title: Predictability of physicochemical properties of polychlorinated dibenzo-p-dioxins (PCDDs) based on single-molecular descriptor models.
abstract: Polychlorinated dibenzo-p-dioxins (PCDDs) are of global concern due to their persistence, bioaccumulation and toxicity. Although the fate of PCDDs in the environment is determined by their physical-chemical properties, such as aqueous solubility, vapor pressure, octanol/water-, air/water-, and octanol/water-partition coefficients, experimental property data on the entire set of 75 PCDD congeners are limited. The quantitative structure-property relationship (QSPR) approach is applied to predict the properties of all PCDD congeners. Experimental property data available from the literature are correlated against 16 molecular descriptors of five types. Reported and newly developed QSPR models for PCDDs are presented and reviewed. The values calculated by the best QSPRs are further adjusted to satisfy fundamental thermodynamic relationships. Although the single-descriptor models with chlorine number, molar volume, solvent accessible surface area and polarizability are based on good statistical results, these models cannot distinguish among PCDDs having the same chlorine number. The QSPR model based on the hyper-Wiener index of quantum-chemical descriptor gives useful statistical results and is able to distinguish among congeners with the same chlorine number, as well as satisfying thermodynamic relationships. The resulting consistent properties of the 75 PCDD congeners can be used for environmental modeling.
authors.affiliation: Department of Civil Engineering, University of British Columbia, 6250 Applied Science Lane, Vancouver, BC, V6T 1Z4 Canada.
authors.forename: Minhee
authors.initials: M
authors.lastname: Kim
authors.affiliation: Department of Civil Engineering, University of British Columbia, 6250 Applied Science Lane, Vancouver, BC, V6T 1Z4 Canada. Electronic address: lli@civil.ubc.ca.
authors.forename: Loretta Y
authors.initials: LY
authors.lastname: Li
authors.affiliation: Department of Chemical and Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, BC, V6T 1Z3 Canada.
authors.forename: John R
authors.initials: JR
authors.lastname: Grace
mesh_terms: D004785:Environmental Pollutants / Q000737:chemistry*; D015394:Molecular Structure; D000442:Octanols / Q000737:chemistry*; D000072317:Polychlorinated Dibenzodioxins / Q000737:chemistry*; D021281:Quantitative Structure-Activity Relationship; D012995:Solubility; D055548:Vapor Pressure; D014867:Water / Q000737:chemistry*
chemical_list: D004785:Environmental Pollutants; D000442:Octanols; D000072317:Polychlorinated Dibenzodioxins; D014867:Water
keywords: Internal consistency; Molecular descriptors; PCDDs; Physical-chemical properties; Quantitative structure-property relationships