ORGN 113 |
| Hydroxyl radical (HO) plays an important part in different environmental processes. Therefore, hydroxyl radical has received a great deal of attention, and kinetic studies of this important species in aqueous solutions have been reported for a wide range of organic molecules. However, there is great difficulty for kinetic studies of hydroxyl radical reactions with aromatic compounds in aqueous solutions because some of these organic compounds have low solubility in water. Also, there is an increasing body of evidence, which suggests that these reactions in nature are not truly aqueous. In our research, laser flash photolysis (LFP) methodology was employed to obtain rate coefficients of reactions of hydroxyl radical with 16 benzene derivatives with varying degree of substitution as well as substituents in acetonitrile. Rate coefficients were correlated with different parameters including ionization potential (IP) values and Hammett constants. Indeed, IP values have the best correlation with the rate coefficients in spite of the different steric effects imposed by substituent groups. This implies that hydroxyl radical addition is a major pathway for this reactive intermediate when reacting with benzene derivatives. Density functional theory was used to theoretically study these HO reactions through radical addition and hydrogen-atom abstraction pathways. The computational results are consistent with the experimental data, and were used to investigate additional reaction details. |
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Process R&D, Physical Organic Chemistry, Heterocycles, Aromatics, Metal-Mediated Reactions
8:00 PM-10:00 PM, Sunday, March 25, 2007 Hyatt Regency Chicago -- Riverside Center, Poster
Division of Organic Chemistry |