◽  
pp. 26559-26568 ◽  
Author(s):  
Angappan Mano Priya ◽  
Gisèle El Dib ◽  
Lakshmipathi Senthilkumar ◽  
Chantal Sleiman ◽  
Alexandre Tomas ◽  
...  
Keyword(s):  
Rate Constants ◽  
Theoretical Study ◽  
Oh Radicals ◽  
First Time ◽  
Kinetics Of

Absolute experimental and theoretical rate constants are determined for the first time for the reaction of 3-hydroxy-3-methyl-2-butanone with OH as a function of temperature. The atmospheric implications are discussed.

scholarly journals Theoretical Study of the Iron Complexes with Lipoic and Dihydrolipoic Acids: Exploring Secondary Antioxidant Activity

Antioxidants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 674
Author(s):  
Roger Monreal-Corona ◽  
Jesse Biddlecombe ◽  
Angela Ippolito ◽  
Nelaine Mora-Diez
Keyword(s):  
Antioxidant Activity ◽  
Electron Transfer ◽  
Rate Constant ◽  
Thermodynamic Stability ◽  
Rate Constants ◽  
Theoretical Study ◽  
Oh Radicals ◽  
Single Electron Transfer ◽  
Coordination Numbers ◽  
Ph Conditions

The thermodynamic stability of twenty-nine Fe(III) complexes with various deprotonated forms of lipoic (LA) and dihydrolipoic (DHLA) acids, with coordination numbers 4, 5 and 6, is studied at the M06(SMD)/6-31++G(d,p) level of theory in water under physiological pH conditions at 298.15 K. Even though the complexes with LA- are more stable than those with DHLA−, the most thermodynamically stable Fe(III) complexes involve DHLA2−. The twenty-four exergonic complexes are used to evaluate the secondary antioxidant activity of DHLA and LA relative to the Fe(III)/Fe(II) reduction by O2•− and ascorbate. Rate constants for the single-electron transfer (SET) reactions are calculated. The thermodynamic stability of the Fe(III) complexes does not fully correlate with the rate constant of their SET reactions, but more exergonic complexes usually exhibit smaller SET rate constants. Some Cu(II) complexes and their reduction to Cu(I) are also studied at the same level of theory for comparison. The Fe(III) complexes appear to be more stable than their Cu(II) counterparts. Relative to the Fe(III)/Fe(II) reduction with ascorbate, DHLA can fully inhibit the formation of •OH radicals, but not by reaction with O2•−. Relative to the Cu(II)/Cu(I) reduction with ascorbate, the effects of DHLA are moderate/high, and with O2•− they are minor. LA has minor to negligible inhibition effects in all the cases considered.

An experimental and theoretical study on the kinetics of the reaction between 4-hydroxy-3-hexanone CH3 CH2 C(O)CH(OH)CH2 CH3 and OH radicals

2018 ◽  
Vol 50 (8) ◽  
pp. 556-567 ◽  
Author(s):  
Gisèle El Dib ◽  
Basheer Aazaad ◽  
Senthilkumar Lakshmipathi ◽  
Hélène Laversin ◽  
Estelle Roth ◽  
...  
Keyword(s):  
Theoretical Study ◽  
Oh Radicals ◽  
Kinetics Of

scholarly journals Kinetics of the gas-phase reactions of OH radicals with alkanes and cycloalkanes

2003 ◽  
Vol 3 (6) ◽  
pp. 2233-2307 ◽  
Author(s):  
R. Atkinson
Keyword(s):  
Gas Phase ◽  
Rate Constants ◽  
Relative Rate ◽  
Oh Radicals ◽  
Gas Phase Reactions ◽  
Temperature Dependent ◽  
Temperature Range ◽  
Dependent Rate ◽  
Temperature Ranges ◽  
Kinetics Of

Abstract. The available database concerning rate constants for gas-phase reactions of the hydroxyl (OH) radical with alkanes through early 2003 is presented over the entire temperature range for which measurements have been made (~180-2000 K). Measurements made using relative rate methods are re-evaluated using recent rate data for the reference compound (generally recommendations from this review). In general, whenever more than one study has been carried out over an overlapping temperature range, recommended rate constants or temperature-dependent rate expressions are presented. The recommended 298 K rate constants, temperature-dependent parameters, and temperature ranges over which these recommendations are applicable are listed in Table 1.

Ultra-low temperature kinetics of neutral–neutral reactions: rate constants for the reactions of OH radicals with butenes between 295 and 23 K

1994 ◽  
Vol 90 (11) ◽  
pp. 1473-1478 ◽  
Author(s):  
Ian R. Sims ◽  
Ian W. M. Smith ◽  
Pascal Bocherel ◽  
André Defrance ◽  
Daniel Travers ◽  
...  
Keyword(s):  
Low Temperature ◽  
Rate Constants ◽  
Oh Radicals ◽  
Low Temperature Kinetics ◽  
Kinetics Of

