title: QSARs for phenols and phenolates: oxidation potential as a predictor of reaction rate constants with photochemically produced oxidants.
abstract: Quantitative structure-activity relationships (QSARs) for prediction of the reaction rate constants of phenols and phenolates with three photochemically produced oxidants, singlet oxygen, carbonate radical, and triplet excited state sensitizers/organic matter, are developed. The predictive variable is the one-electron oxidation potential (E1), which is calculated for each species using density functional theory. The reaction rate constants are obtained from the literature, and for singlet oxygen, are augmented with new experimental data. Calculated E1values have a mean unsigned error compared to literature values of 0.04-0.06 V. For singlet oxygen, a single linear QSAR that includes both phenols and phenolates is developed that predicts experimental rate constants, on average, to within a factor of three. Predictions for only 6 out of 87 compounds are off by more than a factor of 10. A more limited data set for carbonate radical reactions with phenols and phenolates also gives a single linear QSAR with prediction of rate constant being accurate to within a factor of three. The data for the reactions of phenols with triplet state sensitizers demonstrate that two sensitizers, 2-acetonaphthone and methylene blue, most closely predict the reactivity trend of triplet excited state organic matter with phenols. Using sensitizers with stronger reduction potentials could lead to overestimation of rate constants and thus underestimation of phenolic pollutant persistence.
authors.affiliation: Department of Civil, Environmental, and Geo- Engineering, University of Minnesota, 500 Pillsbury Drive SE, Minneapolis, Minnesota 55455-0116, USA. arnol032@umn.edu.
authors.forename: William A
authors.identifier: http://orcid.org/0000-0003-0814-5469
authors.initials: WA
authors.lastname: Arnold
authors.affiliation: Department of Civil, Environmental, and Geo- Engineering, University of Minnesota, 500 Pillsbury Drive SE, Minneapolis, Minnesota 55455-0116, USA. arnol032@umn.edu.
authors.forename: Yan
authors.initials: Y
authors.lastname: Oueis
authors.affiliation: Department of Civil, Environmental, and Geo- Engineering, University of Minnesota, 500 Pillsbury Drive SE, Minneapolis, Minnesota 55455-0116, USA. arnol032@umn.edu.
authors.forename: Meghan
authors.initials: M
authors.lastname: O'Connor
authors.affiliation: Department of Chemistry, Seattle University, 901 12th Avenue, Seattle, WA 98122, USA. latchd@seattle.edu.
authors.forename: Johanna E
authors.initials: JE
authors.lastname: Rinaman
authors.affiliation: Department of Chemistry, Seattle University, 901 12th Avenue, Seattle, WA 98122, USA. latchd@seattle.edu.
authors.forename: Miranda G
authors.identifier: http://orcid.org/0000-0002-5204-2785
authors.initials: MG
authors.lastname: Taggart
authors.affiliation: Department of Chemistry, Seattle University, 901 12th Avenue, Seattle, WA 98122, USA. latchd@seattle.edu.
authors.forename: Rachel E
authors.initials: RE
authors.lastname: McCarthy
authors.affiliation: Department of Chemistry, Seattle University, 901 12th Avenue, Seattle, WA 98122, USA. latchd@seattle.edu.
authors.forename: Kimberley A
authors.initials: KA
authors.lastname: Foster
authors.affiliation: Department of Chemistry, Seattle University, 901 12th Avenue, Seattle, WA 98122, USA. latchd@seattle.edu.
authors.forename: Douglas E
authors.initials: DE
authors.lastname: Latch
mesh_terms: D002254:Carbonates; D007700:Kinetics; D010083:Oxidants, Photochemical / Q000737:chemistry*; D010084:Oxidation-Reduction; D010636:Phenols / Q000737:chemistry*; D021281:Quantitative Structure-Activity Relationship; D026082:Singlet Oxygen / Q000737:chemistry
chemical_list: D002254:Carbonates; D010083:Oxidants, Photochemical; D010636:Phenols; D026082:Singlet Oxygen