Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.13/39541

OpenURL Link
Title
Computational study of the oxidation and decomposition of dibenzofuran under atmospheric conditions
Author/Creator
Altarawneh, Mohammednoor;  Kennedy, Eric M.;  Dlugogorski, Bogdan Z.;  Mackie, John C.
Institution
The University of Newcastle. Faculty of Engineering & Built Environment, School of Engineering
Description
The atmospheric degradation of dibenzofuran (DF) initiated by OH addition has been studied by using density functional theory (B3LYP method). Site C1 in DF is predicted to be the favored site for OH addition, with a branching ratio of 0.61 to produce a DF-OH(1) adduct. The calculated reaction rate constant for OH addition to DF has been used to predict the atmospheric lifetime of DF to be 0.45 day. Three different modes of attack of O₂(³∑g) on DF-OH(1) have been examined. Abstraction of hydrogen gem to OH in DF-OH(1) by O₂(³∑g) (producing 1-dibenzofuranol I) and dioxygen addition in the three radical sites in cis and trans orientation (relative to the ispo-added OH) of the π-delocalized electron system of DF-OH(1) are feasible under atmospheric conditions. The free energy of activation (at 298.15 K) for the formation of 1-dibenzofuranol is 15.1 kcal/ mol with a free energy change of -36.3 kcal/mol, while the formation of DF-OH(1)-O₂adducts are endergonic by 9.2-21.8 kcal/mol with a 16.3-23.6 kcal/mol free energy of activation. On the basis of the calculated reaction rate constants, the formation of 1-dibenzofuranol is more important than the formation of DF-OH-O₂adducts. The results presented here are a first attempt to gain a better understanding of the atmospheric oxidation of dioxin-like compounds on a precise molecular basis.
Relation
Journal of Physical Chemistry A Vol. 112, Issue 30, p. 6960-6967
Publisher Link
http://dx.doi.org/10.1021/jp800093j
Date
2008
Publisher
American Chemical Society
Keyword(s)
dibenzifuran;  atmospheric oxidation;  dioxin-like compounds
Resource Type
journal article
Identifier
http://hdl.handle.net/1959.13/39541
Identifier
ISSN:1089-5639
Reviewed
Reviewed
7 Visitors 8 Hits 0 Downloads
Save/E-mail Citation
Citation Format
E-mail Address
Subject
"Journal of Physical Chemistry A"
 
OR