Autoxidation of SIV inhibited by chlorophenols reacting with sulfate radicals

2007 ◽  
Vol 4 (5) ◽  
pp. 355 ◽  
Author(s):  
Józef Ziajka ◽  
Krzysztof J. Rudzinski
Keyword(s):  
Rate Constants ◽  
Advanced Oxidation Processes ◽  
Natural Waters ◽  
Food Additives ◽  
Advanced Oxidation ◽  
Detailed Knowledge ◽  
Sulfate Radicals ◽  
Oxidation Processes ◽  
First Time ◽  
Kinetics Of

Environmental context. Chlorophenols pollute natural waters and soils, as well as urban waste water systems. Although toxic and carcinogenic to animals and humans, a detailed knowledge of their action is limited. A new approach to effective degradation in the environment is advanced oxidation processes with sulfate radicals. The radicals can originate from the oxidation of sulfur dioxide or sulfites to make these common pollutants and food additives interact with chlorophenols. The main goal of this work is to determine rate constants for reactions of these chlorophenols with sulfate radicals in order to shed some light on the chemical kinetics of these reactions. Abstract. Kinetic experiments have shown that six chlorophenols (CPs) inhibit the autoxidation of SIV catalysed by Fe(ClO4)3 in aqueous solution at 25°C and pH ≈ 3.0. Efficiency of the inhibition decreases with the number of chlorine substituents for all CPs except for 2,5-dichlorophenol (2,5-DCP), which ranked between the tri- and tetrachlorophenols. The inhibition is explained by reactions of chlorophenols with sulfate radicals, the chain carriers in the mechanism of autoxidation. Rate constants for these reactions are determined for the first time, using the reversed-rates method with ethanol as a reference inhibitor: 8.7 × 109 (4-CP), 7.4 × 109 (2,4-DCP), 1.9 × 109 (2,5-DCP), 2.4 × 109 (2,4,5-TCP), 2.9 × 109 (2,4,6-TCP), and 7.5 × 108 (2,3,5,6-TTCP); 4.3 × 107 (ethanol reference) M–1 s–1. Linear correlations were derived for the estimation of rate constants for the remaining chlorophenols using sums of Brown substituent coefficients or relative strengths of O–H bonds. The results can be used in the development of advanced oxidation processes that utilise sulfate radicals for mineralisation of chlorophenols in wastewaters, and also demonstrate that chlorophenols can extend the lifetimes of SO2 and sulfites in natural and atmospheric waters.

scholarly journals Kinetics of the gas-phase reactions of OH radicals with alkanes and cycloalkanes

2003 ◽  
Vol 3 (4) ◽  
pp. 4183-4358 ◽  
Author(s):  
R. Atkinson
Keyword(s):  
Gas Phase ◽  
Rate Constants ◽  
Relative Rate ◽  
Oh Radicals ◽  
Reference Compound ◽  
Gas Phase Reactions ◽  
Temperature Dependent ◽  
Temperature Range ◽  
Dependent Rate ◽  
Kinetics Of

Abstract. The available database concerning rate constants for gas-phase reactions of the hydroxyl (OH) radical with alkanes through early 2003 is presented ove the entire temperature range for which measurements have been made (~180–2000 K). Measurements made using relative rate methods are re-evaluated using recent rate data for the reference compound (generally recommendations from this review). In general, whenever more than one study has been carried out over an overlapping temperature range, recommended rate constants or temperature-dependent rate expressions are presented.

scholarly journals The kinetics of oxygen exchange between the sulfite ion and water

1970 ◽  
Vol 48 (13) ◽  
pp. 2035-2041 ◽  
Author(s):  
R. H. Betts ◽  
R. H. Voss
Keyword(s):  
Aqueous Solution ◽  
Ionic Strength ◽  
Rate Constant ◽  
Rate Constants ◽  
Time Rate ◽  
A Value ◽  
First Time ◽  
Kinetics Of ◽  
Sulfite Ion ◽  
Gross Rate

Oxygen of mass 18 was used as a stable tracer to measure the rate of exchange between the sulfite ion and water as a function of pH and total sulfite concentration. A value for the rate constant of hydration of SO2 in aqueous solution was determined. The gross rate constants k1 and k−1 for the overall reaction[Formula: see text]at 24.7 °C and ionic strength = 0.9 were evaluated from exchange results to be [Formula: see text]Also, for the first time, rate constants for the pyrosulfite equilibrium[Formula: see text]Were obtained[Formula: see text]at 24.7 °C and ionic strength = 0.9

Mechanism and Kinetics of the Oxidation of 1,3-Butadien-1-yl (n-C4H5): A Theoretical Study

2021 ◽  
Author(s):  
Denis P Porfiriev ◽  
Valeriy N. Azyazov ◽  
Alexander Mebel
Keyword(s):  
Potential Energy ◽  
Rate Constants ◽  
Energy Surface ◽  
Theoretical Study ◽  
Branching Ratios ◽  
Dependent Rate ◽  
Mechanism And Kinetics ◽  
Temperature And Pressure ◽  
Product Branching ◽  
Kinetics Of

Ab initio CCSD(T)-F12/cc-pVTZ-f12//B3LYP/6-311G(d,p) calculations of the C4H5O2 potential energy surface have been combined with Rice-Ramsperger-Kassel-Marcus Master Equation (RRKM-ME) calculations of temperature- and pressure-dependent rate constants and product branching ratios to...

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