Molecular Modeling Studies of the Reactions of Phenoxy Radical Dimers: Pathways To Dibenzofurans
The B3LYP hybrid density functional computational technique was applied to describe the sequence of phenoxy radicals coupling reactions leading to the formation of dibenzofurans. Reaction kinetic parameters were estimated for key reactions. Aromatization of bis-keto dimers of phenoxy radicals follow...
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Published in | The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory Vol. 109; no. 49; pp. 11198 - 11205 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
United States
American Chemical Society
15.12.2005
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Online Access | Get full text |
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Summary: | The B3LYP hybrid density functional computational technique was applied to describe the sequence of phenoxy radicals coupling reactions leading to the formation of dibenzofurans. Reaction kinetic parameters were estimated for key reactions. Aromatization of bis-keto dimers of phenoxy radicals followed by intermediate dehydration or dehydroxylation was demonstrated to be a strongly stereoselective process. While the S,S-diastereomer of the ortho-C//ortho-C keto dimer forms (o,o‘)-dihydroxybiphenyl, a known dibenzofuran intermediate, via inter-ring hydrogen transfer reaction, the less stable R,S-stereoisomer can easily be transformed into another 5-hydroxyl-4,5-cyclohexadiene-2,3-benzofuran intermediate that provides an energetically more favorable pathway for formation of dibenzofuran. The possible channels of radical-chain processes that convert these intermediates to dibenzofuran and polychlorinated dibenzofurans are discussed. |
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Bibliography: | istex:12A5AA308D1E7890FE8345C9D53DC1C87252998E ark:/67375/TPS-6352QH4S-S ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 1089-5639 1520-5215 |
DOI: | 10.1021/jp053047l |