title: Selection of representative congener for polychlorinated trans-azobenzenes (PCt-ABs) based on comprehensive thermodynamical and quantum-chemical characterization.
abstract: Thirty-one thermodynamical and quantum-chemical descriptors were used to characterize all 209 chloro trans-azobenzenes (Ct-ABs, PCt-ABs) in terms of their environmental stability and specific dioxin-like toxicity. Some of the PCt-ABs are produced as a by-side impurity during the manufacture of 3,4-dichloroaniline (DCA) and its derivatives and thus can be found in technical products of certain chloroaniline herbicides. A prepared basic thermodynamic and quantum-chemical property data matrix of PCt-ABs was interpreted using Principal Component Analysis (PCA). The PCA of the thermodynamic and quantum-chemical data matrix created a three-dimensional model that explained 78% (68% + 6% + 4%) of the total variance in the data set. The loading plot shows that the first Principal Component (PC) is influenced by variables describing molecular weight, polarizability and lipophilicity. The second PC was strongly influenced by the most positive partial charge on atoms and the most negative partial charge on atoms. The third PC depends on energy of the highest occupied molecular orbital. Next, factors extracted from PCA were used for selection of a representative set of eight trans-chloroazobenzene congeners, which seemed in the best way reflect a diverse property of all 209 PCt-ABs.
authors.affiliation: Department of Environmental Chemistry and Ecotoxicology, University of Gdańsk, Gdańsk, Poland.
authors.forename: Agata J
authors.initials: AJ
authors.lastname: Wilczyńska-Piliszek
authors.forename: Tomasz
authors.initials: T
authors.lastname: Puzyn
authors.forename: Sławomir
authors.initials: S
authors.lastname: Piliszek
authors.forename: Jerzy
authors.initials: J
authors.lastname: Falandysz
mesh_terms: D002722:Chlorobenzenes / Q000737:chemistry*; D004147:Dioxins; D004785:Environmental Pollutants / Q000032:analysis*; D006540:Herbicides / Q000737:chemistry*; D025341:Principal Component Analysis; D013816:Thermodynamics
chemical_list: D002722:Chlorobenzenes; D004147:Dioxins; D004785:Environmental Pollutants; D006540:Herbicides