Estimation of n-Octanol/water Partition Coefficients （lgKow） and the Aqueous Solubility （-lgSw） of all PCDF Congeners by Density Functional Theory

1 INTRODUCTION As is widely known, PCDFs together with poly- chlorinated dibenzo-p-dioxins (PCDDs) and poly- chlorinated biphenyls (PCBs) have been included in many blacklists, such as “persistent organic pol- lutants (POPs)” and suspected “environmental en- docrine disruptors (EEDs)”. This is because PC- DFs are chemically and thermally stable and com- plex PCDF mixtures are generally resistant to bio- degradation. Although the concentration of these chemicals is quite low o…     

QSPR Studies on lgK_(ow) and lgK_(oc) of Fluorobenzenes and Property Parameters Based on HF and DFT Calculations

1 INTRODUCTION Quantitative structure-activity relationship (QSAR) equation could be employed to predict the biological activities of unknown compounds, which is signifi- cant for initial screening and evaluation of toxic compounds[1]. Soil sorption coeff…     

QSPR Study on Octanol/water Partition Coefficient （lgKow） of Substituted Naphthalin Compounds

Structural parameters of 24 substituted naphthalin compounds were computed at four levels using Hartree-Fock and DFT methods. Based on the experimental data of octanol/water partition coefficient (lgKow),three-parameter (energy of the highest occupied molecular orbital (EHOMO),the most positive atomic net charges of molecule (q+) and molecular average polari-zability (α)) dependent equations were developed using structural parameters as theoretical des-criptors. Especially,lgKow dependent equation calculated at the HF/6-311G** level is more advantageous than others in view of their correlation and predictive abilities. This dependent equation was validated by variance inflation factors (VIF) and t-test methods and used to predict lgKow of eight designed compounds. Upon comparison,the predictive abilities of our work are all more advantageous than those calculated from molecular property calculator program.