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.
ASJC Scopus subject areas
- Computational Theory and Mathematics
- Computer Science Applications
- Information Systems