Kinetics of reactions of OH with organic carbonyl compounds in aqueous solution

The OH radical plays an important role in tropospheric chemistry. The OH radical is a very strong oxidant and its reactivity contributes to the atmospheric degradation of volatile organic compounds in aqueous solution. In this work the temperature dependencies of the rate constants for the reactions of OH with the following organic carbonyl compounds, (1) methyl ethyl ketone (MEK), (2) acetonylacetone, (3) isobutyraldehyde, (4) ethyl formate and (5) diacetyl are studied. By means of laser flash photolysis and applying a competition kinetics method the following Arrhenius expressions were obtained: The errors stated throughout this study are statistical errors for a confidence interval of 95%. Reaction mechanisms are discussed and Evans–Polanyi correlations are presented.

[1]  A. Mellouki,et al.  Temperature Dependence for the Rate Coefficients of the Reactions of the OH Radical with a Series of Formates , 1997 .

[2]  G. Bras,et al.  Kinetic study of the reactions OH + Mono-, Di-, and trichloroacetaldehyde and acetaldehyde by laser photolysis-resonance fluorescence at 298 K , 1992 .

[3]  M. G. Evans,et al.  Inertia and driving force of chemical reactions , 1938 .

[4]  J. Bott,et al.  A shock tube study of the reaction of methyl radicals with hydroxyl radicals , 1991 .

[5]  J. Boag,et al.  Reactions of the hydroxyl radical. Part 2.—Determination of absolute rate constants , 1965 .

[6]  D. Jacob Chemistry of OH in remote clouds and its role in the production of formic acid and peroxymonosulfate , 1986 .

[7]  S. Mezyk Rate constant and activation energy determination for reaction of e−(aq) and •OH with 2-butanone and propanal , 1994 .

[8]  P. I. Smurthwaite,et al.  Kinetics and mechanisms of the reactions of OH with some oxygenated compounds of importance in tropospheric chemistry , 1994 .

[9]  D. Gutman,et al.  Kinetics and thermochemistry of the acetyl radical: study of the acetyl + hydrogen bromide .fwdarw. acetaldehyde + bromine atom reaction , 1992 .

[10]  D. Golden,et al.  Free-radical and molecule thermochemistry from studies of gas-phase iodine-atom reactions , 1969 .

[11]  G. Buxton,et al.  Critical Review of rate constants for reactions of hydrated electrons, hydrogen atoms and hydroxyl radicals (⋅OH/⋅O− in Aqueous Solution , 1988 .

[12]  H. Herrmann,et al.  A LASER FLASH PHOTOLYSIS KINETIC STUDY OF REACTIONS OF THE CL2- RADICAL ANION WITH OXYGENATED HYDROCARBONS IN AQUEOUS SOLUTION , 1999 .

[13]  Y. Pocker,et al.  Hydration of propionaldehyde, isobutyraldehyde, and pivalaldehyde. Thermodynamic parameters, buffer catalysis and transition state characterization , 1969 .

[14]  H. Herrmann,et al.  Kinetics of aqueous phase reactions relevant for atmospheric chemistry. , 2003, Chemical reviews.

[15]  A. Lloyd,et al.  Relative rate constants for the reaction of the hydroxyl radical with selected ketones, chloroethenes, and monoterpene hydrocarbons , 1976 .

[16]  J. L. Kurz Hydration of acetaldehyde. I. Equilibrium thermodynamic parameters , 1967 .

[17]  John U. White Long Optical Paths of Large Aperture , 1942 .

[18]  David M. Golden,et al.  Hydrocarbon Bond Dissociation Energies , 1982 .

[19]  R. Overend,et al.  Rates of hydroxyl radical reactions. 4. Reactions with methanol, ethanol, 1-propanol, and 2-propanol at 296 K , 1978 .

[20]  P. Wine,et al.  A temperature-dependent kinetics study of the aqueous phase reactions OH + SCN− → SCNOH− and SCN + SCN− ⇆(SCN)2− , 1992 .

[21]  J. Wells,et al.  The hydroxyl radical reaction rate constant and atmospheric transformation products of 2-butanol and 2-pentanol , 1998 .

[22]  M. Kurylo,et al.  A kinetic investigation of the gas-phase reactions of hydroxyl radicals with cyclic ketones and diones: mechanistic insights , 1988 .

[23]  J. Boag,et al.  Spectroscopic studies of reactions of the OH radical in aqueous solutions. Reaction of OH with the ferrocyanide ion , 1965 .

[24]  Man Nien Schuchmann,et al.  The rapid hydration of the acetyl radical. A pulse radiolysis study of acetaldehyde in aqueous solution. , 1988 .

[25]  Roger Atkinson,et al.  Kinetics and mechanisms of the gas-phase reactions of the hydroxyl radical with organic compounds under atmospheric conditions , 1986 .

[26]  L. Janssen,et al.  Kinetics and chemical equilibrium of the hydration of formaldehyde , 2002 .

[27]  O. Nielsen,et al.  Absolute and Relative Rate Constants for the Reactions of Hydroxyl Radicals and Chlorine Atoms with a Series of Aliphatic Alcohols and Ethers at 298 K , 1990 .

[28]  J. Baxendale,et al.  Pulse radiolysis of aqueous thiocyanate and iodide solutions , 1968 .