Thermodynamic descriptors derived from density functional theory calculations in prediction of aquatic toxicity

Martin Smieško, Emilio Benfenati

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Abstract

Ab initio Density Functional Theory methods at the B3LYP/6-311+G(2d,p)//HF/ 3-21G(d) level in the gas and solvent phases (Conductor-like Polarizable Continuum Model) were used to calculate the thermodynamic and charge related descriptors including the first-order dissociation constant for a set of 53 substituted phenols. The absolute values of the pKa DFT descriptor showed significant deviations from the experimental values of dissociation constants, but the relative trends were well-described (R2 = 0.929, n = 40). The descriptors were used for the design of predictive models for two aquatic species Pimephales promelas and Tetrahymena pyriformis. In both cases the best performing 2-descriptor models were based on the descriptors ΔHgas298 and ClogP and showed good predictivity with R2 = 0.853, RCV2 = 0.834 for Pimephales and R2 = 0.864, RCV2 = 0.833 for Tetrahymena. The descriptors, models and the mode of action of the compounds are discussed.

Original languageEnglish
Pages (from-to)379-385
Number of pages7
JournalJournal of Chemical Information and Modeling
Volume45
Issue number2
DOIs
Publication statusPublished - Mar 2005

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ASJC Scopus subject areas

  • Chemistry(all)
  • Computational Theory and Mathematics
  • Computer Science Applications
  • Information Systems

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